KR20130143007A - Articles and devices for thermal energy storage and methods thereof - Google Patents

Abstract

The present invention relates to a product (2) and a heat storage device (80) for storing thermal energy. The product 2 comprises a metal base sheet 12 and a metal cover sheet 14, wherein the metal base sheet and the metal cover sheet are hermetically connected to form one or more enclosed spaces 18. The product 2 comprises a thermal energy storage material 16 contained in an enclosed space 18. The enclosed space preferably comprises liquid water, substantially free of water, or at a temperature of about 25 ° C., at a concentration of about 1% by volume or less based on the total volume of the enclosed space 18. The article includes one or more of the following features to be durable: a) the pressure 36 in the enclosed space is about 700 Torr or less when the temperature of the thermal energy storage material is about 25 ° C; b) the metal cover sheet 14 comprises one indentation into the enclosed space, a protrusion out of the enclosed space, or both, having a size and number sufficient to reduce the maximum von Mises stress in the cover sheet during thermal cycling. Or more of the reinforcing features 34; c) metal cover sheet 14 and / or metal base sheet 12 include one or more volume expansion features 62; Or d) the metal cover sheet has a thickness t _c and the metal base sheet has a thickness t _b , where t _c is greater than t _b . For example, the product does not leak after thermal cycling at about 25 to about 240 ° C. for 1,000 cycles.

Description

Products and apparatus for thermal energy storage and method thereof {ARTICLES AND DEVICES FOR THERMAL ENERGY STORAGE AND METHODS THEREOF}

The present invention relates to thermal energy storage using thermal energy storage materials and to packaging of thermal energy storage materials to enable both effective heat storage and effective heat transfer.

Priority claim

The present invention claims priority to US Provisional Application No. 61 / 373,008, filed Aug. 12, 2010, and US Patent Application No. 13 / 207,607, filed Aug. 2011, to which reference is made herein. To quote as a whole.

In general, industry has been actively seeking new approaches to effectively capture and store waste heat so that it can be used at a more appropriate time. In addition, the desire to achieve energy storage in dense spaces requires the development of new materials capable of storing high energy content per unit weight and unit volume. Potential applications of the innovative technology include urban and / or commercial building heating as well as transportation, solar energy and industrial manufacturing processes.

In the context of the transport industry, it is well known that internal combustion engines operate inefficiently. Sources of inefficiency include heat lost from exhaust, cooling, radiant heat and mechanical losses from the system. It is estimated that more than 30% of the fuel energy supplied to the internal combustion engine is lost to the environment by the engine exhaust.

Internal combustion engines at " cold start " operate at substantially lower efficiency, since combustion occurs at non-optimal temperatures and internal combustion engines must perform excess work against friction due to the high viscosity of the cooling lubricant, Generate more exhaust gas, or both. This problem is even more important for hybrid electric vehicles in which the internal combustion engine operates intermittently to delay cold start conditions and / or cause multiple occurrences of cold start conditions during a single operating period of the vehicle. To solve the problem, original equipment manufactures are looking for a solution that can effectively store and release waste heat. The basic idea is to reduce and minimize the duration and frequency of cold start, ultimately to improve internal combustion engine efficiency, reduce emissions by recovering and storing waste heat during normal vehicle operation and then releasing the heat later. Or both.

To be a practical solution, the energy density and fire density requirements for thermal energy storage systems are very high. Applicant has previously filed 1) “Thermal Energy Storage Materials,” US Patent Application Publication No. 2009-0211726 (Soukhojak), published August 27, 2009. Etc); 2) US Patent Application Publication No. 2009-0250189 (Bank et al.), Entitled “Heat Storage Devices” and published October 8, 2009; 3) PCT Application PCT / US09 / 67823, entitled “Heat Transfer Systems Utilizing Thermal Energy Storage Materials,” filed December 14, 2009; And 4) US Provisional Application No. 61 / 299,565, filed Jan. 29, 2010 entitled “Thermal Energy Storage”. These prior applications are incorporated herein by reference in their entirety.

Heat storage devices and exhaust heat recovery devices are known in the prior art. However, to provide long term (eg, about 6 hours or more) heat storage capacity, they generally occupy large volumes, require large amounts of heat transfer fluid pumping, and require relatively large pumps to overcome hydraulic resistance. in need. Therefore, there is a need for a heat storage system that can provide new combinations of high energy density, high power density, long heat residence time, light weight, low hydraulic resistance to heat transfer fluid flow, or any combination thereof.

The problem of packaging thermal energy storage materials for applications requiring lightweight systems, such as in transportation, requires both rigid packaging and lightweight packaging. For example, a package may contain a large amount of thermal energy storage material, may contain a thermal energy storage material over a wide range of temperatures (a large change in volume may occur), or in a plurality of cells or capsules sealed together. The packaging must be durable so that it can contain, or any combination thereof. The need for a lightweight thermal energy storage system may require reducing the weight of the package.

For example, it is lightweight, has a high energy density, or has a high power density; Durable (eg, the capsule does not leak upon heating to a temperature of about 400 ° C .; the capsule does not leak on repeated heating for more than about 1,000 cycles at a temperature of about 25 to about 240 ° C .; or both are possible There is a need for a thermal energy storage material encapsulated in a capsule.

One aspect of the invention is a base sheet (preferably a metal base sheet); A cover sheet (preferably a metal cover sheet) which is hermetically connected to the base sheet and forms a capsule structure comprising one, two or more sealed spaces; An article comprising a thermal energy storage material contained within an enclosed space and having a liquidus temperature of at least about 150 ° C .; Wherein the enclosed space is substantially free of water or comprises liquid water at a temperature of about 25 ° C. at a concentration of about 1% by volume or less based on the total volume of the enclosed space 18; The product does not leak after thermal cycling for about 1,000 cycles at about 25 to about 240 ° C., including one or more of the following features: a) The pressure in the confined space is at a temperature of about 25 ° C. of the thermal energy storage material; A vacuum of about 700 Torr or less; b) the cover sheet comprises an indentation into the enclosed space, a protrusion out of the enclosed space, or both, having a size and number sufficient to reduce the maximum von Mises stress in the cover sheet upon thermal cycling. One or more reinforcing features; c) the base sheet and / or cover sheet comprise one or more volume expansion features; Or d) the cover sheet has a thickness t _c and the base sheet has a thickness t _b , where t _c is greater than t _b . The reinforcement feature is a base sheet and / or cover where the maximum von Mises stress is applied to the same pressure without the reinforcement feature when the pressure in the enclosed space increases (eg due to thermal expansion, or melting of the thermal energy storage material). It can be any feature (eg, indentation or protrusion) that redistributes stresses in the base sheet and cover sheet, so as to be reduced relative to the sheet. Without limitation, examples of reinforcing features that can be used in metal cover sheets include dimples, chevrons, ribs, or any combination thereof.

In a particularly preferred aspect of the invention, the capsule structure has one or more fluid passages large enough to allow the heat transfer fluid to flow through the one or more fluid passages; When the capsule structure is in contact with the heat transfer fluid, the heat energy transfer material is isolated from the heat transfer fluid.

Another aspect of the invention is a device comprising a container and a stack of two or more products within the container. For example, the device may contain a number of products described herein. Preferably, each product includes a fluid passageway and contains a thermal energy storage material. Preferably, the article having a fluid passageway is stacked such that its fluid passageways are generally aligned, preferably axially.

Another aspect of the present invention provides a method for forming a trough comprising: i) forming one, two or more troughs in a base sheet; ii) at least partially fill one, two or more troughs with a thermal energy storage material; iii) at least partially connecting (eg sealingly connecting) the first metal foil (eg, base sheet) to the second metal foil (eg, cover sheet) to form an enclosed space. A method of making a product, such as a product described herein, wherein the thermal energy storage material comprises a metal salt and the metal salt is molten during the connecting step.

Another aspect of the invention is directed to a method of heat storage comprising delivering a sufficient amount of thermal energy to an article of the present invention such that the heat energy storage material in the article is heated to a temperature of about 200 ° C. or more.

The products, devices, systems and methods of the present invention may advantageously contain high concentrations of thermal energy storage materials (eg, may have high energy density) such that large amounts of thermal energy can be stored; It may have a high surface area between the heat transfer fluid and the heat energy storage material-containing product (e.g., preferably has a high power density greater than about 8 kW / L) so that heat can be quickly transferred into and / or out of the heat energy storage material. May have); May have multiple flow paths with similar or identical hydraulic resistance such that heat is transferred uniformly to and / or from different regions; Have rotational symmetry such that they can be easily arranged; Have a strong and durable structure; Have a high heat storage density to be used for applications requiring compact designs, lightweight components, or both; Have a lower hydraulic resistance (eg, a pressure drop less than about 1.5 kPa at a heat transfer fluid pumping rate of about 10 liters / minute) so that the pumping requirements for the heat transfer fluid are reduced; The capsule structure comprising the thermal energy storage material is heated to a temperature of about 400 ° C. and is strong enough to prevent leakage of the thermal energy storage material from the enclosed space; The capsule structure having the heat energy storage material is sufficiently durable to prevent leakage of the heat energy storage material from the enclosed space after repeated heating at about 25 to about 240 ° C. for at least about 1,000 cycles; Or combinations thereof.

The present invention is further described in the following detailed description with reference to a number of figures referred to as non-limiting examples of aspects of the invention, wherein like reference numerals indicate similar parts throughout the several views of the figures.
1 is a view of an exemplary product having a closed compartment.
2A is a cross sectional view of an exemplary product including multiple enclosed spaces.
FIG. 2B is a diagram of an exemplary cross section of a single capsule having a closed space that can be used in an article. FIG.
3 is a diagram of an exemplary base sheet that may be used in a product.
4A is a diagram of an exemplary cover sheet having a chevron that can be used in an article.
4B is a diagram of an exemplary capsule including a cover sheet with dimples that can be used in an article having one or more capsules.
4C is a view of a portion of an exemplary cover sheet that includes dimples that may be used in an article.
FIG. 4D is a view of an exemplary cover sheet having a number of reinforcing features, such as a number of protrusions and / or recesses that may be used in an article. FIG.
5A is a diagram of an exemplary cross section of a hermetic compartment at the temperature at which the compartment is sealed.
5B is a diagram of an exemplary cross section of a hermetic compartment at a temperature below the sealing temperature.
5C is a diagram of an exemplary cross section of a hermetic compartment at a temperature above the sealing temperature.
6A, 6B and 6C are diagrams of example sheets molded to have ribs.
7A and 7B are illustrations illustrating sheets having volume expansion features that increase the volume of the enclosed space (eg, to accommodate volume expansion of the thermal energy storage material when heated and / or melted).
8 is an exemplary graph showing the relationship between the thickness of the cover sheet and the maximum von Mises stress in the cover sheet when the cover sheet is used in a product containing the heat energy storage material and the heat energy storage material is heated.
9 is an exemplary graph showing the relationship between the thickness of the cover sheet and the maximum expected von Mises stress in the cover sheet, for a cover sheet comprising a flat cover sheet and ribs.
10 is an exemplary diagram illustrating the relationship between the thickness of a cover sheet and the maximum expected von Mises stress in the cover sheet, for a flat cover sheet, a cover sheet with dimples, a cover sheet with chevrons, and a cover sheet with ribs. It is a graph.
11 is an exemplary view of a portion of tooling that may be used to make a sheet comprising a rib.
12 illustrates an exemplary stack of articles.
13 illustrates the surface of a base sheet of an article comprising one or more closure compartments. 13 illustrates that the closure compartment can have a primary seal and one or more secondary seals.
14 is a diagram of an exemplary heat storage device.
15 is a diagram of example tooling for embossing a base sheet.
FIG. 16 illustrates the surface of a base sheet of an article including one or more spaces filled with a thermal energy storage material using a nozzle.

In the following detailed description, certain aspects of the invention are described in terms of preferred embodiments. However, as long as the following description is specific to a particular aspect or particular use of the present technology, the following description is merely illustrative and is merely intended to provide a concise description of the exemplary aspect. Accordingly, the invention is not limited to the specific aspects described below, but rather the invention includes all alternatives, modifications and equivalents falling within the true scope of the appended claims.

As shown from the teachings herein, the present invention provides certain products, devices, systems and methods for storing thermal energy and / or delivering stored thermal energy to a fluid. For example, the products and devices for storing thermal energy of the present invention are more effective at storing thermal energy, or enable more evenly transfer of thermal energy, or enable the transfer of thermal energy under smaller pressure drops of the heat transfer fluid. Or any combination thereof.

Various aspects of the present invention provide one or more enclosed spaces (ie, capsules) and one encapsulated in one or more enclosed spaces of the capsule structure such that thermal energy storage material cannot flow out of or otherwise be removed from the capsule structure. It is based on the product containing the capsule structure which has the above heat energy storage material. When the thermal energy storage material is heated in operation, the volume may increase due to thermal expansion, due to the difference in density of the liquid and solid phases of the thermal energy storage material, or both. The increase in volume of the thermal energy storage material may be at least about 5%, at least about 10%, at least about 15%, or even at least about 20%. For example, metal salts, such as lithium nitrate, may increase by 20% or more in volume when heated to about 23 to about 300 ° C. It will be appreciated that the pressure in the confined space may increase when the thermal energy storage material is heated. The capsule structure must be durable enough to prevent leakage or breakage as the thermal energy storage material expands in use. The capsule structure preferably has a geometry that allows the heat transfer fluid to effectively remove heat from the heat energy storage material. Without limitation, examples of preferred capsule structures are described in U.S. Patent Application Publication Nos. 2009/0250189 and January 29, 2010, published by Soukozak et al., Published October 8, 2009, which is incorporated herein by reference. US Provisional Application No. 61 / 299,565, which is incorporated herein by reference. For example, the capsule structure may have a geometry that includes one or more fluid passageways that are large enough to allow fluid (eg, heat transfer fluid) to flow through the fluid passageway. The thermal energy storage material may be sufficiently encapsulated in one or more confined spaces such that the thermal energy storage material is isolated from the fluid when the heat transfer fluid contacts the capsule structure.

