Thermoacoustic device

Abstract

To enhance design flexibility of a thermoacoustic device.SOLUTION: A thermoacoustic device includes: piping that is configured to form an annular shape and can be filled with work gas; a prime mover; and a cooler. The piping includes: a first accommodation part that accommodates the prime mover; a second accommodation part that accommodates the cooler; and a waveguide part that connects the first accommodation part and the second accommodation part. The waveguide part includes: a main pipe part; and two enlargement parts having a larger inner diameter than that of the main pipe part. An inner diameter of each of the first accommodation part and the second accommodation part is larger than that of the main pipe part. A volume of each of the two enlargement parts is 30% or more of that of the first accommodation part. The volumes of the two enlargement parts are equal to each other.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The technology disclosed in this specification relates to a thermoacoustic device.

Background Art

[0002] In a thermoacoustic engine (thermoacoustic device) including a loop tube filled with a working gas that propagates sound waves, and a prime mover and a passive machine (energy converter) incorporated in the loop tube, it is known to provide a sound field adjustment mechanism in the middle of the loop tube. The sound field adjustment mechanism is, for example, an expansion tube having a larger flow path cross-sectional area than other parts of the loop tube. A technique has been proposed to improve the energy conversion efficiency by arranging the prime mover and the passive machine at symmetric positions in the loop tube and arranging the sound field adjustment mechanism in a predetermined section of the loop tube (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above thermoacoustic device, the section where the sound field adjustment mechanism can be arranged is extremely limited, for example, at a position of 5 to 10% of the total length of the loop tube from the prime mover, and there is a problem that the degree of freedom in design is low.

[0005] Note that such a problem is the same when the energy converter is used for applications other than the above thermoacoustic device (for example, a heat pump that performs heat transfer by inputting acoustic energy into a heat accumulator).

[0006] This specification discloses a technology capable of solving the above-described problems.

Means for Solving the Problems

[0007] The technology disclosed in this specification can be realized, for example, in the following forms. (1) The thermoacoustic device disclosed in this specification includes a pipe configured in a circular shape and capable of enclosing a working gas, a regenerator having one surface and the other surface and having a plurality of through-passages penetrating from the one surface to the other surface, a first heat exchanger disposed opposite to the one surface of the regenerator and provided with a first flow path through which a first fluid can flow, and a second heat exchanger disposed opposite to the other surface of the regenerator and provided with a second flow path through which a second fluid can flow. The two energy converters include a prime mover that converts thermal energy into acoustic energy, and a cooler that generates a temperature gradient when the acoustic energy amplified by the prime mover is input. The pipe includes a first accommodating portion that houses the prime mover, a second accommodating portion that houses the cooler, and a waveguide portion that connects the first accommodating portion and the second accommodating portion. The waveguide portion includes a main pipe portion and two enlarged portions having an inner diameter larger than the inner diameter of the main pipe portion. The first accommodating portion and the second accommodating portion have an inner diameter larger than the inner diameter of the main pipe portion, and the volume of each of the enlarged portions is 30% or more of the volume of the first accommodating portion, and the two enlarged portions have equal volumes to each other.

[0008] According to the above configuration, the thermoacoustic device can be operated even if there are relatively large fluctuations in the positional relationship between the two accommodating portions or between the accommodating portion and the enlarged portion. Thereby, the degree of freedom in the design of the thermoacoustic device is increased.

[0009] (2) In the thermoacoustic device described in (1) above, at least one of the enlarged portions is arranged between the first heat exchanger provided in the prime mover and the cooler, and at least one of the enlarged portions may be arranged between a position separated by a distance D1 calculated by the following formula (1) from the first accommodating portion and a position separated by a distance D2 calculated by the following formula (2). The central portion between both ends of the enlarged portion may be arranged. D1 = La × 0.2 ····· (1) D2 = La × 0.3 ····· (2) (In the formula, La represents the total length of the pipeline.)

[0010] If the positional relationship of at least one enlarged portion with respect to the first accommodating portion is within the above range, even if there are relatively large fluctuations in the arrangement of the second accommodating portion and the enlarged portion, the thermoacoustic device can be operated. Thereby, the degree of freedom in the design of the thermoacoustic device is increased.

