Thermoacoustic device

Abstract

To provide a thermoacoustic device capable of suppressing leakage of sound waves while achieving downsizing.SOLUTION: In a thermoacoustic device 1, a housing 4 houses in the inside, a heat accumulator 2, a high-temperature side heat exchanger 31, and a low-temperature side heat exchanger 32, and is connected to a fluid pipe 11. The heat accumulator 2 is held in an arrangement direction Z of the low-temperature side heat exchanger 32, the heat accumulator 2 and the high-temperature side heat exchanger 31 by the high-temperature side heat exchanger 31 and the low-temperature side heat exchanger 32. At least one of the high-temperature side heat exchanger 31 and the low-temperature side heat exchanger 32 is a movable heat exchanger 30. The movable heat exchanger 30 disposed so as to be movable in the arrangement direction Z to the housing 4 is elastically pressed to the heat accumulator 2 side. A movable introduction pipe 301 and a movable leading pipe 302 which are fixed to the movable heat exchanger 30 are each slidably inserted into a pipe insertion hole 401 formed in the housing 4.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] For example, as disclosed in Patent Document 1, a thermoacoustic device including a regenerator, a high-temperature side heat exchanger that heats one end of the regenerator, and a low-temperature side heat exchanger that cools the other end of the regenerator is known. The thermoacoustic device described in Patent Document 1 attempts to absorb the difference in dimensional changes between components due to thermal expansion with a wave spring by arranging the wave spring between the high-temperature side heat exchanger and the regenerator.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the thermoacoustic device described in Patent Document 1 has four pipes, a low-temperature side heat exchanger, a high-temperature side heat exchanger, a regenerator, a wave spring, a spacer arranged between the low-temperature side heat exchanger and the regenerator, etc. between two unit flanges. Then, by fastening the two unit flanges with a plurality of bolts and nuts, while sealing with a seal portion interposed between the flanges provided at the ends of the pipes or between the flange of the pipe and the low-temperature side heat exchanger, the four pipes, heat exchangers, regenerator, etc. are fixed. Therefore, the structure tends to be complicated and the device tends to be enlarged.

[0005] The present invention has been made in view of such problems, and an object thereof is to provide a thermoacoustic device that can suppress sound wave leakage while achieving miniaturization.

Means for Solving the Problems

[0006] One aspect of the present invention includes a fluid pipe (11) filled with a working fluid and a thermoacoustic conversion unit (12) provided in the fluid pipe. The thermoacoustic conversion unit a regenerator (2) that generates sound waves by a temperature gradient; a high-temperature side heat exchanger (31) disposed at one end of the regenerator and heating the one end of the regenerator; a low-temperature side heat exchanger (32) disposed at the other end of the regenerator and cooling the other end of the regenerator; a housing (4) that houses the regenerator, the high-temperature side heat exchanger, and the low-temperature side heat exchanger inside and is connected to the fluid pipe. The regenerator is sandwiched by the low-temperature side heat exchanger and the high-temperature side heat exchanger in the arrangement direction (Z) of the low-temperature side heat exchanger, the regenerator, and the high-temperature side heat exchanger. At least one of the high-temperature side heat exchanger and the low-temperature side heat exchanger is a movable heat exchanger (30) that is provided movably in the arrangement direction with respect to the housing and is elastically pressed toward the regenerator side. A movable introduction pipe (301) for introducing a heat medium into the movable heat exchanger and a movable lead-out pipe (302) for leading out the heat medium from the movable heat exchanger to the outside are fixed to the movable heat exchanger. A pipe insertion hole (401) that communicates the inside and the outside of the housing is formed in the housing along the arrangement direction. In the thermoacoustic device (1), the movable introduction pipe and the movable lead-out pipe are each slidably inserted into the pipe insertion hole.

Advantages of the Invention

[0007] In the above-described thermoacoustic device, the regenerator is sandwiched in the longitudinal direction by the high-temperature side heat exchanger and the low-temperature side heat exchanger. Further, at least one of the high-temperature side heat exchanger and the low-temperature side heat exchanger is a movable heat exchanger that is provided so as to be movable in the longitudinal direction with respect to the housing and is elastically pressed toward the regenerator side. Furthermore, the movable inlet pipe and the movable outlet pipe are each slidably inserted into a pipe insertion hole that communicates the inside and the outside of the housing along the longitudinal direction. Therefore, while simplifying the structure, even if the dimensions of the heat exchanger and the regenerator change due to a temperature change, it is possible to prevent a gap from being formed between the heat exchanger and the regenerator. As a result, while achieving miniaturization, it is possible to suppress the leakage of sound waves. Also, even if the heat exchanger and the regenerator expand due to a temperature rise, it is possible to suppress the load stress applied to the regenerator.

[0008] As described above, according to the above aspect, it is possible to provide a thermoacoustic device that can suppress the leakage of sound waves while achieving miniaturization. Note that the reference numerals in parentheses described in the claims and the means for solving the problems indicate the correspondence with the specific means described in the embodiments described later, and do not limit the technical scope of the present invention.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0010] (Embodiment 1) An embodiment of a thermoacoustic device will be described with reference to FIGS. 1 to 7. As shown in FIG. 1, the thermoacoustic device 1 of this embodiment includes a fluid pipe 11 filled with a working fluid and a thermoacoustic conversion unit 12 provided in the fluid pipe 11. As shown in FIG. 2, the thermoacoustic conversion unit 12 includes a heat accumulator 2, a high-temperature side heat exchanger 31, a low-temperature side heat exchanger 32, and a housing 4. The heat accumulator 2 generates sound waves due to a temperature gradient. The high-temperature side heat exchanger 31 is disposed at one end of the heat accumulator 2 and heats one end of the heat accumulator 2. The low-temperature side heat exchanger 32 is disposed at the other end of the heat accumulator 2 and cools the other end of the heat accumulator 2. The housing 4 houses the heat accumulator 2, the high-temperature side heat exchanger 31, and the low-temperature side heat exchanger 32 inside and is connected to the fluid pipe 11.