Use a metal base sheet having a pressure in a confined space that is a vacuum of about 700 Torr or less when the temperature of the thermal energy storage material is about 25 ° C., or comprising one or more reinforcing features (eg, one or more ribs), Use a metal cover sheet that includes one or more reinforcing features (eg, one or more ribs, one or more dimples, one or more chevrons, or any combination thereof), or use a cover sheet having a thickness greater than the thickness of the base sheet. Various approaches have been identified that advantageously improve the durability of the capsule structure, including using or any combination thereof.

By reducing the pressure in the sealed space at a temperature of about 25 ° C., the pressure in the sealed space can also be reduced when the heat energy storage material is heated. At a temperature of about 25 ° C., the pressure in the confined space can be reduced to about 700 Torr or less using any convenient means. For example, the cover sheet and base sheet when the thermal energy storage material has a sufficiently high connection temperature, T _j such that the thermal energy storage material shrinks when the thermal energy storage material in the enclosed space cools and the pressure in the closed space drops below about 700 Torr. Can be connected to form a closed space. The connection temperature may be higher than the liquidus temperature T _{L, TESM} of the thermal energy storage material. Preferably, the connection temperature T _j is at least about T _{L , TESM} + 10 ° C., more preferably at least about T _{L , TESM} + 20 ° C., even more preferably at least about T _{L , TESM} + 30 ° C., more preferably Is at least about T _{L , TESM} + 40 ° C., even more preferably at least about T _{L , TESM} + 50 ° C., most preferably at least about T _{L , TESM} + 60 ° C. By way of example, T _j is at least about 200 ° C., preferably at least about 230 ° C., more preferably at least about 250 ° C., even more preferably at least about 270 ° C., most preferably at least about 290 ° C. The temperature of the thermal energy storage material when the base sheet and cover sheet are connected may be about 700 ° C. or less, preferably about 500 ° C. or less, even more preferably about 400 ° C. or less.

In another example, the cover sheet and the base sheet can be connected while a vacuum is applied to the area to be a closed space. If used, the vacuum should have a pressure low enough so that the sealing space becomes a vacuum upon sealingly connecting the base sheet and the cover sheet. For example, a vacuum having a pressure of about 700 Torr or less, about 660 Torr or less, about 600 Torr or less, about 550 Torr or less, about 500 Torr or less, about 400 Torr or less or about 300 Torr or less may be applied. Thus, the entire connection process can be carried out in a vacuum environment. The cover sheet and the base sheet can be connected while the pressure in the area to be the enclosed space is at least about 0.1 Torr, preferably at least about 1.0 Torr, more preferably at least about 10 Torr. Lower pressures may also be used. Preferably, when the base sheet and the cover sheet are sealingly connected, the thermal energy storage material has a predetermined sealing temperature which is elevated, so that a vacuum is formed in the enclosed space upon cooling the product to about 25 ° C. The preset sealing temperature can be any temperature at which the density of the thermal energy storage material is lower than the density at 25 ° C. Preferably, the predetermined sealing temperature is higher than the liquidus temperature of the thermal energy storage material (eg, at least about 10 ° C, at least about 30 ° C or at least about 60 ° C higher than the liquidus temperature). The predetermined sealing temperature may be at least about 50 ° C, at least about 100 ° C, at least about 150 ° C, at least about 200 ° C, at least about 250 ° C or at least about 300 ° C. The preset sealing temperature is preferably low enough so that the thermal energy storage material does not decompose during the sealing process. The predetermined sealing temperature may be about 500 ° C. or less, about 400 ° C. or less or about 350 ° C. or less.

If the thermal energy storage material in the confined space has a temperature of about 25 ° C., the confined space is preferably about 600 Torr or less, more preferably about 500 Torr or less, even more preferably about 400 Torr or less, most preferably About 300 Torr or less vacuum. The lower limit for the pressure in the confined space when the thermal energy storage material is 25 ° C. is based on manufacturability, preferably at least about 0.1 Torr, more preferably at least about 1 Torr, most preferably at least about 10 Torr to be.

The durability of the capsule structure can be increased by adding one or more reinforcing features to the base sheet, cover sheet, or both. The reinforcement feature is a base sheet and / or cover where the maximum von Mises stress is applied to the same pressure without the reinforcement feature when the pressure in the enclosed space increases (eg due to thermal expansion, or melting of the thermal energy storage material). It can be any feature that redistributes the stresses in the base sheet and cover sheet to be reduced relative to the sheet. The reinforcing feature may be an indentation or protrusion formed in the sheet. Thus, the reinforcing feature can be a change in the profile of the sheet. The reinforcing feature can act by redistributing the stress in the closed space (eg, the stress obtained when heating the closed space) such that the maximum von Mises stress is reduced. The reinforcing feature may be described by its depth (ie, the amount of change in profile, for example, relative to the area farther from the reinforcing feature), its length, its width, or any combination thereof. The reinforcing features are preferably at least about 0.1 mm, more preferably at least about 0.2 mm, even more preferably at least about 0.3 mm, even more preferably at least about 0.4 mm, more preferably at least about 0.5 mm, most Preferably it has a depth of at least about 0.6 mm. The reinforcement features preferably have a depth that is small enough so that the effect of packing or stacking multiple capsule structures as described herein does not significantly affect. Thus, the reinforcement features preferably have a depth of about 10 mm or less, more preferably about 5 mm or less, even more preferably about 3 mm or less and most preferably about 2 mm or less. Without limitation, examples of reinforcing features that can be used include ribs, dimples, chevrons, and the like. The reinforcing features may comprise protrusions or indentations, such as ribs, having a length to width greater than about 1, preferably at least about 2, more preferably at least about 4, most preferably at least about 10. have. When used, two ribs in the base sheet or cover sheet in the region of the enclosed space may be parallel, at right angles or at an acute angle. Reinforcing features generally have a circular cross section, such as a dimple. The reinforcement features can be arranged in a repeating pattern, eg, a chevron pattern, comprising a plurality of reinforcement features aligned in one direction and a plurality of reinforcement features aligned in different directions. The reinforcement feature is preferably located on the seat area containing the enclosed space. Reinforcing features located in the seat area that do not contain a confined space may also be present.

Reinforcement features (e.g., reinforcement features in the cover sheet) may have the same capsule structure (e.g. For example, such as a generally flat and smooth cover sheet, the sheet may have a sufficient size and number to be lower than the von Mises stress of a generally smooth surface, generally flat, or both). The reinforcement features are preferably such that the von Mises stress in the capsule structure containing the thermal energy storage material at 250 ° C. has the same capsule structure (eg, the sheet generally has a smooth surface or , Generally flat, or both), at least about 5%, more preferably at least about 10%, even more preferably at least about 15%, even more preferably about 20% It is present in sufficient size and number so as to be at least%, more preferably at least about 30%, most preferably at least about 40%.

The reinforcing features (optionally in conjunction with one or more of the other features disclosed herein) may comprise a metal (eg, a metal of the cover sheet, or base) at a maximum von Mises stress S _{Max , 250} vs. 250 ° C. in the base sheet and cover sheet. sheet and the cover sheet of the bottom) of the yield stress S _Y, the ratio preferably from about 0.95 or less _{to 250,} more preferably about 0.09 or less, and still more preferably about 0.85 or less, even more preferably about 0.80 or less, and most It may be used to reduce the maximum von Mises stress in the enclosed space containing the thermal energy storage material, preferably to be about 0.70 or less.

The durability of the capsule structure can be increased by adding one or more ribs to the base sheet, cover sheet or both. Preferably, the base sheet and cover sheet are rib structures (eg, sufficient number of ribs and / or sufficient sizes to provide sufficient rigidity to the capsule structure such that the capsule structure is not sufficiently curved as the wheel and otherwise not as sufficiently as the wheel). Ribs).

It will be appreciated that in accordance with the teachings herein, the base sheet may have a structure that is generally more rigid than the cover sheet, such as comprising one or more troughs. Advantageously, the thickness of the base sheet can be sufficiently reduced so that the rigidity of the base sheet more closely matches the rigidity of the cover sheet. By reducing the thickness of the base sheet, the volume of the base sheet and / or packaging material may be reduced, or the weight of the base sheet and / or packaging material may be reduced, or both. Thus, a higher proportion of the capsule structure weight may be the weight of the thermal energy storage material. Thus, the base sheet may have a thickness of t _b (eg, average thickness) and the cover sheet may have a thickness of about t _c (eg, average thickness), where t _c is greater than t _b Big. The ratio of t _c / t _b is preferably at least about 1.05, more preferably at least about 1.10, even more preferably at least about 1.15, even more preferably at least about 1.20, even more preferably at least about 1.25, even more. More preferably about 1.30 or more, most preferably about 1.35 or more. The difference between t _c and t _b is preferably at least about 0.01 mm, more preferably at least about 0.02 mm, even more preferably at least about 0.03 mm, even more preferably at least about 0.035 mm, even more preferably About 0.04 mm or more, most preferably about 0.05 mm or more. The difference between t _c and t _b is preferably about 1 mm or less, more preferably about 0.5 mm or less, and most preferably about 0.25 mm or less. By way of example, i) the ratio of t _c / t _b may be at least about 1.05, at least about 1.10, at least about 1.20, or at least about 1.30; ii) the difference between t _c / t _b can be at least about 0.01 mm, at least about 0.02 mm, at least about 0.03 mm, or at least about 0.05 mm; Or (i) and (ii).

The base sheet, cover sheet or both may have one or more volume expansion features such that the volume of the enclosed space can be reversibly increased when the thermal energy storage material expands upon heating and / or melting. Examples of volume expansion features include wrinkles, pleats, convolutions, folds, oscillations, and the like. By way of example, the volume expansion feature may include one, two or more convolutions, folds or pleats. Preferred volume expansion features may generally have a bellows or accordion form (though typically no orifices). Reinforcing features, such as one or more dimples, one or more chevrons, or one or more ribs, may also serve as volume expansion features. It will be appreciated that the size, shape, and number of volume expansion features of the volume expansion features affect the amount by which the volume of the enclosed space can be expanded. When used, the volume expansion feature may be sufficient to increase the volume of the enclosed space by at least about 5%, preferably at least about 10%, more preferably at least about 13%, most preferably at least about 15%. The volume expansion feature has an internal pressure of about 35 kPa when the thermal energy storage material is heated from about 25 ° C. to a temperature at which the thermal energy storage material is a liquid (eg, about 200 ° C., about 240 ° C. or about 250 ° C.). It is possible to allow the enclosed space to expand sufficiently to increase by less than or equal to (preferably about 20 kPa or less, more preferably about 10 kPa or less).

Another aspect of the invention includes a new arrangement comprising a plurality of products, a new device comprising one or more products, a new method for manufacturing the product, and a new method for using one or more of the products. By using the new product, it is possible to store large amounts of heat energy, to transfer heat energy into or out of the heat energy storage material quickly, to be dense, lightweight or to have a low pressure drop of the heat transfer fluid Or it is possible to assemble a device which can be any combination of these.

The capsule structure generally has a dimension in one direction that is smaller than the dimension in the other direction. Without limitation, examples of capsule structures are described in US patent application Ser. No. 12 / 389,598, filed Feb. 20, 2009, entitled “Heat Storage Devices,” which is incorporated herein by reference. And US Provisional Application No. 61 / 299,565, filed Jan. 29, 2010, entitled “Thermal Energy Sorage”.

The capsule structure and / or the shape of the product may be defined by the packaging space and may be molded in an odd number. The article may comprise a cover sheet having a top surface (ie, a cover sheet) and a base sheet having a bottom surface which is generally opposed. The cover sheet (e.g., top surface of the cover sheet), the base sheet (e.g., bottom surface of the base sheet), or both are generally flat (or can be flat) (e.g., generally flat Phases), generally arcuate, or any combination thereof. Preferably, the base sheet and / or the bottom surface of the base sheet generally comprise an arcuate portion or are generally arcuate and the top surface of the product is generally planar (eg, the cover sheet is generally flat). , Or both. In various aspects of the present invention, the planar cover sheet generally includes one or more reinforcing features (eg, one or more ribs, dimples, chevrons, or other protrusions or recesses as described herein) and / or one or more Volume expansion features. As described herein, the cover sheet can also be replaced by a second base sheet. Thus, the capsule structure can be bounded by two base sheets which are the same or different.

The capsule structure may include one or more openings, for example a fluid passage. For example, the capsule structure can include one or more fluid passageways such that a fluid, such as a heat transfer fluid, can flow through the product without contacting the thermal energy storage material. Without limitation, the capsule structure may be found in paragraphs 7-12 of US Provisional Application No. 61 / 299,565, filed Jan. 29, 2010, entitled “Thermal Energy Storage”, which is incorporated herein by reference. 28-43 and 54-67 and fluid passages having one or more features described in FIGS. 1, 2, 3, 4, 5, 6 and 7.

The cover sheet and base sheet can include one or more openings. The cover sheet and the base sheet may be arranged such that one or more openings of the cover sheet overlap with one or more openings of the base sheet. Thus, the cover sheet and the base sheet can have one or more corresponding openings. The cover sheet has an outer periphery in the areas furthest from the center of the cover sheet. The cover sheet may have one or more opening perimeters in the area of the cover sheet near the opening of the cover sheet (preferably near the center). The base sheet may have an outer periphery in an area far from the center of the base sheet, and may have an opening periphery near the opening (preferably near the center) of the base sheet. The cover sheet and the base sheet may each be sealedly attached to one another or to one or more other optional sub-structures (eg, outer rings) along each circumference of the sheets to form one or more sealed spaces therebetween. Can be. The cover sheet and base sheet are each sealedly attached to one another or to one or more other optional sub-structures (eg, inner rings) along the periphery of each opening of the sheets to form one or more sealed spaces therebetween. Can be. Preferably, the cover sheet and the base sheet are hermetically attached to each other along their respective periphery, along one or more of their respective corresponding opening perimeters, or both along. Most preferably, the cover sheet and the base sheet are hermetically attached to each other along both their respective periphery and one or more of their respective opening periphery. It will be appreciated that the cover sheet and base sheet may also be hermetically attached to one another or to one or more other optional sub-structures along one or more additional regions (other than their periphery) such that a plurality of enclosed spaces are formed.