[0011] (3) Another thermoacoustic device disclosed in this specification includes a pipe configured in a ring shape and capable of enclosing a working gas, a regenerator having one surface and the other surface and having a plurality of through passages penetrating from the one surface to the other surface, a first heat exchanger disposed opposite to the one surface of the regenerator and including a first flow path through which a first fluid can flow, and a second heat exchanger disposed opposite to the other surface of the regenerator and including a second flow path through which a second fluid can flow. The two energy converters include a first energy converter and a second energy converter. One of the two energy converters is a prime mover that converts thermal energy into acoustic energy, and the other is a cooler that generates a temperature gradient when the acoustic energy amplified by the prime mover is input. The pipe includes a first accommodating portion that houses the prime mover, a second accommodating portion that houses the cooler, and a waveguide portion that connects the first accommodating portion and the second accommodating portion. The waveguide portion includes a main pipe portion and two enlarged portions having an inner diameter larger than the inner diameter of the main pipe portion. The first accommodating portion and the second accommodating portion have an inner diameter larger than the inner diameter of the main pipe portion, and the two enlarged portions have equal volumes. There is no enlarged portion disposed between the second heat exchanger provided in the prime mover and the cooler. The central portion between both ends of the second accommodating portion may be disposed between a position separated by a distance D3 calculated by the following formula (3) from the first accommodating portion and a position separated by a distance D4 calculated by the following formula (4). D3 = La × 0.2 ····· (3) D4 = La × 0.3 ····· (4) (In the formula, La represents the total length of the pipeline.)

[0012] If the positional relationship of the second accommodating part with respect to the first accommodating part is within the above range, even if there are relatively large fluctuations in the volume and arrangement of the enlarged part, the thermoacoustic device can be operated. Thereby, the degree of freedom in the design of the thermoacoustic device is increased.

[0013] Note that the technology disclosed in this specification can be realized in various forms, for example, in the form of a thermoacoustic device or a manufacturing method thereof.

Brief Description of the Drawings

[0014]

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Mode for Carrying Out the Invention

[0015] A. Embodiment: A-1. Configuration of the thermoacoustic device 100A The embodiment will be described with reference to FIGS. 1 to 7. The thermoacoustic device 100A of the present embodiment is a cooling device for maintaining the temperature of an object at a temperature lower than the normal temperature by using acoustic energy.

[0016] (Overall configuration of the thermoacoustic device 100A) As shown in FIG. 1, the thermoacoustic device 100A includes a pipe 200, and a prime mover 400 and a cooler 500 disposed inside the pipe 200.

[0017] The pipe 200 is made of metal, for example, and as shown in FIG. 1, it includes a plurality of main pipes 210, 220, 230, 240, two enlarged pipes 250, 260, a prime mover pipe 270, and a cooler pipe 280. The prime mover 400 is accommodated inside the prime mover pipe 270, and the cooler 500 is accommodated inside the cooler pipe 280.

[0018] The plurality of main pipes 210, 220, 230, 240 and the enlarged pipes 250, 260, the prime mover pipe 270, and the cooler pipe 280 constitute a loop-shaped pipeline 290. The pipeline 290 can enclose a working gas inside. The working gas is not particularly limited as long as it is a gas that can transmit sound waves, and an inert gas composed of helium, argon, or a mixed gas of helium and argon, or air is preferably used.

[0019] Each of the plurality of main pipes 210, 220, 230, 240 has a constant inner diameter over the entire length. The plurality of main pipes 210, 220, 230, 240 are pipes of the same diameter as each other. The main pipe 210 is a pipe connecting the prime mover pipe 270 and the first enlarged pipe 250. The main pipe 220 is a pipe connecting between the two enlarged pipes 250, 260. The main pipe 230 is a pipe connecting the second enlarged pipe 260 and the cooler pipe 280. The main pipe 240 is a pipe connecting the cooler pipe 280 and the prime mover pipe 270.

[0020] As shown in FIG. 2, the first enlarged pipe 250 is a pipe having openings at both ends, and includes two small straight pipe portions 252 and 256, two tapered portions 253 and 255, and a large straight pipe portion 254. The two small straight pipe portions 252 and 256 are two short straight pipe-shaped portions respectively arranged at both ends of the first enlarged pipe 250. The large straight pipe portion 254 is located at the center between the two small straight pipe portions 252 and 256, and is a short straight pipe-shaped portion having an inner diameter larger than that of the small straight pipe portions 252 and 256. The two tapered portions 253 and 255 connect between one of the small straight pipe portions 252 and 256 and the large straight pipe portion 254, and between the other small straight pipe portion 252 and 256 and the large straight pipe portion 254 respectively, and are portions where the diameter is reduced from the large straight pipe portion 254 toward each of the two small straight pipe portions 252 and 256. The inner diameters of the small straight pipe portions 252 and 256 are equal to the inner diameters of the main pipes 210, 220, 230, and 240.

