WO2024171254A1

WO2024171254A1 - Thermoacoustic device

Info

Publication number: WO2024171254A1
Application number: PCT/JP2023/004781
Authority: WO
Inventors: 典之深谷
Original assignee: 中央精機株式会社
Priority date: 2023-02-13
Filing date: 2023-02-13
Publication date: 2024-08-22

Abstract

A thermoacoustic device 10 comprises: a prime mover 30 that includes a heat accumulator 50A, a first heat exchanger 60A that is provided with a first heat transfer tube 61 in which a heating medium can flow, and a second heat exchanger 70A that is provided with a second heat transfer tube 71 in which a coolant can flow; piping 20 in which the prime mover 30 is accommodated in the inside, and in which a working gas can be filled; and a water jacket 90 that is attached to the piping 20 and in which a coolant for cooling the piping 20 can flow. The piping 20 is provided with accommodation piping 23A in which the prime mover 30 is accommodated in the inside and which has one end 231A located on the first heat exchanger 60A side and the other end 231B located on the second heat exchanger 70A side, first main piping 21A that is connected to the one end 231A of the accommodation piping 23A, and a heat-insulating member 80 that is interposed between the accommodation piping 23A and the first main piping 21A and that has lower heat conductivity than the accommodation piping 23A and the first main piping 21A, the water jacket 90 being attached to the first main piping 21A.

Description

Thermoacoustic Device

The technology disclosed in this specification relates to thermoacoustic devices.

A thermoacoustic engine (thermoacoustic device) comprises a pipe filled with a working gas that propagates sound waves, and a prime mover (energy converter) built into the pipe. The energy converter comprises a heat accumulator, and a heater and cooler (heat exchanger) disposed at both ends of the heat accumulator. Such an energy converter can be used, for example, as a thermoacoustic engine that converts thermal energy into acoustic energy (sound waves) by self-excited vibration of the working gas due to a temperature gradient generated between both ends of the heat accumulator.

In general, the greater the temperature gradient between both ends of the heat storage unit, the greater the efficiency of conversion from thermal energy to acoustic energy. However, there are cases where the transfer of heat between the heat exchanger and the piping reduces the temperature gradient between both ends of the heat storage unit, resulting in a decrease in energy conversion efficiency. To solve this problem, a configuration has been proposed in which an insulating member is interposed between two pipes that are connected to each other (see Patent Document 1).

JP 2017-3136 A

In the above configuration, if the temperature of the piping becomes close to or higher than the heat resistance temperature of the insulating material, there is a concern that the insulating material may be damaged by heat, causing the working gas to leak, reducing the operating efficiency of the thermoacoustic device.

(1) The thermoacoustic device disclosed in this specification comprises an energy converter including a heat accumulator having one side and another side and having a plurality of through passages penetrating from the one side to the other side, a first heat exchanger arranged opposite the one side of the heat accumulator and having a first flow path through which a first fluid can flow, and a second heat exchanger arranged opposite the other side of the heat accumulator and having a second flow path through which a second fluid having a lower temperature than the first fluid can flow, a pipe in which the energy converter is housed and in which a working gas can be sealed, and a heat exchanger arranged in the pipe. and a third flow path through which a third fluid for cooling the piping can flow, the piping includes a first piping section in which the energy converter is housed and which has one end located on the first heat exchanger side and the other end located on the second heat exchanger side, a second piping section connected to the one end of the first piping section, and an insulating member interposed between the first piping section and the second piping section and having a lower thermal conductivity than the first piping section and the second piping section, and the third flow path is attached to the second piping section.

With the above configuration, the piping can be cooled by the third fluid, and the insulating member can also be cooled through the piping. This prevents the insulating member from being damaged by heat, causing the working gas to leak out of the piping and reducing the operating efficiency of the thermoacoustic device.

(2) In the thermoacoustic device described in (1) above, the first piping section and the second piping section may be made of metal, and the insulating member may be made of resin.

The above configuration (1) can be suitably applied to a combination in which the first piping section and the second piping section are made of metal and the insulating member is made of resin.