The capsule structure may optionally include one or more sub-structures that form one or more sealed spaces when sealedly attached to the base sheet and the cover sheet. Without limitation, when used, the sub-structure is one of the features described in US Provisional Application No. 61 / 299,565, entitled "Thermal Energy Storage," filed Jan. 29, 2010, which is incorporated herein by reference. Or any combination. For example, the base sheet, cover sheet or both may be attached to one or more rings, for example one or more inner rings, one or more outer rings or both. The substructure, when used, is a honeycomb, or paragraph 83 of US Patent Application Publication No. 2009-0250189 to Bank et al., Published October 8, 2009, which is incorporated herein by reference. It may include other open cell structures as described in.

The thickness of the capsule structure is defined by the average spacing between the top surface of the product (eg the top surface of the cover sheet) and the bottom surface of the product (eg the bottom surface of the base sheet). The article may have a geometry that is thin enough so that heat can be quickly provided from the fluid to the heat energy storage material and / or quickly removed from the heat energy storage material into the fluid. The article may have a thickness less than the length or diameter of the article.

For example, the ratio of the length or diameter of the article to the thickness of the article may be at least about 2, at least about 5, at least about 10 or at least about 20. Without limitation, the ratio of the length or diameter of the product to the thickness of the product may be about 1,000 or less, preferably about 300 or less, more preferably about 150 or less. Preferably, the thickness of the article is about 80 mm or less, more preferably about 20 mm or less, even more preferably about 10 mm or less, most preferably about 8 mm or less. The thickness of the article is preferably at least about 0.5 mm, more preferably at least about 1 mm.

The longest dimension of the product (e.g., length or diameter of the product) typically means that the product has a large volume (e.g. to contain a large amount of thermal energy storage material) and a large surface area (e.g., rapid delivery of thermal energy). Much larger than the thickness of the product so that you can have both). The longest dimension of the article is preferably at least about 30 mm, more preferably at least about 50 mm and most preferably at least about 100 mm. The longest dimension is defined by the application and can be any length that meets the needs for heat storage, heat transfer, or both in a particular application. The longest dimension of the article is typically less than about 2 m (ie, 2000 mm), but articles with the longest dimension of about 2 m or more may also be used.

The product may have one or more sides. For example, the article may have one or more non-planar sides. The article may have a single side that is generally arcuate, generally non-planar, generally continuous, or any combination thereof. Preferably, one or more aspects are generally equidistant from the center of the product such that the product can be placed in a container having a generally cylindrical cavity having a cavity diameter that is only slightly larger than the average diameter of the product. If the ratio of the cavity diameter to the average diameter of the product is low, the product occupies most of the cavity. For example, the ratio of the maximum diameter of the product to the average diameter of the product may be less than about 1.8, preferably less than about 1.2, more preferably less than about 1.1, and most preferably less than about 1.05. It will be appreciated that the ratio of the maximum diameter to the average diameter of the product is at least about 1.0 (eg, at least about 1.001).

Most of the capsule structure is a volume encapsulated (ie, the volume of one or more enclosed spaces) such that the product can contain a relatively large amount of thermal energy storage material. The total volume of the one or more enclosed spaces of the product is preferably at least about 50% by volume, more preferably at least about 80% by volume, even more preferably at least about 85% by volume, based on the total volume of the product. Preferably at least about 90% by volume. The total volume of at least one enclosed space of the article is typically less than about 99.9 volume percent based on the total volume of the article. The remaining volume that is not occupied by the thermal energy storage material may be encapsulated, void space (eg, containing one or more gases), one or more structures to improve heat transfer between the thermal energy storage material and the capsule structure, or any thereof. Combinations or substantially all of them. The structure for improving heat transfer between the heat energy storage material and the capsule structure is a material having a relatively high thermal conductivity (for example, as compared to the heat energy storage material) that can increase the amount of heat flow from the heat energy storage material to the heat transfer fluid. It may include any structure made. Preferred structures for improving the amount of heat flow include fins, wire meshes, projections into enclosed spaces, and the like.

The article is preferably easy to laminate with other identical shaped articles or with other articles having a generally mating surface. For example, two articles to be laminated may have opposing faces, which are generally bonding surfaces, such that when laminated, the two articles overlap one another. It will be appreciated that one approach to stacking products so that they easily overlap one another is to choose a shape with a high degree of rotational symmetry (eg, the shape of an arcuate surface, the shape of a confined space, or both). . Rotational symmetry may be about an axis in the stacking direction (eg, an axis through the fluid passage of the capsule structure). The order of rotational symmetry typically describes the number of apparent rotations between two surfaces that are stacked on each other, where the surfaces will overlap one another. The degree of rotational symmetry of the article, the base sheet (eg the arcuate surface of the base sheet) or both is preferably at least 2, more preferably at least 3, even more preferably at least 5, most preferably at least 7 That's it.

The product preferably has a capsule structure that is difficult to bend. For example, the capsule structure may not have a cross section where the cover sheet and the base sheet are in contact with most or even all of the length of the cross section (eg, the diameter of the capsule structure). Two or more rings of capsule that are rotated relative to each other such that the arrangement of capsules is selected so that the orders of rotational symmetry are not even, For example, there are a variety of approaches that can be used to ensure that the capsule structure is difficult to bend, including selecting an arrangement of capsules, including concentric rings), or any combination thereof. It will be appreciated that other geometries and other methods can be used to produce capsule products that resist bending. For example, the capsule structural material may be selected to be generally rigid and the structure may include one or more ribs (eg, in a tangential direction).

The thermal energy storage materials of the product may all be in a single hermetic space. The thermal energy storage material of the article may optionally be distributed between multiple closed spaces such that only a portion of the thermal energy storage material may be removed if the sealed space is perforated or otherwise leaked despite the improvements described herein. Thus, the number of enclosed spaces (eg, enclosed spaces containing thermal energy storage materials) in the product may be at least one, at least two, at least three, at least four, or at least five. The upper limit on the number of enclosed spaces is defined by the requirements of the application for practical and specific applications. Nevertheless, the number of enclosed spaces in products is typically less than 1,000. However, very large products can have more than 1,000 confined spaces. For the same reason, the volume fraction of the thermal energy storage material found in any single closed compartment is about 100%, less than about 55%, less than about 38%, less than about 29% or about based on the total volume of heat energy storage material in the product. May be less than 21%. Typically, the enclosed space comprises at least 0.1 volume percent of the thermal energy storage material in the product. However, it will be appreciated that the product may include one or more enclosed spaces that are substantially or completely free of thermal energy storage materials.

The enclosed space is optionally in a pattern that facilitates effective stacking of the product of the present invention and / or effective energy transfer into and / or from the capsule, e.g. the innermost ring each containing one or more enclosed spaces (e.g. For example, it may be arranged in a plurality of concentric rings, including the ring closest to the opening periphery) and the outermost ring (eg, the ring closest to the outer periphery). The sealed space in one ring may generally have a repeating pattern. For example, each group of enclosed spaces or two, three, four or more enclosed spaces in a ring may generally have the same shape and size. The number of enclosed spaces in each ring can be the same or different. Preferably, the outermost ring has more hermetic space than the innermost ring, or the average length of the hermetic space of the outermost ring is less than the uniform length of the hermetic space of the innermost ring (measured in the radial direction from the opening to the outer circumference). Or both, the volume change between the closed spaces of the outermost and innermost rings is reduced.

As discussed below, the product may be placed in a container, for example a container having a generally cylindrical cavity. Preferably, the cavity may be only slightly larger in dimension than the longest dimension of the product. For example, the diameter of the cavity of the container may only be slightly larger than the diameter of the capsule structure of the product. The diameter of the cavity should be large enough so that the product can be inserted into the cavity. When a product (or stack of products) is placed in a container, it may be desirable for the fluid to flow between the outer periphery of the product and the inner wall of the container. This can be achieved by designing the relationship between the interior of the container and the form of the product to form and maintain a fluid flow path. Any method of forming the fluid flow path can be used. Thus, the article may optionally have one or more indentations along its periphery so that space is formed for flowing the heat transfer fluid (eg, the cover sheet and the base sheet have one or more corresponding indentations along their respective perimeters). May have wealth). Alternatively or additionally, the cavity of the container may have a surface with one or more grooves for flowing fluid between the outer periphery of the product and the surface of the container. As another example, the diameter of the product may be sufficiently small compared to the internal diameter of the cavity so that fluid can flow along the entire outer periphery of the product. For example, the product may have one or more indentations, or the container may have one or more grooves for each enclosed space of the outermost ring of the enclosed space. The indents or grooves may have any shape, such as polygonal, arcuate, wedge, or the like, provided they are large enough to allow the heat transfer fluid to flow. When used, the minimum dimensions of the indentations and / or grooves are typically at least about 0.1 mm. It will be appreciated that a combination of two or more methods of forming the fluid flow path can be used. For example, a product may have one or more indentations along its outer circumference and the product may have a sufficiently small diameter so that when placed in a cavity the fluid may flow along its entire outer circumference.

Products for containing thermal energy storage materials include a base sheet shaped to include one or more troughs suitable for holding a liquid. The base sheet can be used in a process where one or more troughs are filled with a thermal energy storage material, generally covered with a flat cover sheet, and then connected to the cover sheet (preferably while the thermal energy storage material is at least partially molten). have. The base sheet can optionally have one or more protrusions, so that the two products only partially overlap when the product is laminated with another product that generally has a surface to be bonded to the base sheet. Thus, the one or more protrusions can act as spacers that separate the general bond surface such that fluid (eg, heat transfer fluid) can flow between the bond surfaces. When used, the protrusions preferably cover only a small portion of the base sheet surface such that the one or more protrusions do not substantially impede the flow of the fluid. The height of the protrusions may be selected to define the height (eg, average height) of the flow path between the two general joining surfaces.

The base sheet may also contain one or more volume expansion features and / or one or more reinforcing features, such as one or more ribs, one or more dimples, one or more chevrons, or any combination thereof that functions to reinforce the base sheet. It may include. Surprisingly, it has been observed that when heating a product containing a thermal energy storage material, troughs, reinforcement features, volume expansion features, or any combination thereof, of the base sheet can reduce the maximum stress on the base sheet. For example, the maximum stress on the base sheet, for example the maximum von Mises stress, is made of the same material as the base sheet (eg, the same metal) and has the same thickness when the heat energy storage material in the enclosed space is heated. It may be less than the maximum von Mises stress of the flat cover sheet. The relatively low stress in the base sheet may provide an opportunity to reduce the weight of the product and / or increase the amount of thermal energy storage material in the product by using a smaller thickness (eg, less than the thickness of the cover sheet). Can be.

It has also been surprisingly observed that by adding optional reinforcing features such as ribs, dimples or chevrons to the base sheet, the thickness of the base sheet, cover sheet or both can be further reduced. When used, the reinforcement features preferably have a maximum von Mises stress of the sheet (eg base sheet or cover sheet) preferably at least about 2%, more preferably at least about 5%, most preferably It is of sufficient size, shape and number to be reduced by at least about 10%. The reinforcing features may include features that are protrusions (ie, extending away from the enclosed space), features that are recesses (ie, entered into the enclosed space), or both. Preferred reinforcement features protrude or dent by a depth / height of at least about 0.2 mm, more preferably at least about 0.4 mm, most preferably at least about 0.6 mm. Preferred reinforcement features protrude or dent by a depth / height of about 5 mm or less, more preferably about 3 mm or less, most preferably about 1 mm or less.

When stacking articles, they can be arranged such that cover sheets from two adjacent articles are at least partially in contact with each other. It may be desirable for the two cover sheets to have a large contact area such that there is little gap or space between the two cover sheets so that they are in good thermal communication and / or no space is wasted. Thus, the cover sheet may include only recesses. Good contact between the two cover sheets can also be achieved by having a cover sheet which is a general bonding surface. For example, the first cover sheet may have one or more recesses joined to one or more protrusions of the second cover sheet and / or vice versa.

The base sheet and the cover sheet are attached to form an enclosed space containing a heat energy storage material. Attachment of the base sheet and cover sheet may include a primary seal around one or more (eg, all) sealed spaces such that the sealed space is isolated from any other sealed space and / or from areas outside the product. . Attachment of the base sheet and the cover sheet may comprise one or more secondary seals, for example seals that isolate the sealed space from an area outside the product and / or from another sealed space if the primary seal is broken.

Without limitation, preferred thermal energy storage materials for thermal storage devices include materials that can represent relatively high density of thermal energy as sensible heat, latent heat, or preferably both. The heat energy storage material is preferably compatible with the operating temperature of the heat storage device. For example, the thermal energy storage material is preferably solid at the lower operating temperature of the heat storage device, at least partially liquid (eg, completely liquid) at the maximum operating temperature of the heat storage device, or the maximum operating temperature of the device. Not much destroyed or decomposed, or any combination thereof. The thermal energy storage material preferably does not destroy or decompose very much when heated to the maximum operating temperature of the device for at least about 1,000 hours or even at least about 10,000 hours.

The thermal energy storage material may be a phase change material having a transition temperature from solid to liquid. The transition temperature from the solid to liquid of the thermal energy storage material may be liquidus temperature, melting temperature or eutectic temperature. If the thermal energy storage material is at least partially or substantially completely in the liquid state, the transition temperature from solid to liquid must be high enough so that enough energy is stored to heat one or more objects to be heated to the desired temperature. The transition temperature from solid to liquid must be low enough so that the heat transfer fluid, one or more objects to be heated, or both are not heated to a temperature at which they can decompose. Thus, the desired temperature of the transition temperature from solid to liquid can depend on the object to be heated and the heat transfer method. For example, in applications that transfer stored heat to an engine (eg, an internal combustion engine) using glycol / water heat storage fluids, the maximum solid to liquid transition temperature may be the temperature at which the heat transfer fluid decomposes. . As another example, if the heat transfer fluid has a high decomposition temperature, the stored heat can be transferred to the cell's electrochemical cell using the heat transfer fluid, and the maximum solid to liquid temperature is such that the electrochemical cell is degraded or otherwise Can be determined by the temperature at which it breaks. The transition temperature from solid to liquid may be at least about 30 ° C, preferably at least about 35 ° C, more preferably at least about 40 ° C, even more preferably at least about 45 ° C, most preferably at least about 50 ° C. . The thermal energy storage material is from solid to liquid below about 400 ° C., preferably below about 350 ° C., more preferably below about 290 ° C., even more preferably below about 250 ° C., and most preferably below about 200 ° C. It may have a transition temperature. Depending on the application, the transition temperature from solid to liquid is about 30 to about 100 ° C., about 50 to about 150 ° C., about 100 to about 200 ° C., about 150 to about 250 ° C., about 175 to about 400 ° C., about 200 to about It will be appreciated that it may be about 375 ° C, about 225 to about 400 ° C, or about 200 to about 300 ° C.

