Thermoacoustic device

Abstract

To provide a thermoacoustic device capable of improving heat efficiency.SOLUTION: A thermoacoustic device that utilizes an oscillating flow comprises: a thermoacoustic core having a first heat exchanger installed at one end of a heat storage device that converts the energy of the oscillating flow into thermal energy and vice versa; and a second heat exchanger installed at the other end of the heat storage device; a holding member that holds the thermoacoustic core; and an outer shell that houses the thermoacoustic core. The holding member contacts an outer shell at a position where, when viewed from a radial direction, it overlaps with one heat exchanger with a smaller temperature difference from a room temperature out of the first heat exchanger and the second heat exchanger, or at a position where, when viewed from the radial direction, it overlaps with a region of the heat storage device on the side of the one heat exchanger.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a thermoacoustic device. [Background technology]

[0002] Technologies for reusing waste heat from factories, cars, etc. have been researched. One possible way to recycle waste heat is to use an external combustion engine. Known examples of external combustion engines include steam turbines that use the Rankine cycle and Stirling engines that use the Stirling cycle. These external combustion engines are configured to output power from a heat source.

[0003] As another external combustion engine, a thermoacoustic device equipped with a heat storage device that converts between the energy of an oscillating flow and thermal energy is known. In a thermoacoustic device, the compression and expansion of an oscillating flow plays the role of a piston, and the device can output cold heat, electricity, etc. from input thermal energy without having any moving parts. A typical thermoacoustic device is equipped with a thermoacoustic core composed of a heat storage device made of a porous body having one to an infinite number of narrow flow paths, a pair of heat exchangers that absorb and release heat with the outside, and a pipe connected to the upstream and downstream sides of the thermoacoustic core and through which a working gas flows. When a predetermined temperature difference that exceeds a critical condition occurs in the heat storage device, the heat storage device can generate and amplify the oscillating flow. In a thermoacoustic device, energy conversion similar to that of a Stirling cycle is performed, so there is a possibility of achieving high thermal efficiency. Therefore, a thermoacoustic device has attracted attention as a highly efficient heat engine that does not have moving parts and can reuse waste heat.

[0004] One method of extracting the oscillating flow generated in a thermoacoustic device as an output is the heat pump effect using the thermoacoustic phenomenon. When an oscillating flow such as sound waves is input into a heat storage device and the fluid in the heat storage device is forced to vibrate, a temperature difference occurs between both ends of the heat storage device. The heat pump effect of this sound wave can be used to perform "refrigeration" or "heating."

[0005] As an example of a thermoacoustic device, Non-Patent Document 1 discloses a thermoacoustic device in which a thermoacoustic core configured as a thermoacoustic prime mover that generates and amplifies an oscillating flow from thermal energy such as waste heat, and a thermoacoustic core configured as a thermoacoustic cooler that performs refrigeration using the oscillating flow generated and amplified in the thermoacoustic prime mover are arranged in series along the axial direction of the flow path.

[0006] In addition, in a thermoacoustic device, the temperature range that can be used as a heat source is widened by reducing the temperature difference required for the thermoacoustic core to operate. Therefore, research and development into low-temperature operation of a thermoacoustic prime mover and a thermoacoustic cooler is actively conducted. In addition, by connecting a thermoacoustic prime mover and a thermoacoustic cooler, a thermal operation / thermoacoustic cooler can be configured in which the oscillating flow generated and amplified by the thermoacoustic prime mover is input to the thermoacoustic cooler to perform cooling by the heat pump effect. For example, Non-Patent Document 2 discloses a thermoacoustic device in which one thermoacoustic prime mover and one thermoacoustic cooler are arranged in series in a loop. In addition, Non-Patent Document 3 discloses a thermoacoustic device in which a thermoacoustic prime mover and a thermoacoustic cooler are evenly arranged. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Jiaxin Chi, Yupeng Yang, Zhanghua Wu, Rui Yang, Ping Li, Jingyuan Xu, Limin Zhang, Jianying Hu, Ercang Luo,Numerical and experimental investigation on a novel heat-driven thermoacoustic refrigerator for room-temperature cooling, Applied Thermal Engineering, Volume 218, 2023, 119330, ISSN 1359-4311 [Non-Patent Document 2] T. Yazaki, et al., “A pistonless Stirling cooler”, Applied Physics Letters 81, pp. 157-159, (2002) [Non-Patent Document 3] H. Wang, et al., “Study on a novel looped heat-driven thermoacoustic refrigerator with direct-coupling configuration for room temperature cooling”, International Journal of Refrigeration 123, pp.180-188, (2021) Summary of the Invention [Problem to be solved by the invention]

[0008] In the thermoacoustic device of Non-Patent Document 1, each thermoacoustic core is directly fixed to the outer shell that houses each thermoacoustic core. Therefore, it is difficult to reduce the amount of heat flowing from the heat exchanger on the high temperature side of the thermoacoustic motor to the outer shell, and therefore it is difficult to increase the amount of heat transferred to the heat accumulator out of the amount of heat input to the heat exchanger.

[0009] In addition, in the thermoacoustic device of Non-Patent Document 3, the high-temperature heat exchanger of the thermoacoustic motor and the room-temperature heat exchanger of the thermoacoustic cooler are arranged adjacent to each other, so that the amount of heat transferred from the high-temperature heat exchanger of the thermoacoustic motor to the room-temperature heat exchanger of the thermoacoustic cooler through the outer shell tends to be large. Therefore, the temperature of the heat storage unit of the thermoacoustic cooler tends to be high.

[0010] In view of the above circumstances, an object of the present invention is to provide a thermoacoustic device that can improve thermal efficiency. [Means for solving the problem]

[0011] (1) One aspect of the present invention is a thermoacoustic device that utilizes an oscillating flow, comprising a thermoacoustic core having a first heat exchanger installed at one end of a heat storage device that converts the energy of the oscillating flow into thermal energy and vice versa, and a second heat exchanger installed at the other end of the heat storage device, a retaining member that holds the thermoacoustic core, and an outer shell that houses the thermoacoustic core, wherein the retaining member contacts the outer shell at a position where it overlaps, when viewed from a radial direction, with one of the first heat exchanger or the second heat exchanger that has a smaller temperature difference from room temperature, or at a position where it overlaps, when viewed from a radial direction, with a region of the heat storage device on the side of the one heat exchanger.

[0012] According to the present invention, it is possible to increase the thermal resistance between the outer shell and one of the first and second heat exchangers, which has a larger temperature difference from room temperature. As a result, in the thermoacoustic prime mover, which is a thermoacoustic core for driving the thermoacoustic device, the amount of heat transferred from the first prime mover heat exchanger, which is a heat exchanger on the high temperature side, to the outer shell through the retaining member can be reduced, thereby improving the thermal efficiency of the thermoacoustic device. Also, in the thermoacoustic cooler, which is a thermoacoustic core for output of the thermoacoustic device, the amount of heat transferred to the first cooling heat exchanger, which is a heat exchanger on the low temperature side, through the retaining member can be reduced. As a result, it is possible to suppress the temperature rise of each of the first cooling heat exchanger and one end of the cooling heat storage unit. Therefore, it is possible to increase the amount of cold heat output from the first cooling heat exchanger, thereby improving the thermal efficiency of the thermoacoustic device.

[0013] (2) One aspect of the present invention is a thermoacoustic device described in (1), in which the retaining member seals the movement of fluid between the outer shell and the thermoacoustic core.

[0014] According to the present invention, it is possible to suppress the flow of fluid between the outer shell and the thermoacoustic core, thereby reducing the energy loss of the convection and oscillatory flow of the fluid caused by the fluid flowing between the outer shell and the thermoacoustic core.

[0015] (3) One aspect of the present invention is a thermoacoustic device described in (1) or (2), which has a plurality of the thermoacoustic cores and a plurality of the retaining members, each of the plurality of retaining members retaining a different thermoacoustic core.

[0016] According to the present invention, in each of the multiple thermoacoustic cores, the thermal resistance between the outer shell and the first heat exchanger can be increased, thereby improving the thermal efficiency of the thermoacoustic device.

[0017] (4) One aspect of the present invention is a thermoacoustic device described in any one of (1) to (3), in which multiple adjacent thermoacoustic cores and multiple retaining members are contained in one outer shell portion, and each of the multiple retaining members holds a different thermoacoustic core and is in contact with the outer shell portion.

[0018] According to the present invention, the stress applied to the holding member for holding the thermoacoustic cores can be reduced compared to when one holding member holds multiple thermoacoustic cores. This reduces the rigidity required for the holding member, allowing the holding member to be made thinner and more suitably increasing the thermal resistance between the first heat exchanger and the outer shell. This makes it possible to more suitably increase the thermal efficiency of the thermoacoustic device.

[0019] (5) One aspect of the present invention is a thermoacoustic device as described in any one of claims 1 to 4, comprising a thermoacoustic unit, wherein the multiple thermoacoustic cores include a thermoacoustic prime mover and a thermoacoustic cooler, the thermoacoustic unit being configured with the thermoacoustic prime mover and the thermoacoustic cooler arranged adjacent to each other in the axial direction, and in the thermoacoustic unit, a heat exchanger that is the cooling side of the heat exchangers of the thermoacoustic cooler and a heat exchanger that is close to room temperature of the heat exchangers of the thermoacoustic prime mover are arranged adjacent to each other.

[0020] According to the present invention, since the axial distance between the first cooling heat exchanger and the first driving heat exchanger can be increased, the amount of heat flowing from the first driving heat exchanger to the first cooling heat exchanger through the fluid and the outer shell can be reduced. Therefore, the temperature of the first driving heat exchanger can be prevented from decreasing and the temperature of the first cooling heat exchanger can be prevented from increasing, thereby improving the thermal efficiency of the thermoacoustic device.

[0021] (6) One aspect of the present invention is a thermoacoustic device described in (5), in which the thermoacoustic unit has a membrane member having a membrane structure arranged between the thermoacoustic prime mover and the thermoacoustic cooler.

[0022] According to the present invention, since the temperature of the membrane member can be prevented from becoming too high, deterioration of the membrane member made of a rubber material that does not have high heat resistance can be prevented. Therefore, the Gedeon flow can be stably suppressed, and the thermal efficiency of the thermoacoustic device can be prevented from decreasing.

[0023] (7) One aspect of the present invention is a thermoacoustic device according to (5) or (6), comprising a plurality of the thermoacoustic units.