[0011] The heat accumulator 2 is sandwiched in the arrangement direction Z of the low-temperature side heat exchanger 32, the heat accumulator 2, and the high-temperature side heat exchanger 31 by the high-temperature side heat exchanger 31 and the low-temperature side heat exchanger 32. At least one of the high-temperature side heat exchanger 31 and the low-temperature side heat exchanger 32 is a movable heat exchanger 30. The movable heat exchanger 30 is elastically pressed against the heat accumulator 2 side while being provided so as to be movable in the arrangement direction Z with respect to the housing 4.

[0012] The movable heat exchanger 30 is fixed with a movable introduction pipe 301 for introducing a heat medium into the movable heat exchanger 30 and a movable discharge pipe 302 for discharging the heat medium from the movable heat exchanger 30 to the outside. Further, in the housing 4, a pipe insertion hole 401 communicating the inside and the outside of the housing 4 is formed along the arrangement direction Z. The movable introduction pipe 301 and the movable discharge pipe 302 are each slidably inserted into the pipe insertion hole 401. Further, in the present embodiment, the low-temperature side heat exchanger 32 is the movable heat exchanger 30.

[0013] The thermoacoustic device 1 of the present embodiment can be used, for example, as a power generation means using the exhaust gas discharged from an industrial furnace (not shown) or the like as a heat source. Industrial furnaces include heating furnaces, firing furnaces, drying furnaces, exhaust gas treatment furnaces, etc. that heat an object to be heated or an ambient gas by burning fuel. Further, as shown in FIG. 1, the fluid pipe 11 of the thermoacoustic device 1 of the present embodiment is of a loop type having an annular pipe 111 formed in an annular shape and a branch pipe 112 branched from the annular pipe 111. The thermoacoustic conversion unit 12 is configured to convert the heat of the exhaust gas into sound waves. The thermoacoustic conversion unit 12 can be arranged, for example, one or more in the middle of the fluid pipe 11. In the present embodiment, one thermoacoustic conversion unit 12 is arranged in the middle of the annular pipe 111.

[0014] The thermoacoustic conversion unit 12 is used to amplify sound waves circulating in the fluid pipe 11 filled with the working fluid. The thermoacoustic conversion unit 12 can generate sound waves and amplify sound waves by vibrating the working fluid using the temperature difference at both ends of the regenerator 2 (see FIG. 2). The working fluid of the thermoacoustic device 1 can be, for example, helium, argon, etc. In the present embodiment, the working fluid is compressed helium gas.

[0015] In addition, the thermoacoustic device 1 includes a sound wave utilization device 13. In this embodiment, the sound wave utilization device 13 is a generator. The generator 13 is composed of a linear generator that converts vibration caused by sound waves into electricity using electromagnetic induction. Then, the sound waves amplified by the thermoacoustic conversion unit 12 are utilized by the generator 13 and converted into electricity. The sound wave utilization device may be various devices other than the generator 13. For example, it can be a device for heating or cooling.

[0016] The high-temperature-side heat medium, which is the heat medium introduced into the high-temperature-side heat exchanger 31 (see FIG. 2), circulates between the exhaust gas heat exchanger (not shown) that exchanges heat with the exhaust gas and the high-temperature-side heat exchanger 31. Then, the high-temperature-side heat medium transfers the heat of the exhaust gas recovered by the exhaust gas heat exchanger to the heat accumulator 2 and the working fluid via the high-temperature-side heat exchanger 31, heating the heat accumulator 2 and the working fluid. The temperature of the high-temperature-side heat medium sent from the exhaust gas heat exchanger to the high-temperature-side heat exchanger 31 can be, for example, about 300°C. Also, various heat medium oils are used for the high-temperature-side heat medium. As the heat medium oil, for example, synthetic heat medium oil, paraffin-based polymer oil, diphenyl-based heat medium oil, synthetic heat medium oil, etc. can be adopted.

[0017] The low-temperature-side heat medium, which is the heat medium introduced into the low-temperature-side heat exchanger 32 (see FIG. 2), is used to cool the heat accumulator 2 and the working fluid via the low-temperature-side heat exchanger 32. Various fluids with a temperature lower than that of the exhaust gas and the high-temperature-side heat medium can be used for the low-temperature-side heat medium. In this embodiment, the low-temperature-side heat medium is the circulating water used in the factory.

[0018] Although illustration is omitted, the high-temperature side heat exchanger 31 has a fluid flow path through which sound waves transmitted through the working fluid pass, and a heat medium flow path through which the high-temperature side heat medium flows, formed around the fluid flow path via a heat transfer wall. The working fluid is heated by the high-temperature side heat medium flowing through the heat medium flow path in the fluid flow path of the high-temperature side heat exchanger 31. The fluid flow path of the high-temperature side heat exchanger 31 penetrates the high-temperature side heat exchanger 31 along the alignment direction Z. The low-temperature side heat exchanger 32 has a fluid flow path through which sound waves transmitted through the working fluid pass, and a refrigerant flow path through which the low-temperature side heat medium flows, formed around the fluid flow path via a heat transfer wall. The working fluid is cooled by the low-temperature side heat medium flowing through the refrigerant flow path in the fluid flow path of the low-temperature side heat exchanger 32. The fluid flow path of the low-temperature side heat exchanger 32 penetrates the low-temperature side heat exchanger 32 along the alignment direction Z. Further, the high-temperature side heat exchanger 31 heats one end face of the heat storage 2 in the alignment direction Z, and the low-temperature side heat exchanger 32 cools the other end face of the heat storage 2 in the alignment direction Z. In the present embodiment, the heat exchangers 31 and 32 each have a substantially cylindrical shape. The heat exchangers 31 and 32 can be made of a metal such as stainless steel, for example. Also, in the alignment direction Z, the side on which the low-temperature side heat exchanger 32 is arranged with respect to the high-temperature side heat exchanger 31 is referred to as the front side Z1, and the opposite side is referred to as the rear side Z2.