In some applications, such as transportation related applications, it may be desirable for thermal energy materials to efficiently store energy in small spaces. Thus, the thermal energy storage material has a high heat of fusion density (expressed in units of MJ / L), which is defined as the product of heat of fusion (expressed in MJ / kg) and density (measured at 25 ° C. and expressed in kg / L). Can be. The thermal energy storage material may have a fusion heat density of at least about 0.1 MJ / L, preferably at least about 0.2 MJ / L, more preferably at least about 0.4 MJ / L and most preferably at least about 0.6 MJ / L. Typically, the thermal energy storage material has a heat of fusion density of less than about 5 MJ / L. However, thermal energy storage materials with higher fusion heat densities can also be used.

In some applications, such as transportation related applications, it may be desirable for the thermal energy storage material to be lightweight. For example, the thermal energy storage material is less than about 5 g / cm ³ , preferably less than about 4 g / cm ³ , more preferably less than about 3.5 g / cm ³ , most preferably less than about 3 g / cm ³ It can have a density of (measured at about 25 ℃). The lower limit on density is feasibility. The thermal energy storage material may have a density (measured at about 25 ° C.) of at least about 0.6 g / cm ³ , preferably at least about 1.2 g / cm ³ , more preferably at least about 1.7 g / cm ³ .

The enclosed space can contain any thermal energy storage material known in the art. Examples of thermal energy storage materials that can be used in the thermal energy storage material compartment are both described in Atul Sharma, V.V. Tyagi, C. R. Chen, D. Buddhi, "Review on thermal energy storage with phase change materials and applications", Renewable and Sustainable Energy Reviews 13, 318-345 (2009); and Belen Zalba, Jose Ma Marin, Luisa F. Cabeza, Haraid Mehling, "Review on thermal energy storage with phase change: materials, heat transfer analysis and applications", Applied Thermal Engineering 23, 251-283 (2003). Substances are included. Other examples of preferred heat energy storage materials that can be used in heat transfer devices include U.S. Patent Application Publication No. 2009/0211726 (named "Thermal Energy Storage Materials", published August 27, 2009) and 2009/0250189 (named "Heat Storage Devices", published October 8, 2009), and US Provisional Application No. 61 / 299,565 (named "thermal energy storage", January 2010) Thermal energy storage materials described in paragraphs 54-63 of the 29 application).

The thermal energy storage material may comprise an organic material, an inorganic material, or a mixture of organic and inorganic materials that exhibit a transition temperature from solid to liquid, heat of fusion density, or both, as described above. Organic compounds that can be used include paraffinic and non-paraffinic organic materials such as fatty acids. Inorganic materials that can be used include salt hydrates and metals. Thermal energy storage materials may generally be compounds or mixtures (eg eutectic mixtures) having a transition from solid to liquid at a single temperature. The thermal energy storage material may be a compound or mixture having a transition from solid to liquid over a series of temperature ranges (eg, at least about 3 ° C., or at least about 5 ° C.).

Without limitation, the thermal energy storage materials include nitrate, nitrite, bromide, chloride, other halides, sulfates, sulfides, phosphates, phosphites, hydroxides, carboxylates, bromates, mixtures thereof and combinations thereof. One or more inorganic salts selected from may be included.

The thermal energy storage material may comprise (or consist essentially of or may consist of one or more first metal containing materials, and more preferably one or more first metal containing materials and one or more second metal containing materials. Can be made). An intermetallic compound, such as a first metal containing material, a second metal containing material, or both comprising a substantially pure metal, a substantially pure metal and one or more additional alloying components (eg, one or more other metals) (intermetallic), metal compounds (eg, salts, oxides, etc.), or any combination thereof. One preferred approach is to use one or more metal containing materials as part of the metal compound; A more preferred approach is to use a mixture of two or more metal compounds. By way of example, preferred metal compounds may be selected from oxides, hydroxides, compounds comprising nitrogen and oxygen (eg, nitrates, nitrites, or both), halides, or any combination thereof. Ternary, quaternary or other multicomponent material systems may also be used. The thermal energy storage material herein may be a mixture of two or more materials exhibiting eutectic.

The volume of thermal energy storage material in one or more enclosed spaces of the product is large enough to allow the product to store large amounts of thermal energy. The ratio of the volume of thermal energy storage material contained in the product to the total volume of at least one enclosed space, the volume of the thermal energy storage material to the total volume of the product, or both (at a temperature of about 25 ° C., or if the thermal energy storage material is liquid Volume measured at phosphorus temperature) is preferably at least about 0.5, more preferably at least about 0.7 and most preferably at least about 0.9. The ratio of the volume of thermal energy storage material contained in the product to the total volume of at least one enclosed space, the volume of the thermal energy storage material to the total volume of the product, or both (at a temperature of about 25 ° C., or if the thermal energy storage material is liquid Volume measured at phosphorus temperature) is typically less than about 1.0, more typically less than about 0.995.

Since the enclosed space may comprise a volume containing air, a gas such as N ₂ , or an inert gas such as He, Ar, or the like, the thermal energy storage material may expand when heated. For example, the enclosed space may have an area that does not contain a heat energy storage material at a temperature of about 25 ° C., so that when the heat energy storage material is heated above its liquidus temperature, the heat energy storage material may be perforated in the cover sheet or base sheet. It can be expanded without producing or causing one or more sheets to peel off. The volume of the enclosed space containing no thermal energy storage material at 25 ° C. (eg the volume of the enclosed space containing gas) is at least about 0.5% based on the total internal volume of the enclosed space, preferably about 1 At least%, most preferably at least about 1.5%.

The thermal energy storage material, enclosed space, or both, may be substantially free or completely free of materials that evaporate or sublime when the product is used to store heat so that the pressure in the enclosed space does not increase significantly. For example, the thermal energy storage material, enclosed space, or both may be from about 25 to about 100 ° C, preferably from about 25 to about 150 ° C, more preferably from about 25 to about 200 ° C, most preferably from about 25 to about 300 It may be substantially free of substances that evaporate or sublime at a temperature of < RTI ID = 0.0 > Thus, the thermal energy storage material, enclosed space or both may be substantially free of water. In applications where a temperature of about 100 ° C. or higher is used to store thermal energy, it may be desirable for the confined space to be substantially free or completely free of water. If present, the concentration of water in the enclosed space may be about 5% by weight or less, more preferably about 1% by weight or less, even more preferably about 0.2% by weight or less and most preferably about 0.1% by weight or less.

1 illustrates a portion of a product 2 having a capsule structure. A portion of the outer surface (bottom surface) of the base sheet 12 of the product is shown in FIG. 1. The product includes a number of capsules 10. As shown in FIG. 1, the capsule 10 may be arranged in a periodic arrangement 11. The base sheet may have one or more troughs 8, for example a trough that may be used to hold the thermal energy storage material prior to and / or during attachment of the base sheet to the cover sheet. The base sheet also includes a lip region 6. The lip region can be used to attach the base sheet to the cover sheet. Thus, the lip region may be a region that is not covered with a thermal energy storage material when the base sheet and the cover sheet are attached.

2A is a cross-sectional view of an exemplary capsule structure 2 comprising one or more enclosed spaces 18. 2B is a cross-sectional view of a single capsule, such as a capsule structure with one capsule 10 or a portion of a capsule structure 2 with multiple capsules 10. As illustrated in FIGS. 2A and 2B, the capsule 10 may be an enclosed space 18 containing a thermal energy storage material 16, and optionally, a gap 20 or other space that is generally free of thermal energy storage material. have. The article may include one or more primary seals 22, for example, a seal that isolates the enclosed space 18 from an area outside the article 24, from another enclosed space, or both. The article may include one or more secondary seals 22 'that may isolate the enclosed space if the primary seal 22 breaks. As illustrated in FIGS. 2A and 2B, the enclosed space 18 may be formed by attaching the base sheet 12 around the lip region 6 to the cover sheet 14 (eg, a generally flat cover sheet). Can be. The base sheet may also include the trough region 8. The thickness 13 of the base sheet can be reduced (eg, compared to the thickness 15 of the cover sheet) due to the strengthening of the base sheet by the trough 8 ′. The seal (eg, primary seal 11, secondary seal 22 ′, or both) can be formed by welding the base sheet and cover sheet, for example by laser welding.

One or more sealed spaces can be made by connecting the metal cover sheet and the metal base sheet under one, two or more welds, wherein the welds completely surround one or more sealed spaces. Individual enclosed spaces can be manufactured using a single continuous weld or multiple welds. Multiple welds can form a continuous perimeter. Many welds may be discontinuous. For example, each enclosed space may have one weld along the outer circumference and a second weld along the inner circumference.

3 is a schematic view of a portion of a forming sheet 40 (eg, base sheet 12) that may be used in a product 2 having multiple enclosed spaces. The molded sheet may have an opening 46 (eg, generally a circular opening) near the sheet center. 3 shows only about one quarter of the forming sheet 40 and thus only one quarter of the opening 46. 3 shows the bottom surface 41 of the molded sheet 40. The molded sheet has a plurality of trough regions 8 and a plurality of lip regions 6. The trough region preferably provides a trough 55 that may contain a thermal energy storage material. The trough region 8 may be arranged with a plurality of rings 50, 50 ', 50 "of the trough. As illustrated, the forming sheet may also have the innermost ring 50 of the trough and the outermost ring of the trough. 50 '. The molded sheet may also have one or more additional trough rings 50 "between the innermost and outermost rings 50, 50' of the trough. As illustrated in FIG. 3, some or all of the troughs in the ring, or even some or all of the troughs in the other rings, may have approximately the same shape, approximately the same volume, substantially match, or any combination thereof. Can be. The number of troughs in the innermost ring of troughs may be more than, less than, or the same as the number of troughs in the outermost ring of troughs. Preferably, the number of troughs in the innermost ring of the forming sheet 40 is less than the number of troughs in the outermost ring, as illustrated in FIG. 6. Some or preferably all of the trough region 8 has a lip region 6 around the trough region. Thus, the trough region 8 may be spaced apart from other trough regions by the lip region 6. The molded sheet 40 may have an outer circumferential portion 45, an inner circumferential portion 47, or both. As illustrated in FIG. 3, the molded sheet may have one or more indentations 51 near the outer periphery 45. One or more indentations may be used in the flow channel or flow path along the outer periphery 45. Preferably, the outer circumference of the bottom surface of the molded sheet 40 generally has a circle (except for optional one or more indentations 51). As illustrated in FIG. 3, the outer circumferential portion 45, the inner circumferential portion 47, and preferably both may be lip regions 6.

4A illustrates a portion of cover sheet 14 having chevron 30. The dimensions in FIG. 4A (eg, x, y, z or any combination thereof) may be in units of mm. Chevron 30 may have a periodicity (in one or more directions) of about 3 mm or more, a periodicity of about 50 mm or less, or both. The periodicity of the chevron may be small enough so that a portion of the cover sheet above the individual enclosed space has a plurality of chevrons 30. For example, the number of chevrons 30 on the area of the cover sheet 14 over a single enclosed space may be about 2 or more, about 5 or more, about 10 or more, about 20 or more or about 30 or more. Chevron 30 may have a periodicity of about 5 mm. Chevron 30 may have a depth of about 0.2 mm or more, a depth of about 4 mm or less, or both. For example, the chevron 30 may have a depth of about 1 mm. It will be appreciated that chevrons with higher or lower periodicity and / or larger or smaller depths may also be used. The dimensions in FIG. 4A (eg, x, y, z or any combination thereof) may be the same or different arbitrary units, or may be units of mm. The chevron may be in a portion of the cover sheet covering the enclosed space, in an area of the cover sheet remote from the enclosed space, or both. It will be appreciated that the chevron can be used for the base sheet, cover sheet or both.

4B is a schematic diagram of an exemplary capsule 10 having a cover sheet 14 that includes dimples 32. 4C is a top view of a portion of the cover sheet 14 over a single capsule, such as the capsule illustrated in FIG. 4B. As illustrated in FIGS. 4B and 4C, the cover sheet 14 may comprise one or more dimples, and in particular one or more recessed dimples 33. Dimples 32 may be present in any arrangement. For example, the dimples may have a brick wall pattern, so that adjacent rows of dimples are moved. The dimples preferably have a periodicity of at least about 1 mm, more preferably at least about 2 mm and most preferably at least about 3 mm. The periodicity of the dimples is preferably about 30 mm or less, more preferably about 15 mm or less, and most preferably about 10 mm or less. The periodicity of the dimples may be small enough so that the cover sheet portions on the individual sealed spaces have a plurality of dimples 32. For example, the number of dimples 32 on the cover sheet 14 area over a single enclosed space may be at least about 2, at least about 5, at least about 10, at least about 20 or at least about 30. The dimples preferably have a depth of at least about 0.1 mm, more preferably at least about 0.2 mm, even more preferably at least about 0.3 mm, more preferably at least about 0.5 mm, most preferably at least about 0.5 mm. The dimples preferably have a depth of about 3 mm or less, more preferably about 2 mm or less and most preferably about 1 mm or less. It will be appreciated that dimples with higher or lower periodicity and / or larger or smaller depths may also be used. Dimples 32 may be present in the portion of the cover sheet covering the enclosed space, in the area of the cover sheet remote from the enclosed space, or both. It will be appreciated that the dimples can be used for the base sheet, cover sheet, or both.