[0024] According to the present invention, since waste heat can be supplied to each of a plurality of thermoacoustic prime movers, the amount of heat that can be supplied to the thermoacoustic device can be increased. Also, since cold heat can be output from each of a plurality of thermoacoustic coolers, the amount of cold heat output from the thermoacoustic device can be increased.

[0025] (8) One aspect of the present invention is a thermoacoustic device that utilizes an oscillating flow, comprising a thermoacoustic unit having a thermoacoustic prime mover that converts thermal energy into oscillating flow energy, and a thermoacoustic cooler that converts the energy of the oscillating flow into thermal energy, wherein each of the thermoacoustic prime mover and the thermoacoustic cooler has a first heat exchanger installed at one end of a heat accumulator that converts the energy of the oscillating flow into thermal energy and a second heat exchanger installed at the other end of the heat accumulator, and wherein a heat exchanger that is the cooling side of the heat exchangers of the thermoacoustic cooler and a heat exchanger that is close to room temperature of the heat exchangers of the thermoacoustic prime mover are arranged axially adjacent to each other in this thermoacoustic device.

[0026] According to the present invention, since the axial distance between the first cooling heat exchanger and the first driving heat exchanger can be increased, the amount of heat flowing from the first driving heat exchanger to the first cooling heat exchanger through the fluid and the outer shell can be reduced. Therefore, the temperature of the first driving heat exchanger can be prevented from decreasing and the temperature of the first cooling heat exchanger can be prevented from increasing, thereby improving the thermal efficiency of the thermoacoustic device. Effect of the Invention

[0027] According to one aspect of the present invention, the thermal efficiency of a thermoacoustic device can be improved. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a schematic diagram showing an example of use of the thermoacoustic device of the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram illustrating an example of a thermoacoustic core according to the first embodiment. [Diagram 3] FIG. 3 is a schematic diagram showing another example of the thermoacoustic device according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing an example of use of the thermoacoustic device according to the second embodiment. [Diagram 5] FIG. 5 is a schematic diagram showing a thermoacoustic unit according to the second embodiment. [Figure 6]FIG. 6 is a schematic diagram showing a thermoacoustic unit of a thermoacoustic device according to a first modified example of the second embodiment. [Figure 7] FIG. 7 is a schematic diagram showing a thermoacoustic unit of a thermoacoustic device according to a second modified example of the second embodiment. [Figure 8] FIG. 8 is a schematic diagram showing a thermoacoustic unit of a thermoacoustic device according to a third modified example of the second embodiment. [Figure 9] FIG. 9 is a schematic diagram showing a thermoacoustic unit of a thermoacoustic device according to a fourth modified example of the second embodiment. [Figure 10] FIG. 10 is a schematic diagram showing an example of use of the thermoacoustic device according to the third embodiment. [Figure 11] FIG. 11 is a schematic diagram showing a thermoacoustic unit according to the third embodiment. [Figure 12] FIG. 12 is a schematic diagram showing a thermoacoustic unit of a thermoacoustic device according to a first modified example of the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] In each drawing, the axial direction Da is the direction in which the housing that contains the thermoacoustic core and the fluid extends. The axial direction Da is the tube axis direction of the housing. In the following description, the side toward which the arrow of the axial direction Da points (+Da side) is referred to as the "one axial side", and the opposite side to the side toward which the arrow of the axial direction Da points (-Da side) is referred to as the "other axial side". In addition, among the axial Da ends of each member constituting the thermoacoustic device, the end on one axial side may be referred to as the "one end" and the end on the other axial side may be referred to as the "other end".

[0030] The outer periphery of the thermoacoustic engine and the waveguide may have a circular shape, but may also have an elliptical shape, a rounded polygonal shape, a polygonal shape, or the like. In order to facilitate the explanation of the configuration of the invention, the thermoacoustic engine and the waveguide are typically shaped like a circle. The first axis J1 shown in each drawing is the central axis of the outer periphery. The first axis J1 is a virtual axis extending in the axial direction Da. In the following explanation, the radial direction centered on the first axis J1 is simply referred to as the "radial direction", and the circumferential direction centered on the first axis J1 is simply referred to as the "circumferential direction". The circumferential direction is indicated by an arrow θ1.

[0031] The second axis J2 shown in each drawing is a virtual axis extending in a direction perpendicular to the axial direction Da. In the following description, the circumferential direction about the second axis J2 is simply referred to as the "second circumferential direction." In each drawing, the second circumferential direction is indicated by an arrow θ2.

[0032] First Embodiment The thermoacoustic device 10 shown in FIG. 1 is a thermoacoustic device that utilizes an oscillating flow in a housing 20. The thermoacoustic device 10 generates and amplifies an oscillating flow of a fluid F accommodated in the housing 20 by thermal energy supplied to the thermoacoustic device 10, converts the oscillating flow into energy such as thermal energy, and outputs the energy. The heat source that supplies the thermal energy may be any heat energy that can be supplied from a moving body such as an automobile, a ship, or an aircraft, a factory, a waste treatment plant, or a water heater, or from heat collected from sunlight, and is not limited to these. The thermoacoustic device 10 of this embodiment includes a housing 20, a thermoacoustic core 31, a holding member 40, and a fluid F.

[0033] The housing 20 is a conduit that accommodates the thermoacoustic core 31, the holding member 40, and the fluid F therein. The housing 20 is a flow path through which the fluid F flows in the axial direction Da. The housing 20 is annular. In the present embodiment of FIG. 1, the housing 20 is an approximately rectangular annular shape that surrounds the second axis J2. The housing 20 has a plurality of outer shell parts 21a and a plurality of waveguides 21c. The housing 20 is not limited to an approximately rectangular annular shape, and may have other shapes such as annular, elliptical, and polygonal annular shapes. The housing 20 may be rounded or angular. In addition, the tube axes of the plurality of outer shell parts 21a and the plurality of waveguides 21c may not be arranged on the same plane, and the tube axes of each of the outer shell parts 21a and each of the waveguides 21c may be curved three-dimensionally.

[0034] The outer shell portion 21a accommodates the thermoacoustic core 31 and the holding member 40 therein. The outer shell portion 21a is cylindrical and extends in the axial direction Da. In this embodiment, the outer shell portion 21a is cylindrical and has a first axis J1 as its center. The outer shell portion 21a may have other shapes, such as a prismatic column extending in the axial direction Da. The outer shell portion 21a holds the thermoacoustic core 31 and the holding member 40. In this embodiment of FIG. 1, the housing 20 has four outer shell portions 21a. The outer shell portions 21a are arranged at intervals of approximately 90° along the second circumferential direction. Note that the intervals at which the outer shell portions 21a are arranged are not limited to approximately 90°, and in the case of an approximately square ring shape, the angle is not limited as long as the combination of the four corners is 360° in total. In addition, when the housing 20 has a substantially triangular ring shape, the interval at which the outer shell parts 21a are arranged is not particularly limited as long as the sum of the three angles is 180°. The number of the outer shell parts 21a of the housing 20 may be three or less, or five or more.

[0035] In the present embodiment of FIG. 1, the waveguide 21c is tubular and curved at approximately 90°. In the present embodiment, the housing 20 has four waveguides 21c. The waveguides 21c are arranged at intervals of approximately 90° along the second circumferential direction. Each waveguide 21c connects a pair of outer shell parts 21a arranged adjacent to each other in the second circumferential direction. As a result, the outer shell parts 21a are connected via each waveguide 21c, and the housing 20 is configured in a substantially quadrangular ring shape. The angle of the waveguide 21c changes depending on the shape of the housing 20, and when the housing 20 is polygonal ring-shaped, the angle is equal to the angle constituting the interior angle of the polygonal ring.

[0036] The fluid F is sealed inside the housing 20. As the fluid F, a fluid capable of transmitting an oscillatory flow, such as a gas such as air, helium, and argon, a liquid such as water and ethanol, and a mixture of a gas, liquid, and vapor, can be used. In this embodiment, the pressure of the fluid F is higher than atmospheric pressure in order to increase the conversion efficiency between the energy of the oscillatory flow and thermal energy in the thermoacoustic core 31. Note that the fluid F is not limited to the above-mentioned materials as long as it is capable of transmitting an oscillatory flow, and may be composed of other materials. In addition, the pressure of the fluid F may be the same as atmospheric pressure, or may be lower than atmospheric pressure.

[0037] The thermoacoustic core 31 converts thermal energy such as input waste heat into the energy of a vibration flow. The thermoacoustic core 31 also converts the energy of the vibration flow into thermal energy and outputs it. The thermoacoustic core 31 is housed inside the outer shell portion 21a. The thermoacoustic core 31 is held in the outer shell portion 21a via a holding member 40. The thermoacoustic device 10 has a plurality of thermoacoustic cores 31. In this embodiment, the thermoacoustic device 10 has four thermoacoustic cores 31. Each thermoacoustic core 31 is housed inside a different outer shell portion 21a. The number of thermoacoustic cores 31 in the thermoacoustic device 10 may be three or less, or five or more.

[0038] In this embodiment, the multiple thermoacoustic cores 31 include a thermoacoustic prime mover 33 and a thermoacoustic cooler 35. In this embodiment, the thermoacoustic device 10 has two thermoacoustic prime movers 33 and two thermoacoustic coolers 35. At least one of the thermoacoustic prime movers 33 and the thermoacoustic coolers 35 may utilize a phase change phenomenon for mutual conversion between the energy of the oscillating flow and thermal energy. Note that the multiple thermoacoustic cores 31 may include a thermoacoustic heating machine (not shown) in addition to the thermoacoustic prime movers 33 and the thermoacoustic coolers 35.

[0039] Each thermoacoustic core 31 has a heat accumulator 31a, a first heat exchanger 31e, and a second heat exchanger 31g. The heat accumulator 31a converts the energy of the oscillating flow into thermal energy and vice versa. The heat accumulator 31a has one or more small-diameter flow passages (not shown). The flow passages extend along the axial direction Da and open on both sides in the axial direction. The oscillating flow flows inside the flow passages. The flow passages are formed, for example, by a honeycomb structure formed of ceramics and a structure in which a large number of stainless steel mesh thin plates are laminated. The flow passages may be formed of foam metal, steel wool, or the like, may be formed by rolling up an uneven film, or may be formed by combining thin plates having different flow passage diameters and flow passage shapes. The flow passages are formed, for example, in a cross section having a circular tube shape, a parallel plate shape, a polygonal shape, or a pin array shape. In this embodiment, the heat accumulator 31a includes a motive heat accumulator 33a and a cooling heat accumulator 35a. The heat accumulator 31a may convert between the energy of the oscillating flow and thermal energy by utilizing the evaporation and condensation of liquid, that is, the phase change phenomenon of liquid.

