RU2495339C1 - Storage reservoir for food products with cold accumulation - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: storage reservoir is made in the form of an underground facility having a chamber for arrangement of products and containing a tank with liquid for cold accumulation and a device for cooling of that liquid in the form of a gravity-assisted heat pipe. The latter has a tight housing filled with cooling agent and containing in-series connected parts being an evaporation zone, a transport zone and a condensation zone located above the ground surface. Peculiar features of the storage reservoir consist in the fact that the chamber on some part of the surface area of its floor has a cavity, in which the above reservoir is arranged. The reservoir is made from elastic material, enclosed in a stiff protective casing and adjoins its inner surface. At that, some part of the gravity-assisted heat pipe, which is its transport zone, passes vertically through the chamber, and a ground layer located above it till connection to the part being the condensation zone. Housing of the gravity-assisted heat pipe in the evaporation zone is made from easily deformed metal and bent along a screw line so that it envelopes the reservoir together with the casing, thus providing cooling of the liquid in the reservoir till its freezing.

EFFECT: simpler design of a storage reservoir.

5 cl, 3 dwg

Description

The invention relates to means for cooling or freezing, and more particularly, to said means with accumulation of cold, namely, to a food storage facility for use mainly in domestic conditions.

Known storage for products according to the patent of the USSR for the invention No. 1566178, publ. 05/23/1990 [1], during the operation of which accumulation of cold takes place. It contains a chamber located in the ground, provided at the bottom with cooling means. The latter is the end sections located with a slight slope to the horizon of the parts of several L-shaped heat pipes. Each of these parts, located with a slight inclination to the horizon, is connected by a curved part of the pipe to the vertical part. The pipe is charged with refrigerant. The mentioned part, having a slight inclination to the horizon, is the evaporation zone of the heat pipe. In this part, the coolant evaporates, taking away heat from the adjacent soil. The curved part and the lower section of the vertical part of the pipe are the transport zone. On it, the evaporated coolant rises to the upper section of the vertical part of the pipe, located in the air above the soil surface. Here, the steam, interacting with the pipe wall, cools and passes into the liquid phase. The latter flows down the wall of the transport zone to the evaporation zone, and the cycle repeats. According to modern terminology, such a pipe refers to gravitational heat pipes, because the reverse (from the condensation zone to the evaporation zone) motion of the coolant is ensured by gravity (see, for example: A. Abrosimov, S. Zaletaev. Soil coolers. Designs and calculation methods. Palmarium Academic Publishing, 2012 [2]). Gravity heat pipes work under the condition that the ambient temperature in the evaporation zone is higher than in the condensation zone. This condition is observed in the winter. During this period, the soil cools and accumulates cold. Due to this cold, a lower temperature is provided in the specified chamber in the warm season.

However, the specific heat capacity of the soil is low, which leads to an insufficient increase in the efficiency of the storage in the warm season of this type compared to a simple cellar located below the surface of the soil. In addition, the implementation of pipes in the condensation zone described in the patent [1] provides only an increase in their diameter without additional measures to increase heat transfer.

For the above reasons, a traditional glacier cellar may well compete with this storage facility (see, for example: AM Gorbov. Arrangement of cellars and storehouses. Moscow, Publishing House "ACT", 2007 [3]). Such a cellar is an underground structure containing a chamber equipped for entry and exit from it with a vertical or inclined vestibule and stairs. The specified chamber on part of the floor area has a recess designed to fill with ice in the winter. Due to the fact that the cellar’s chamber is underground, in it in the warm season, the temperature remains below the temperature of the air above the soil surface, and in the cold period it is higher. At the same time, the presence of ice in the indicated recess allows you to further reduce the temperature in the cellar during the summer period, since the stored ice in this case acts as a cold accumulator. In the warm season, heating the ice to the melting temperature, its melting, as well as the subsequent evaporation of water produce a significantly greater selection of heat from the environment than heating the soil cooled in winter in the storage according to the patent [1]. At the same time, it is possible to store products that require special conditions, placing them, called household storage on ice. However, the operation of the cellar [3], as indicated above, is associated with the need to store ice in the winter and load it into the aforementioned cavity. In addition, it is necessary to remove the water formed during the melting of the ice, or to ensure its outflow, if the terrain allows this. All this complicates the use of the cellar and makes it time-consuming.