4D shows an exemplary top view of a portion of a sheet (eg, cover sheet 14) that includes reinforcing features. Reinforcing features 34 may generally be arranged in an irregular pattern. As illustrated in FIG. 4D, the reinforcement features 34 may have different shapes, different sizes, or both. The periodicity of the reinforcement features can be small enough so that the portion of the cover sheet 14 on the individual enclosed space has a number of reinforcement features 34. For example, the number of reinforcing features 34 on the area of the cover sheet 14 over a single enclosed space may be at least about 2, at least about 5, at least about 10, at least about 20, or at least about 30.

5A, 5B and 5C illustrate pressures 36, 36 ′, 36 ″ in sealed spaces 18 ′, 18 ′ ′ at different temperatures, sealed at different temperatures. As illustrated in Fig. 5A, at the sealing temperature, the internal pressure 36 and the external pressure 38 of the enclosed spaces 18 ', 18 "may be approximately the same. As illustrated in Fig. 5B, the enclosed space ( The pressure 36 'inside 18' may be higher than the external pressure 38 when the enclosed space 18 'is sealed at a low temperature and the product 2 is heated to a higher temperature, as illustrated in Figure 5b. If the temperature is higher than the sealing temperature, there may be a net outward force 35 on the cover sheet 14 due to the pressure difference. Figure 5c shows the pressure 36 "inside the enclosed space 18". ) May be lower than the external pressure 38 when sealed at high temperature and then reduced in temperature, as illustrated in Fig. 5B, when the temperature is lower than the sealing temperature, due to the pressure difference on the cover sheet 14 There may be a net inward force 35.

6A, 6B, and 6C show illustrative examples of sheets (eg, cover sheets) that include rib structures 39 that include protrusions and recesses. 6A is a topographic view of the seat area for a single capsule. FIG. 6B is a photograph of a portion of a sheet that includes multiple features of FIG. 6A. 6C illustrates the influence of structural features on the force on the sheet when the enclosed space comprising the sheet is heated. As illustrated in FIG. 6, the ribs may be defined by a top sheet area around the enclosed space. For example, the cover sheet may have a lip area without ribs or other reinforcing features in the area where the cover sheet is attached to the base sheet.

7A and 7B show a sheet 60 including volume expansion features 62 such that the enclosed space can increase in volume as the thermal energy storage material expands in the enclosed space and decrease in volume as the thermal energy storage material shrinks. (For example, the base sheet 12) is illustrated. 8A is a schematic of a portion of base sheet 12 having volume expansion features 62. As shown in FIG. 7A, the volume expansion feature 62 may include one or more corrugations, eg, one or more convolutions 64. The volume expansion feature can include a bellows. 7A illustrates volume expansion feature 62 in base sheet 12. However, it will be appreciated that the base sheet 12, cover sheet 14, or both may include one or more volume expansion features 62. The volume expansion feature can act by causing the sheet to reversibly shrink into a closed space. FIG. 7B is an exemplary cross sectional view of a portion of the capsule 10 including the seat 60, the cover sheet 14, and the thermal energy storage material 16 having the volume expansion features 62. The thermal energy storage material 16 may be present in the enclosed space 18 sealed by the primary seal 22, and preferably the secondary seal 22 ′.

8 shows an exemplary relationship between the expected peak von Mises stress in the cover sheet when the capsule 10 is heated to about 250 ° C. as a function of the thickness of the cover sheet 15. 8 also shows the yield stress of the metal used to make the cover sheet. At small thicknesses, the peak von Mises stress is higher than the yield stress of the metal, and the cover sheet may bend or crack. At larger thicknesses, the peak von Mises stress is lower than the yield stress of the metal and the cover sheet does not bend or break. FIG. 9 is a function of the thickness of the cover sheet 15 for a generally flat cover sheet and a cover sheet having a rib structure shown in FIG. 6, the expected peak von Mises stress in the cover sheet when the capsule is heated to about 250 ° C. FIG. An exemplary relationship between the two is shown. The thickness of the cover sheet necessary to prevent the cover sheet from bending can be reduced when the rib structure is used. Thus, the rib structure of FIG. 6 may enable products and heat storage devices that are lightweight, contain larger amounts of heat energy storage materials, or both.

FIG. 10 is generally a function of the thickness of the cover sheet for a flat cover sheet and a cover sheet having the rib structure shown in FIG. 6, the chevron structure of FIG. 4A and the dimple pattern of FIG. 4B, wherein the capsule is heated to about 250 ° C. FIG. An example relationship between the expected peak von Mises stress in the cover sheet is shown. The thickness of the cover sheet necessary to prevent the cover sheet from bending can be reduced when different reinforcing structures are used. Thus, the structures of FIGS. 4A, 4B and 6 may enable products and heat storage devices that are lightweight, contain larger amounts of heat energy storage materials, or both.

FIG. 11 illustrates a portion of tooling 61 that can be used to manufacture a sheet having one or more reinforcing features, such as one or more ribs (eg, cover sheet 14). The tooling can be used in an embossing process. It will be appreciated that the embossing process may be a continuous process or a batch process.

The product containing the thermal energy storage material may preferably be laminated with another identical product or with a second product generally having a bonding surface (eg, generally a bonding base sheet). The product may be laminated in the axial layer and in the space between adjacent axial layers such that the heat transfer fluid may flow between the axial layers. The axial layer generally contains one, two or more products. The axial layer (eg each axial layer) preferably contains one or two products. For example, the axial layer may have two products in contact on a surface, such as a base surface or a cover surface, so that the fluid generally cannot flow between the two products. Thus, a portion of the product (eg, each product except the product at the end of the stack) is generally in first contact with the surface of the first adjacent product such that fluid cannot flow along the first surface. (E.g., base surface), and a second adjacent article (e.g., generally opposite to the second surface so as to be able to flow along some, most, or all of the second surface). It may have a second surface separated from). Separation between two adjacent axial layers can be by any method of separation known in the art. By way of example, preferred spacing methods include one or more protrusions on one or more product surfaces, a spacer material between two layers, a capillary structure between two layers, or any combination thereof. Preferably, the second surface of the article generally has an arcuate shape and the article partially overlaps with the second adjacent article. The spacing between two partially overlapping products is preferably generally constant (except for protrusions or other spacers that allow adjacent products to separate). The stack of articles may comprise rotating the axial layer (eg, rotating the article), or otherwise arranging the axial layer such that the axial layer at least partially overlaps with the adjacent axial layer. It will be recognized. The flow of fluid between two opposing surfaces of two adjacent axial layers is generally radial in direction and can generally be described as radial flow. Each pair of axial layers spaced apart has a radial flow path. The stack of articles typically has a number of radial flow paths (eg, two, three or more). Two or more, for example, each radial flow path may have the same flow length, the same thickness, the same cross sectional shape, or any combination thereof. For example, two or more (eg all) radial flow paths may coincide. It will be appreciated that when the opening (ie fluid passageway) is in the center of the product, the radial flow path may generally be symmetric regardless of the flow direction.

When laminated (for example in laminates containing three or more products), the article preferably has one or more openings corresponding to the openings from each of the remaining products (possibly except at the end of the stack). A portion of the fluid is from the first product in the stack by flowing through each of the corresponding openings of the products inserted between the first and last products without flow (i.e. generally without radial flow) between adjacent products. May flow to the last product in the stack. Flow through the opening is generally axial, and can generally be described as axial flow.

As noted above, the stack of articles may define a central axial flow path (eg, through a central axis formed by the opening of the product) and one or more radial flow paths that are generally perpendicular to the central axial flow path.

The stack of articles can generally be tightly packed (eg, except for a radial flow path) such that the stack of articles is dense and contains a large amount of thermal energy storage material. Thus, the radial flow path generally has a small height (in the direction between adjacent products), for example an average height. The height of the radial flow path is preferably less than about 15 mm, more preferably less than about 5 mm, even more preferably less than about 2 mm, even more preferably less than about 1 mm, most preferably less than about 0.5 mm. The height of the radial flow path is typically large enough to allow fluid to flow through the flow path. Typically the height of the radial flow path (eg, average height) is greater than about 0.001 mm (eg greater than about 0.01 mm).

12 shows one of the inventions comprising a plurality of articles 2 having one or more enclosed spaces 18 for containing thermal energy storage material 16, each arranged to form a stack 70 of articles. The embodiment is illustrated. The article 2 may comprise a molded sheet, for example a base sheet 12 having generally an arcuate surface 41. The surface 41 of one article may generally be bonded to the surface of a second article. The product may be arranged such that adjacent products partially overlap each other. The product illustrated in FIG. 12 generally has an inner ring 9 of the same capsule and generally an outer ring 17 of the same capsule. The article illustrated in FIG. 12 has a rotational symmetry of degree 1 and therefore has only one position where the two facing products partially overlap. To facilitate lamination of the article, each article may have one or more positioning features. It will be appreciated that products with higher orders of symmetry can be used. For example, the product may have a single ring of capsules (or even a single capsule), or the product may have an integer multiple of capsules (eg, 1, 2, 1) for each capsule of the second ring of capsules. May have a first ring of capsules having three or more). As illustrated in FIG. 12, the article 2 may generally have a circular cross section (eg in a direction perpendicular to the stacking direction). The outer periphery of each product may have a number of indentations 51 large enough to permit fluid flow. The article 2 may have a sealed space 74 arranged in one or more concentric rings of the sealed space. Each article 2 may have a fluid passage 46. The fluid passage 46 may generally be near the center of the product 2 such that an axial flow path 84 is created when the products are stacked (eg, axially stacked). The axial flow path 84 preferably comprises a fluid passage 46 of each product 2.

13 illustrates a product 2 comprising an odd number of capsules 10. The product can have an odd number of rotational symmetry, so it cannot be easily deformed around its diameter. The article 2 may generally have a circular cross section with one or more openings 46 in the center of the article. The opening 46 may be generally circular. As illustrated in FIG. 13, one or more, or each capsule or sealed space may have a primary seal 22 that isolates the sealed space from the exterior of the product. The article may also have one or more secondary seals 22 '. The secondary seal can include a seal near the inner circumference 47 (ie, the opening perimeter) of the product, a seal near the outer circumference 45 of the product, or both. Secondary seal 22 ′ may be sufficient to prevent leakage of thermal energy storage material 16 from enclosed space 18 if primary seal 22 is broken.

The articles described herein (eg, laminates of articles) can be used in heat storage devices. The heat storage device may include a vessel or other housing having one or more orifices for flowing the heat transfer fluid into the vessel and one or more orifices for flowing the heat transfer fluid out of the vessel. The heat storage device has one or more heat transfer fluid compartments. Preferably, the heat storage device comprises a single heat transfer fluid compartment. The heat transfer fluid compartment may comprise a continuous space in the vessel between the inlet and outlet through which the heat transfer fluid may flow or may consist substantially of a continuous space. The vessel is preferably at least partially insulated so that heat loss from the vessel to the surroundings can be reduced or minimized.

The heat storage device may contain a large amount of heat energy storage material, transfer heat energy quickly and / or uniformly between the heat transfer fluid and the heat energy storage material, or may be generally dense or store heat for a long time. Or may be designed to be any combination thereof.

The interior of the container of the heat storage device can have any form that can hold the product stack. Preferably, the shape inside the container is such that the stack of products occupies most of the internal volume of the container. The ratio of the total volume of thermal energy storage material (e.g. measured at about 25 ° C.) to the total internal volume of the container (measured at about 25 ° C.) contained in the enclosed space of the product in the container is at least about 0.3, preferably about 0.5 or more, more preferably about 0.6 or more, even more preferably about 0.7 or more, and most preferably about 0.8 or more. The upper limit for the volume of heat energy storage material in the vessel is the required value for the space for the heat transfer fluid to come into contact with the product to transfer heat energy. The ratio of the total volume of thermal energy storage material (eg measured at about 25 ° C.) to the total internal volume of the container (measured at about 25 ° C.) contained in the enclosed space of the product in the container is less than about 0.99, preferably about May be less than 0.95.

The heat storage device has a heat transfer fluid compartment for flow, which may contain the fluid as the heat transfer fluid circulates through the device. The heat transfer fluid compartment is preferably connected to one or more orifices (eg, one or more inlets) for flowing heat transfer into the heat transfer fluid compartment. The heat transfer fluid compartment is preferably connected to one or more orifices (eg, one or more outlets) for flowing heat transfer out of the heat transfer fluid compartment. The heat transfer fluid compartment is a space defined at least in part by one or more heat transfer fluid compartment walls, a space defined at least in part by one or more products, a space defined at least in part by a receptacle or container of the heat transfer device, Or any combination thereof.

The heat transfer fluid compartment defines a flow path of heat transfer fluid through the heat storage device. The heat transfer fluid compartment generally includes an axial flow path through the opening of the stack of articles. The heat transfer fluid compartment generally includes a radial flow path between two adjacent products. It will be appreciated that the radial flow may be an inward flow from the outer periphery of the product to the opening, or an outward flow from the opening of the product to the outer periphery. The heat transfer fluid compartment comprises a flow path generally having an axial component (and optionally a tangential component) between the outer circumference of the product and the wall of the container. Preferably, the composite radial flow path has a relatively high hydraulic resistance. For example, the composite radial flow path has a hydraulic resistance that is greater than (more preferably more than two times greater) the hydraulic resistance of the central axial flow path, the outer axial flow path, or both.

The heat transfer fluid compartment preferably has sufficient thermal communication with the enclosed space containing the heat energy storage material to remove heat or provide heat to the heat energy storage material. The heat transfer fluid compartment is preferably in direct thermal communication with one or more (or more preferably all) enclosed spaces. Direct thermal communication can be any path of shortest distance between the enclosed space and the portion of the heat transfer fluid compartment that is free of materials with low thermal conductivity. Low thermal conductivity materials are those having a thermal conductivity of less than about 100 W / (mK), preferably less than about 10 W / (mK), more preferably less than about 3 W / (mK). It includes. For example, the heat transfer fluid or heat transfer fluid compartment may be in contact with the walls of one or more (or preferably all) enclosed spaces, or may have a high thermal conductivity (eg, about 5 W / (mK) Or at least about 12 W / (m · K), or at least about 110 W / (m · K)).