(3) The thermoacoustic device described in (1) or (2) above may further include a connecting flow path that connects the second flow path and the third flow path.

With this configuration, the second fluid that has passed through the second flow path can be supplied to the third flow path via the connecting flow path. In other words, the second fluid doubles as the third fluid. This eliminates the need to provide a separate pump or the like for circulating the third fluid through the third flow path, simplifying the configuration of the thermoacoustic device.

(4) In the thermoacoustic device described in any one of (1) to (3) above, the distance between the third flow path and the insulating member may be shorter than the distance between the insulating member and the first heat exchanger.

With this configuration, the third fluid can efficiently cool the insulating member, suppressing damage to the insulating member. In addition, it is possible to suppress a decrease in the operating efficiency of the thermoacoustic device caused by the effect of cooling by the third fluid on the energy converter.

(5) In the thermoacoustic device described in any one of (1) to (4) above, the third flow path may be arranged on the outer periphery of the second piping section.

With this configuration, the third flow path is easier to handle and the configuration of the thermoacoustic device can be simplified compared to a configuration in which the third flow path is arranged inside the second piping.

The thermoacoustic device disclosed in this specification can suppress a decrease in the operating efficiency of the thermoacoustic device.

FIG. 1 is a perspective view showing a thermoacoustic device according to a first embodiment, with a part cut away; FIG. 2 is a cross-sectional view of the thermoacoustic device of the first embodiment taken along line II-II in FIG. FIG. 3 is a partially enlarged cross-sectional view showing the inside of a circle R in FIG. FIG. 1 is a perspective view of a heat storage device according to a first embodiment; FIG. 2 is a diagram illustrating a shape of a first heat transfer tube provided in a first heat exchanger in the first embodiment; FIG. 2 is a diagram illustrating a shape of a second heat transfer tube provided in a second heat exchanger in the first embodiment; FIG. 13 is a schematic diagram showing the configuration of a circulation pipe for supplying cooling water to a water jacket in the second embodiment.

Specific examples of the technology disclosed in this specification are described below with reference to the drawings. Note that the present invention is not limited to these examples, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

<Embodiment 1>
A first embodiment will be described with reference to Fig. 1 to Fig. 6. A thermoacoustic device 10 of this embodiment is a cooling device for maintaining the temperature of an object at a temperature lower than room temperature by utilizing acoustic energy.

(Overall configuration of thermoacoustic device 10)
The thermoacoustic device 10 includes a pipe 20, a prime mover 30 (an example of an energy converter) and a cooler 40 disposed inside the pipe 20, a heat insulating member 80 disposed midway through the pipe 20, a water jacket 90 (an example of a third flow path) for cooling the pipe 20, and a connection pipe 92 (an example of a connection flow path) connecting the second heat exchanger 70A and the water jacket 90. The prime mover 30 includes a heat accumulator 50A, a first heat exchanger 60A, and a second heat exchanger 70A.

(Pipe 20)
As shown in FIG. 1, the piping 20 includes a plurality of main pipes 21, a plurality of (two in this embodiment) diffuser pipes 22, and a plurality of (two in this embodiment)

containment pipes

23A and 23B. In this embodiment, the main pipe 21, the diffuser pipe 22, and the

containment pipes

23A and 23B are made of metal. The motor 30 is housed inside one of the containment pipes 23A (an example of a first piping section), and the cooling machine 40 is housed inside the other containment pipe 23B. The main pipe 21, the diffuser pipe 22, and the

containment pipes

23A and 23B form a loop-shaped pipe P1. The pipe P1 can be filled with a working gas. There is no particular limitation on the working gas as long as it is a gas that can transmit sound waves, but an inert gas such as helium, argon, or a mixture of helium and argon, or air is preferably used.

As shown in FIG. 1, the multiple main pipes 21 connect between the two containing

pipes

23A and 23B, between the containing pipe 23A and the expansion pipe 22, between the containing pipe 23B and the expansion pipe 22, and between the two expansion pipes 22. Each main pipe 21 has openings at both ends and is a pipe with a constant inner diameter.