Glacier cellar according to the patent of the Russian Federation for utility model No. 101479, publ. 01/20/2011 [4], in comparison with the cellar [3], has the advantage that its design provides for the possibility of transportation and installation of storage ready for operation without mounting the case. However, it retains the disadvantages of the cellar [3] associated with the need to prepare ice and load it into the compartment of the cellar intended for this purpose. This compartment is located between one of the internal vertical walls of the cellar and its outer wall. The vertical orientation of the cellar walls cooled by ice does not allow storage of products by placing them on ice.

It is also known storage for food products according to the patent of the Russian Federation for the invention No. 2023384, publ. 11/30/1994 [5]. It is an underground structure with a chamber for placing products, surrounded by perimeter sealed in the ground hermetically filled with liquid for accumulating cold containers with immersed parts of the casing of vertical heat pipes, which are evaporation zones. This part of the casing of each heat pipe is connected through a part, which is a transport zone, to a part, which is a condensation zone. The latter is completely above the surface of the soil and is equipped with fins. The elements of this storage, called heat pipes in [5], as follows from the description of their work, are also gravitational heat pipes, studied in detail in the monograph [2]. A similar [5] implementation of the storage is described in the patent of the Russian Federation for the invention No. 2023383, publ. 11/30/1994 [6]. Compared with the patent [5], the pipes of the patent [6] have a more complex shape, and containers with liquid for accumulating cold, in which there are parts of the pipe body, which are evaporation zones, are installed inside the chamber for placing products, and not only around the perimeter cameras, but also in its upper and lower parts. At the end of winter, the inner space of the chamber is separated from the mentioned containers by removable thermal insulation. In the storages according to patents [5] and [6], the accumulation of cold is more efficient than in the storages according to the patent [1], since it is carried out not by soil, but by a frozen liquid (fresh or salted water) having a high specific heat. Moreover, the condensation zones of the heat pipes have radiators in the form of the above-mentioned fins, which contribute to an increase in heat transfer. Compared with the traditional glacier cellar and the cellar according to the patent [4], the storages according to the patents [5] and [6] are more convenient to maintain, without requiring ice storage and loading it into the designated part of the storage.

However, these storages, requiring a large number of heat pipes, are complex and applicable for storage of products on an industrial scale rather than in domestic conditions. Above the surface of the soil there should be enough free space to accommodate the stockade from the zones of condensation of the heat pipes (in particular this relates to the storage according to the patent [6]). Having the indicated predominant scope, the storages according to the patents [5] and [6] provide an unnecessarily low and evenly distributed temperature throughout the chamber in comparison with that which is sufficient for domestic purposes. The indicated containers with water, in which ice forms, accumulating cold, are isolated from the chamber space by its walls or thermal insulation, which makes it difficult to use certain products for storage, called ice storage. In this case, the evaporation zone of each heat pipe inside the tank and surrounded by water is isolated last from the surrounding soil (and in the storage according to the patent [6] it is generally isolated from soil, since together with the said tank it is inside the chamber). Water in the liquid state has significantly lower thermal conductivity, and its layer between the evaporation zone and the wall of the tank, behind which there is soil, which is a heat source, represents additional thermal resistance (and in the storage according to the patent [6] only the heat of the internal space is used cameras). This circumstance affects in the direction of reducing the efficiency of the pipe, which is higher, the greater the difference in ambient temperatures in the zones of evaporation and condensation. The tightness of each of the containers with liquid for accumulating cold should be ensured under conditions when heat pipes pass through its neck and in the entire range of operating temperatures, the change of which causes a change in the volume of the medium filling the container. This leads to the fact that when a pipe or tank fails, replacing either of them requires the simultaneous removal of both of them on the surface (and if there are several heat pipes at once in the same evaporation tank, as shown in the illustrations for patents [5 ], [6], - removing the tank together with several such pipes), and the removal of tanks under the thickness of the soil requires the prior removal of the latter. The containers themselves have a complicated structure, in particular, their walls are equipped with membranes to compensate for changes in the volume of liquid during its freezing.

The closest known storage facility to the present invention

according to the patent [5].

The present invention is aimed at achieving a technical result, which consists in simplifying the design of a food storage facility by using a single container with liquid for accumulating cold and a single gravitational heat pipe, as well as in improving the efficiency of cold storage. In the proposed storage facility, when cooling a liquid that accumulates cold, the heat is not removed “from the inside” - along the surface of the evaporation zone of a relatively thin heat pipe passing along the axis of the tank with such a liquid, but “outside” - along the many times larger side surface of this tank. In addition, higher reliability and better maintainability of the storage are ensured due to the flexible evaporation zone of the gravitational heat pipe being arranged and its placement outside the liquid storage tank for accumulating cold and using the simplest design of this storage tank. Below, when disclosing the essence of the invention and considering its specific implementation, other types of achieved technical result can be named.