The heat transfer fluid compartment is preferably in direct thermal communication with at least one (or more preferably all) enclosed space in the heat storage device. Direct thermal communication can be any path of shortest distance between the heat energy storage compartment and the portion of the heat transfer fluid compartment that is free of low thermal conductivity material. For example, the heat transfer fluid or heat transfer fluid compartment may be in contact with a wall (eg, base sheet or cover sheet) of one or more (or preferably all) enclosed spaces, or may have high thermal conductivity (eg For example, a material having at least about 5 W / (m · K), at least about 12 W / (m · K), or at least about 110 W / (m · K)) may be substantially or completely separated from the enclosed space. Can be. Very thin layers of material with low thermal conductivity (eg, less than about 0.1 mm, preferably less than about 0.01 mm, more preferably less than about 0.001 mm) have no appreciable effect on heat transfer. It will be appreciated that there may be between the fluid compartment and the thermal energy storage material compartment.

The size and shape of the confined space and / or product may be selected to maximize heat transfer to and from the phase change material contained in the capsule. The average thickness of the article may be relatively short so that heat can be quickly released from the center of the enclosed space. The average thickness of the article, confined space, or both is less than about 100 mm, preferably less than about 30 mm, more preferably less than about 10 mm, even more preferably less than about 5 mm, most preferably about 3 may be less than mm. The average thickness of the article, the enclosed space, or both may be at least about 0.1 mm, preferably at least about 0.5 mm, more preferably at least about 0.8 mm, most preferably at least 1.0 mm.

The article preferably has a relatively high surface area to volume ratio such that the area of contact with the heat transfer fluid is relatively high. For example, the article may have a surface that maximizes contact with the heat transfer fluid compartment, or the article may have a geometry that maximizes heat transfer between the capsule and the heat transfer fluid compartment, or both. The ratio of the total surface area of the interface between the heat transfer fluid compartment and the product in the heat storage device to the total volume of heat energy storage material in the heat storage device is at least about 0.02 mm ⁻¹ , preferably at least about 0.05 mm ⁻¹ , more preferably May be about 0.1 mm ⁻¹ or more, even more preferably about 0.2 mm ⁻¹ or more, and most preferably about 0.3 mm ^{−1 or} more.

The heat storage device has a container for containing a stack of products. The stack of products may be contained in one or more cavities of the container. Examples of containers that can be used without limitation include US Patent Application Publication No. 2009-0211726, published August 27, 2009, PCT Application PCT / US09 / 67823, filed December 14, 2009. And US Provisional Application No. 61 / 299,565, filed Jan. 29, 2010. Preferred vessels include one or more orifices (eg, one or more inlets) for flowing the heat transfer fluid into the cavity of the vessel, and one or more orifices (eg, one or more outlets) for flowing the heat transfer fluid out of the cavity of the vessel ) The inlet and outlet may be on the same side of the heat storage device or on another side (eg, opposite side). In addition to the orifice, the vessel is preferably sealed or configured such that fluid flowing through the vessel does not leak out of the vessel, or that fluid flowing through the vessel may have a pressure greater than ambient pressure, or both. .

Heat storage devices are used for applications that require long term heat storage, generally heat storage in cold environments (eg, environments having temperatures below about 0 ° C., or temperatures below about −30 ° C.), or both. Can be. Preferably, heat stored in the heat storage device is slowly lost to the environment. Therefore, in the present invention, some form of thermal insulation is preferably used. The better the insulation of the system, the longer the storage time.

Any known thermal insulation form that reduces the rate of heat loss by the heat storage device can be used. For example, any thermal insulation can be used as disclosed in US Pat. No. 6,889,751, which is incorporated herein by reference in its entirety. The heat storage device is preferably a (thermally) insulated container and thus is insulated on one or more surfaces. Preferably, some or all surfaces exposed to the surroundings or the exterior will have adjacent insulation. The insulating material can act by reducing convective heat loss, reducing radiant heat loss, reducing conducted heat loss, or any combination thereof. Preferably, the insulation can be achieved through the use of insulation materials or structures, which preferably have a relatively low thermal conductivity. Insulation can be made using gaps between opposing spaced walls. The gap may be secured by a gaseous medium, for example an air layer, or possibly a vacuum layer (eg, using a Dewar vessel), a material or structure with low thermal conductivity, low Material or structure with thermal emissivity, material or structure with low convection, or any combination thereof. Without limitation, the insulation may contain ceramic insulation (eg, quartz or glass insulation), polymer insulation, or any combination thereof. The insulation can be in the form of fibers, in the form of foams, dense layers, coatings or any combination thereof. The insulation may be in the form of a woven fabric, a knit material, a nonwoven fabric, or a combination thereof. The heat transfer device is insulated using a bottle containing a dewar bottle, more particularly a generally opposed wall configured to define an internal storage cavity, and a wall cavity between the opposing walls, the wall cavity being evacuated to below atmospheric pressure. Can be. The walls may also use reflective surface coatings (eg, mirror surfaces) to minimize radiant heat losses.

Preferably, vacuum insulation is provided around the heat storage device and / or the heat storage system. More preferably, vacuum insulation is provided as disclosed in US Pat. No. 6,889,751, which is incorporated herein by reference in its entirety.

The heat storage device may optionally include one or more compression means for the stack of articles such that the spacing between the layers is generally maintained. The compression means can be any means capable of applying a compression force to a stack of articles. The compressive force must be high enough so that the two products do not rotate relative to each other, axially move relative to each other, or both. The compressive force should be low enough so that the product is not permanently deformed, cracked or both. Preferred compression means allow a slight change in product thickness when the temperature of the heat energy storage material changes, when the heat energy storage material changes between the solid and liquid phases, or both. By way of example, the one or more compression means may comprise one or more springs above the stack of articles, one or more springs below the stack of articles, or both. Without limitation, using a compression means such as a spring, when the thermal energy storage material is heated, a phase transition (e.g., transition from solid to liquid) occurs, or both, it is radial between two adjacent products. The change in the thickness of the flow path can be reduced or minimized.

The heat storage device may have a plurality of flow paths for the flow of heat transfer fluid through the device. Each flow path may comprise one or more radial flows between two adjacent products. Preferably, two or more (eg, each) flow paths through the heat storage device have similar total length, similar total hydraulic resistance, or both. Without limitation, thermal storage devices are described in US Patent Application Publication Nos. 2009-0211726, published August 27, 2009, PCT Application PCT / US09 / 67823, filed December 14, 2009, and the United States. May include one or more seals, one or more plates, one or more connectors, or one or more flow paths for the heat transfer fluid as described in provisional application 61 / 299,565, filed Jan. 29, 2010. have.

Capsule structures and articles containing thermal energy storage materials can be manufactured using any method that provides for encapsulation of thermal energy storage materials. Without limitation, the method may utilize one or any combination of the following: cutting or perforating an opening (eg, a hole) through the cover sheet, or a base sheet (eg, a thin sheet such as foil) Cutting or perforating an opening (e.g., a hole) through the mold), or molding (thermoforming, stamping, embossing or deforming) the base sheet to define a pattern in a sheet comprising one or more recessed or trough regions, Forming a base sheet to define a pattern in a sheet comprising one or more lip regions or one or more trough regions, cutting out or perforating an outer circumference (eg, generally a circular outer circumference) on the base sheet, or on a cover sheet Cut out or perforate the outer periphery (e.g. generally a circular outer periphery), or trough (e.g., a trough formed from a base sheet) ) Is sealed with a heat energy storage material, the trough (e.g., filled trough) is covered with a cover sheet, or the cover sheet is sealedly attached (e.g., to form one or more confined spaces containing heat energy storage material). Base sheet), or sealingly attaching the base sheet along the outer periphery, sealingly attaching the base sheet along the opening periphery, sealingly attaching the cover sheet along the opening periphery (eg, to the base sheet), Or the cover sheet is sealedly attached (for example to the base sheet) along the outer circumference. The molding process of the article preferably comprises stamping, embossing or thermoforming the base sheet. The molding process of the product may use one or more process steps to produce the capsule described in US patent application Ser. No. 12 / 389,598, filed February 20, 2009, entitled “Thermal Storage Device”. The method of forming the article may optionally include one or any combination of the following: sealingly attaching the base sheet to one or more substructures, such as an inner ring, an outer ring, or both; Hermetically attach the cover sheet to one or more substructures, such as an inner ring, an outer ring, or both; Or ablate, stamp or perforate one or more indentations along the outer periphery of the base sheet and / or cover sheet. 15 is a photograph of an example tooling that may be used to emboss a sheet (eg, base sheet). FIG. 15 illustrates the sheet 5 placed in the tooling 61 before forming the sheet 5 into the base sheet 12.

A process for making a cover sheet, base sheet, or both embosses or forms a sheet such that the sheet includes one or more reinforcing features such as one or more dimples, one or more ribs, one or more chevrons, or any combination thereof. It may comprise one or more steps.

The manufacturing process of the product may include filling the base sheet with a thermal energy storage material. The base sheet can be filled when the thermal energy storage material is in a solid state or a molten state. Preferably, the base sheet is filled when the thermal energy storage material is in the molten state. Thus, the process may include heating and / or melting the thermal energy storage material.

The manufacturing process of the product may comprise connecting the top sheet and the base sheet to form one or more sealed spaces. The connecting step may include forming a primary seal. Preferably, the connecting step includes both forming a primary seal and forming a secondary seal. The connecting step preferably takes place while the thermal energy storage material is in the molten state. For example, the connecting step may occur when the thermal energy storage material is at a temperature of at least about 100 ° C., at least about 150 ° C., at least about 200 ° C., at least about 250 ° C., or at least about 300 ° C.

The manufacturing process of the product may comprise partially connecting the base sheet and the cover sheet to form a partially sealed space that may contain liquid when the base sheet and cover sheet are generally not in a horizontal orientation. . The space between the base sheet and the cover sheet can be at least partially filled by inserting the nozzle tip into the space to be filled and pumping the heat energy storage material (preferably in molten state) into the partially sealed space through the nozzle. . Thus, the space between the base sheet and the cover sheet can be at least partially filled while the sheets are vertical, and the trough of the base sheets can be filled while the base sheet is generally vertical. It will be appreciated that the above approach for filling a space with a heat energy storage material may provide a larger volume of heat energy storage material. For example, the volume percent of the enclosed space occupied by air or other gases may be about 8% or less, about 6% or less, about 5% or less, about 4% or less, about 3% or less, about 2% or less, or about 1% or less. Can be. The above approach for filling space can also be used to fill the space between two base sheets. Thus, the cover sheet may be a second base sheet. After filling the space with the thermal energy storage material, the remaining portion of the primary seal can be formed so that the filled space becomes a sealed space. With respect to the secondary seal, if present, at least a portion of the secondary seal (eg in the area where the nozzle is inserted) is not formed until after the thermal energy storage material has been inserted into the space. An article having multiple enclosed spaces can be filled by a process comprising one or more of the following steps: forming a portion of the primary seal to partially seal the one or more spaces (e.g., the base sheet and cover sheet By connecting, or by connecting two base sheets), inserting the thermal energy storage material into one or more spaces, forming the remainder of the primary seal (e.g., sealing the space), rotating the filled product and The thermal energy storage material is then inserted into at least one other space having a portion of the primary seal and forms the remainder of the primary seal of the at least one other space.

FIG. 16 illustrates an example of a product 2 having one or more (eg four) capsules 10 filled with a thermal energy storage material and one or more (eg five) spaces filled. It is. The space to be filled has a partial primary seal 74. The space to be filled may optionally include a partial secondary seal 75. The space to be filled preferably has a filling area 76 without a complete primary seal 22 and without a complete secondary seal 22 ′. The enclosed space can be filled using a nozzle 77 inserted or disposed in the filling region 76. It will be appreciated that the nozzle may be placed in the filling region before, during or after forming the partial primary seal 74. As illustrated in FIG. 16, the nozzle 77 can be inserted into the top of the space to be filled, so that the thermal energy storage material 16 does not leak out of the filling region 76. After inserting the thermal energy storage material 16 into the space to be filled, the process may comprise one or more of the following steps: removing the nozzle (preferably before rotating the product) or rest of the primary seal. (Preferably before rotating the product) or form a secondary seal or the remainder of the secondary seal. Thus, the product may comprise 1) a partial primary seal between the two sheets (e.g., by laser welding two sheets), and 2) two sheets of thermal energy storage material (e.g., molten). It can be manufactured using a machine that can be injected into the space between and 3) complete the primary seal. If multiple confined spaces are desired, the process can include one or more steps of rotating the sheet so that another space between the sheets can be filled.

Sheets suitable for encapsulating the thermal energy storage material include any thin metal sheet (eg, metal foil) that is durable, corrosion resistant, or both, so that the sheet preferably contains the thermal energy storage material without leakage. It may contain. The metal sheet can operate in a vehicle environment under repeated thermal cycling for at least one year, preferably at least five years. The metal sheet may have a substantially inert outer surface which otherwise contacts the thermal energy storage material in operation. The outer surface of the metal sheet in contact with the thermal energy storage material should comprise or consist essentially of one or more materials that do not react significantly with, or corrode, or both of the materials when in contact with the thermal energy storage material. do. Without limitation, exemplary metal sheets that may be used include metal sheets having one or more layers of brass, copper, aluminum, nickel-iron alloys, bronze, titanium, stainless steel, and the like. The sheet may generally be a noble metal or the sheet may comprise a metal having an oxide layer (eg, a natural oxide layer, or an oxide layer that may be produced on the surface). One exemplary metal sheet is an aluminum foil comprising a layer of aluminum or an aluminum containing alloy (eg, an aluminum alloy containing at least 50% by weight, preferably at least 90% by weight of aluminum). Another exemplary metal sheet is stainless steel. Preferred stainless steels include austenitic stainless steel, ferritic stainless steel or martensitic stainless steel. Without limitation, stainless steel may comprise chromium in a concentration of at least about 10% by weight, preferably at least about 13% by weight, more preferably at least about 15% by weight and most preferably at least about 17% by weight. Stainless steel may comprise carbon at a concentration of less than about 0.30 weight percent, preferably less than about 0.15 weight percent, more preferably less than about 0.12 weight percent, and most preferably less than about 0.10 weight percent. For example, stainless steel 304 (SAE name) contains 19 weight percent chromium and about 0.08 weight percent carbon. Preferred stainless steels also include molybdenum containing stainless steel, such as 316 (SAE designation). The metal sheet may have a coating known in the art that can reduce or eliminate corrosion of the metal sheet.