[0040] The first heat exchanger 31e is disposed on one axial side (+Da side) of the heat accumulator 31a. The first heat exchanger 31e is installed at one end 31b of the heat accumulator 31a. The first heat exchanger 31e is connected to one end 31b of the heat accumulator 31a. The second heat exchanger 31g is disposed on the other axial side (-Da side) of the heat accumulator 31a. The second heat exchanger 31g is installed at the other end 31c of the heat accumulator 31a. The second heat exchanger 31g is connected to the other end 31c of the heat accumulator 31a. In this embodiment, the temperature difference between the temperature of the first heat exchanger 31e and room temperature is larger than the temperature difference between the temperature of the second heat exchanger 31g and room temperature. In this embodiment, the first heat exchanger 31e includes a first motive heat exchanger 33e and a first cooling heat exchanger 35e. In this embodiment, the second heat exchanger 31g includes a second motive heat exchanger 33g and a second cooling heat exchanger 35g.

[0041] The thermoacoustic prime mover 33 converts thermal energy into oscillating flow energy. The thermoacoustic prime mover 33 may be a motive thermoacoustic core 31 that utilizes an oscillating flow, such as a standing wave type oscillating flow, a traveling wave type oscillating flow, or a phase change type oscillating flow. As shown in FIG. 2, the thermoacoustic prime mover 33 has a motive heat accumulator 33a, a first motive heat exchanger 33e, and a second motive heat exchanger 33g.

[0042] When a temperature difference occurs between one end 33b and the other end 33c of the prime mover heat accumulator 33a, a thermoacoustic phenomenon occurs in the prime mover heat accumulator 33a, thereby generating an oscillating flow or amplifying the oscillating flow. The first prime mover heat exchanger 33e is installed at one end 33b of the prime mover heat accumulator 33a. The first prime mover heat exchanger 33e is a heat exchanger on the high temperature side of the thermoacoustic prime mover 33. The first prime mover heat exchanger 33e exchanges heat with the one end 33b of the prime mover heat accumulator 33a via a heat medium whose temperature is higher than that of the heat medium of the second prime mover heat exchanger 33g.

[0043] The second prime mover heat exchanger 33g is installed at the other end 33c of the prime mover heat accumulator 33a. The second prime mover heat exchanger 33g is a heat exchanger on the room temperature side of the thermoacoustic prime mover 33. The second prime mover heat exchanger 33g exchanges heat with the other end 33c of the prime mover heat accumulator 33a via a room temperature heat medium. The temperature of the second prime mover heat exchanger 33g is closer to room temperature than the temperature of the first prime mover heat exchanger 33e. Note that the heat medium of the second prime mover heat exchanger 33g has a lower temperature than the heat medium of the first prime mover heat exchanger 33e, and it is sufficient that a temperature difference is obtained between the first prime mover heat exchanger 33e and the second prime mover heat exchanger 33g. Therefore, the heat medium of the second prime mover heat exchanger 33g may be a medium that maintains a stable temperature, such as groundwater, seawater, river water, or factory cooling water, or a medium that is lower than room temperature, such as liquid nitrogen or natural gas, using a chiller, etc. In addition, a medium with a temperature higher than room temperature, such as waste hot water or cooling oil, may be used as long as its temperature is lower than that of the first prime mover heat exchanger 33e. However, the lower the temperature of the second prime mover heat exchanger 33g, the larger the temperature difference with the first prime mover heat exchanger 33e.

[0044] A heat medium such as a high-temperature gas or liquid having a higher temperature than the heat medium of the second motive heat exchanger 33g is circulated in the first motive heat exchanger 33e. As a result, high-temperature heat is supplied to one end 33b of the motive heat accumulator 33a, so that the temperature of one end 33b of the motive heat accumulator 33a can be made higher than the temperature of the second motive heat exchanger 33g. In addition, a heat medium such as a room-temperature gas or liquid is circulated in the second motive heat exchanger 33g. As a result, the temperature of the other end 33c of the motive heat accumulator 33a can be made room temperature. Note that the heat medium of the second motive heat exchanger 33g has a lower temperature than the first motive heat exchanger 33e, and it is only necessary that a temperature difference is obtained between the first motive heat exchanger 33e and the second motive heat exchanger 33g. Therefore, the heat medium of the second prime mover heat exchanger 33g may be a medium that maintains a stable temperature, such as groundwater, seawater, river water, or factory cooling water, or a medium that is lower than room temperature, such as liquid nitrogen or natural gas, or a chiller. In addition, a medium that is higher than room temperature, such as waste hot water or cooling oil, may be used as long as it is lower in temperature than the first prime mover heat exchanger 33e. Therefore, in the prime mover heat accumulator 33a, a temperature difference is formed between one end 33b of the prime mover heat accumulator 33a, which is the high temperature side, and the other end 33c of the prime mover heat accumulator 33a, which is the room temperature side, so that a thermoacoustic phenomenon occurs, and the oscillating flow of the fluid F can be generated and amplified. As a result, the prime mover heat accumulator 33a converts thermal energy into the energy of the oscillating flow. The oscillating flow generated and amplified in the prime mover heat accumulator 33a propagates inside the housing 20.

[0045] The heat supplied to the first motive heat exchanger 33e may be, for example, unused heat discarded as waste heat. The heat source of the heat supplied to the first motive heat exchanger 33e is not particularly limited, and may be, for example, sunlight, geothermal heat, an engine, or a device that generates heat in various facilities such as a factory.

[0046] The room temperature is the temperature of the atmosphere outside the thermoacoustic device 10 and the temperature outside the thermoacoustic core 31, such as the temperature of the outer shell 21a. Specifically, the room temperature and the atmospheric temperature can be mentioned. The room temperature may be the temperature of a medium that can stably supply heat (including cold) to generate a temperature difference between the first driving heat exchanger 33e and the first cooling heat exchanger 35e.

[0047] The thermoacoustic cooler 35 converts the energy of the oscillating flow into thermal energy. The thermoacoustic cooler 35 is an output thermoacoustic core that receives the oscillating flow generated and amplified in the thermoacoustic prime mover 33 and outputs the output. In this embodiment, the thermoacoustic cooler 35 is a cooler that outputs cold heat as an output. As shown in FIG. 3, the thermoacoustic cooler 35 has a cooling heat storage unit 35a, a first cooling heat exchanger 35e, and a second cooling heat exchanger 35g.

[0048] When the oscillating flow is input to the cooling heat storage 35a, a temperature difference is generated between one end 35b and the other end 35c of the cooling heat storage 35a due to a heat pump effect. The first cooling heat exchanger 35e is installed at one end 35b of the cooling heat storage 35a. The first cooling heat exchanger 35e is a heat exchanger on the cooling side of the thermoacoustic cooler 35. The first cooling heat exchanger 35e exchanges heat with the one end 35b of the cooling heat storage 35a via a heat medium whose temperature is lower than room temperature. The first cooling heat exchanger 35e extracts cold heat from the one end 35b of the cooling heat storage 35a.

[0049] The second cooling heat exchanger 35g is installed at the other end 35c of the cooling heat storage 35a. The second cooling heat exchanger 35g is a heat exchanger on the room temperature side of the thermoacoustic cooler 35. The second cooling heat exchanger 35g exchanges heat with the other end 35c of the cooling heat storage 35a via a room temperature heat medium. The temperature of the second cooling heat exchanger 35g is closer to room temperature than the temperature of the first cooling heat exchanger 35e. The heat medium of the second cooling heat exchanger 35g may be a medium that maintains a stable temperature, such as groundwater, seawater, river water, or factory cooling water, or a medium that is lower than room temperature, such as liquid nitrogen or natural gas, using a chiller, etc. In addition, the temperature of the heat medium of the second cooling heat exchanger 35g may be a medium that is higher than room temperature, such as waste hot water, cooling oil, or high temperature air in a room, as long as it is higher than the temperature of the heat medium of the first cooling heat exchanger 35e. When the temperature of the second cooling heat exchanger 35g is lower than room temperature, a lower temperature of cold can be extracted from the first cooling heat exchanger 35e.

[0050] As described above, when the vibration flow generated and amplified in the thermoacoustic motor 33 is input to the cooling heat storage 35a, a temperature difference is formed between one end 35b and the other end 35c of the cooling heat storage 35a due to the heat pump effect. As described above, the other end 35c of the cooling heat storage 35a is heat exchanged with a room temperature heat medium by the second cooling heat exchanger 35g. Therefore, a temperature difference is generated between one end 35b and the other end 35c of the cooling heat storage 35a based on the other end 35c of the cooling heat storage 35a, which is at room temperature, and an endothermic reaction occurs at the one end 35b of the cooling heat storage 35a, which is the cooling side. Therefore, cold can be output from the cooling heat storage 35a by exchanging heat with the one end 35b of the cooling heat storage 35a via the first cooling heat exchanger 35e.

[0051] In the thermoacoustic device 10 of this embodiment, the thermoacoustic cooler 35 may be replaced with a generator and a heating machine depending on the use of the thermoacoustic device 10. In the thermoacoustic device 10 in which the thermoacoustic cooler 35 is replaced with a generator, the generator can convert the energy of the oscillating flow into electric power, and electric power can be output. In the thermoacoustic device 10 in which the thermoacoustic cooler 35 is replaced with a heating machine, the heating machine can convert the energy of the oscillating flow into thermal energy, and heat can be output.

[0052] The holding member 40 holds the thermoacoustic core 31. As shown in FIG. 1, the holding member 40 is cylindrical and extends in the axial direction Da. The holding member 40 is housed inside the outer shell 21a. The thermoacoustic device 10 has a plurality of holding members 40. In this embodiment, the thermoacoustic device 10 has eight holding members 40. Each holding member 40 holds a different thermoacoustic core 31. That is, each holding member 40 holds a different thermoacoustic prime mover 33 or thermoacoustic cooler 35. As shown in FIG. 2 and FIG. 3, the holding member 40 has a holding portion 41, a sealing portion 42, and a protruding portion 43. In this embodiment, the holding portion 41, the sealing portion 42, and the protruding portion 43 are part of the same single member. Each of the holding portion 41, the sealing portion 42, and the protruding portion 43 may be separate members. In this case, the holding portion 41, the sealing portion 42, and the protruding portion 43 can be joined to each other by adhesion, welding, or the like to form the holding member 40. The thickness of each of the holding portion 41, the sealing portion 42, and the protruding portion 43 is thinner than the thickness of the outer shell portion 21a. That is, the thickness of the holding member 40 is thinner than the thickness of the outer shell portion 21a.