The multiple main pipes 21 include a first main pipe 21A (an example of a second piping section) that is connected to the housing pipe 23A that houses the prime mover 30. As shown in Figures 2 and 3, the first main pipe 21A has a flange 211 at one end that is connected to the housing pipe 23A. The flange 211 is an annular portion that extends outward from the opening edge at one end of the first main pipe 21A. The flange 211 has a seal groove 212 and multiple bolt insertion holes 213. The seal groove 212 is an annular groove that is arranged on one surface of the flange 211 that faces the housing pipe 23A. An annular seal ring S is arranged inside the seal groove 212. The bolt insertion hole 213 is a through hole through which a bolt B can be inserted.

As shown in FIG. 1, the expansion pipe 22 is a pipe that has openings at both ends and the inside diameter of the central portion between the two ends is larger than that of the main pipe 21.

As shown in Figures 1 and 2, the accommodating pipe 23A is a pipe whose inner diameter in the central portion between both ends is larger than that of the main pipe 21. More specifically, the accommodating pipe 23A is a pipe having openings at both ends, and is equipped with two first straight pipe sections 232, two tapered sections 233, a second straight pipe section 234, and a flange 235.

The two first straight pipe sections 232 are two short straight pipe sections arranged at one end 231A and the other end 231B of the containing pipe 23A, respectively, and have approximately the same outer diameter and inner diameter as the main pipe 21. The second straight pipe section 234 is located in the center between the two first straight pipe sections 232, and is a short straight pipe section having a larger inner diameter than the first straight pipe section 232. The two tapered sections 233 connect between the first straight pipe section 232 and the second straight pipe section 234 on one side, and between the first straight pipe section 232 and the second straight pipe section 234 on the other side, respectively, and are sections whose diameter narrows from the second straight pipe section 234 toward the first straight pipe section 232.

As shown in Figures 2 and 3, the flange 235 is an annular portion extending outward from the opening edge at one end 231A of the receiving pipe 23A, and has an outer diameter approximately equal to that of the flange 211 of the first main pipe 21A. The flange 235 has a seal groove 236 and a plurality of bolt insertion holes 237. The seal groove 236 is an annular groove arranged on one surface of the flange 235 facing the first main pipe 21A. An annular seal ring S is arranged inside the seal groove 236. The seal ring S is made of rubber, for example. The bolt insertion hole 237 is a through hole through which a bolt B can be inserted, and is arranged in a position aligned with the bolt insertion hole 213 of the flange 211.

The configuration of the storage pipe 23B is the same as that of the storage pipe 23A except for the details, so a description will be omitted.

(Thermal insulation member 80)
2 and 3, the heat insulating member 80 is a member sandwiched between the flange 235 of the accommodation pipe 23A and the flange 211 of the first main pipe 21A, and has an annular shape with a through hole 81 in the center. The outer diameter of the heat insulating member 80 is equal to or slightly smaller than the outer diameters of the

flanges

211, 235, and the inner diameter is approximately equal to the inner diameters of the first main pipe 21A and the first straight pipe section 232. The heat insulating member 80 has a plurality of bolt insertion holes 82. The bolt insertion holes 82 are through holes through which the bolts B can be inserted, and are arranged at positions aligned with the bolt insertion holes 213, 237 of the

flanges

211, 235.

The heat insulating member 80 is made of resin and has a lower thermal conductivity than the metal containing pipe 23A and the first main pipe 21A. For example, a super engineering plastic that functions for a long period of time in a high temperature environment of 150°C or higher can be preferably used as the resin that constitutes the heat insulating member 80. For example, PEEK (polyether ether ketone) with a continuous use temperature (upper limit temperature at which 50% or more of the strength is maintained after a long period of treatment (40,000 hours)) of approximately 200-250°C and PTFE (polytetrafluoroethylene) with a continuous use temperature of approximately 260°C can be preferably used as the super engineering plastic. Other examples include PAI (polyamideimide), PEI (polyetherimide), PES (polyethersulfone), and PPS (polyphenylene sulfide).