The metal sheet has a sufficiently large thickness so that no holes or cracks are formed when forming the sheet, filling the capsule with a thermal energy storage material, using the capsule, or any combination thereof. In applications such as transportation, the metal sheet is preferably relatively thin so that the weight of the heat storage device is not significantly increased by the metal sheet. The thickness of the metal sheet may be at least about 10 μm, preferably at least about 20 μm, more preferably at least about 50 μm. The metal sheet may have a thickness of less than about 3 mm, preferably less than 1 mm, more preferably less than 0.5 mm (eg less than about 0.25 mm).

FIG. 14 illustrates a cross section of an exemplary heat storage device 80 having a plurality of products 2 "and 2" ', each having a heat energy storage material 16 encapsulated in a plurality of enclosed spaces 18. FIG. The product is generally arranged in an insulated container 82 which may have a cylindrical shape. The device comprises a product 2 "having a first adjacent product 2" ') (a) and a second adjacent product 2 "' (b). The product 2" and its first adjacent The product 2 "'(a) may be arranged with the top surface (i.e., the outer surface) of its respective flat cover sheet which is generally in contact. The product 2" and the second adjacent product 2 "' (b) may generally have a bonding surface (eg, the outer surface of its respective base sheet may generally be a bonding surface) and they may be arranged to partially overlap each other. The product 2 "and its second adjacent product 2" '(b) so as to be able to flow through the radial flow path 83 in a generally radial direction between the products 2 "and (2"') (b) Spacers (not shown) may be used to maintain the distance between them. The space between the product 2 "and the second adjacent product 2" '(b) may be made from one of the sheets of product 2 As illustrated in Fig. 14, each product has a surface (e.g., capable of being in contact with the heat transfer fluid such that the heat transfer fluid is in direct contact with each product, preferably the respective enclosed space). Surface of the base sheet), as illustrated in Fig. 14, each radial flow path 83 may have the same length, the same cross section, or even coincide. It may have an opening 46 near its center. The opening may be part of a compartment through which the heat transfer fluid flows through the device. Products 2 "and 2" 'may have their openings in a central axial flow path 84 The space between the outer periphery of the products 2 "and 2" 'and the inner surface of the container 85 is also part of the heat transfer fluid compartment and forms an outer axial flow path 86. The heat storage device is in fluid communication with the central axial flow path 84. It may have a first orifice 87. The heat storage device 80 may have a first seal or plate 88 that separates the first orifice 87 from the outer axial flow path 86. . The container 82 can have a second orifice 89 that can be on the same side of the container as the first orifice 87, or on different sides of the container, as illustrated in FIG. 14. The heat storage device may have a second seal 90 that separates the second orifice 89 from the central axial flow path. The first seal, the second seal, or both can prevent the fluid from flowing between the two axial flow paths 84 and 86 without flowing through the radial flow path 83. The container 82 is preferably insulated. For example, the container may have an inner wall 91 and an outer wall 92. The space 93 between the two walls can be evacuated or filled with insulating material with low thermal conductivity. The apparatus may also have one or more springs, for example one or more compression springs 94, which apply a compressive force to the stack of articles.

FIG. 14 illustrates a heat storage device 80 having two orifices 87 and 89 on one side of the container. The apparatus may use a tube 95 connected to the first orifice 87 to flow fluid between the first orifice and the region 96 of the central axis flow path 84 furthest from the first orifice. With reference to FIG. 14, the first seal 88 and the second seal 90 allow fluid to flow from the first orifice 87 to the second orifice 89 without a first flow through the radial flow path 83. Can be used to prevent that. By selecting the sizes for the two axial flow paths 84 and 86, the heat storage device 80 can be defined as a Tichelmann system.

The pressure in one or more, or all enclosed spaces, may be below atmospheric pressure, for example under vacuum, when the temperature is about 25 ° C. For example, the pressure in the sealed space at 25 ° C. may preferably be about 600 Torr or less, about 500 Torr or less, about 400 Torr or less, about 300 Torr or less, or about 100 Torr or less. The vacuum in the enclosed space may be the result of applying a vacuum when the cover sheet and the base sheet are hermetically connected, or the result of hermetically connecting the cover sheet and the base sheet when the thermal energy storage material is at elevated temperature, or both. For example, the process of sealingly connecting the base sheet and the cover sheet may include about 600 Torr or less, about 500 Torr or less, about 400 Torr or less, about 300 Torr or less, about 200 Torr or less, about 100 Torr or less, or about 50 Torr or less. Applying a vacuum of the trough region of the base sheet.

The heat storage device may be used in a heat storage system that uses one or more heat transfer fluids to transfer heat into the heat storage device, to transfer heat out of the heat storage device, or both.

The heat storage device where the fluid is (eg, not solidified), and other components that the fluid circulates through upon cooling (eg, a heat providing component, one or more connection tubes or lines, a heat removal component, Or any combination thereof), the heat transfer fluid used to transfer heat into and / or out of the heat energy storage material may be any liquid or gas. The heat transfer fluid may be any heat transfer fluid or coolant known in the art capable of transferring heat at the temperatures used in the heat storage device. The heat transfer fluid may be a liquid or a gas. Preferably, the heat transfer fluid may flow at the lowest operating temperature (eg, lowest expected ambient temperature) that may be exposed in use. For example, the heat transfer fluid may be liquid or gas at a pressure of about 1 atmosphere and at a temperature of about 25 ° C., preferably about 0 ° C., more preferably −20 ° C., and most preferably about −40 ° C. have. Without limitation, preferred heat transfer fluids for heating and / or cooling one or more electrochemical cells are liquid at about 40 ° C.

Heat transfer fluids typically must be able to transport large amounts of thermal energy as sensible heat. The heat transfer fluid is at least about 1 J / g · K, preferably at least about 2 J / g · K, more preferably at least about 2.5 J / g · K, most preferably at least about 3 J / g · K Specific heat (eg, measured at about 25 ° C.). Preferably, the heat transfer fluid is a liquid.

Heat transfer fluids and working fluids that may be used are described in US Patent Application Publication No. 2009-0250189 published October 8, 2009 and PCT Application PCT / US09 / 67823, filed December 14, 2009. Included. For example, any engine coolant known in the art can be used as the heat transfer fluid. The system preferably uses a single heat transfer fluid to transfer heat into the heat energy storage material in the heat storage device and to remove heat from the heat energy storage material in the heat storage device. Alternatively, the system may use a first heat transfer fluid for transferring heat to the heat energy storage material and a second heat transfer fluid for removing heat from the heat energy storage material.

Without limitation, heat transfer fluids that can be used alone or in admixture include heat transfer fluids known to those skilled in the art, preferably water, one or more alkylene glycols, one or more polyalkylenes Fluids containing glycols, one or more oils, one or more refrigerants, one or more alcohols, one or more betaines or any mixture thereof are included.

The heat storage system may optionally include one or more heaters. The heater may be any heater capable of increasing the temperature of the heat energy storage material in the heat storage device to a temperature above its transition temperature. The heater can be any heater that converts energy (eg, electrical energy, mechanical energy, chemical energy, or any combination thereof) to heat (eg, thermal energy). One or more heaters may be one or more electric heaters. One or more heaters may be used to heat some or all of the heat energy storage material in the heat storage device. Preferably, the system includes one or more heaters in thermal communication with the heat storage device. For example, the system may include one or more heaters in the insulation of the heat storage device. The electric heater may use electricity from one or more electrochemical cells, from an external source, or both. For example, when the vehicle is plugged into an outlet connected to a stationary, the heat storage device may be maintained at a temperature above the liquidus temperature of the heat energy storage material in the heat storage device using electricity from an external source. When the vehicle is not plugged into an outlet connected to the stationary, the heat storage device may be maintained at a temperature above the liquidus temperature of the heat energy storage material in the heat storage device using electricity generated from the electrochemical cell.

The heat storage device may be used in a process for heating one or more components. The process includes flowing a heat transfer fluid through a heat transfer device. Flowing the heat transfer fluid through the heat storage device may include flowing a heat transfer fluid having an initial temperature through the inlet of the device; Flowing the heat transfer fluid through the axial flow path such that the heat transfer fluid can be divided into a plurality of radial flow paths; The heat transfer fluid flows through the radial flow path such that the heat transfer fluid removes heat from the heat energy storage material, wherein the heat energy storage material has a temperature higher than the initial temperature of the heat transfer fluid; The heat transfer fluid flows through different axial flow paths so that a plurality of radial flow paths can rejoin; A heat transfer fluid having an outlet temperature flows through the outlet of the device; Or any combination thereof. Preferably, the heat transfer fluid outlet temperature is higher than the initial temperature of the heat transfer fluid. The process for heating one or more components may use a flow passage through a heat storage device comprising a radial flow passage and a selected one of two axial flow passages, the flow passage having an overall flow length, wherein the total flow length is It is generally constant for different radial flow paths.

The heat storage device and / or heat storage system may be characterized as having a relatively high power (eg, measured upon initial 30 or 60 seconds heating) to enable rapid heating of components such as internal combustion engines. . The heat storage device and / or heat storage system may be characterized by an average power of at least about 5 W, preferably at least about 10 W, more preferably at least about 15 W, most preferably at least about 20 W.

The heat storage device and / or heat storage system may be characterized as having a relatively high power density, thereby maintaining a large amount of thermal energy in relatively small components. For example, the heat storage device and / or heat storage system may be at least about 4 kW / L, preferably at least about 8 kW / L, more preferably at least about 10 kW / L, most preferably at least about 12 kW / L. It may be characterized by having a power density of L or more.

The heat storage device and / or heat storage system may be characterized as having a relatively low pressure drop of the heat transfer fluid (as measured at a heat transfer fluid flow rate of about 10 L / min). For example, the heat storage device and / or heat storage system may have a heat transfer fluid pressure drop of less than about 2.0 kPa, preferably less than about 1.5 kPa, more preferably less than about 1.2 kPa, and most preferably less than about 1.0 kPa. It may be characterized by having.

By way of example, a thermal energy storage system can be used in a transport vehicle (eg, a motor vehicle) for storing energy from engine exhaust gas. When the engine produces exhaust gas, the bypass valve can direct the flow of gas through the heat storage device to charge the heat storage device or through the bypass line to prevent the heat storage device from overheating. . For example, during periods when the vehicle is parked, when the engine is stopped, a substantial portion of the heat stored in the heat storage device can be retained for a long time (eg due to vacuum insulation around the heat storage device). Preferably, at least 50% of the thermal energy storage material in the heat storage device remains in the liquid state even after the vehicle has been parked for 16 hours at an ambient temperature of about −40 ° C. If the vehicle has been parked long enough for the engine to cool substantially (e.g. for more than 2 or 3 hours) (e.g. so that the temperature difference between the engine and the surroundings is less than about 20 ° C), heat storage Heat stored in the apparatus may be indirectly discharged into the cooling engine or other heat receiver by flowing a heat transfer fluid (eg, engine coolant) through a heat exchanger comprising a condenser for the working fluid. The working fluid is circulated in the capillary pumping loop using a capillary structure inside the heat storage device where the working fluid is evaporated. Heat from the working fluid is transferred from the heat exchanger to the engine coolant. By using a heat storage device, the heat to be otherwise discarded can be collected during pre-start to mitigate cold start and / or to provide immediate cockpit heating.

Heat transfer using the working fluid can be initiated by opening the working fluid valve (ie, the discharge valve). A closed working fluid receiver connected to the loop via an additional liquid line serves to accommodate changes in the working fluid liquid volume inside the loop without a substantial pressure change. Once enough or all of the useful heat is transferred from the heat storage device, the discharge valve can be closed. The working fluid remaining in the heat storage device may be condensed in the condenser after evaporation (eg from heat remaining in the heat storage device or when the heat storage device begins to fill). When the working fluid is discharged from the heat storage device, the liquid level of the working fluid level may change (eg, rise).

The heat storage device may optionally be a cross flow exchanger (ie, having a flow direction for the working fluid and a vertical flow direction for the flow of the exhaust gas). For example, in operation, the heat storage device may comprise 1) exhaust gas; 2) stagnant phase change material (eg inside a capsule such as a blister pack); And 3) three chambers occupied by the working fluid. All three chambers are spaced apart by thin walls made of a suitable material, preferably stainless steel. The exhaust gas may flow between the surfaces of the capsule of phase change material within the blister (eg curved surface) or the working fluid may be different from the surfaces of the capsule of phase change material inside the blister (eg flat Surface) can generally flow in a direction perpendicular to the gas flow direction. The liquid working fluid entering the chamber preferably wets the capillary structure (e.g., metal wick), and vapor pressure and gravity due to capillary forces acting on the working fluid liquid meniscus formed inside the capillary Is moved up for the combined force of. The flow is continued by continuous evaporation of the liquid using heat taken from the blister internal phase change material. The vapor of the working fluid flows out of the capillary structure through the vapor channel which can engage between the columns of the capillary structure compressed between the surface (eg flat surface) of the capsule of phase change material inside the blister. Is released to the top of the. The vapor of the working fluid flows inside the condenser, where it transfers its evaporative and sensible heat to cold cooling water and becomes liquid and recovered to the heat storage device, partially capped with liquid working fluid (e.g., metal Wicking) to continue the circulation in the loop pumped only by the capillary forces present inside. All columns of the capillary structure can be connected to a common porous base. The porous base can be used to dispense liquid working fluid entering the different columns from the bottom of the device.