[0053] Next, the configuration of the holding member 40 for holding the thermoacoustic motor 33 will be described. As shown in FIG. 2, the holding portion 41 is cylindrical and extends in the axial direction Da with the first axis J1 as the center. In the radial direction, the holding portion 41 is disposed between the thermoacoustic motor 33 and the outer shell portion 21a. The holding portion 41 is disposed with a gap in the radial direction from the outer shell portion 21a. One end 41a of the holding portion 41 is located on the other axial side (-Da side) of the first prime mover heat exchanger 33e. In this embodiment, the other end 41b of the holding portion 41 overlaps with the second prime mover heat exchanger 33g as viewed in the radial direction. The inner peripheral surface of the holding portion 41 contacts the outer peripheral surface of the prime mover heat accumulator 33a. As a result, the holding member 40 holds the thermoacoustic motor 33. The inner peripheral surface of the holding portion 41 may contact the outer peripheral surface of the second prime mover heat exchanger 33g. Also, when viewed from the radial direction, the other end 41b of the retaining portion 41 may be disposed at a position overlapping with the second prime mover heat exchanger 33g side of the prime mover heat accumulator 33a, that is, the region on the second heat exchanger 31g side.

[0054] In this embodiment, the sealing portion 42 protrudes radially outward from the other end 41b of the holding portion 41. When viewed from the axial direction Da, the sealing portion 42 is annular about the first axis J1. The radially outer end of the sealing portion 42 contacts the outer shell portion 21a in the radial direction. That is, the holding member 40 contacts the outer shell portion 21a. As a result, the holding member 40 is held by the outer shell portion 21a. Therefore, the thermoacoustic prime mover 33 is held by the outer shell portion 21a via the holding member 40. The sealing portion 42 contacts the outer shell portion 21a in the radial direction over the entire circumference. As a result, the holding member 40 seals the movement of the fluid F between the outer shell portion 21a and the thermoacoustic prime mover 33, i.e., the thermoacoustic core 31. The shape of the sealing portion 42 is not limited to this embodiment as long as it can seal the movement of the fluid F between the outer shell portion 21a and the thermoacoustic core 31. For example, when the outer shell portion 21a has an elliptical shape, a rounded polygonal shape, a polygonal shape, or the like, the shape of the sealing portion 42 may be an elliptical shape, a rounded polygonal shape, a polygonal shape, or the like.

[0055] In this embodiment, the sealing portion 42 contacts the outer shell portion 21a at a position overlapping the second motive heat exchanger 33g, i.e., the second heat exchanger 31g, as viewed from the radial direction. As a result, the holding member 40 contacts the outer shell portion 21a at a position overlapping the first motive heat exchanger 33e, i.e., the first heat exchanger 31e, or the second heat exchanger 31g, whichever has a smaller temperature difference from room temperature, of the second heat exchanger 31g. The holding member 40 may contact the outer shell portion 21a at a position overlapping the region of the motive heat accumulator 33a on the second heat exchanger 31g side, as viewed from the radial direction.

[0056] The protruding portion 43 protrudes radially outward from one end 41a of the holding portion 41. When viewed from the axial direction Da, the protruding portion 43 has an annular shape centered on the first axis J1. In this embodiment, the protruding portion 43 faces the outer shell portion 21a with a gap therebetween in the radial direction. The protruding portion 43 does not necessarily have to be provided.

[0057] Next, the configuration of the holding member 40 for holding the thermoacoustic cooler 35 will be described. In the following description, the same configuration as that of the holding member 40 for holding the thermoacoustic motor 33 will not be described. As shown in FIG. 3, one end 41a of the holding portion 41 is located on the other axial side (-Da side) of the first cooling heat exchanger 35e. In this embodiment, the other end 41b of the holding portion 41 overlaps with the second cooling heat exchanger 35g when viewed from the radial direction. The inner circumferential surface of the holding portion 41 contacts with the outer circumferential surface of the cooling heat accumulator 35a. As a result, the holding member 40 holds the thermoacoustic cooler 35. Note that, when viewed from the radial direction, the other end 41b of the holding portion 41 may be disposed at a position overlapping with the second cooling heat exchanger 35g side of the cooling heat accumulator 35a, that is, the region on the second heat exchanger 31g side.

[0058] The radially outer end of the sealing portion 42 contacts the outer shell portion 21a in the radial direction. As a result, the thermoacoustic cooler 35 is held by the outer shell portion 21a via the holding member 40. The sealing portion 42 contacts the outer shell portion 21a in the radial direction over the entire circumference. As a result, the holding member 40 seals the movement of the fluid F between the outer shell portion 21a and the thermoacoustic cooler 35, i.e., the thermoacoustic core 31. In this embodiment, the holding member 40 contacts the outer shell portion 21a at a position overlapping the first cooling heat exchanger 35e, i.e., the first heat exchanger 31e, or the second cooling heat exchanger 35g, i.e., the second heat exchanger 31g, which has a smaller temperature difference from the room temperature, of the first cooling heat exchanger 35e, i.e., the first heat exchanger 31e, or the second cooling heat exchanger 35g, i.e., the second heat exchanger 31g. The holding member 40 may contact the outer shell portion 21a at a position overlapping the region of the cooling heat accumulator 35a on the second heat exchanger 31g side when viewed from the radial direction.

[0059] According to this embodiment, the thermoacoustic device 10 is a thermoacoustic device that uses an oscillating flow, and includes a thermoacoustic core 31 having a first heat exchanger 31e installed at one end of a heat accumulator 31a that converts the energy of the oscillating flow into thermal energy and a second heat exchanger 31g installed at the other end of the heat accumulator 31a, a holding member 40 that holds the thermoacoustic core 31, and an outer shell portion 21a that houses the thermoacoustic core 31. The holding member 40 contacts the outer shell portion 21a at a position where it overlaps with the second heat exchanger 31g, which has a smaller temperature difference from room temperature, of the first heat exchanger 31e or the second heat exchanger 31g, as viewed from the radial direction. Therefore, the axial distance Da between the first heat exchanger 31e, which has a larger temperature difference from room temperature, of the first heat exchanger 31e or the second heat exchanger 31g, and the sealing portion 42, which is a portion of the holding member 40 that contacts the outer shell portion 21a, can be increased. Therefore, when viewed from the radial direction, the thermal resistance between the first heat exchanger 31e and the outer shell portion 21a can be increased compared to when the retaining member 40 contacts the outer shell portion 21a at a position overlapping with the first heat exchanger 31e.

[0060] Therefore, in the thermoacoustic prime mover 33, the amount of heat transferred from the first prime mover heat exchanger 33e, which is a high-temperature side heat exchanger, to the outer shell portion 21a via the holding member 40 can be reduced. This makes it possible to reduce the amount of heat dissipated to the external atmosphere out of the amount of heat supplied to the first prime mover heat exchanger 33e. Therefore, the temperature of the one end 33b of the prime mover heat accumulator 33a can be efficiently increased, thereby improving the thermal efficiency of the thermoacoustic device 10.

[0061] Furthermore, in the thermoacoustic cooler 35, the amount of heat transferred from the external atmosphere or the like to the first cooling heat exchanger 35e, which is a low-temperature side heat exchanger, via the holding member 40 can be reduced. This makes it possible to suppress an increase in the temperatures of the first cooling heat exchanger 35e and the one end 35b of the cooling heat accumulator 35a. Therefore, the amount of cold energy output from the first cooling heat exchanger 35e can be increased, thereby improving the thermal efficiency of the thermoacoustic device 10.

[0062] In addition, in this embodiment, the pressure of the fluid F is higher than atmospheric pressure in order to increase the conversion efficiency between the energy of the vibration flow and the thermal energy in the thermoacoustic core 31 as described above. In this embodiment, since the outer shell portion 21a serves as a pressure-resistant container for accommodating the fluid F, the holding member 40 does not need to have a pressure-resistant function. Therefore, as described above, the thickness of the holding member 40 can be made thinner than the thickness of the outer shell portion 21a, so that the thermal resistance between the first heat exchanger 31e and the outer shell portion 21a can be more suitably increased. Therefore, the amount of heat dissipated from the first driving heat exchanger 33e to the outer shell portion 21a and the atmosphere outside the thermoacoustic device 10 can be reduced, and the amount of heat transferred to the first cooling heat exchanger 35e via the holding member 40 can be reduced, so that the thermal efficiency of the thermoacoustic device 10 can be more suitably increased.

[0063] Moreover, in this embodiment, the housing 20 is annular. Therefore, the thermoacoustic device 10 can generate self-excited vibration. Therefore, the thermoacoustic device 10 can generate and amplify an oscillating flow without requiring an input source of the oscillating flow such as an acoustic driver. Therefore, an increase in the number of parts of the thermoacoustic device 10 can be suppressed, and the configuration of the thermoacoustic device 10 can be simplified.

[0064] According to this embodiment, the retaining member 40 seals off the movement of the fluid F between the outer shell portion 21a and the thermoacoustic core 31. This makes it possible to suppress the fluid F from flowing between the outer shell portion 21a and the thermoacoustic core 31. This makes it possible to reduce the energy loss of the convection and oscillatory flow of the fluid F caused by the fluid F flowing between the outer shell portion 21a and the thermoacoustic core 31.

[0065] According to this embodiment, the thermoacoustic device 10 has a plurality of thermoacoustic cores 31 and a plurality of holding members 40, and each of the plurality of holding members 40 holds a different thermoacoustic core 31. Therefore, in each of the plurality of thermoacoustic cores 31, the thermal resistance between the outer shell portion 21a and the first heat exchanger 31e can be increased, so that the amount of heat dissipated from each first driving heat exchanger 33e to the outer shell portion 21a and the atmosphere outside the thermoacoustic device 10 can be reduced, and the amount of heat transferred to each first cooling heat exchanger 35e via the holding member 40 can be reduced, so that the thermal efficiency of the thermoacoustic device 10 can be improved.

[0066] In addition, since the present embodiment has a plurality of thermoacoustic prime movers 33, it is possible to lower the temperature of the one end 33b of the prime mover heat accumulator 33a required for each thermoacoustic prime mover 33 to generate and amplify the oscillating flow, thereby more suitably improving the thermal efficiency of the thermoacoustic device 10.