[0019] In the present embodiment, as shown in FIG. 2, a fixing portion 313 fixed to the housing 4 is provided on the outer peripheral surface of the high-temperature side heat exchanger 31. In the present embodiment, as will be described later, the high-temperature side heat exchanger 31 is fixed to the housing 4 so as not to be able to move relative to the housing 4. The high-temperature side heat exchanger 31 and the fixing portion 313 are fixed to each other by welding.

[0020] The fixing portion 313 has an annular portion 314 fixed to the high-temperature side heat exchanger 31 so as to cover the outer peripheral surface of the high-temperature side heat exchanger 31, and a protruding flange portion 315 protruding outward from the central portion of the annular portion 314 in the alignment direction Z. The annular portion 314 and the protruding flange portion 315 are integrally formed. Also, as will be described later, the protruding flange portion 315 of the fixing portion 313 is fixed to the housing 4.

[0021] The fixed portion 313 is formed with two communication holes 316 that communicate the high-temperature side heat exchanger 31 with the outside. A high-temperature side introduction pipe 311 for introducing a high-temperature side heat medium into the high-temperature side heat exchanger 31 is inserted into one of the communication holes 316, and a high-temperature side discharge pipe 312 for discharging the high-temperature side heat medium from the high-temperature side heat exchanger 31 to the outside is inserted into the other communication hole 316. The high-temperature side introduction pipe 311 and the high-temperature side discharge pipe 312 are fixed to the fixed portion 313 by welding in a state of being inserted into the communication holes 316, respectively.

[0022] Further, an annular movement restricting portion 14 is fixed by welding to the front side Z1 surface of the outer peripheral end portion of the high-temperature side heat exchanger 31 and the front side Z1 surface of the annular portion 314 of the fixed portion 313. The movement restricting portion 14 has a main body portion 141 fixed to the high-temperature side heat exchanger 31 and the fixed portion 313, and an annular convex portion 142 protruding forward to the front side Z1 from an end portion on the inner peripheral side of the main body portion 141. The annular convex portion 142 is provided along the outer peripheral surface of the heat storage device 2. The heat storage device 2 is restricted from moving in the radial direction by the annular convex portion 142.

[0023] In addition, an annular outer peripheral portion 321 is provided on the outer peripheral surface of the low-temperature side heat exchanger 32 which is the movable heat exchanger 30, as shown in FIG. 3. The low-temperature side heat exchanger 32 and the outer peripheral portion 321 are fixed to each other by welding. Two communication holes 320 are formed in the outer peripheral portion 321. One of the communication holes 320 communicates the low-temperature side heat exchanger 32 with the movable introduction pipe 301, and the other communication hole 320 communicates the low-temperature side heat exchanger 32 with the movable discharge pipe 302. The movable introduction pipe 301 and the movable discharge pipe 302 are fixed to the outer peripheral portion 321 by welding in a state of being inserted into the front ends of the communication holes 320, respectively. Further, in this embodiment, the movable introduction pipe 301 is a pipe for introducing a low-temperature side heat medium into the low-temperature side heat exchanger 32, and the movable discharge pipe 302 is a pipe for discharging the low-temperature side heat medium from the low-temperature side heat exchanger 32 to the outside.

[0024] Also, although illustration is omitted, the heat accumulator 2 has an outer peripheral wall portion that constitutes the wall portion on the outer peripheral side, and a cell wall portion that forms a plurality of through holes along the arrangement direction Z on the inner peripheral side of the outer peripheral wall portion. The cell wall portion can be formed as a wall portion such as a lattice shape or a honeycomb shape, for example. The sound wave transmitted by the working fluid passes through the through holes partitioned by the outer peripheral wall portion and the cell wall portion. Further, the heat accumulator 2 can amplify the sound wave by vibrating the working fluid in the through holes by utilizing the temperature difference at both ends thereof. Also, in the present embodiment, the cell density of the heat accumulator 2 is 7000 cpsi (cell per square inch) or more.

[0025] The heat accumulator 2 can be made of a metal material such as stainless steel or a ceramic, for example. In the present embodiment, the heat accumulator 2 is made of a ceramic. The heat accumulator 2 can be made of alumina or cordierite, for example. In the present embodiment, the heat accumulator 2 is made of alumina. Also, the surface pressure acting between the movable heat exchanger 30 and the heat accumulator 2 is 1 to 20 MPa. In the present embodiment, the heat accumulator 2 has a substantially cylindrical shape.

[0026] Also, as shown in FIG. 2, the heat accumulator 2 is sandwiched and fixed in the arrangement direction Z by the high-temperature side heat exchanger 31 and the low-temperature side heat exchanger 32, which is the movable heat exchanger 30, in a state movable in the arrangement direction Z. Therefore, the movable heat exchanger 30 presses the heat accumulator 2 toward the rear side Z2, and also presses the high-temperature side heat exchanger 31 toward the rear side Z2 via the heat accumulator 2. That is, the end face on the rear side Z2 of the movable heat exchanger 30 is in pressure contact with the end face on the front side Z1 of the heat accumulator 2, and the end face on the rear side Z2 of the heat accumulator 2 is in pressure contact with the end face on the front side Z1 of the high-temperature side heat exchanger 31.