The proposed food storage (hereinafter - the storage), as well as closest to it known by the patent [5], is made in the form of an underground structure having a chamber for placing products, and contains a container with liquid for accumulating cold, as well as a means for cooling this fluid in the form of a gravitational heat pipe. The latter has a sealed housing filled with a refrigerant, containing serially connected parts, which are the evaporation zone, the transport zone, and the condensation zone located above the soil surface.

To achieve the aforementioned technical result in the storage according to the invention, in contrast to the specified closest to it, the floor of the specified chamber on a part of its area has a recess in which the indicated container with liquid for accumulating cold is placed. This container is made of elastic material with a volume reserve for expansion of the specified liquid when it passes from the liquid phase to the solid phase and is enclosed in a hard protective casing that is open from above and can fit to its inner surface. The body of the gravitational heat pipe in the evaporation zone is made of easily deformable metal and is curved along a helical line covering the indicated container with a protective casing in which it is enclosed, along its perimeter and height. Moreover, part of the gravitational heat pipe, which is its transport zone, passes vertically through the chamber for placing products and the soil layer above it until it connects to the part that is the condensation zone of the gravitational heat pipe.

The described implementation of the evaporation zone and its location with the coverage of the tank with liquid for accumulating cold outside provide effective cooling of the specified liquid. In this case, the gravitational tube body curved in the form of a helix (spiral) in the evaporation zone, with one part of its surface facing the specified container and in contact with its protective casing, and the rest of its surface in direct contact with the soil, which is a heat source. This ensures the greatest temperature difference between the zones of evaporation and condensation and increases the efficiency of heat transfer. Filling the specified capacity with liquid for accumulating cold can be carried out after completion of the construction of the storage. The replacement of this liquid or its removal and the subsequent removal of the tank itself for its replacement can be carried out without any excavation work directly through the storage chamber and the entrance to it. The liquid can be easily pumped out or pumped into the container, and the container without liquid is just a bag that can be easily removed or, conversely, placed in a protective casing located in the chamber recess intended for it. During storage operation, the container located in the protective casing is accessible from above, and products intended for storage on ice can be placed on it directly or on the grating installed above it. The use of a single heat pipe indicates the simplicity of the storage design. Moreover, the only part of it located above the ground surface - the condensation zone only slightly limits the possibility of using the area above the storehouse in comparison with the minimum of such a restriction due to the supply and exhaust ventilation pipes usually provided for in the storehouse design, which also come to the surface. All parts of the gravitational heat pipe, with the exception of a small portion of the transport zone passing through a layer of soil above the chamber for placing products, are freely accessible. Therefore, taking into account the fulfillment of its most complex and critical part — the evaporation zone — from easily deformable metal, the repair and replacement of the gravitational heat pipe are facilitated.

These factors confirm the achievement of the above technical result.

In a preferred particular case of the storage, the food storage chamber is equipped with supply and exhaust ventilation. In addition, it can be thermally and waterproofed. Including, it can be waterproofed at the boundary of the contact of the hard protective casing with the floor of this chamber in the upper part of the specified recess, which houses a container with a liquid for accumulating cold, enclosed in the specified casing.

The storage can also be equipped with a grating made removable with the possibility of placement above the tank with liquid to accumulate cold. This flooring can be used to place products on it that require special storage conditions and therefore are located in the closest proximity to the source of cold. The flooring can be removed, in which case the products can be placed directly on the surface of the liquid storage tank, i.e. actually on ice.

The invention is illustrated by drawings, which show:

- figure 1 is a General view of the storage,

- figure 2 is a top view of a container with a liquid for accumulating cold, enclosed in a protective casing and covered with it by a spiral zone of evaporation of the gravitational heat pipe,

- figure 3 is a cross section of the body of a gravitational heat pipe in the evaporation zone.