[0067] <Second embodiment> The thermoacoustic device 210 of this embodiment is a thermoacoustic device that utilizes an oscillatory flow in a housing 220. As shown in Fig. 4, the thermoacoustic device 210 of this embodiment includes a thermoacoustic unit 230. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

[0068] As shown in FIG. 4, the housing 220 of this embodiment is an approximately square ring shape. The housing 220 has a plurality of outer shell parts 221a and a plurality of waveguides 21c. The outer shell part 221a of this embodiment houses the thermoacoustic unit 230 and the holding member 240 inside. The outer shell part 221a holds the thermoacoustic unit 230 and the holding member 240. The housing 220 is not limited to an approximately square ring shape, and may have other shapes such as annular, elliptical, and polygonal ring shapes. The housing 220 may be rounded or angular. In this embodiment, the housing 220 has four outer shell parts 221a. The outer shell parts 221a are arranged at intervals of approximately 90° along the axial direction Da. The intervals at which the outer shell parts 221a are arranged are not limited to approximately 90°, and in the case of an approximately square ring shape, the angle is not limited as long as the total of the four corners is a combination of 360°. Furthermore, when the housing 220 is substantially triangular, the interval at which the outer shell portions 221a are arranged is not particularly limited as long as the sum of the three angles is 180°. Furthermore, the number of outer shell portions 221a that the housing 220 has may be three or less, or may be five or more. The other configurations of the housing 220 of the supplementary embodiment are the same as the other configurations of the housing 20 of the first embodiment described above.

[0069] The thermoacoustic unit 230 converts thermal energy such as input waste heat into energy of the oscillating flow. The thermoacoustic unit 230 also converts the energy of the oscillating flow into thermal energy and outputs it. The thermoacoustic unit 230 is housed inside the outer shell 221a. The thermoacoustic unit 230 is held in the outer shell 221a via a holding member 240. The thermoacoustic device 210 includes a plurality of thermoacoustic units 230. In this embodiment, the thermoacoustic device 210 includes four thermoacoustic units 230. Each thermoacoustic unit 230 is housed inside a different outer shell 221a. Each thermoacoustic unit 230 is composed of a plurality of thermoacoustic cores 31 adjacent to each other along the axial direction Da. The plurality of thermoacoustic cores 31 adjacent to each other are housed in one outer shell 221a. In this embodiment, the thermoacoustic unit 230 is composed of two thermoacoustic cores 31. The number of thermoacoustic units 230 included in the thermoacoustic device 210 may be three or less, or may be five or more. The number of thermoacoustic cores 31 included in the thermoacoustic unit 230 may be three or more.

[0070] In this embodiment, the multiple thermoacoustic cores 31 include a thermoacoustic prime mover 33 and a thermoacoustic cooler 35. In this embodiment, each thermoacoustic unit 230 is composed of one thermoacoustic prime mover 33 and one thermoacoustic cooler 35. In this embodiment, the thermoacoustic device 210 has four thermoacoustic prime movers 33 and four thermoacoustic coolers 35.

[0071] In this embodiment, in each thermoacoustic unit 230, the thermoacoustic prime mover 33 is disposed on one axial side (+Da side) of the thermoacoustic cooler 35. The thermoacoustic prime mover 33 is disposed at a distance from the thermoacoustic cooler 35 in the axial direction Da. As shown in FIG. 5, the first cooling heat exchanger 35e, which is the cooling side of the thermoacoustic cooler 35, is disposed at one end 35b of the cooling heat accumulator 35a. In addition, the second prime mover heat exchanger 33g, which is the room temperature side of the thermoacoustic prime mover 33, is disposed at the other end 33c of the prime mover heat accumulator 33a. Therefore, in each thermoacoustic unit 230, the heat exchanger on the cooling side of the heat exchangers of the thermoacoustic cooler 35, i.e., the first cooling heat exchanger 35e, and the heat exchanger of the thermoacoustic prime mover 33 whose temperature is close to room temperature, i.e., the second prime mover heat exchanger 33g, are disposed adjacent to each other.

[0072] The holding member 240 holds the thermoacoustic core 31. As shown in FIG. 4, the thermoacoustic device 210 has a plurality of holding members 240. In this embodiment, the thermoacoustic device 210 has eight holding members 240. Each holding member 240 holds a different thermoacoustic core 31. That is, each holding member 240 holds a different thermoacoustic prime mover 33 or thermoacoustic cooler 35. Two holding members 240 are housed in one outer shell 221a. That is, a plurality of holding members 240 are housed in one outer shell 221a. As shown in FIG. 5, the holding member 240 has a holding portion 241, a sealing portion 242, and a protruding portion 43. The thickness of the holding member 240 is thinner than the thickness of the outer shell 221a.

[0073] Next, the configuration of the holding member 240 for holding the thermoacoustic motor 33 will be described. The holding portion 241 is cylindrical and extends in the axial direction Da with the first axis J1 as the center. One end 241a of the holding portion 241 is located on the other axial side (-Da side) of the first prime mover heat exchanger 33e. In this embodiment, the other end 241b of the holding portion 241 overlaps with the region of the prime mover heat accumulator 33a on the second prime mover heat exchanger 33g side when viewed from the radial direction. In this embodiment, the region of the prime mover heat accumulator 33a on the second prime mover heat exchanger 33g side is a portion of the prime mover heat accumulator 33a that is closer to the second prime mover heat exchanger 33g than the center in the axial direction Da. The inner circumferential surface of the holding portion 241 contacts the outer circumferential surface of the prime mover heat accumulator 33a. As a result, the holding member 240 holds the thermoacoustic motor 33.

[0074] The sealing portion 242 protrudes radially outward from the other end 241b of the holding portion 241. The radially outer end of the sealing portion 242 contacts the outer shell portion 221a in the radial direction. As a result, the thermoacoustic prime mover 33 is held by the outer shell portion 221a via the holding member 240. The sealing portion 242 contacts the outer shell portion 221a in the radial direction over the entire circumference. As a result, the holding member 240 seals the movement of the fluid F between the outer shell portion 221a and the thermoacoustic prime mover 33, i.e., the thermoacoustic core 31. In this embodiment, as viewed from the radial direction, the sealing portion 242 contacts the outer shell portion 221a at a position overlapping the second prime mover heat exchanger 33g side of the prime mover heat accumulator 33a, i.e., the region on the second heat exchanger 31g side. As a result, the holding member 240 comes into contact with the outer shell portion 221a at a position overlapping with a region of the first heat exchanger 31e or the second heat exchanger 31g of the heat accumulator 31a, whichever is the second heat exchanger 31g, which has a smaller temperature difference from room temperature.

[0075] Next, the configuration of the holding member 240 for holding the thermoacoustic cooler 35 will be described. In the following description, the same configuration as that of the holding member 240 for holding the thermoacoustic motor 33 will not be described. One end 241a of the holding portion 241 is located on the other axial side (-Da side) of the first cooling heat exchanger 35e. In this embodiment, the other end 241b of the holding portion 241 overlaps with the area of ​​the cooling heat accumulator 35a on the second cooling heat exchanger 35g side when viewed from the radial direction. The inner circumferential surface of the holding portion 241 contacts the outer circumferential surface of the cooling heat accumulator 35a. As a result, the holding member 240 holds the thermoacoustic cooler 35.

[0076] The radially outer end of the sealing portion 242 contacts the outer shell portion 221a in the radial direction. As a result, the thermoacoustic cooler 35 is held by the outer shell portion 221a via the holding member 240. The sealing portion 242 contacts the outer shell portion 221a in the radial direction over the entire circumference. As a result, the holding member 240 seals the movement of the fluid F between the outer shell portion 221a and the thermoacoustic cooler 35, i.e., the thermoacoustic core 31. In this embodiment, the holding member 240 contacts the outer shell portion 221a at a position overlapping with a region of the second heat exchanger 31g side, which has a smaller temperature difference from room temperature, of the first heat exchanger 31e or the second heat exchanger 31g of the heat accumulator 31a. Other configurations of the holding member 240 are the same as other configurations of the holding member 40 of the first embodiment described above.

[0077] According to this embodiment, the holding member 40 contacts the outer shell portion 221a at a position overlapping the region of the first heat exchanger 31e or the second heat exchanger 31g of the heat accumulator 31a, which has a smaller temperature difference from room temperature, among the first heat exchanger 31e or the second heat exchanger 31g. Therefore, as in the above-mentioned first embodiment, the thermal resistance between the first heat exchanger 31e and the outer shell portion 221a can be increased. Therefore, the amount of heat dissipated from the first driving heat exchanger 33e to the outer shell portion 221a and the atmosphere outside the thermoacoustic device 210 can be reduced, and the amount of heat transferred to the first cooling heat exchanger 35e via the holding member 240 can be reduced, so that the thermal efficiency of the thermoacoustic device 210 can be improved.

[0078] According to this embodiment, a plurality of thermoacoustic cores 31 and a plurality of holding members 240 adjacent to each other are housed in one outer shell portion 221a, and each of the plurality of holding members 240 holds a different thermoacoustic core 31 from the others, and contacts the outer shell portion 221a. Therefore, compared to the case where a plurality of thermoacoustic cores 31 are held by one holding member 240, the stress applied to the holding member 240 for holding the thermoacoustic cores 31 can be reduced. As a result, the rigidity required for the holding member 240 can be reduced, and the thickness of the holding member 240 can be reduced. Therefore, the thermal resistance between the first heat exchanger 31e and the outer shell portion 221a can be increased. Therefore, the amount of heat radiated from the first driving heat exchanger 33e to the outer shell portion 221a and the atmosphere outside the thermoacoustic device 210 can be reduced, and the amount of heat transferred to the first cooling heat exchanger 35e via the holding member 240 can be reduced, so that the thermal efficiency of the thermoacoustic device 210 can be improved.

[0079] According to this embodiment, the thermoacoustic device 210 includes a thermoacoustic unit 230, and the multiple thermoacoustic cores 31 include a thermoacoustic prime mover 33 and a thermoacoustic cooler 35. The thermoacoustic unit 230 is configured by the thermoacoustic prime mover 33 and the thermoacoustic cooler 35 arranged adjacent to each other in the axial direction Da. In the thermoacoustic unit 230, the first cooling heat exchanger 35e, which is the cooling side of the heat exchangers of the thermoacoustic cooler 35, and the second prime mover heat exchanger 33g, which is the heat exchanger of the thermoacoustic prime mover 33 and has a temperature close to room temperature, are arranged adjacent to each other. Therefore, compared to a configuration in which the first cooling heat exchanger 35e, which is the cooling side of the thermoacoustic cooler 35, and the first prime mover heat exchanger 33e, which is the high temperature side of the thermoacoustic prime mover 33, are arranged adjacent to each other, the distance in the axial direction Da between the first cooling heat exchanger 35e and the first prime mover heat exchanger 33e can be made longer. Therefore, the amount of heat flowing from the first driving heat exchanger 33e to the first cooling heat exchanger 35e through the fluid F and the outer shell portion 221a can be reduced. Therefore, the temperature of the first driving heat exchanger 33e can be prevented from decreasing and the temperature of the first cooling heat exchanger 35e can be prevented from increasing, thereby improving the thermal efficiency of the thermoacoustic device 210.