[0027] In addition, the thermoacoustic device 1 includes a housing 4 that houses the heat exchangers 31 and 32 and the regenerator 2 in order to prevent the working fluid from leaking to the outside. In this embodiment, as shown in FIG. 2, the housing 4 has a first housing portion 41 that houses the movable heat exchanger 30 inside, and a second housing portion 42 provided so as to have a substantially symmetric shape with the first housing portion 41. The first housing portion 41 and the second housing portion 42 each have a cylindrical outer peripheral portion 411 and 421 that cover the housing space 40, which is the space inside the housing 4, from the outer peripheral side, and flange portions 412 and 422 that project from one end in the arrangement direction Z of the outer peripheral portions 411 and 421 toward the outer peripheral side. Further, the first housing portion 41 and the second housing portion 42 also each have connecting portions 413 and 423 that are provided at the other end in the arrangement direction Z of the outer peripheral portions 411 and 421 and are connected to the fluid pipe 11. Specifically, the flange portion 412 projects from the end on the rear side Z2 of the outer peripheral portion 411 of the first housing portion 41 toward the outer peripheral side, and the flange portion 422 projects from the end on the front side Z1 of the outer peripheral portion 421 of the second housing portion 42 toward the outer peripheral side. Further, the connecting portion 413 is provided at the end on the front side Z1 of the outer peripheral portion 411 of the first housing portion 41. The connecting portion 423 is provided at the end on the rear side Z2 of the outer peripheral portion 421 of the second housing portion 42.

[0028] Then, the protruding flange portion 315 of the fixing portion 313 fixed to the high-temperature side heat exchanger 31 is fastened and fixed to the housing 4 in a state of being sandwiched in the arrangement direction Z by the flange portion 412 of the first housing portion 41 and the flange portion 422 of the second housing portion 42. Specifically, through holes (not shown) penetrating along the arrangement direction Z are formed in the flange portions 412, 422, and the protruding flange portion 315, respectively. Then, a bolt 191, which is a fastening member, is inserted through these through holes, and the flange portions 412, 422 and the protruding flange portion 315 are fastened and fixed to each other by the bolt 191 and the nut 192. The flange portions 412, 422 and the protruding flange portion 315 are fastened and fixed to each other by the fastening members 191, 192 at a plurality of locations in the circumferential direction of the housing 4.

[0029] In addition, fluid pipes 11 are connected to the connecting portions 413 and 423 of the housing 4, respectively. Specifically, an annular pipe flange portion 113 protruding to the outer peripheral side is formed at the end of the fluid pipe 11. The pipe flange portion 113 and the connecting portions 413 and 423 of the housing 4 are fastened and fixed to each other in the alignment direction Z by bolts (not shown).

[0030] In addition, a first fluid communication hole 402, which will be described later, is formed in the connecting portion 413 of the first accommodating portion 41, and is configured such that sound waves can propagate between the fluid pipe 11 fixed to the connecting portion 413 and the accommodating space 40 via the working fluid. A second fluid communication hole 404 is formed in the connecting portion 423 of the second accommodating portion 42, and is configured such that sound waves can propagate between the accommodating space 40 and the fluid pipe 11 fixed to the connecting portion 423 via the working fluid. That is, the second fluid communication hole 404 penetrates the connecting portion 423 of the second accommodating portion 42 in the alignment direction Z and communicates the accommodating space 40 with the inside of the fluid pipe 11.

[0031] In this embodiment, two pipe insertion holes 401 are formed in the housing 4. A movable introduction pipe 301 is slidably inserted into one of the pipe insertion holes 401 in the alignment direction Z, and a movable discharge pipe 302 is slidably inserted into the other pipe insertion hole 401 in the alignment direction Z. That is, the movable introduction pipe 301 and the movable discharge pipe 302 are each provided so as to be movable in the alignment direction Z with respect to the housing 4. As shown in FIG. 3, a seal member 18 made of an elastomer is provided on the inner peripheral surface of the pipe insertion hole 401, and seals between the housing 4 and the movable introduction pipe 301 and between the housing 4 and the movable discharge pipe 302. The seal member 18 can be, for example, an O-ring made of nitrile rubber, silicone rubber, fluororubber, or the like.

[0032] Further, as shown in FIGS. 3 to 5, the thermoacoustic device 1 has a through hole penetrating in the alignment direction Z, and has a pressing member 51 that presses the movable heat exchanger 30 toward the regenerator 2. Further, as shown in FIG. 3, the housing 4 is formed with a first fluid communication hole 402 that penetrates in the alignment direction Z and communicates the inside of the housing 4 and the inside of the fluid pipe 11. The first fluid communication hole 402 is formed on the side opposite to the regenerator 2 with respect to the movable heat exchanger 30 in the alignment direction Z. A female thread is formed on the inner peripheral surface 403 of the first fluid communication hole 402.

[0033] The thermoacoustic device 1 has a through hole penetrating in the alignment direction Z and has a push screw 52 having a male thread formed on the outer peripheral surface. The push screw 52 is screwed into the female thread formed on the inner peripheral surface 403 of the first fluid communication hole 402. The push screw 52 is disposed on the side opposite to the movable heat exchanger 30 with respect to the pressing member 51 in the alignment direction Z. The push screw 52 presses the pressing member 51 toward the regenerator 2 via an elastic member 53.