The proposed storage is (Fig. 1) an underground structure containing a hydro- and thermally insulated chamber 1 for placing products, having walls 3 in contact with the ground 2, a floor and a ceiling with a hatch 4. Access to the hatch 4 in the private Fig. 1 in the case of performing storage, it is carried out through an inclined vestibule 5 with a door 6 and a ladder 7, which extends to the floor of the chamber 1. Instead of an inclined vestibule with a door, a vertical shaft can be used, which instead of door 6 has a horizontal hatch at the surface level soil or floor of the room, in the underground of which the storage can be placed. The chamber 1 is equipped with supply and exhaust ventilation provided, respectively, by pipes 8 and 9, the first of which does not reach the floor level of chamber 1, and the second is lowered slightly below the ceiling.

The camera 1 on the part of the floor area (Fig. 1 to the right) has a recess in which a hard protective cover 10 is opened, open at the top, with a container 11 with liquid for accumulating cold. Hard protective casing 10 may be made of metal or durable plastic. The container 11 can be made of elastic material, for example, from rubber or plastic, which allows this container to take the form corresponding to the shape of the protective casing 10 when filling it with liquid for accumulating cold (ordinary fresh water or a salt solution, such as sodium chloride in water) adjacent to its inner surface. When the liquid freezes in the tank 11, this tank is protected from rupture by the walls of the hard protective casing 10. The hard protective casing simultaneously plays the role of a waterproofing that prevents the penetration of moisture from the soil into the chamber 1. When constructing the storage, waterproofing is also performed along the contact boundary 17 of the hard protective casing 10 with the floor a chamber for storing products in the upper part of the recess, in which is placed a container with a liquid for accumulating cold, enclosed in the specified casing. The container 11 has a neck with a hermetically sealed lid 12 (see also FIG. 2, which is an enlarged sectional view of the secant plane AA shown in FIG. 1; numeral 18 shows folds of a “bag” of elastic material used in the case illustrated by this figure, as a container 11 for a cold storage liquid). Above the tank 11, a removable trellised floor 13 can be installed.

A rigid protective casing 10 with a container 11 with a liquid for accumulating cold is enclosed around its perimeter and height (at least to the upper liquid level in the tank 11) by turns of a spiral evaporator 14. The latter is a tube made of easily deformable metal (for example , aluminum alloy AD-00) with a damped lower end, the longitudinal axis of which is curved in a helical line. This tube is connected (or made integrally) with a vertical pipe 15 that passes into a finned tube 16 located above the surface of the soil and blanked from above. The named parts (hermetic 14, vertical tube 15 and the finned tube 16 continuing it) form the body of the gravitational heat pipe containing, respectively, an evaporation zone, a transport zone and a condensation zone. The housing having these zones is sealed and in operating condition is charged (partially filled) with refrigerant (the elements necessary for filling are not shown in the drawings). As a refrigerant, it is preferable to use one of the freons. Refrigerant charge can be carried out both at the manufacturer of the gravitational heat pipe, and directly during the construction of the storage. The implementation of the evaporation zone or the entire gravitational heat pipe of easily deformable metal allows you to transport it in a compactly folded form and give the desired shape during the construction of the storage, as well as during its replacement and repair of the storage.

During the operation of the gravitational heat pipe as part of the design of the proposed storage facility in the cold season, when the air temperature in the condensation zone 16 is lower than the soil temperature in the evaporation zone 14, in the latter, the refrigerant evaporates. In Fig. 3, showing in enlarged scale a vertical section of the fragment / evaporation zone shown in Fig. 1, it can be seen that in this zone the liquid phase of the refrigerant 19 occupies the lower part of the lumen of the tube 14 curved along the helix, which is the evaporation zone. The steam generated in the evaporation zone, shown in Fig. 3 by curved arrows, moves in the upper part 20 of the lumen of the tube 14 along a spiral path determined by the shape of this tube to the transport zone 15 and then to the condensation zone 16. In this zone, refrigerant vapor passes into the liquid phase. The liquid phase under the action of gravity flows down the vertical pipe 15, which is the transport zone, into the evaporation zone, after which the cycle repeats.

In more detail, the processes that occur during the functioning of a gravitational heat pipe of this type are considered in the patent of the Russian Federation for utility model No. 108581 [7]. In the present invention, such a heat pipe is used in other conditions, in interaction with a liquid for accumulating cold, filling the container intended for it, with their specific relative position described above, and affects the achievement of the above types of technical result only in conjunction with the features characterizing the presence of such a capacity, its implementation and the mentioned relative position.