Bolts B are inserted into the bolt holes 213, 82, and 237, and nuts N are screwed onto the tips of the bolts B, fastening the two

flanges

211 and 235 and the insulating member 80 together. Seal rings S seal the gaps between the insulating member 80 and the two

flanges

211 and 235, respectively, preventing the working gas from leaking to the outside.

(Prime mover 30)
The prime mover 30 is a device for converting thermal energy into acoustic energy (sound waves), and is disposed inside the second straight pipe section 234 provided in the accommodation pipe 23A. As shown in Fig. 1 and Fig. 2, the prime mover 30 includes a heat accumulator 50A, a first heat exchanger 60A, and a second heat exchanger 70A. The first heat exchanger 60A, the heat accumulator 50A, and the second heat exchanger 70A are disposed in this order from one end 231A to the other end 231B.

(Heat storage unit 50A)
The heat accumulator 50A is a thick disk having one surface 50F1 (the surface on the right side in FIG. 2) and the other surface 50F2 (the surface on the left side in FIG. 2). The heat accumulator 50A is disposed in a position perpendicular to the axial direction of the accommodation pipe 23A (the left-right direction in FIG. 2) with the one surface 50F1 facing the one end 231A and the other surface 50F2 facing the other end 231B.

As shown in FIG. 4, the heat storage device 50A includes a laminate 52 in which multiple circular metal meshes 51 are stacked in a compressed state, and a fixing body 53 fixed to the outer circumferential surface of the laminate 52. The metal mesh 51 is a mesh-like member in which multiple metal thin wires are woven. The multiple metal meshes 51 have approximately the same outer shape and are stacked with the positions of their outer edges aligned. The laminate 52 is formed by connecting the meshes (gaps between the thin wires) of the multiple metal meshes 51, and has a large number of fine through passages P2 that penetrate from one surface 50F1 to the other surface 50F2 of the laminate 52. The fixing body 53 is fixed to the outer circumferential surface of the laminate 52 and plays a role in holding the outer edges of the multiple metal meshes 51 so that they do not separate from each other. The fixing body 53 keeps the multiple metal meshes 51 in a more compressed state than when they are simply stacked without their outer edges being fixed.

(First heat exchanger 60A, second heat exchanger 70A)
As shown in FIG. 2, the first heat exchanger 60A is disposed adjacent to one surface 50F1 of the heat storage unit 50A. As shown in FIG. 5, a known heat exchanger including a first heat transfer tube 61 (an example of a first flow path) and fins disposed around the first heat transfer tube 61 can be used as the first heat exchanger 60A. A high-temperature heat transfer medium (an example of a first fluid) can flow inside the first heat transfer tube 61, and heat exchange is performed between the working gas near the first heat exchanger 60A and the heat transfer medium. For example, heat transfer oil warmed by exhaust heat from a factory can be used as the heat transfer medium. The temperature of the heat transfer oil is, for example, about 200-400°C.

The second heat exchanger 70A is disposed adjacent to the other surface 50F2 of the heat storage unit 50A, as shown in FIG. 2. As the second heat exchanger 70A, a known heat exchanger including a second heat transfer tube 71 (an example of a second flow path) and fins disposed around the second heat transfer tube 71, as shown in FIG. 6, can be used. A refrigerant (an example of a second fluid) that is lower in temperature than the heat medium flowing inside the first heat transfer tube 61 can flow inside the second heat transfer tube 71, and the working gas near the second heat exchanger 70A has a temperature lower than that of the heat medium. In this embodiment, water at room temperature is used as the refrigerant supplied to the second heat transfer tube 71.