[0034] That is, the push screw 52 presses the movable heat exchanger 30 toward the rear side Z2 via the elastic member 53 and the pressing member 51. The movable heat exchanger 30 pressed by the push screw 52 presses the regenerator 2 toward the rear side Z2 and, via the regenerator 2, presses the high-temperature side heat exchanger 31 toward the rear side Z2. As a result, the end face on the rear side Z2 of the movable heat exchanger 30 and the end face on the front side Z1 of the regenerator 2 are in pressure contact without forming a gap between the movable heat exchanger 30 and the regenerator 2. Further, the end face on the front side Z1 of the high-temperature side heat exchanger 31 and the end face on the rear side Z2 of the regenerator 2 are in pressure contact without forming a gap between the high-temperature side heat exchanger 31 and the regenerator 2.

[0035] As shown in FIGS. 3 to 5, the pressing member 51 has an annular pressing portion 511 disposed closer to the movable heat exchanger 30 than the first fluid communication hole 402, and a cylindrical portion 512 extending from a portion on the inner peripheral side of the annular pressing portion 511 toward the front side Z1. As shown in FIG. 5, the outer peripheral end portion of the annular pressing portion 511 presses the outer peripheral side portion of the movable heat exchanger 30 toward the rear side Z2 over the entire circumference. In FIG. 5, the drawings of the housing 4 and the like are omitted. Further, as shown in FIG. 3, the surface on the rear side Z2 of the annular pressing portion 511 faces the movable heat exchanger 30 in the arrangement direction Z, and is formed to incline toward the rear side Z2 from the opening end on the rear side Z2 of the through hole formed in the pressing member 51 toward the outer peripheral side. That is, the surface on the rear side Z2 of the annular pressing portion 511 is formed to face the movable heat exchanger 30 side as it goes toward the outer peripheral side. The annular pressing portion 511 presses only the outer peripheral side portion of the movable heat exchanger 30 without blocking the fluid flow path formed in the movable heat exchanger 30.

[0036] In the arrangement direction Z, a gap G1 is formed between the surface on the front side Z1 of the annular pressing portion 511 and the surface on the rear side Z2 of the connecting portion 413 of the housing 4. Also, in the arrangement direction Z, a gap G2 is formed between the surface on the front side Z1 of the outer peripheral portion 321 fixed to the movable heat exchanger 30 and the surface on the rear side Z2 of the connecting portion 413. The widths of the gap G1 and the gap G2 in the arrangement direction Z can be, for example, 1 mm or less.

[0037] Further, the cylindrical portion 512 of the pressing member 51 is disposed inside the first fluid communication hole 402. The cylindrical portion 512 has a cylindrical thin-walled portion 513 that is thinner in the radial thickness than the connecting portion 514 of the cylindrical portion 512 with the annular pressing portion 511. The thin-walled portion 513 is formed to protrude toward the front side Z1 from the inner peripheral end portion of the connecting portion 514. A member accommodation space 510 for accommodating the elastic member 53 is formed between the outer peripheral surface of the thin-walled portion 513 and the inner peripheral surface of the first fluid communication hole 402. That is, the elastic member 53 is disposed between the thin-walled portion 513 and the inner peripheral surface 403 of the first fluid communication hole 402.

[0038] The elastic member 53 is configured to be elastically deformable in the alignment direction Z. The elastic member 53 has a through-hole penetrating in the alignment direction Z. The thermoacoustic device 1 of the present embodiment has two annular elastic members 53. In the present embodiment, the elastic member 53 is a disc spring. The two elastic members 53 are arranged in the member accommodation space 510 so as to face each other in the alignment direction Z. Of the two elastic members 53, the elastic member 53 arranged on the rear side Z2 is formed so as to go toward the rear side Z2 as it goes toward the outer side in the radial direction of the elastic member 53, and the elastic member 53 arranged on the other front side Z1 is formed so as to go toward the front side Z1 as it goes toward the outer side in the radial direction of the elastic member 53. Further, the elastic member 53 is arranged in a state of being elastically compressed in the alignment direction Z. Thereby, the movable heat exchanger 30 is elastically pressed toward the regenerator 2 side.

[0039] In the present embodiment, an annular spacer 54 is arranged on the front side Z1 of the elastic member 53. And the push screw 52 presses the pressing member 51 toward the rear side Z2 via the spacer 54 and the two elastic members 53. The pressing member 51, the elastic member 53, the spacer 54, and the push screw 52 can be made of a metal such as stainless steel, for example.

[0040] Next, the operation and effects of the present embodiment will be described. In the thermoacoustic device 1 described above, the regenerator 2 is sandwiched in the alignment direction Z by the high-temperature side heat exchanger 31 and the low-temperature side heat exchanger 32. Further, at least one of the high-temperature side heat exchanger 31 and the low-temperature side heat exchanger 32 is the movable heat exchanger 30. Furthermore, the movable introduction pipe 301 and the movable discharge pipe 302 are slidably inserted into the pipe insertion holes 401 that communicate the inside and the outside of the housing 4 along the alignment direction Z, respectively. Therefore, even if the dimensions of the heat exchangers 31, 32, and the regenerator 2 change due to a temperature change while simplifying the structure, it is possible to prevent a gap from being formed between the heat exchangers 31, 32 and the regenerator 2. As a result, while achieving miniaturization, it is possible to suppress the leakage of sound waves. Further, even if the heat exchangers 31, 32 and the regenerator 2 expand due to a temperature rise, it is possible to suppress the load stress applied to the regenerator 2.