[0080] In addition, in this embodiment, the first cooling heat exchanger 35e, which is the cooling side of the thermoacoustic cooler 35, and the second prime mover heat exchanger 33g, which is the room temperature side of the thermoacoustic prime mover 33, are arranged adjacent to each other, so that the temperature difference between the thermoacoustic prime mover 33 and the thermoacoustic cooler 35 can be made smaller than in a configuration in which the first cooling heat exchanger 35e and the first prime mover heat exchanger 33e are arranged adjacent to each other. Therefore, the amount of heat flowing from the thermoacoustic prime mover 33 to the thermoacoustic cooler 35 through the fluid F and the outer shell portion 221a can be reduced, so that the thermal efficiency of the thermoacoustic device 210 can be improved.

[0081] Furthermore, in this embodiment, as described above, the amount of heat flowing from the thermoacoustic prime mover 33 to the thermoacoustic cooler 35 via the fluid F and the outer shell portion 221a can be reduced, so that the distance between the thermoacoustic prime mover 33 and the thermoacoustic cooler 35 can be easily shortened. Therefore, when the outer diameter of the thermoacoustic prime mover 33 and the outer diameter of the thermoacoustic cooler 35 are each larger than the inner diameter of the waveguide 21c, it is easy to arrange the thermoacoustic prime mover 33 and the thermoacoustic cooler 35 at a position where the non-acoustic impedance is high. Therefore, the thermal efficiency of the thermoacoustic device 210 can be improved.

[0082] According to this embodiment, the thermoacoustic device 210 includes a plurality of thermoacoustic units 230. Therefore, waste heat can be supplied to each of the plurality of thermoacoustic prime movers 33, so that the amount of heat that can be supplied to the thermoacoustic device 210 can be increased. In addition, cold heat can be output from each of the plurality of thermoacoustic coolers 35, so that the amount of cold heat that can be output by the thermoacoustic device 210 can be increased.

[0083] In addition, in this embodiment, since the multiple thermoacoustic units 230 are arranged inside the annular housing 20, it is possible to lower the temperature of the one end 33b of the motor heat accumulator 33a, which is necessary for the thermoacoustic motor 33 of each thermoacoustic unit 230 to generate and amplify the oscillating flow. Therefore, it is possible to more suitably increase the thermal efficiency of the thermoacoustic device 210.

[0084] <First Modification of Second Embodiment> 6, a thermoacoustic device 310 of this modification includes a thermoacoustic unit 330. In the following description, the same components as those in the above-described second embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0085] Although not shown, the thermoacoustic device 310 includes a plurality of thermoacoustic units 330. In this modification, the thermoacoustic device 310 includes four thermoacoustic units 330. The thermoacoustic units 330 are housed inside different outer shells 221a. In this modification, each thermoacoustic unit 330 includes one thermoacoustic prime mover 33 and one thermoacoustic cooler 35. In each thermoacoustic unit 330, the thermoacoustic prime mover 33 is disposed on the other axial side (-Da side) of the thermoacoustic cooler 35. The thermoacoustic prime mover 33 is disposed at an interval from the thermoacoustic cooler 35 in the axial direction Da. The thermoacoustic prime mover 33 and the thermoacoustic cooler 35 are held by different holding members 240.

[0086] In this modification, in each thermoacoustic unit 330, the heat exchanger on the high temperature side among the heat exchangers of the thermoacoustic prime mover 33, i.e., the first prime mover heat exchanger 33e, and the heat exchanger whose temperature is close to room temperature among the heat exchangers of the thermoacoustic cooler 35, i.e., the second cooling heat exchanger 35g, are arranged adjacent to each other. Therefore, in this modification, the amount of heat flowing from the first prime mover heat exchanger 33e to the first cooling heat exchanger 35e through the fluid F and the outer shell portion 221a can be reduced. Therefore, the temperature of the first prime mover heat exchanger 33e can be prevented from decreasing and the temperature of the first cooling heat exchanger 35e can be prevented from increasing, thereby improving the thermal efficiency of the thermoacoustic device 310.

[0087] According to this modification, the thermoacoustic device 310 includes a plurality of thermoacoustic units 330. Therefore, waste heat can be supplied to each of the plurality of thermoacoustic prime movers 33, so that the amount of heat that can be supplied to the thermoacoustic device 310 can be increased. In addition, cold heat can be output from each of the plurality of thermoacoustic coolers 35, so that the amount of cold heat that can be output by the thermoacoustic device 310 can be increased.

[0088] <Second Modification of Second Embodiment> 7, a thermoacoustic device 410 of this modification includes a housing 420 and a thermoacoustic unit 430. In the following description, the same components as those in the second embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

[0089] Although not shown, the housing 420 of this modification is, for example, substantially rectangular annular. The housing 420 has four outer shell parts 421a and four waveguides 21c. The outer shell part 421a of this modification accommodates the thermoacoustic unit 430 and the holding member 240 therein. The length of the axial direction Da of the outer shell part 421a of this modification is longer than the length of the axial direction Da of the outer shell part 221a of the second embodiment described above. Other configurations of the housing 420 of this modification are the same as other configurations of the housing 220 of the second embodiment described above.

[0090] Although not shown, the thermoacoustic device 410 includes a plurality of thermoacoustic units 430. In this modification, the thermoacoustic device 410 includes four thermoacoustic units 430. The thermoacoustic units 430 are housed inside different outer shells 421a. In this modification, each thermoacoustic unit 430 includes two thermoacoustic prime movers 33 and one thermoacoustic cooler 35. In each thermoacoustic unit 430, one thermoacoustic prime mover 33 is disposed on one axial side (+Da side) of the thermoacoustic cooler 35. One thermoacoustic prime mover 33 is disposed adjacent to the thermoacoustic cooler 35 in the axial direction Da. The other thermoacoustic prime mover 33 is disposed on one axial side of the one thermoacoustic prime mover 33. The other thermoacoustic prime mover 33 is disposed adjacent to the one thermoacoustic prime mover 33 in the axial direction Da. Each of the thermoacoustic prime movers 33 and thermoacoustic coolers 35 is held by a different holding member 240 .

[0091] In this modification, in each thermoacoustic unit 430, the heat exchanger on the cooling side of the thermoacoustic cooler 35, i.e., the first cooling heat exchanger 35e, and the heat exchanger on the temperature close to room temperature of one of the thermoacoustic prime movers 33, i.e., the second prime mover heat exchanger 33g, are arranged adjacent to each other. Therefore, compared to a configuration in which the first cooling heat exchanger 35e on the cooling side of the thermoacoustic cooler 35 and the first prime mover heat exchanger 33e on the high temperature side of each of the two thermoacoustic prime movers 33 are arranged adjacent to each other, the distance in the axial direction Da between the first cooling heat exchanger 35e and the first prime mover heat exchanger 33e can be made longer. Therefore, the amount of heat flowing from the first prime mover heat exchanger 33e to the first cooling heat exchanger 35e through the fluid F and the outer shell portion 421a can be reduced. Therefore, a decrease in the temperature of the first driving heat exchanger 33e and an increase in the temperature of the first cooling heat exchanger 35e can be suppressed, and therefore the thermal efficiency of the thermoacoustic device 410 can be improved.

[0092] In addition, in this modification, since each thermoacoustic unit 430 has two thermoacoustic prime movers 33 arranged adjacent to each other, the distance between the thermoacoustic prime movers 33 can be easily shortened. Therefore, the temperature of the one end 33b of the prime mover heat accumulator 33a, which is required for each thermoacoustic prime mover 33 to generate and amplify the oscillating flow, can be more suitably lowered. Therefore, the thermal efficiency of the thermoacoustic device 410 can be more suitably increased.

[0093] <Third Modification of Second Embodiment> 8, a thermoacoustic device 510 of this modification includes a thermoacoustic unit 530. In the following description, the same components as those in the second modification of the second embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

[0094] Although not shown, the thermoacoustic device 510 includes a plurality of thermoacoustic units 530. In this modification, the thermoacoustic device 510 includes four thermoacoustic units 530. The thermoacoustic units 530 are housed inside different outer shells 421a. In this modification, each thermoacoustic unit 530 includes one thermoacoustic prime mover 33 and two thermoacoustic coolers 35. In each thermoacoustic unit 530, one thermoacoustic cooler 35 is disposed on the other axial side (-Da side) of the thermoacoustic prime mover 33. One thermoacoustic cooler 35 is disposed adjacent to the thermoacoustic prime mover 33 in the axial direction Da. The other thermoacoustic cooler 35 is disposed on the other axial side of the one thermoacoustic cooler 35. The other thermoacoustic cooler 35 is disposed adjacent to the one thermoacoustic cooler 35 in the axial direction Da. The thermoacoustic prime mover 33 and each of the thermoacoustic coolers 35 are held by different holding members 240 .

[0095] In this modification, in each thermoacoustic unit 530, the heat exchanger on the cooling side of the heat exchangers of one thermoacoustic cooler 35, i.e., the first cooling heat exchanger 35e, and the heat exchanger of the thermoacoustic prime mover 33 whose temperature is close to room temperature, i.e., the second prime mover heat exchanger 33g, are arranged adjacent to each other. This can reduce the amount of heat flowing from the first prime mover heat exchanger 33e to the first cooling heat exchanger 35e through the fluid F and the outer shell 421a. This can suppress the temperature of the first prime mover heat exchanger 33e from decreasing and the temperature of the first cooling heat exchanger 35e from increasing, thereby improving the thermal efficiency of the thermoacoustic device 510.