[0021] Since the second enlarged pipe 260 has the same configuration as the first enlarged pipe 250, detailed description thereof is omitted. The second enlarged pipe 260 has the same shape and dimensions as the first enlarged pipe 250.

[0022] As shown in FIG. 2, the prime mover pipe 270 is a pipe having openings at one end 270E1 and the other end 270E2, and includes two small straight pipe portions 272 and 276, two tapered portions 273 and 275, and a large straight pipe portion 274. The two small straight pipe portions 272 and 276 are two short straight pipe-shaped portions respectively arranged at both ends of the prime mover pipe 270. The large straight pipe portion 274 is located at the center between the two small straight pipe portions 272 and 276, and is a short straight pipe-shaped portion having an inner diameter larger than that of the small straight pipe portions 272 and 276. The two tapered portions 273 and 275 connect between one of the small straight pipe portions 272 and 276 and the large straight pipe portion 274, and between the other small straight pipe portion 272 and 276 and the large straight pipe portion 274 respectively, and are portions where the diameter is reduced from the large straight pipe portion 274 toward each of the two small straight pipe portions 272 and 276. The inner diameters of the small straight pipe portions 272 and 276 are equal to the inner diameters of the main pipes 210, 220, 230, and 240.

[0023] Since the configuration of the piping 280 for the cooler is the same as that of the piping 270 for the prime mover, a detailed description thereof is omitted. The piping 280 for the cooler has the same shape and dimensions as the piping 270 for the prime mover.

[0024] (Configuration of the prime mover 400) The prime mover 400 is a device for converting thermal energy into acoustic energy (sound waves), and is disposed inside the large straight pipe portion 274 of the piping 270 for the prime mover. As shown in FIGS. 1 and 2, the prime mover 400 includes a regenerator 410, a first heat exchanger 420, and a second heat exchanger 430. The first heat exchanger 420, the regenerator 410, and the second heat exchanger 430 are arranged in this order from one end 270E1 to the other end 270E2.

[0025] (Regenerator 410) The regenerator 410 has a thick disc shape having one surface 410F1 (the right surface in FIG. 2) and the other surface 410F2 (the left surface in FIG. 2). As shown in FIG. 2, the regenerator 410 is arranged in a posture perpendicular to the axial direction of the piping 270 for the prime mover such that one surface 410F1 faces the one end 270E1 of the piping 270 for the prime mover and the other surface 410F2 faces the other end 270E2 of the piping 270 for the prime mover.

[0026] As shown in FIG. 3, the regenerator 410 includes a laminate 412 in which a plurality of circular metal meshes 411 are stacked in a compressed state, and a fixing body 413 fixed to the outer peripheral surface of the laminate 412. The metal mesh 411 is a mesh-like member in which a plurality of metal wires are woven. The plurality of metal meshes 411 have substantially the same outer shape and are stacked with their outer peripheral edges aligned. The laminate 412 is formed by connecting the meshes (gaps between the thin wires) of the plurality of metal meshes 411, and has a large number of fine through-passages 414 penetrating from one surface 410F1 to the other surface 410F2 of the laminate 412. The fixing body 413 is fixed to the outer peripheral surface of the laminate 412 and serves to hold the outer peripheral edges of the plurality of metal meshes 411 so as not to be separated from each other.

[0027] (First heat exchanger 420, second heat exchanger 430) As shown in FIG. 2, the first heat exchanger 420 is arranged adjacent to one surface 410F1 of the heat accumulator 410. As the first heat exchanger 420, as shown in FIG. 4, a known heat exchanger including a first heat transfer tube 421 (an example of a first flow path) and fins (not shown) arranged around the first heat transfer tube 421 can be used. A high-temperature heat medium (an example of a first fluid) can flow inside the first heat transfer tube 421, and heat exchange is performed between the working gas in the vicinity of the first heat exchanger 420 and the heat medium. As the heat medium, for example, heat medium oil heated by waste heat from a factory can be used. The temperature of the heat medium oil is, for example, about 200 - 400°C.

[0028] As shown in FIG. 2, the second heat exchanger 430 is arranged adjacent to the other surface 410F2 of the heat accumulator 410. As the second heat exchanger 430, as shown in FIG. 5, a known heat exchanger including a second heat transfer tube 431 (an example of a second flow path) and fins (not shown) arranged around the second heat transfer tube 431 can be used. A refrigerant (an example of a second fluid) having a lower temperature than the heat medium flowing inside the first heat transfer tube 421 can flow inside the second heat transfer tube 431, and the working gas in the vicinity of the second heat exchanger 430 becomes a temperature lower than the temperature of the heat medium. In the present embodiment, normal-temperature water is used as the refrigerant supplied to the second heat transfer tube 431.