[0041] Specifically, for example, assume a case where the dimensions in the arrangement direction Z of the heat exchangers 31 and 32 and the heat accumulator 2 become smaller due to a decrease in the temperature of the heat medium, the temperature around the thermoacoustic device 1, or the like. In this case, as the dimensions in the arrangement direction Z of the heat exchangers 31 and 32 and the heat accumulator 2 become smaller, the size of the elastic member 53 in the arrangement direction Z, which is elastically compressed, becomes larger, and the pressing member 51 moves rearward to Z2 by the elastic force of the elastic member 53. That is, when the pressing member 51 is pressed by the elastic member 53, as shown by the dashed line in FIG. 6, the pressing member 51 moves rearward to Z2, and the movable heat exchanger 30 pressed by the pressing member 51 also moves rearward to Z2. Further, the movable introduction pipe 301 and the movable discharge pipe 302 fixed to the movable heat exchanger 30 also move rearward to Z2 while sliding with respect to the inner peripheral surface of the pipe insertion hole 401. Therefore, even if the dimensions of the heat exchangers 31 and 32 and the heat accumulator 2 become smaller, it is possible to prevent a gap from being formed between the heat exchangers 31 and 32 and the heat accumulator 2. At this time, as the pressing member 51 and the movable heat exchanger 30 move rearward to Z2, the widths of the gaps G1 and G2 in the arrangement direction Z also become larger. Also, assume a case where the temperature of the heat medium, the temperature around the thermoacoustic device 1, or the like rises, or a case where the thermoacoustic device 1 changes from the stopped state to the operating state and the temperature of the thermoacoustic device 1 rises. At this time, even if the dimensions in the arrangement direction Z of the heat exchangers 31 and 32 and the heat accumulator 2 become larger, the pressing member 51 and the movable heat exchanger 30 move forward to Z1 with respect to the housing 4. Therefore, it is possible to prevent a gap from being formed between the heat exchangers 31 and 32 and the heat accumulator 2. Also, at this time, the elastic member 53 is compressed in the arrangement direction Z, and the widths of the gaps G1 and G2 in the arrangement direction Z become smaller.

[0042] The thermoacoustic device 1 can convert heat into sound waves by providing a temperature gradient in the regenerator 2. The graph in Fig. 7 is a graph showing the relationship between the work flow, which can be obtained by multiplying the pressure p of the sound wave by the velocity v of the sound wave, and the leakage gap, which is the gap between the heat exchanger and the regenerator. Here, the work flow represents the energy of the sound wave. As shown in the graph of Fig. 7, when there is no leakage gap, the heat energy supplied to the regenerator can be efficiently converted into the work flow. On the other hand, when even a slight leakage gap is formed, the heat energy cannot be sufficiently converted into the work flow, and the thermoacoustic conversion efficiency is likely to decrease. Specifically, when a leakage gap is formed, the sound wave propagated between the heat exchanger and the regenerator leaks from the leakage gap to the outside of the heat exchanger and the regenerator and into the housing accommodation space, so that the work flow tends to become smaller. In addition, the sound wave leaking into the accommodation space re-enters the regenerator or the heat exchanger through the leakage gap, which is likely to cause a phase difference in the sound wave, and this also causes the work flow to tend to become smaller. As a result, there is a possibility that a sound wave having sufficient energy cannot be propagated to the generator. Therefore, the thermoacoustic device 1 of this embodiment has a movable heat exchanger 30. Therefore, with a relatively simple structure, it is possible to prevent a leakage gap from being formed between the heat exchangers 31 and 32 and the regenerator 2. Therefore, miniaturization can be achieved, leakage of sound waves from between the heat exchangers 31 and 32 and the regenerator 2 can be suppressed, and furthermore, the occurrence of a phase difference in the sound wave can also be suppressed. As a result, it is possible to suppress the decrease in the work flow and improve the thermoacoustic conversion efficiency.

[0043] In addition, the thermoacoustic device 1 of this embodiment can sufficiently press the heat exchangers 31 and 32 against the regenerator 2 by the movable heat exchanger 30, so that heat transfer between the heat exchangers 31 and 32 and the regenerator 2 can be promoted. As a result, it becomes possible to sufficiently provide a temperature difference in the regenerator 2, and the thermoacoustic conversion efficiency can be improved.

[0044] Further, as described above, the thermoacoustic device 1 of this embodiment has a configuration in which the regenerator 2 is elastically pressed in the longitudinal direction Z by the movable heat exchanger 30. Therefore, even if there are dimensional variations in the heat exchangers 31 and 32 and the regenerator 2 as compared with the dimensions at the time of design, it is possible to suppress the formation of gaps between the heat exchangers 31 and 32 and the regenerator 2. As a result, the reliability of the product can be improved.

[0045] The low-temperature side heat exchanger 32 is the movable heat exchanger 30. Therefore, it is easy to seal between the housing 4 and the movable introduction pipe 301 and between the housing 4 and the movable discharge pipe 302 at the pipe insertion hole 401. That is, the temperature of the heat medium flowing through the movable introduction pipe 301 or the like can be set to a predetermined temperature or lower. Therefore, for example, when sealing between the housing 4 and the movable introduction pipe 301 or the like with a seal member 18 such as an O-ring at the pipe insertion hole 401, the degree of freedom in selecting the material of the seal member 18 or the like can be increased. As a result, it is possible to easily suppress the leakage of the working fluid from the housing 4 and to movably provide the movable introduction pipe 301 and the movable discharge pipe 302 with respect to the housing 4.