(Cooling machine 40)
The cooling machine 40 is a heat pump that generates a temperature gradient by inputting acoustic energy generated by the prime mover 30 and maintains the temperature of the object at a temperature lower than room temperature, and is disposed inside the other housing pipe 23B as shown in FIG. 1. The cooling machine 40 includes a heat accumulator 50B and a first heat exchanger 60B and a second heat exchanger 70B disposed on both sides of the heat accumulator 50B. The heat accumulator 50B and the

heat exchangers

60B and 70B provided in the cooling machine 40 have the same configuration as the heat accumulator 50A and the

heat exchangers

60A and 70A provided in the prime mover 30. A medium at a constant temperature (water at room temperature in this embodiment) can flow inside the heat transfer tube provided in the first heat exchanger 60B, and the working gas near the first heat exchanger 60B becomes about room temperature. The heat transfer tubes of the second heat exchanger 70B are connected to a heat exchanger provided in an external cooling facility, and a refrigerant can circulate inside the heat transfer tubes.

(Water jacket 90)
The water jacket 90 is disposed on the outer periphery of the first main pipe 21A and is a member for cooling the first main pipe 21A. As shown in Figs. 1 and 2, the water jacket 90 is an annular member having an inner diameter substantially equal to the outer diameter of the first main pipe 21A and has a flow groove 91. The flow groove 91 is disposed on the inner periphery of the water jacket 90 and is a groove through which a refrigerant (third fluid) for cooling the first main pipe 21A can flow. The water jacket 90 is made of, for example, metal and is joined to the outer periphery of the first main pipe 21A by welding.

As shown in FIG. 2, the distance D1 between the water jacket 90 and the insulating member 80 is shorter than the distance D2 between the insulating member 80 and the first heat exchanger 60A. In this embodiment, the "distance D1 between the water jacket 90 and the insulating member 80" is the distance between the surface of the water jacket 90 facing the insulating member 80 and the surface of the insulating member 80 facing the water jacket 90, and the "distance D2 between the insulating member 80 and the first heat exchanger 60A" is the distance between the surface of the insulating member 80 facing the first heat exchanger 60A and the surface of the first heat exchanger 60A facing the insulating member 80.

(Connection pipe 92)
The connection pipe 92 is a pipe that connects the second heat transfer pipe 71 and the water jacket 90 and allows a refrigerant to flow through. The connection pipe 92 allows the refrigerant that has passed through the second heat transfer pipe 71 to be supplied to the water jacket 90. In other words, the connection pipe 92 allows the refrigerant for generating a temperature gradient between both ends of the heat accumulator 50A to also serve as the refrigerant for cooling the first main pipe 21A.

(Operation of the thermoacoustic device 10)
When the thermoacoustic device 10 is operated, a heat medium is passed through the first heat transfer tube 61. Then, heat exchange occurs between the working gas in the vicinity of the one surface 50F1 of the heat accumulator 50A and the heat medium. As a result, the temperature of the working gas in the vicinity of the one surface 50F1 of the heat accumulator 50A is adjusted to approach the temperature of the heat medium. In addition, water at room temperature as a refrigerant is passed through the second heat transfer tube 71. Then, heat exchange occurs between the working gas in the vicinity of the other surface 50F2 of the heat accumulator 50A and the water at room temperature. As a result, the temperature of the working gas in the vicinity of the other surface 50F2 of the heat accumulator 50A is adjusted to approach room temperature.

The action of the

heat exchangers

60A and 70A creates a temperature gradient between the first surface 50F1 and the second surface 50F2 of the heat storage device 50A. As a result, the working gas inside the passage P2 becomes unstable and starts to vibrate. This vibration generates acoustic energy (sound waves). The generated acoustic energy is output from the first surface 50F1 of the heat storage device 50A (the surface where the first heat exchanger 60A is arranged), transmitted through the working gas sealed inside the pipe P1, and reaches the cooling device 40 (see the arrow in Figure 1).

When acoustic energy transmitted by the working gas is input to the heat storage device 50B provided in the cooling device 40, a temperature gradient is generated between one side facing the first heat exchanger 60B and the other side facing the second heat exchanger 70B. Since room temperature water flows through the first heat exchanger 60B arranged on the input side of the acoustic energy in the cooling device 40, the temperature of the working gas near the second heat exchanger 70B in the heat storage device 50B is adjusted to a temperature lower than room temperature by the amount of the generated temperature gradient. Heat exchange occurs between this working gas, which is lower than room temperature, and the refrigerant, and the cooled refrigerant is supplied to an external cooling facility to cool the target object.