[0029] (Cooling machine 500) The cooler 500 is a heat pump that generates a temperature gradient by receiving acoustic energy amplified by the prime mover 400 and maintains the temperature of the object at a temperature lower than the normal temperature. As shown in FIG. 1, it is arranged inside the cooler piping 280. The cooler 500 includes a heat accumulator 510 having one surface 510F1 and the other surface 510F2, a first heat exchanger 520 arranged on one surface 510F1 of the heat accumulator 510, and a second heat exchanger 530 arranged on the other surface 510F2 of the heat accumulator 510 (see also FIG. 6). The heat accumulator 510, and the heat exchangers 520 and 530 provided in the cooler 500 have the same configuration as the heat accumulator 410, and the heat exchangers 420 and 430 provided in the prime mover 400. A medium at a constant temperature (water at normal temperature in this embodiment) can flow inside the heat transfer pipes provided in the first heat exchanger 520, and the operating gas in the vicinity of the first heat exchanger 520 reaches a temperature of about normal temperature. The heat transfer pipes provided in the second heat exchanger 530 are connected to the heat exchanger provided in the external cooling facility, and a refrigerant can circulate inside these heat transfer pipes.

[0030] A-2. Operation of the thermoacoustic device 100A: When operating the thermoacoustic device 100A, a heat medium is flowed through the first heat transfer pipe 421. Then, heat exchange occurs between the operating gas near the one surface 410F1 in the heat accumulator 410 and the heat medium. As a result, the temperature of the operating gas near the one surface 410F1 in the heat accumulator 410 is adjusted to approach the temperature of the heat medium. Also, water at normal temperature as a refrigerant is flowed through the second heat transfer pipe 431. Then, heat exchange occurs between the operating gas near the other surface 410F2 in the heat accumulator 410 and the water at normal temperature. As a result, the temperature of the operating gas near the other surface 410F2 in the heat accumulator 410 is adjusted to approach the normal temperature.

[0031] Due to the operation of such heat exchangers 420 and 430, a temperature gradient is generated between one surface 410F1 and the other surface 410F2 of the heat accumulator 410. Then, the working gas inside the through-passage 414 becomes unstable and starts to vibrate. This vibration amplifies the acoustic energy (sound waves). The amplified acoustic energy is output from one surface 410F1 of the heat accumulator 410, transmitted through the working gas enclosed inside the pipeline 290, and reaches the cooler 500 (refer to the arrow in Fig. 1).

[0032] The acoustic energy transmitted by the working gas is input from one surface 510F1 to the heat accumulator 510 provided in the cooler 500. Then, a temperature gradient is generated between one surface 510F1 facing the first heat exchanger 520 and the other surface 510F2 facing the second heat exchanger 530. Since normal-temperature water is flowing through the first heat exchanger 520 arranged on one surface 510F1 where acoustic energy is input in the cooler 500, the temperature of the working gas near the second heat exchanger 530 in the heat accumulator 510 is adjusted to a temperature lower than the normal temperature by the amount of the generated temperature gradient. Heat exchange is performed between this working gas at a temperature lower than the normal temperature and the refrigerant, and the refrigerant at a low temperature is supplied to external cooling equipment to cool the object.

[0033] A-3. Detailed Configuration of the Pipe 200: As shown in Fig. 2, the main pipe 210 and the two small straight pipe parts 256 and 272 adjacent to it constitute a first main pipe part 292 having a constant inner diameter. Among the first enlarged pipes 250, the tapered parts 253 and 255 and the large straight pipe part 254 constitute a first enlarged part 296 (an example of an enlarged part) having a larger inner diameter than the first main pipe part 292. Among the pipes 270 for the prime mover, the tapered parts 273 and 275 and the large straight pipe part 274 constitute a first accommodating part 298 having a larger inner diameter than the first main pipe part 292.