[0046] The thermoacoustic device 1 includes a pressing member 51 and a pressing screw 52. The pressing screw 52 presses the pressing member 51 toward the regenerator 2 via an elastic member 53. Therefore, it is easy to manage the load for pressing the regenerator 2 by the movable heat exchanger 30. That is, by adjusting the elastic force of the elastic member 53 and the tightening degree of the pressing screw 52, it is possible to easily adjust the pressing force of the movable heat exchanger 30 against the regenerator 2. Therefore, while sufficiently suppressing the leakage of sound waves, heat transfer between the heat exchangers 31 and 32 and the regenerator 2 can be promoted. Therefore, the temperature gradient in the regenerator 2 can be made even larger, and sound waves can be generated more efficiently. Further, since it is easy to adjust the pressing force of the movable heat exchanger 30 against the regenerator 2, it is possible to suppress the pressing force from becoming too large. Therefore, damage and deformation in the regenerator 2 and the heat exchangers 31 and 32 can be sufficiently suppressed.

[0047] The regenerator 2 is made of ceramic. Therefore, the thermal conductivity of the regenerator 2 can be made relatively low. Therefore, it is easy to increase the temperature difference between the end on the high-temperature side heat exchanger 31 side in the regenerator 2 and the end on the low-temperature side heat exchanger 32 side in the regenerator 2. As a result, sound waves can be generated more efficiently. Also, the surface pressure acting between the movable heat exchanger 30 and the regenerator 2 is 1 to 20 MPa. That is, the surface pressure acting on the regenerator 2 is 20 MPa or less. Therefore, damage to the regenerator 2 due to overload can be suppressed. Also, since the surface pressure acting between the movable heat exchanger 30 and the regenerator 2 is 1 MPa or more, the contact pressure between the movable heat exchanger 30 and the regenerator 2 can be sufficiently ensured. As a result, heat transfer between the heat exchangers 31, 32 and the regenerator 2 can be performed efficiently.

[0048] The regenerator 2 is made of alumina. Therefore, the regenerator 2 can be easily manufactured. As a result, the manufacturability can be improved.

[0049] Also, the regenerator 2 can be made of cordierite. In this case, the heat insulation property of the regenerator 2 can be further improved, and the temperature difference in the regenerator 2 can be further increased. As a result, sound waves can be generated even more efficiently.

[0050] The thermoacoustic device 1 has a movement restricting portion 14. Therefore, the movement of the regenerator 2 in the radial direction can be surely suppressed. Therefore, it is possible to surely suppress the displacement of the position of the regenerator 2 with respect to the heat exchangers 31, 32. As a result, the leakage of sound waves can be further suppressed, and heat transfer between the heat exchangers 31, 32 and the regenerator 2 can be further ensured.

[0051] Also, the high-temperature side heat exchanger 31, which is the heat exchanger other than the movable heat exchanger 30, is provided with a fixing portion 313 having a protruding flange portion 315. Therefore, the high-temperature side heat exchanger 31 can be easily fixed to the housing 4. Therefore, the manufacturability of the thermoacoustic conversion portion 12 can be improved.

[0052] As described above, according to this embodiment, it is possible to provide the thermoacoustic device 1 that can suppress the leakage of sound waves while achieving miniaturization.

[0053] In the above-described Embodiment 1, the low-temperature side heat exchanger 32 is the movable heat exchanger 30. However, the high-temperature side heat exchanger can also be a movable heat exchanger, and furthermore, both the low-temperature side heat exchanger and the high-temperature side heat exchanger can be movable heat exchangers.

[0054] In the above-described Embodiment 1, the flange portions 412 and 422 and the fixing portion 313 are fastened and fixed to each other by the fastening members 191 and 192. However, the flange portion and the fixing flange portion can be fixed to each other by, for example, welding.

[0055] In the above-described Embodiment 1, the thermoacoustic device 1 has two elastic members 53. However, the thermoacoustic device can also have one elastic member, or can have three or more elastic members.

[0056] In the above-described Embodiment 1, the push screw 52 presses the movable heat exchanger 30 toward the rear side Z2 by pressing the pressing member 51 toward the regenerator 2 side via the elastic member 53. However, the pressing member can also be configured such that, for example, the pressing member itself has elasticity in the arrangement direction. That is, without using an elastic member, the movable heat exchanger can be elastically pressed by the push screw and the pressing member. Also, the movable heat exchanger can be elastically pressed only by the elastic force of the elastic member.

[0057] (Experimental Example 1) In this example, as shown in the graph of FIG. 8, using a thermoacoustic device having the same basic structure as in Embodiment 1, the surface pressure acting between the movable heat exchanger and the regenerator was changed, and the relationship between the surface pressure and the thermal resistance between the movable heat exchanger and the regenerator was examined. As experimental conditions, the material of the movable heat exchanger was stainless steel, and the material of the regenerator was alumina. Also, in this example, the thermal resistance between the movable heat exchanger and the regenerator was 0.5 cm 2When it is below K / W, it is used as a criterion for efficiently transferring heat from the movable heat exchanger to the heat accumulator. Therefore, in this example, the surface pressure that satisfies this criterion was determined. Also, the graph of Fig. 8 shows the approximate curve in the plot of the experimental results.

[0058] As shown in the graph of Fig. 8, it can be seen that as the surface pressure increases, the thermal resistance decreases. Also, from the graph of Fig. 8, when the surface pressure is 1 MPa or more, the thermal resistance becomes 0.5 cm 2 K / W or less. From this result, it can be said that the thermoacoustic device of Embodiment 1 in which the surface pressure acting between the movable heat exchanger and the heat accumulator is 1 MPa or more can efficiently transfer heat from the movable heat exchanger to the heat accumulator.