Here, if heat from the heat medium passing through the first heat transfer tube 61 is transferred to the storage pipe 23A and then moves to the first main pipe 21A and the pipe 20 beyond, the temperature difference between both ends of the heat accumulator 50A becomes small, and the efficiency of conversion from thermal energy to acoustic energy by the prime mover 30 may decrease. To avoid this, a heat insulating member 80 is arranged between the storage pipe 23A and the first main pipe 21A connected to this storage pipe 23A. The heat insulating member 80 prevents the heat transferred to the storage pipe 23A from being transferred to the first main pipe 21A beyond, thereby preventing a decrease in the efficiency of conversion from thermal energy to acoustic energy.

However, as heat from the heat medium is transferred to the containing pipe 23A, the temperature of the containing pipe 23A can reach a high temperature close to that of the heat medium. For this reason, for example, if the temperature of the containing pipe 23A reaches a temperature close to or exceeds the heat resistance temperature of the resin that constitutes the insulating member 80, there is a concern that the insulating member 80 in contact with the containing pipe 23A may be damaged by heat. If the insulating member 80 is damaged, the working gas may leak outside the pipe 20, and the operating efficiency of the thermoacoustic device 10 may decrease.

In this embodiment, the refrigerant that has passed through the second heat transfer tube 71 is supplied to the water jacket 90 via the connecting pipe 92, so that the first main pipe 21A is cooled by this refrigerant, and the insulating member 80 that is in contact with the first main pipe 21A is also cooled. This makes it possible to prevent the insulating member 80 from being damaged and causing the working gas to leak from the pipe 20, and to prevent a decrease in the operating efficiency of the thermoacoustic device 10.

The thermoacoustic device 10 also includes a connection pipe 92, and the refrigerant that has passed through the second heat transfer tube 71 is supplied to the water jacket 90 via the connection pipe 92. This configuration eliminates the need to provide a separate pump or the like for circulating the refrigerant through the water jacket 90, simplifying the configuration of the thermoacoustic device 10.

Furthermore, the distance D1 between the water jacket 90 and the insulating member 80 is shorter than the distance D2 between the insulating member 80 and the first heat exchanger 60A. Because the distance D1 between the water jacket 90 and the insulating member 80 is relatively short, the insulating member 80 is efficiently cooled by the refrigerant passing through the inside of the water jacket 90, and damage to the insulating member 80 is efficiently suppressed. Furthermore, because the distance D2 between the insulating member 80 and the first heat exchanger 60A is relatively long, the influence of the cooling by the refrigerant passing through the inside of the water jacket 90 is suppressed from extending to the periphery of the first heat exchanger 60A. This prevents the temperature gradient between both ends of the heat storage device 50A from becoming smaller, and suppresses a decrease in energy conversion efficiency.

In addition, the water jacket 90 is disposed on the outer periphery of the first main pipe 21A. With this configuration, the water jacket 90 can be easily handled, and the configuration of the thermoacoustic device 10 can be simplified.

(Action and Effect)
As described above, the thermoacoustic device 10 of this embodiment includes the heat accumulator 50A having one surface 50F1 and the other surface 50F2 and having a plurality of through passages P2 penetrating from the one surface 50F1 to the other surface 50F2, the first heat exchanger 60A arranged opposite to the one surface 50F1 of the heat accumulator 50A and including a first heat transfer tube 61 through which a heat medium can flow, and the second heat exchanger 70A arranged opposite to the other surface 50F2 of the heat accumulator 50A and including a second heat transfer tube 71 through which a refrigerant having a lower temperature than the heat medium can flow, the prime mover 30, the piping 20 in which the prime mover 30 is accommodated and in which a working gas can be sealed, and the piping 20 and a water jacket 90 through which a refrigerant for cooling the piping 20 can flow, the piping 20 accommodates a prime mover 30 inside and comprises a accommodating piping 23A having one end 231A located on the first heat exchanger 60A side and the other end 231B located on the second heat exchanger 70A side, a first main pipe 21A connected to the one end 231A of the accommodating piping 23A, and an insulating member 80 interposed between the accommodating piping 23A and the first main pipe 21A and having a lower thermal conductivity than the accommodating piping 23A and the first main pipe 21A, and the water jacket 90 is attached to the first main pipe 21A.