[0034] Similarly, a portion of the second enlarged pipe 260 having an inner diameter larger than that of the main pipe portions 292, 293, 294, and 295 constitutes a second enlarged portion 297 (an example of an enlarged portion), and a portion of the cooling machine pipe 280 having an inner diameter larger than that of the main pipe portions 292, 293, 294, and 295 constitutes a second housing portion 299. And the remaining portions constitute a second main pipe portion 293, a third main pipe portion 294, and a fourth main pipe portion 295 having the same inner diameter as the first main pipe portion 292. As shown in FIG. 6, the first main pipe portion 292 connects the first housing portion 298 and the first enlarged portion 296. The second main pipe portion 293 connects the first enlarged portion 296 and the second enlarged portion 297. The third main pipe portion 294 connects the second enlarged portion 297 and the second housing portion 299. The fourth main pipe portion 295 connects the second housing portion 299 and the first housing portion 298. The main pipe portions 292, 293, 294, 295 and the enlarged portions 296, 297 constitute a waveguide portion 291 that connects the first housing portion 298 and the second housing portion 299.

[0035] In this embodiment, the first enlarged portion 296, the second enlarged portion 297, the first housing portion 298, and the second housing portion 299 have equal volumes with each other. Note that nothing is arranged inside the first enlarged portion 296, and the volume of the first enlarged portion 296 is the sum of the volumes of the tapered portions 253, 255 and the large straight pipe portion 254. The same applies to the second enlarged portion 297. Also, the prime mover 400 is arranged inside the first housing portion 298, and the volume of the first housing portion 298 is obtained by subtracting the volume occupied by the internal space of the first heat transfer pipe 421 and the internal space of the through-passage 414 of the heat accumulator 510 in the members constituting the prime mover 400 from the sum of the volumes of the tapered portions 273, 275 and the large straight pipe portion 274. The same applies to the second housing portion 299.

[0036] Between a first heat exchanger 420 provided in the prime mover 400 and the cooler 500, two enlarged portions 296 and 297 are arranged. Also, no enlarged portion is arranged between a second heat exchanger 430 provided in the prime mover 400 and the cooler 500. That is, along the direction in which the acoustic energy amplified by the prime mover 400 is transmitted (the direction indicated by the dotted arrows in FIGS. 2 and 6), the first housing portion 298, the first enlarged portion 296, the second enlarged portion 297, and the second housing portion 299 are arranged in this order.

[0037] As shown in FIG. 7, of the two enlarged portions 296 and 297, the first enlarged portion 296 close to the first housing portion 298 (that is, on the upstream side of the flow of the acoustic energy amplified by the prime mover 400) is arranged between a position separated by a distance D1 calculated by the following formula (1) from the boundary position BP1 between the first housing portion 298 and the first main pipe portion 292 and a position separated by a distance D2 calculated by the following formula (2). More specifically, in the pipe line 290, it is preferable that the central portion CP1 between both ends of the first enlarged portion 296 is arranged between a position separated by the distance D1 from the boundary position BP1 and a position separated by the distance D2. Note that the distances D1 and D2 are distances measured along the pipe line 290 with the boundary position BP1 as a starting point.

[0038] D1 = La × 0.2 ····· (1) D2 = La × 0.3 ····· (2) In the formula, La represents the total length of the pipe line 290.

[0039] Also, as shown in FIG. 7, the second housing portion 299 is preferably arranged between a position separated by a distance D3 calculated by the following formula (3) from the boundary position BP2 between the first housing portion 298 and the fourth main pipe portion 295 and a position separated by a distance D4 calculated by the following formula (4). More specifically, in the pipe line 290, it is preferable that the central portion CP2 between both ends of the second housing portion 299 is arranged between a position separated by the distance D3 from the boundary position BP2 and a position separated by the distance D4. Note that the distances D3 and D4 are distances measured along the pipe line 290 with the boundary position BP2 as a starting point.

[0040] D3 = La × 0.2 ····· (3) D4 = La × 0.3 ····· (4) (In the formula, La represents the total length of the pipeline.)

[0041] A - 4. Effects of this embodiment: As described above, the thermoacoustic device 100A of this embodiment includes a pipe 200 configured in a ring shape and capable of enclosing a working gas, a prime mover 400, and a cooler 500. The prime mover 400 has a regenerator 410 having a first surface 410F1 and a second surface 410F2 and a plurality of through passages 414 penetrating from the first surface 410F1 to the second surface 410F2, and a first heat exchanger 420 disposed opposite to the first surface 410F1 of the regenerator 410 and including a first heat transfer pipe 421 through which a heat medium can flow, and a second heat exchanger 430 disposed opposite to the second surface 410F2 of the regenerator 410 and including a second heat transfer pipe 431 through which normal temperature water can flow. Similarly, the cooler 500 includes a regenerator 510, a first heat exchanger 520, and a second heat exchanger 530. The pipe 200 includes a first accommodating portion 298 and a second accommodating portion 299 in which the prime mover 400 and the cooler 500 are respectively accommodated, and a waveguide portion 291 connecting the first accommodating portion 298 and the second accommodating portion 299. The waveguide portion 291 includes main pipe portions 292, 293, 294, 295 and two enlarged portions 296, 297 having an inner diameter larger than the inner diameters of the main pipe portions 292, 293, 294, 295. The accommodating portions 298, 299 have an inner diameter larger than the inner diameters of the main pipe portions 292, 293, 294, 295, and the volume of each of the two enlarged portions 296, 297 is 30% or more of the volume of the accommodating portions 298, 299, and the two enlarged portions 296, 297 have equal volumes to each other.