The refrigerant charge volume of the gravitational heat pipe with zones 14, 15, 16 is selected so as to prevent drying out of the condensate stream moving from the condensation zone 16 through the transport zone 15 to the evaporation zone 14. Condensate returns to the evaporation zone in the oncoming steam stream. In this case, the condensate stream occupies a small part of the cross section of the body of the gravitational heat pipe both in the evaporation zone (this is shown in Fig. 3) and in the transport zone and the condensation zone. Therefore, the steam flow passes almost unhindered from the evaporation zone to the condensation zone through the transport zone. The heat transferred by the refrigerant from the evaporation zone to the condensation zone is emitted to the environment by the radiator, which is the fin of the pipe in zone 16. The adjacent turns of the spiral formed by the curved tube 14 in the evaporation zone surrounding the container 11 located in the casing 10 are close, as shown in FIG. 1, allows to increase the heat exchange surface area and to obtain a large heat removal. As a result, cooling and freezing of the liquid in the tank 11 occurs. The cooled and frozen liquid in this tank becomes a cold accumulator, providing in the warm season an additional decrease in temperature in chamber 1, increasing the difference between it and the air temperature above the ground surface compared to the difference which would take place due to natural reasons in an underground storage without the use of a gravitational heat pipe. The cooling effect of the liquid accumulating cold is manifested as a result of the expenditure of heat on the melting of the liquid (ice) in the solid phase and a further rise in the temperature of the melted ice. The soil in contact with the curved tube 14, the evaporation zone of the gravitational heat pipe, is also cooled in the cold season and plays the role of an additional cold accumulator. The surface of the container 11, which is open at the top, makes it possible to place products requiring special storage conditions both directly on this surface (on ice) and on a removable grating 13.

In the warm season, when the air temperature above the soil surface becomes higher than the ambient temperature in the evaporation zone, the circulation of the coolant stops.

The elastic tank 11 can easily be replaced, if necessary, without any earthwork directly through the hatch 4. Likewise, the most critical - the evaporation part 14 of the gravitational heat pipe can be replaced due to its flexibility. To do this, it is enough to disconnect it from the vertical pipe 15, and after installing a new evaporation part, make a tight connection with the pipe 15 and carry out refrigerant charging operations.

The proposed storage may find application for the storage of food products, mainly in domestic conditions.

Information sources

1. USSR patent for the invention No. 1566178, publ. 05/23/1990.

2. A. Abrosimov, S. Zaletaev. Soil coolers. Designs and calculation methods. Ed. Palmarium Academic Publishing, 2012.

3. A.M. Humps. The device of cellars and sheds. Moscow, ed. "ACT". 2007.

4. RF patent for utility model No. 101479, publ. 01/20/2011.

5. RF patent for the invention No. 2023384, publ. 11/30/1994.

6. RF patent for the invention No. 2023383, publ. 11/30/1994.

7. RF patent for utility model No. 108581, publ. 09/20/2011.

Claims (5)

1. Storage for food products, made in the form of an underground structure having a chamber for placing products and containing a container with liquid for accumulating cold, as well as means for cooling this liquid in the form of a gravitational heat pipe, which has a sealed case filled with refrigerant, containing serially connected parts that are the evaporation zone, the transport zone and the condensation zone located above the soil surface, characterized in that the food storage chamber is partly flat the shields of its floor are made with a recess in which the indicated container with a liquid for accumulating cold is placed, this container is made of elastic material with a reserve by volume for expanding the specified liquid when it enters the solid phase and is enclosed in a hard protective cover open from above with the ability to fit its inner surface, the body of the gravitational heat pipe in the evaporation zone is made of easily deformable metal and is curved along a helix covering a container with a liquid for accumulating cold together with a rigid protective casing in which this container is enclosed by its perimeter and height, with a part of the gravitational heat pipe, which is its transport zone extends vertically through said chamber and located above the layer of soil to the junction with a portion, which condensation zone. 2. The storage according to claim 1, characterized in that the chamber for placing products is equipped with supply and exhaust ventilation. 3. The storage according to claim 1, characterized in that it is equipped with trellised flooring, removable with the possibility of placement above the tank with liquid to accumulate cold. 4. The storehouse according to claim 3, characterized in that the chamber for placing products is equipped with supply and exhaust ventilation. 5. Storage according to any one of claims 1 to 4, characterized in that the chamber for placing products is thermally and waterproofed, including having waterproofing at the contact boundary of the hard protective casing with the floor of this chamber at the top of said recess in which the container is located with a liquid for accumulating cold, enclosed in the specified casing.

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