With the above configuration, the first main pipe 21A can be cooled by the refrigerant, and the insulating member 80 can also be cooled via the first main pipe 21A. This prevents the insulating member 80 from being damaged by heat, causing the working gas to leak from the piping 20, and thus reducing the operating efficiency of the thermoacoustic device 10.

Furthermore, the receiving pipe 23A and the first main pipe 21A are made of metal, and the insulating member 80 is made of resin. In such a combination, the above configuration can be suitably applied.

The thermoacoustic device 10 further includes a connection pipe 92 that connects the second heat transfer tube 71 and the water jacket 90.

With this configuration, the refrigerant that has passed through the second heat transfer tube 71 can be supplied to the water jacket 90 via the connecting pipe 92. In other words, the refrigerant circulating through the second heat transfer tube 71 also serves as the refrigerant circulating through the water jacket 90. This eliminates the need to provide a separate pump or the like for circulating the refrigerant through the water jacket 90, simplifying the configuration of the thermoacoustic device 10.

Furthermore, the distance D1 between the water jacket 90 and the insulating member 80 is shorter than the distance D2 between the insulating member 80 and the first heat exchanger 60A.

With this configuration, the heat insulating member 80 can be efficiently cooled by the refrigerant flowing through the water jacket 90, and damage to the heat insulating member 80 can be suppressed. In addition, a decrease in the operating efficiency of the thermoacoustic device 10 caused by the influence of cooling by the refrigerant on the prime mover 30 can be suppressed.

The water jacket 90 is also arranged on the outer periphery of the first main pipe 21A. With this configuration, compared to a configuration in which the third flow path is arranged inside the second piping section, the water jacket 90 is easier to handle, and the configuration of the thermoacoustic device 10 can be simplified.

<Embodiment 2>
The thermoacoustic device 100 of embodiment 2 differs from embodiment 1 in that it does not have a connecting flow path connecting the second heat transfer tube 71 and the water jacket 90, but has an independent circulation piping 101 that supplies refrigerant to the water jacket 90.

The circulation pipe 101 is connected to the water jacket 90 and is used to supply refrigerant to the water jacket 90. As shown in FIG. 7, the water jacket 90 and the circulation pipe 101 form a looped pipe line, and a refrigerant (third fluid) for cooling the first main pipe 21A, which is different from the refrigerant flowing through the second heat transfer pipe 71, can flow through this pipe line. A cooling device 102 for cooling the refrigerant that has been heated by heat transfer from the first main pipe 21A, and a pump P for transporting the refrigerant are provided midway through the circulation pipe 101.

The rest of the configuration is the same as in embodiment 1, so the same components as in embodiment 1 are given the same reference numerals and the description is omitted.

In this embodiment, as in the first embodiment, the first main pipe 21A can be cooled by the refrigerant, and the insulating member 80 can also be cooled via the first main pipe 21A. This prevents the insulating member 80 from being damaged by heat, causing the working gas to leak from the piping 20, and thus reducing the operating efficiency of the thermoacoustic device 100.