[0042] According to the above configuration, even if there are relatively large fluctuations in the positional relationship between the two accommodating portions 298, 299, or between the accommodating portions 298, 299 and the enlarged portions 296, 297, the thermoacoustic device 100A can be operated. As a result, the degree of freedom in the design of the thermoacoustic device 100A is increased.

[0043] In addition, expansion portions 296 and 297 are arranged between a first heat exchanger 420 provided in the prime mover 400 and the cooler 500, and a central portion CP between both ends of the first expansion portion 296 is arranged between a position separated by a distance D1 calculated by the following formula (1) and a position separated by a distance D2 calculated by the following formula (2) from a first accommodation portion 298 that accommodates the prime mover 400.

[0044] D1 = La × 0.2 ····· (1) D2 = La × 0.3 ····· (2) (In the formula, La represents the total length of the pipeline.)

[0045] In addition, the second accommodation portion 299 is arranged between a position separated by a distance D3 calculated by the following formula (3) and a position separated by a distance D4 calculated by the following formula (4) from a boundary position BP2 between the first accommodation portion 298 and the fourth main pipe portion 295.

[0046] D3 = La × 0.2 ····· (3) D4 = La × 0.3 ····· (4) (In the formula, La represents the total length of the pipeline.)

[0047] If the positional relationship of the second accommodation portion 299 with respect to the first accommodation portion 298 is within the above range, the thermoacoustic device 100A can be operated even if there are relatively large fluctuations in the volume and arrangement of the expansion portions 296 and 297. Thereby, the degree of freedom in the design of the thermoacoustic device 100A is increased.

[0048] A-5. Performance Evaluation: The relationship between the arrangement of the accommodation portion and the expansion portion in the thermoacoustic device and the operability of the thermoacoustic device was evaluated by simulation.

[0049] (Calculation Example 1-1) A thermoacoustic device 100A having the same configuration as the above embodiment was set as a simulation model (see FIG. 6). The specifications of the expansion portions 296 and 297 were set as shown in Table 1, and the volume of each of the two expansion portions was set to 100% of the volume of the first accommodation portion.

[0050] The following calculation conditions were given to the above simulation model. In the regenerator provided in the prime mover, the temperature (high-temperature surface temperature T hot ) of the surface (one surface 410F1) where the first heat exchanger is arranged: search range: 100 - 300 °C In the regenerator provided in the cooler, the temperature (low-temperature surface temperature T ewf ) of the surface (the other surface 510F2) where the second heat exchanger is arranged: target temperature: -20 °C In the regenerator provided in the prime mover, the surface (the other surface 410F2) where the second heat exchanger is arranged, in the regenerator provided in the cooler, the surface (one surface 510F1) where the first heat exchanger is arranged, and the temperature T of the working gas enclosed inside the pipeline amb : 20 °C Type of working gas: helium Average pressure of the working gas: 3 MPa

[0051] The total of the lengths L1, L2, L3, and L4 of the main pipes 292, 293, 294, and 295 was fixed at 10 m, and the lengths L1, L2, L3, and L4 of each of the main pipes 292, 293, 294, and 295 were varied at 0.1 m intervals from 0.1 m to 6 m to search for the high-temperature surface temperature T at which vibration of the working gas occurs (that is, the thermoacoustic device operates). hot was searched.

[0052] (Calculation Example 1-2) The specifications of the enlarged parts were set as shown in Table 1, and the volume of each of the two enlarged parts was set to 50% of the volume of the first accommodating part. Other conditions were set in the same manner as in Calculation Example 1-1, and analysis was performed.

[0053] (Calculation Example 1-3) The specifications of the enlarged parts were set as shown in Table 1, and the volume of each of the two enlarged parts was set to 30% of the volume of the first accommodating part. Other conditions were set in the same manner as in Calculation Example 1-1, and analysis was performed.