[0096] <Fourth Modification of the Second Embodiment> 9, a thermoacoustic device 610 of this modification includes a thermoacoustic unit 630. In the following description, the same components as those in the above-described second embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0097] Although not shown, the thermoacoustic device 610 includes a plurality of thermoacoustic units 630. In this modification, the thermoacoustic device 610 includes four thermoacoustic units 630. The thermoacoustic units 630 are housed inside different outer shells 221a. In this modification, each thermoacoustic unit 630 includes one thermoacoustic prime mover 33, one thermoacoustic cooler 35, and a membrane member 651. In each thermoacoustic unit 630, the thermoacoustic cooler 35 is disposed on the other axial side (-Da side) of the thermoacoustic prime mover 33. The thermoacoustic cooler 35 is disposed adjacent to the thermoacoustic prime mover 33 in the axial direction Da. The thermoacoustic prime mover 33 and the thermoacoustic cooler 35 are held by different holding members 240.

[0098] The membrane member 651 is disposed between the thermoacoustic prime mover 33 and the thermoacoustic cooler 35 in the axial direction Da. The membrane member 651 is disk-shaped and centered on the first axis J1. A radially outer end of the membrane member 651 is held by the inner circumferential surface of the outer shell portion 221a. This allows the membrane member 651 to be held by the housing 220. The membrane member 651 has a membrane structure. In this embodiment, the membrane member 651 is made of rubber. The membrane member 651 may be made of other materials such as resin and metal.

[0099] Usually, in an annular thermoacoustic device, a unidirectional flow called the Gedeon flow occurs, and heat is transported in the direction in which the Gedeon flow flows. In this modification, the Gedeon flow flows toward one axial side (+Da side). When the Gedeon flow flows into the thermoacoustic motor 33, the temperature of the thermoacoustic motor 33 decreases, and the thermal efficiency of the thermoacoustic device 610 decreases.

[0100] In contrast, according to this modification, the thermoacoustic unit 630 has a membrane member 651 having a membrane structure disposed between the thermoacoustic prime mover 33 and the thermoacoustic cooler 35. Therefore, the membrane member 651 can prevent the Gedeon flow from flowing into the thermoacoustic prime mover 33. This can prevent the temperature of the thermoacoustic prime mover 33 from decreasing, and therefore the thermal efficiency of the thermoacoustic device 610 from decreasing.

[0101] In addition, in this modification, the membrane member 651 is disposed between the first cooling heat exchanger 35e, which is a heat exchanger on the cooling side of the thermoacoustic cooler 35, and the second prime mover heat exchanger 33g, which is a heat exchanger on the room temperature side of the thermoacoustic prime mover 33. As described above, the Gedeon flow is a one-way flow in this modification. This prevents the temperature of the membrane member 651 from becoming too high, and therefore prevents the membrane member 651, which is made of a rubber material that does not have high heat resistance, from deteriorating. Therefore, the membrane member 651 can stably prevent the Gedeon flow from flowing into the thermoacoustic prime mover 33, and therefore prevents the thermal efficiency of the thermoacoustic device 610 from decreasing.

[0102] <Third embodiment> The thermoacoustic device 710 of this embodiment is a thermoacoustic device that utilizes an oscillating flow. As shown in Fig. 10, the thermoacoustic device 710 of this embodiment includes a housing 720 and a thermoacoustic unit 230. In the following description, the same components as those in the second embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

[0103] The housing 720 of this embodiment is substantially rectangular and annular. The housing 720 has four outer shell parts 721a and four waveguides 21c. The outer shell part 721a accommodates the thermoacoustic unit 230 and the holding member 240 therein. The other configurations of the housing 720 of this embodiment are the same as the other configurations of the housing 220 of the second embodiment described above.

[0104] The thermoacoustic device 710 includes a plurality of thermoacoustic units 230. In this embodiment, the thermoacoustic device 710 includes four thermoacoustic units 230. Each thermoacoustic unit 230 is housed inside a different outer shell portion 721a. In this embodiment, each thermoacoustic unit 230 is configured by a plurality of thermoacoustic cores 31 adjacent to each other along the axial direction Da. The plurality of thermoacoustic cores 31 include a thermoacoustic prime mover 33 and a thermoacoustic cooler 35. In this embodiment, each thermoacoustic unit 230 is configured by two thermoacoustic cores 31. The two thermoacoustic cores 31 constituting each thermoacoustic unit 230 are arranged at an interval in the axial direction Da. The number of thermoacoustic units 230 included in the thermoacoustic device 710 may be three or less, or may be five or more. The number of thermoacoustic cores 31 included in the thermoacoustic unit 230 may be three or more. In this embodiment, each thermoacoustic unit 230 is composed of one thermoacoustic prime mover 33 and one thermoacoustic cooler 35 .

[0105] Each thermoacoustic core 31 has a heat accumulator 31a, a first heat exchanger 31e, and a second heat exchanger 31g. The heat accumulator 31a converts the energy of the oscillating flow into heat energy and vice versa. In this embodiment, the heat accumulator 31a includes a motive heat accumulator 33a and a cooling heat accumulator 35a.

[0106] As shown in FIG. 11, the first heat exchanger 31e is installed at one end 31b of the heat accumulator 31a. The second heat exchanger 31g is installed at the other end 31c of the heat accumulator 31a. In this embodiment, the temperature difference between the temperature of the first heat exchanger 31e and room temperature is larger than the temperature difference between the temperature of the second heat exchanger 31g and room temperature. In this embodiment, the first heat exchanger 31e includes a first motive heat exchanger 33e and a first cooling heat exchanger 35e. In this embodiment, the second heat exchanger 31g includes a second motive heat exchanger 33g and a second cooling heat exchanger 35g.

[0107] The thermoacoustic prime mover 33 converts thermal energy into oscillating flow energy. The thermoacoustic prime mover 33 has a prime mover heat accumulator 33a, a first prime mover heat exchanger 33e, and a second prime mover heat exchanger 33g. That is, the thermoacoustic prime mover 33 has a heat accumulator 31a, a first heat exchanger 31e, and a second heat exchanger 31g. The first prime mover heat exchanger 33e is a high-temperature side heat exchanger, and the second prime mover heat exchanger 33g is a room-temperature side heat exchanger whose temperature is close to room temperature.

[0108] The thermoacoustic cooler 35 converts the energy of the oscillating flow into thermal energy. The thermoacoustic cooler 35 is an output thermoacoustic core that receives the oscillating flow generated and amplified in the thermoacoustic prime mover 33 and extracts cold heat as an output. The thermoacoustic cooler 35 has a cooling heat accumulator 35a, a first cooling heat exchanger 35e, and a second cooling heat exchanger 35g. That is, the thermoacoustic cooler 35 has a heat accumulator 31a, a first heat exchanger 31e, and a second heat exchanger 31g. The first cooling heat exchanger 35e is a heat exchanger on the cooling side, and the second cooling heat exchanger 35g is a heat exchanger on the room temperature side whose temperature is close to room temperature. The other configurations of the thermoacoustic core 31, the thermoacoustic prime mover 33, and the thermoacoustic cooler 35 of this embodiment are the same as the other configurations of the thermoacoustic core 31, the thermoacoustic prime mover 33, and the thermoacoustic cooler 35 of the first embodiment described above.

[0109] In this embodiment, in each thermoacoustic unit 230, the thermoacoustic prime mover 33 is disposed on one axial side (+Da side) of the thermoacoustic cooler 35. The thermoacoustic prime mover 33 is disposed at a distance from the thermoacoustic cooler 35 in the axial direction Da. In each thermoacoustic unit 230, the heat exchanger on the cooling side of the heat exchangers of the thermoacoustic cooler 35, i.e., the first cooling heat exchanger 35e, and the heat exchanger of the thermoacoustic prime mover 33 whose temperature is close to room temperature, i.e., the second prime mover heat exchanger 33g, are disposed adjacent to each other in the axial direction Da. Other configurations of the thermoacoustic unit 230 of this embodiment are the same as other configurations of the thermoacoustic unit 230 of the second embodiment described above.

[0110] In this embodiment, the thermoacoustic prime mover 33 and the thermoacoustic cooler 35 are directly held by the outer shell 721a. More specifically, the outer peripheral surfaces of the prime mover heat accumulator 33a, the first prime mover heat exchanger 33e, and the second prime mover heat exchanger 33g are in contact with the inner peripheral surface of the outer shell 721a. As a result, the thermoacoustic prime mover 33 is directly held by the outer shell 721a. Note that the outer peripheral surfaces of the first prime mover heat exchanger 33e and the second prime mover heat exchanger 33g do not have to be in contact with the inner peripheral surface of the outer shell 721a. Also, the outer peripheral surfaces of the cooling heat accumulator 35a, the first cooling heat exchanger 35e, and the second cooling heat exchanger 35g are in contact with the inner peripheral surface of the outer shell 721a. As a result, the thermoacoustic cooler 35 is directly held by the outer shell 721a. The outer circumferential surfaces of the first cooling heat exchanger 35e and the second cooling heat exchanger 35g may not be in contact with the inner circumferential surface of the outer shell portion 721a. The other configurations of the thermoacoustic device 710 of this embodiment are the same as those of the thermoacoustic device 210 of the second embodiment described above.

[0111] According to this embodiment, the thermoacoustic device 710 is a thermoacoustic device that utilizes an oscillating flow, and is equipped with a thermoacoustic unit 230 having a thermoacoustic prime mover 33 that converts thermal energy into the energy of the oscillating flow, and a thermoacoustic cooler 35 that converts the energy of the oscillating flow into thermal energy. Each of the thermoacoustic prime mover 33 and the thermoacoustic cooler 35 has a first heat exchanger 31e installed at one end of a heat accumulator 31a that converts the energy of the oscillating flow and thermal energy back and forth, and a second heat exchanger 31g installed at the other end of the heat accumulator 31a. The heat exchanger on the cooling side of the heat exchangers of the thermoacoustic cooler 35, i.e., the first cooling heat exchanger 35e, and the heat exchanger whose temperature is close to room temperature among the heat exchangers of the thermoacoustic prime mover 33, i.e., the second prime mover heat exchanger 33g, are arranged adjacent to each other in the axial direction Da. Therefore, compared to a configuration in which the first cooling heat exchanger 35e, which is the cooling side of the thermoacoustic cooler 35, and the first prime mover heat exchanger 33e, which is the high temperature side of the thermoacoustic prime mover 33, are adjacently arranged, the distance in the axial direction Da between the first cooling heat exchanger 35e and the first prime mover heat exchanger 33e can be made longer. Therefore, the amount of heat flowing from the first prime mover heat exchanger 33e to the first cooling heat exchanger 35e through the fluid F and the outer shell portion 721a can be reduced. Therefore, a decrease in the temperature of the first prime mover heat exchanger 33e and an increase in the temperature of the first cooling heat exchanger 35e can be suppressed, thereby improving the thermal efficiency of the thermoacoustic device 710.