In addition, the present invention can be used with additional elements / components / steps. For example, an air conditioning absorption or adsorption circulating refrigeration system may be used as a heat acceptor instead of or in addition to cold angle water (e.g., a condenser may also be used as an evaporator for a refrigerant circulating inside the fluid circulation of the air conditioner). Can be used). In another application, use the same or different capillary pumping loop working fluid and add a mechanically generated turbine to the steam line between the heat storage device and the condenser (eg to resolve the high vapor pressure upstream from the turbine) and / or A steady-state waste heat recovery system, such as a Rankine cycle, may be configured that uses a heat engine to add a liquid pump to the liquid line between the condenser and the heat storage device. The turbine converts some of the heat collected from the waste gas waste heat into useful mechanical or electrical work, thereby improving the overall fuel efficiency of the vehicle.

Example

Example 1 is a product containing seven enclosed spaces containing thermal energy storage materials and suitable for thermal storage. The pack was prepared by filling a base sheet with seven troughs with a thermal energy storage material. Each trough may contain about 7 cm ³ of liquid. The base sheet was covered with a flat cover sheet. The base sheet and cover sheet are made of stainless steel 304 and have a thickness of about 0.102 mm. The thermal energy storage material is a metal salt and has a liquidus temperature of about 195 ° C. The thermal energy storage material was anhydrous or had a moisture concentration of up to about 0.01% by weight. Two sheets were connected while the thermal energy storage material was in the solid state (about 23 ° C.). The base sheet and cover sheet were laser welded together around the periphery of each enclosed space to provide a primary seal. When heated to a temperature of about 250 ° C., the confined space had an internal pressure of about 69 kPa (about 10 psi).

Thermal cycling test

About 10 products of Example 1 were stacked and placed in containers with inlets and outlets. The inlet was connected to the hot receiver of the heat transfer fluid at a temperature of about 250 ° C and the cold receiver of the heat transfer fluid at a temperature of about 15 ° C. The heat transfer fluid was flowed through the vessel until the temperature of the heat energy storage material was about 240 ° C, and then the cold heat transfer fluid was flowed through the vessel until the temperature of the heat energy storage material was about 25 ° C. The temperature of the thermal energy storage material was circulated about every 5 minutes for about 1,000 cycles.

One or more confined spaces of Example 1 were destroyed during thermal cycling testing before reaching 1,000 cycles and / or exhibited leaks in the primary seal. The thermal energy storage material leaked from one or more confined spaces, and Example 1 did not pass the thermal cycling test.

Thermal test

The product of Example 1 was placed in an oven at a temperature of about 400 ° C. for about 30 minutes. The product was then evaluated to determine if there was any leakage or breakage that caused the thermal energy storage material to leak out of the product. One or more leaks and / or breaks were observed and Example 1 did not pass the thermal test.

Example 2 is a product including seven sealed spaces manufactured using the method of Example 1, except that the secondary seal was manufactured by laser welding the base sheet and the cover sheet together near the outer periphery and near the opening periphery. . The product was tested using the same method as described for Example 1. The maximum von Mises stress was higher than the yield stress of the foil. In thermal cycling, the primary seal broke around one or more sealed spaces. The secondary seal did not break after 1,000 heat cycles and the thermal energy storage material did not leak from the product.

Another product of Example 2 was tested by heating to 400 ° C. At 400 ° C., at least one primary seal failed. However, the secondary seal did not break and the thermal energy storage material did not leak.

Example 3 is a product comprising seven confined spaces made using the method of Example 1 except that both the base sheet and the cover sheet use a foil having a thickness of about 0.204 mm. The product was tested using the same method as described for Example 1. The maximum von Mises stress was lower than the yield stress of the foil. The primary seal did not break after 1,000 heat cycles and the thermal energy storage material did not leak from the product.

Another product of Example 3 was tested by heating to 400 ° C. for 20 minutes. At 400 ° C., the seal was not broken and the thermal energy storage material did not leak.

Example 4 is an article comprising seven confined spaces made using the method of Example 1 except that the cover sheet uses a foil having a thickness of about 0.204 mm. The product was tested using the same method as described for Example 1. Maximum von Mises stress was reduced to about 180 MPa lower than the yield stress of the foil. The primary seal did not break after 1,000 heat cycles and the thermal energy storage material did not leak from the product.

Another product of Example 4 was tested by heating to 400 ° C. for 20 minutes. At 400 ° C., the seal was not broken and the thermal energy storage material did not leak.

Example 5 excludes embossing the cover sheet such that the cover sheet over each enclosed space containing the thermal energy storage material has about 15 ribs, including both indentations and protrusions, each having a depth of 0.1 to 0.5 mm. And it is a product containing seven sealed spaces manufactured using the method of Example 1. The product was tested using the same method as described for Example 1. Maximum von Mises stress was reduced to about 233 MPa lower than the yield stress of the foil. The primary seal did not break after 1,000 heat cycles and the thermal energy storage material did not leak from the product. It will be appreciated that one, two or more ribs may be used and the ribs may be indentations, protrusions or both.

Another product of Example 5 was tested by heating to 400 ° C. for 20 minutes. At 400 ° C., the seal was not broken and the thermal energy storage material did not leak.

Example 6 includes seven enclosed spaces prepared using the method of Example 1 except that the enclosed space containing the thermal energy storage material has about 34 dimples recessed about 0.6 mm into the enclosed space. It is a product containing. The dimples of the cover sheet are present in a brick wall pattern as shown schematically in FIG. 4B. The product was tested using the same method as described for Example 1. The maximum von Mises stress was about 590 MPa, which was higher than the yield stress of the foil. The primary seal broke during thermal cycling and thermal energy storage material leaked out of the product. It will be appreciated that several or more dimples may be used and the dimples may be deeper or shallower.

Another product of Example 6 was tested by heating to 400 ° C. for 20 minutes. At 400 ° C., the seal broke and the thermal energy storage material leaked out.

Example 7 is an article comprising seven confined spaces made using the method of Example 1 except that the cover sheet was made of foil having a thickness of about 0.153 mm. The product was tested using the same method as described for Example 1. The maximum von Mises stress was about 282 MPa and lower than the yield stress of the foil. The primary seal did not break during thermal cycling and the thermal energy storage material did not leak from the product after 1,000 heat cycles.

Another product of Example 7 was tested by heating to 400 ° C. for 20 minutes. At 400 ° C., the seal was not broken and the thermal energy storage material did not leak.

Example 8 is an article comprising seven confined spaces made using the method of Example 1, except that the cover sheet was embossed with a plurality of chevrons including recesses and protrusions of about 0.5 mm. The chevrons of the cover sheet are in a repeating pattern as shown schematically in FIG. 4A. The product was tested using the same method as described for Example 1. The maximum von Mises stress was about 600 MPa and higher than the yield stress of the foil.

Example 9 is a product comprising seven confined spaces made using the method of Example 1 except that about 200 Torr of vacuum was applied when welding the cover sheet and base sheet together. When the thermal energy storage material was at a temperature of about 25 ° C., the pressure in the confined space was less than about 400 Torr. The product was tested using the same method as described for Example 1. The maximum von Mises stress was lower than the yield stress of the foil. The primary seal did not break during thermal cycling and the thermal energy storage material did not leak from the product after 1,000 heat cycles.

Another product of Example 9 was tested by heating to 400 ° C. for 20 minutes. At 400 ° C., the seal broke and the thermal energy storage material leaked out.

Example 10 is a product comprising seven confined spaces made using the method of Example 1 except that the cover sheet and base sheet were welded together when the thermal energy storage material was at a temperature of about 250 ° C. When the thermal energy storage material was at a temperature of about 25 ° C., the pressure in the confined space was less than about 400 Torr. The product was tested using the same method as described for Example 1. The maximum von Mises stress was lower than the yield stress of the foil. The primary seal did not break during thermal cycling and the thermal energy storage material did not leak from the product after 1,000 heat cycles.

Another product of Example 10 was tested by heating to 400 ° C. for 20 minutes. At 400 ° C., the seal broke and the thermal energy storage material leaked out.

Preferred aspects of the present invention have been disclosed. However, one of ordinary skill in the art will recognize that certain modifications are made within the teachings of the present invention. Therefore, the following claims should be studied to limit the scope and content of the present invention.

Any numerical values mentioned in this application include all values from the lower limit to the upper limit in increments of one unit, provided there is at least two units of distinction between any lower limit and any upper limit. As an example, the amount of one component, or the value of a process variable such as, for example, temperature, pressure, time, etc., is, for example, 1 to 90, preferably 20 to 80, more preferably 30 to 70. When mentioned, values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 and the like are explicitly listed in the above description. For values below 1, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 as appropriate. These are only specifically intended examples and all possible combinations of numerical values between the listed lower and upper limits should be considered to be expressly mentioned in this application in a similar manner. Unless stated otherwise, all ranges include both endpoints and all numbers between endpoints. The use of "about" or "approximately" in relation to a range applies to both ends of the range. Thus, "about 20 to 30" is intended to include "about 20 to about 30" including at least the specified endpoint. Weight parts as used herein refer to compositions containing 100 parts by weight. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference in all intents. The term "consisting essentially of" to describe a combination must include the identified element, component, component or step, said other element, component, component or step substantially affecting the fundamentally new features of the combination. Does not have The use of the term "comprising" or "containing" to describe a combination of elements, components, components or steps herein also includes aspects that consist essentially of the elements, components, components or steps. Multiple elements, components, components or steps may be provided by a single integrated element, component, component or step. Alternatively, a single integrated element, component, component or step may be divided into separate multiple elements, components, components or steps. The disclosure of “a” or “one” to describe an element, component, component or step does not exclude additional element, component, component or step.

Claims (20)

Metal base sheets;
A metal cover sheet, wherein the metal base sheet and the metal cover sheet are hermetically connected to form one or more sealed spaces;
Thermal energy storage materials contained in confined spaces
As a product containing,
The enclosed space is substantially free of water or comprises liquid water at a temperature of about 25 ° C. at a concentration of about 1% by volume or less based on the total volume of the enclosed space;
A product that does not leak after thermal cycling at about 25 to about 240 ° C. for 1,000 cycles, including one or more of the following features:
a. When the temperature of the thermal energy storage material is about 25 ° C., the pressure in the confined space is about 700 Torr or less;
b. The metal cover sheet includes one or more stiffening features, wherein the reinforcing features are of sufficient size and number to reduce the maximum von Mises stress in the cover sheet during thermal cycling. Include indents into the space, protrusions out of the enclosed space, or both;
c. The metal cover sheet and / or the metal base sheet comprise one or more volume expansion features; or
d. The metal cover sheet has a thickness t _c and the metal base sheet has a thickness t _b , where t _c is greater than t _b . The method of claim 1,
A product in which the pressure in the confined space is a vacuum of about 600 Torr or less at a temperature of about 25 ° C. 3. The method according to claim 1 or 2,
Connecting the metal base sheet and the metal cover sheet when the heat energy storage material is at a connection temperature (T _j ) above the liquidus temperature (T _{L , TESM} ) of the heat energy storage material. The method according to any one of claims 1 to 3,
i) the ratio of the thickness of the metal cover sheet to the thickness of the metal base sheet, t _c / t _b, is at least about 1.05;
ii) the difference between the thickness of the metal cover sheet and the thickness of the metal base sheet, t _c -t _b is at least about 0.02 mm; or
iii) a product that is both i) and ii). The method according to any one of claims 1 to 4,
The article comprises one or more welds connecting the metal cover sheet and the metal base sheet, wherein the one or more welds completely enclose the enclosed space;
The article has an opening near the center of the product such that the heat transfer fluid can flow through the opening;
The product is sealed around the periphery of the opening such that the heat transfer fluid does not contact the thermal energy storage material in the enclosed space. 6. The method according to any one of claims 1 to 5,
The metal cover sheet comprises one or more reinforcing features. 7. The method according to any one of claims 1 to 6,
An article, wherein the metal cover sheet, the metal base sheet, or both comprise one or more volume expansion features. The method of claim 7, wherein
Wherein the one or more volume expansion features comprise dimples, chevrons, wrinkles, folds, convolutions, or any combination thereof. The method according to any one of claims 1 to 8,
Wherein the metal cover sheet is embossed such that the von Mises stress of the product at a temperature of about 250 ° C. is reduced by at least about 10% relative to the generally flat product. 10. The method according to any one of claims 1 to 9,
Wherein the von Mises stress in both the metal base sheet and the metal cover sheet due to thermal expansion of the thermal energy storage material upon repeated thermal cycling between about 30 to about 250 ° C. is lower than the yield stress of the metal of the cover sheet. 11. The method according to any one of claims 1 to 10,
The product does not leak after the enclosed space of the product is heated to about 400 ° C. for about 4 hours. 12. The method according to any one of claims 1 to 11,
Wherein the thermal energy storage material has a liquidus temperature of about 25 ° C. or higher. 13. The method according to any one of claims 1 to 12,
The thermal energy storage material has a liquidus temperature of at least about 150 ° C .; A product wherein the thermal energy storage material is substantially anhydrous. 14. A method of making a product of any one of claims 1 to 13, wherein the metal base sheet comprises one or more troughs that may contain a liquid, the method comprising: at least partially filling the one or more troughs with a thermal energy storage material How to include. 15. The method of claim 14,
And when the base sheet and cover sheet are hermetically connected, the thermal energy storage material has a predetermined temperature above the liquidus temperature of the thermal energy storage material such that a vacuum is formed in the enclosed space upon cooling the product to about 25 ° C. 16. The method according to claim 14 or 15,
Hermetically connecting the base sheet and the cover sheet begins before the step of filling the trough with the thermal energy storage material and is completed after the step of filling the trough with the thermal energy storage material. 17. The method according to any one of claims 14 to 16,
Wherein the article is manufactured by a process comprising connecting a metal base sheet and a metal cover sheet to form a sealed space, wherein the connecting step includes applying a vacuum to the sealed space region before connecting the sheets. , Way. Apparatus comprising at least two laminates of the article of claim 1. The method of claim 18,
Wherein each product comprises an opening, the product is arranged such that the openings are generally axially aligned, and a stack of products is contained within the thermal insulation container. 16. A method of thermal storage comprising transferring a sufficient amount of thermal energy to the article of any one of claims 1 to 15, such that the thermal energy storage material in the article is heated to a temperature of about 200 ° C or more.

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