[0054] (Calculation Example 1-4) The specifications of the enlarged parts were set as shown in Table 1, and the volume of each of the two enlarged parts was set to 10% of the volume of the first accommodating part. Other conditions were set in the same manner as in Calculation Example 1-1, and analysis was performed.

[0055] [Table 1]

[0056] (Calculation Example 2-1) As a simulation model, as shown in FIG. 8, a thermoacoustic device 100B having the same configuration as the thermoacoustic device 100A was set, except that the second enlarged part 297 was not provided, the first enlarged part 296 and the second accommodating part 299 were connected by a second main pipe part 293B, and the first accommodating part 298 and the second accommodating part 299 were connected by a third main pipe part 294B.

[0057] For this simulation model, the same calculation conditions as in Calculation Example 1-1 were given. Also, the specifications of the first enlarged part 296 were set in the same manner as in Calculation Example 1-1, and the volume of the first enlarged part 296 was set to 100% of the volume of the first accommodating part 298. The sum of the lengths L1, L2, and L3 of the main pipe parts 292, 293B, and 294B was fixed at 10 m, and the lengths L1, L2, and L3 of the respective main pipe parts 292, 293B, and 294B were varied at 0.1 m intervals from 0.1 m to 6 m. In the same manner as in Calculation Example 1-1, the high-temperature surface temperature T at which vibration of the working gas occurs was explored. hot was explored.

[0058] (Calculation Example 2-2) The specifications of the first enlarged part were set in the same manner as in Calculation Example 1-2, and the volume of the first enlarged part was set to 50% of the volume of the first accommodating part. Other conditions were set in the same manner as in Calculation Example 2-1, and analysis was performed.

[0059] (Results) Comparing calculation examples 1-1, 1-2, 1-3, and 1-4, all of which have two expansions, it was found that in calculation example 1-4, in which the volume of the expansions is 10% of the volume of the accommodation section, the thermoacoustic device only operates in a range in which the length L4 of the fourth main pipe section is about 2 m, as shown in Figure 21-24. In other words, it was found that in order to operate the thermoacoustic device, the distance between the first accommodation section 298 and the second accommodation section 299 is heavily restricted. However, as long as the length L4 of the fourth main pipe section is about 2 m, the thermoacoustic device can operate even if the values ​​of the length L1 of the first main pipe section and the length L3 of the third main pipe section vary relatively greatly, and it was found that the degree of freedom in designing the thermoacoustic device is high even if the volume of the expansion section is small.

[0060] In calculation examples 1-1, 1-2, and 1-3, in which the volume of the expansion section is 100%, 50%, and 30% of the volume of the accommodation section, the range of the length L1-L4 of the main pipe section in which the thermoacoustic device can operate is wider than in calculation example 1-4, as shown in Figure 9-20, and it was confirmed that the larger the ratio of the volume of the expansion section, the wider the operable range. From this, when focusing on the relationship between the volume of the expansion section and the degree of freedom in designing the thermoacoustic device, it can be said that if the volume of the expansion section is 30% or more of the volume of the accommodation section, the degree of freedom in designing can be increased, preferably 50% or more, and more preferably 100%.

[0061] In addition, when Calculation Example 1-1 and Calculation Example 2-1, and Calculation Example 1-2 and Calculation Example 2-2 are compared, it is confirmed that when the ratio of the volume of the expansion section to the volume of the storage section is the same, the range of the length L1-L4 of the main pipe section in which the thermoacoustic device can operate is wider when there are two expansion sections than when there is one expansion section. This means that the degree of freedom in designing a thermoacoustic device is increased when there are two expansion sections compared to when there is one expansion section.

[0062] Table 2 shows the hot surface temperature T hot The lengths L1, L2, L3, and L4 of the main pipe and the hot surface temperature T when the value of hot The minimum values ​​of are shown in Table 3. The same is true for calculation examples 2-1 and 2-2.

[0063] [Table 2]

[0064] [Table 3]

[0065] B. Modification Examples: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified into various forms without departing from the gist thereof. For example, the following modifications are also possible. (1) In the above-described embodiment, the first accommodating portion 298, the first expanding portion 296, the second expanding portion 297, and the second accommodating portion 299 were arranged in this order. However, the arrangement order of the accommodating portion and the expanding portion is not limited to the above-described embodiment. For example, as in the thermoacoustic device 100C shown in FIG. 33, the positions of the second expanding portion 297 and the second accommodating portion 299 may be interchanged. (2) In the above-described embodiment, one of the two expanding portions was arranged between a position separated by a distance D1 from the boundary position BP1 and a position separated by a distance D2 from the boundary position BP1. However, both of the two expanding portions may be arranged between a position separated by a distance D1 from the boundary position BP1 and a position separated by a distance D2 from the boundary position BP1, only one may be arranged, or none may be arranged.