<Other embodiments>
(1) In the above embodiment, the thermoacoustic device 10 was a cooling device, but the thermoacoustic device does not have to be a cooling device. For example, the thermoacoustic device may be a heating device equipped with a heat pump for heating instead of the cooling machine 40, or may be a power generation device equipped with a generator that converts sound waves output from a prime mover into electric power.
(2) In the above embodiment, the piping 20 is loop-shaped. However, the piping may include, for example, a branch piping that branches off from the loop piping.
(3) In the above embodiment, the thermoacoustic device 10 includes one prime mover 30. However, the thermoacoustic device may include a plurality of prime movers.
(4) In the above embodiment, the thermoacoustic device 10 includes two expanding tubes 22. However, the number of expanding tubes may be one or three or more. The thermoacoustic device may not include an expanding tube.
(5) In the above embodiment, the pipe 20 is made of metal. However, for example, only the first pipe portion and the second pipe portion of the pipe may be made of metal.
(6) In the above embodiment, the accommodating pipe 23A and the first main pipe 21A were made of metal, and the insulating member 80 was made of resin. However, the combination of the first piping section and the second piping section with the insulating member may be any combination in which the insulating member has lower thermal conductivity than the first piping section and the second piping section.
(7) In the above embodiment, the containing pipe 23A was a pipe whose inner diameter in the central portion between both ends was larger than that of the main pipe 21. However, the shape of the first pipe section may be arbitrary, and for example, it may be a pipe having an inner diameter approximately equal to that of the second pipe section over its entire length.
(8) In the above embodiment, the first main pipe 21A is circular, but the shape of the second piping section does not have to be circular and may be, for example, a polygonal tubular shape. In addition, the shapes of the first piping section and the heat insulating member may be any shapes that fit the second piping section.
(9) In the above embodiment, the water jacket 90 is disposed on the outer periphery of the first main pipe 21A. However, the third flow passage may be disposed inside the second piping.
(10) In the above embodiment, the water jacket 90 was welded to the first main pipe 21A, but the shape of the third flow path is arbitrary, and for example, it may be a pipe wrapped around the second piping section.
(11) In embodiment 1, the refrigerant discharged from the water jacket 90 may be cooled and reused as the second fluid and the third fluid, may be reused for a purpose other than as a refrigerant for the thermoacoustic device 10, or may be discarded.
(12) In the second embodiment, the water jacket 90 and the circulation pipe 101 form a looped pipe through which the refrigerant circulates, but the pipe for supplying the third fluid to the third flow path does not have to be looped. In this case, the refrigerant discharged from the water jacket 90 may be reused for a purpose other than the refrigerant for the thermoacoustic device 10, or may be discarded.
(13) In the above embodiment, the first fluid is thermal oil, and the second fluid and the third fluid are water. However, any medium can be used as the first fluid, the second fluid, and the third fluid.

10: Thermoacoustic device 20: Piping 21A: First main pipe (second piping section) 23A: Housing pipe (first piping section) 30: Prime mover (energy converter) 50A: Heat storage device 50F1: One side 50F2: Other side 60A: First heat exchanger 61: First heat transfer tube (first flow path) 70A: Second heat exchanger 71: Second heat transfer tube (second flow path) 80: Insulation member 90: Water jacket (third flow path) 92: Connection pipe (connection flow path) 231A: One end 231B: Other end P2: Through passage

Claims

A heat accumulator having one surface and another surface and a plurality of through passages penetrating from the one surface to the other surface;
a first heat exchanger disposed opposite the one surface of the heat accumulator and including a first flow path through which a first fluid can flow;
a second heat exchanger disposed opposite the other surface of the heat accumulator and including a second flow path through which a second fluid having a lower temperature than the first fluid can flow;
an energy converter comprising:
A pipe that houses the energy converter therein and can seal a working gas therein;
a third flow path attached to the pipe and through which a third fluid for cooling the pipe can flow;
Equipped with
The piping,
a first piping section in which the energy converter is housed and which has one end located on the first heat exchanger side and the other end located on the second heat exchanger side;
a second piping section connected to the one end of the first piping section;
a heat insulating member interposed between the first piping section and the second piping section and having a lower thermal conductivity than the first piping section and the second piping section;
Equipped with
The third flow path is attached to the second piping portion.
Thermoacoustic device.
the first piping section and the second piping section are made of metal,
The heat insulating member is made of resin.
10. The thermoacoustic device of claim 1.
Further comprising a connection flow path connecting the second flow path and the third flow path.
A thermoacoustic device according to claim 1 or 2.
A distance between the third flow path and the heat insulating member is shorter than a distance between the heat insulating member and the first heat exchanger.
A thermoacoustic device according to any one of claims 1 to 3.
The third flow path is disposed on an outer periphery of the second piping portion.
A thermoacoustic device according to any one of claims 1 to 4.