[0112] Furthermore, in this embodiment, as described above, the amount of heat flowing from the thermoacoustic prime mover 33 to the thermoacoustic cooler 35 via the fluid F and the outer shell portion 721a can be reduced, so that the distance between the thermoacoustic prime mover 33 and the thermoacoustic cooler 35 can be easily shortened. Therefore, when the outer diameter of the thermoacoustic prime mover 33 and the outer diameter of the thermoacoustic cooler 35 are each larger than the inner diameter of the waveguide 21c, it is easy to arrange the thermoacoustic prime mover 33 and the thermoacoustic cooler 35 at a position where the non-acoustic impedance is high. Therefore, the thermal efficiency of the thermoacoustic device 710 can be improved.

[0113] Moreover, in this embodiment, the thermoacoustic device 710 includes a plurality of thermoacoustic units 230. Therefore, waste heat can be supplied to each of the plurality of thermoacoustic prime movers 33, so that the amount of heat that can be supplied to the thermoacoustic device 710 can be increased. Also, cold heat can be output from each of the plurality of thermoacoustic coolers 35, so that the amount of cold heat that can be output by the thermoacoustic device 710 can be increased.

[0114] In addition, in this embodiment, since the multiple thermoacoustic units 230 are arranged inside the annular housing 720, it is possible to lower the temperature of the one end 33b of the motor heat accumulator 33a, which is necessary for the thermoacoustic motor 33 of each thermoacoustic unit 230 to generate and amplify the oscillating flow. Therefore, it is possible to more suitably increase the thermal efficiency of the thermoacoustic device 710.

[0115] <First Modification of the Third Embodiment> 12, a thermoacoustic device 810 of this modification includes a housing 820 and a thermoacoustic unit 830. In the following description, the same components as those in the above-described third embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0116] Although not shown, the housing 820 of this modified example is substantially rectangular and annular. The housing 820 has four outer shell parts 821a and four waveguides 21c. The outer shell part 821a of this modified example houses the thermoacoustic unit 830 therein. The length of the axial direction Da of the outer shell part 821a of this modified example is longer than the length of the axial direction Da of the outer shell part 721a of the third embodiment described above. Other configurations of the housing 820 of this modified example are the same as other configurations of the housing 720 of the third embodiment described above.

[0117] Although not shown, the thermoacoustic device 810 includes a plurality of thermoacoustic units 830. In this modification, the thermoacoustic device 810 includes four thermoacoustic units 830. The thermoacoustic units 830 are housed inside different outer shells 821a. In this modification, each thermoacoustic unit 830 includes two thermoacoustic prime movers 33 and one thermoacoustic cooler 35. In each thermoacoustic unit 830, one thermoacoustic prime mover 33 is disposed on one axial side (+Da side) of the thermoacoustic cooler 35. One thermoacoustic prime mover 33 is disposed adjacent to the thermoacoustic cooler 35 in the axial direction Da. The other thermoacoustic prime mover 33 is disposed on one axial side of the one thermoacoustic prime mover 33. The other thermoacoustic prime mover 33 is disposed adjacent to the one thermoacoustic prime mover 33 in the axial direction Da.

[0118] In this modification, in each thermoacoustic unit 830, the heat exchanger on the cooling side of the thermoacoustic cooler 35, i.e., the first cooling heat exchanger 35e, and the heat exchanger on the temperature close to room temperature of one of the thermoacoustic prime movers 33, i.e., the second prime mover heat exchanger 33g, are arranged adjacent to each other. Therefore, compared to a configuration in which the first cooling heat exchanger 35e on the cooling side of the thermoacoustic cooler 35 and the first prime mover heat exchanger 33e on the high temperature side of each of the two thermoacoustic prime movers 33 are arranged adjacent to each other, the distance in the axial direction Da between the first cooling heat exchanger 35e and the first prime mover heat exchanger 33e can be made longer. Therefore, the amount of heat flowing from the first prime mover heat exchanger 33e to the first cooling heat exchanger 35e through the fluid F and the outer shell portion 821a can be reduced. Therefore, a decrease in the temperature of the first driving heat exchanger 33e and an increase in the temperature of the first cooling heat exchanger 35e can be suppressed, and therefore the thermal efficiency of the thermoacoustic device 810 can be improved.

[0119] In addition, in this modification, since each thermoacoustic unit 830 has two thermoacoustic prime movers 33 arranged adjacent to each other, the distance between the thermoacoustic prime movers 33 can be easily shortened. Therefore, the temperature of the one end 33b of the prime mover heat accumulator 33a, which is required for each thermoacoustic prime mover 33 to generate and amplify the oscillating flow, can be more suitably reduced. Therefore, the thermal efficiency of the thermoacoustic device 810 can be more suitably increased.

[0120] Although the embodiments of the present invention have been described above, each configuration and their combinations in the embodiments are merely examples, and addition, omission, substitution, and other modifications of the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

[0121] The number of thermoacoustic cores and the number of thermoacoustic units included in the thermoacoustic device are not limited to those in this embodiment and this modified example, and can be appropriately determined depending on the number of heat sources supplying heat to the thermoacoustic device, the amount of heat supplied to the thermoacoustic device, the amount of cold heat output from the thermoacoustic device, etc. The number of thermoacoustic cores included in the thermoacoustic unit is not limited to that in this embodiment. In addition, the number of thermoacoustic motors and thermoacoustic coolers included in the thermoacoustic device is not limited to that in this embodiment. Furthermore, the number and combination of thermoacoustic motors and thermoacoustic coolers included in the thermoacoustic unit are not limited to that in this embodiment.

[0122] The number of thermoacoustic cores held by the holding member is not limited to 1, and may hold two or more thermoacoustic cores. In this case, the number of holding members included in the thermoacoustic device can be prevented from increasing, and therefore the number of parts of the thermoacoustic device can be prevented from increasing, and the configuration of the thermoacoustic device can be simplified.

[0123] The housing may have a branching portion that branches off from a shape such as a square ring, a ring, an elliptical ring, or a polygonal ring, and an output device that outputs the energy of the oscillating flow, such as a thermoacoustic cooler or a generator, may be disposed at the branching portion. In this case, the energy of the oscillating flow amplified by the housing having a shape such as a square ring, a ring, an elliptical ring, or a polygonal ring, can be output as cold heat or electricity.

[0124] The housing is not limited to a looped rectangular ring, a ring, an elliptical ring, a polygonal ring, or the like, and may be a straight pipe, in which a thermoacoustic unit or a thermoacoustic device, and an output device for outputting the energy of the oscillating flow, such as a thermoacoustic cooler or a generator, may be disposed. The straight pipe is not limited to a linear shape, and may be curved.

[0125] Furthermore, the present invention is not limited to thermoacoustic engines based on the thermoacoustic phenomenon, but can be applied to energy conversion devices such as Stirling engines equipped with a heat storage device that utilizes an oscillating flow of a fluid, pulse tube refrigerators, GM refrigerators, Stirling coolers, and heat pipes. [Explanation of symbols]

[0126] 10,210,310,410,510,610,710,810...thermoacoustic device, 21a,221a,421a,721a,821a...outer shell, 31...thermoacoustic core, 31a,33a,35a...heat accumulator, 31e,33e,35e...first heat exchanger, 31g,33g,35g...second heat exchanger, 33...thermoacoustic prime mover (thermoacoustic core), 35...thermoacoustic cooler (thermoacoustic core), 40,240...holding member, 230,330,430,530,630,830...thermoacoustic unit, 651...membrane member

Claims

1. A thermoacoustic device utilizing an oscillating flow, a thermoacoustic core having a first heat exchanger installed at one end of a heat accumulator that converts the energy of the oscillating flow into thermal energy and vice versa, and a second heat exchanger installed at the other end of the heat accumulator; A holding member for holding the thermoacoustic core; a shell that houses the thermoacoustic core; Equipped with A thermoacoustic device in which the retaining member contacts the outer shell at a position where, when viewed from a radial direction, it overlaps with one of the first heat exchanger or the second heat exchanger which has a smaller temperature difference from room temperature, or at a position where, when viewed from a radial direction, it overlaps with the area of ​​the heat accumulator on the side of the one heat exchanger.

2. The thermoacoustic device of claim 1 , wherein the retaining member seals against fluid movement between the shell and the thermoacoustic core.

3. The thermoacoustic device of claim 1 , comprising a plurality of the thermoacoustic cores and a plurality of the retaining members, each of the plurality of retaining members retaining a different thermoacoustic core.

4. A plurality of the thermoacoustic cores and a plurality of the holding members adjacent to each other are housed in one of the outer shell portions, The thermoacoustic device according to claim 1 , wherein each of the plurality of holding members holds a different thermoacoustic core and is in contact with the outer shell portion.

5. Equipped with a thermoacoustic unit, the plurality of thermoacoustic cores include a thermoacoustic prime mover and a thermoacoustic cooler; The thermoacoustic unit is configured by the thermoacoustic prime mover and the thermoacoustic cooler arranged adjacent to each other in the axial direction, 5. The thermoacoustic device according to claim 1, wherein in the thermoacoustic unit, a heat exchanger that is a cooling side among the heat exchangers of the thermoacoustic cooler and a heat exchanger that is a temperature close to room temperature among the heat exchangers of the thermoacoustic prime mover are arranged adjacent to each other.

6. The thermoacoustic device according to claim 5 , wherein the thermoacoustic unit includes a membrane member having a membrane structure disposed between the thermoacoustic prime mover and the thermoacoustic cooler.

7. The thermoacoustic device of claim 5 comprising a plurality of said thermoacoustic units.

8. A thermoacoustic device utilizing an oscillating flow, A thermoacoustic unit includes a thermoacoustic prime mover that converts thermal energy into oscillating flow energy, and a thermoacoustic cooler that converts oscillating flow energy into thermal energy, Each of the thermoacoustic prime mover and the thermoacoustic cooler has a first heat exchanger installed at one end of a heat accumulator that converts the energy of the oscillating flow into thermal energy and vice versa, and a second heat exchanger installed at the other end of the heat accumulator; A thermoacoustic device in which a heat exchanger that is the cooling side of the heat exchangers of the thermoacoustic cooler and a heat exchanger that is the cooling side of the heat exchangers of the thermoacoustic prime mover and has a temperature close to room temperature are arranged adjacent to each other in the axial direction.

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