Explanation of Reference Numerals

[0066] 100A, 100B, 100C: Thermoacoustic device 200: Pipe 210, 220, 230, 240: Main pipe 250: First enlarged pipe 252, 256: Small straight pipe portion 253, 255: Taper portion 274: Large straight pipe portion 260: Second enlarged pipe 270: Prime mover pipe 270E1: One end 270E2: The other end 272, 276: Small straight pipe portion 273, 275: Taper portion 274: Large straight pipe portion 280: Cooler pipe 290: Pipeline 291: Wave guide portion 292: First main pipe portion 293, 293B: Second main pipe portion 294, 294B: Third main pipe portion 295: Fourth main pipe portion 296: First enlarged portion 297: Second enlarged portion 298: First accommodating portion 299: Second accommodating portion 400: Prime mover (energy converter) 410: Heat accumulator 410F1: One side 410F2: The other side 411: Metal mesh 412: Laminate 413: Fixing body 414: Through passage 420: First heat exchanger 421: First heat transfer pipe (first flow path), 430: Second heat exchanger 431: Second heat transfer pipe (second flow path) 500: Cooler (energy converter) 510: Heat accumulator 510F1: One side 510F2: The other side 520: First heat exchanger 530: Second heat exchanger BP1, BP2: Boundary positions, CP1, CP2: Central portions, D1, D2, D3, D4: Distances, La: Total length of the pipeline

Claims

1. A pipe configured in a ring shape and capable of enclosing a working gas, A regenerator having one surface and the other surface, and a plurality of through passages penetrating from the one surface to the other surface; a first heat exchanger disposed opposite to the one surface of the regenerator and having a first flow path through which a first fluid can flow; and a second heat exchanger disposed opposite to the other surface of the regenerator and having a second flow path through which a second fluid can flow. Two energy converters, Comprising, One of the two energy converters is a prime mover that converts thermal energy into acoustic energy, and the other is a cooler that generates a temperature gradient when the acoustic energy amplified by the prime mover is input, The pipe includes a first housing portion that houses the prime mover, a second housing portion that houses the cooler, and a waveguide portion that connects the first housing portion and the second housing portion, The waveguide portion includes a main pipe portion and two enlarged portions having an inner diameter larger than the inner diameter of the main pipe portion, The first housing portion and the second housing portion have an inner diameter larger than the inner diameter of the main pipe portion, The volume of each of the enlarged portions is 30% or more of the volume of the first housing portion, The two enlarged portions have equal volumes to each other, A thermoacoustic device.

2. At least one of the enlarged portions is disposed between the first heat exchanger provided in the prime mover and the cooler, The central portion between both ends of at least one of the enlarged portions is disposed between a position separated by a distance D1 calculated by the following formula (1) from the first housing portion and a position separated by a distance D2 calculated by the following formula (2). The thermoacoustic device according to Claim 1. D1 = La × 0.2..... (1) D2 = La × 0.3..... (2) (In the formula, La represents the total length of the pipeline.)

3. A pipe configured annularly and capable of enclosing a working gas, a regenerator having one surface and the other surface and a plurality of through-passages penetrating from the one surface to the other surface, a first heat exchanger disposed to face the one surface of the regenerator and having a first flow path through which a first fluid can flow, and a second heat exchanger disposed to face the other surface of the regenerator and having a second flow path through which a second fluid can flow, two energy converters; Comprising One of the two energy converters is a prime mover that converts thermal energy into acoustic energy, and the other is a cooler that generates a temperature gradient when the acoustic energy amplified by the prime mover is input. The pipe includes a first housing portion that houses the prime mover, a second housing portion that houses the cooler, and a waveguide portion that connects the first housing portion and the second housing portion. The waveguide portion includes a main pipe portion and two enlarged portions having an inner diameter larger than the inner diameter of the main pipe portion. The first housing portion and the second housing portion have an inner diameter larger than the inner diameter of the main pipe portion. The two enlarged portions have equal volumes to each other. The enlarged portion is not disposed between the second heat exchanger provided in the prime mover and the cooler. The central portion between both ends of the second housing portion is disposed between a position separated by a distance D3 calculated by the following formula (3) from the first housing portion and a position separated by a distance D4 calculated by the following formula (4). Thermoacoustic device. D3 = La × 0.2 ····· (3) D4 = La × 0.3 ····· (4) (In the formula, La represents the total length of the pipeline.)

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