[0059] (Experimental Example 2) In this example, as shown in Table 1 below, using a thermoacoustic device having the same basic structure as that of Embodiment 1, the surface pressure acting between the movable heat exchanger and the heat accumulator was changed, and the relationship between the surface pressure and the presence or absence of cracks generated in the heat accumulator was examined. In this example, a heat accumulator with a cell density of 7000 cpsi and a heat accumulator with a cell density of 20000 cpsi were used. Also, in this example, the heat accumulator was pressed by the movable heat exchanger so that the surface pressure acting between the movable heat exchanger and the heat accumulator was 1 to 30 MPa. Other conditions are the same as those in Experimental Example 1.

[0060]

Table 1

[0061] As shown in Table 1, in the case of the regenerator with a cell density of 7000 cpsi, no crack was observed when the surface pressure was up to 20 MPa, and cracks were observed when the surface pressure reached 25 MPa or more. Further, in the case of the regenerator with a cell density of 20000 cpsi, no crack was observed when the surface pressure was up to 25 MPa, and cracks were observed when the surface pressure reached 30 MPa. That is, in both the regenerator with a cell density of 7000 cpsi and the regenerator with a cell density of 20000 cpsi, no crack was observed when the surface pressure was 20 MPa or less. From this result, it can be said that the thermoacoustic device of Embodiment 1 in which the surface pressure acting between the movable heat exchanger and the regenerator is 20 MPa or less can sufficiently suppress damage to the regenerator 2.

[0062] The present invention is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the gist thereof.

[0063] <Others> The features of the present invention are shown as follows. [Item 1] A fluid pipe (11) filled with a working fluid and a thermoacoustic conversion unit (12) provided in the fluid pipe are provided. The thermoacoustic conversion unit includes a regenerator (2) that generates sound waves by a temperature gradient, a high-temperature side heat exchanger (31) disposed at one end of the regenerator and heating the one end of the regenerator, a low-temperature side heat exchanger (32) disposed at the other end of the regenerator and cooling the other end of the regenerator, and a housing (4) that houses the regenerator, the high-temperature side heat exchanger, and the low-temperature side heat exchanger inside and is connected to the fluid pipe. The regenerator is sandwiched by the high-temperature side heat exchanger and the low-temperature side heat exchanger in the arrangement direction (Z) of the low-temperature side heat exchanger, the regenerator, and the high-temperature side heat exchanger. Of the high-temperature side heat exchanger and the low-temperature side heat exchanger, at least one is a movable heat exchanger (30) that is provided so as to be movable in the arrangement direction with respect to the housing and is elastically pressed toward the regenerator side. A movable introduction pipe (301) for introducing a heat medium into the movable heat exchanger and a movable discharge pipe (302) for discharging the heat medium from the movable heat exchanger to the outside are fixed to the movable heat exchanger. A pipe insertion hole (401) that communicates the inside and the outside of the housing is formed in the housing along the arrangement direction. The movable introduction pipe and the movable discharge pipe are each slidably inserted into the pipe insertion hole, and this is a thermoacoustic device (1). [Item 2] The thermoacoustic device according to item 1, wherein the low-temperature side heat exchanger is the movable heat exchanger. [Item 3] It has a through hole penetrating in the arrangement direction and a pressing member (51) that presses the movable heat exchanger toward the regenerator side. A first fluid communication hole (402) that penetrates in the arrangement direction and communicates the inside of the housing and the inside of the fluid pipe is formed in the housing. The first fluid communication hole is formed on the side opposite to the regenerator with respect to the movable heat exchanger in the arrangement direction. A female thread is formed on the inner peripheral surface (403) of the first fluid communication hole. It has a through hole penetrating in the arrangement direction and a push screw (52) having a male thread formed on the outer peripheral surface. The push screw is screwed into the female thread formed on the inner peripheral surface of the first fluid communication hole. The push screw is arranged on the side opposite to the movable heat exchanger with respect to the pressing member in the arrangement direction. The push screw presses the pressing member toward the regenerator side via an elastic member (53). The thermoacoustic device according to item 1 or 2. [Item 4] The regenerator is made of ceramic, and the surface pressure acting between the movable heat exchanger and the regenerator is 1 to 20 MPa. The thermoacoustic device according to any one of items 1 to 3. [Item 5] The heat accumulator is the thermoacoustic device according to item 4, made of alumina. [Item 6] The heat accumulator is the thermoacoustic device according to item 4, made of cordierite.

Explanation of symbols

[0064] 1... Thermoacoustic device, 2... Heat accumulator, 4... Housing, 11... Fluid piping, 12... Thermoacoustic conversion section, 30... Movable heat exchanger, 31... High-temperature side heat exchanger, 32... Low-temperature side heat exchanger, 301... Movable introduction piping, 302... Movable discharge piping, 401... Piping insertion hole, Z... Arrangement direction

Claims

1. A fluid pipe (11) filled with a working fluid, and a thermoacoustic conversion unit (12) provided in the fluid pipe, The thermoacoustic conversion unit includes: A regenerator (2) that generates sound waves due to a temperature gradient, A high-temperature side heat exchanger (31) disposed at one end of the regenerator and heating the one end of the regenerator, A low-temperature side heat exchanger (32) disposed at the other end of the regenerator and cooling the other end of the regenerator, A housing (4) that houses the regenerator, the high-temperature side heat exchanger, and the low-temperature side heat exchanger inside and is connected to the fluid pipe, The regenerator is sandwiched by the high-temperature side heat exchanger and the low-temperature side heat exchanger in the arrangement direction (Z) of the low-temperature side heat exchanger, the regenerator, and the high-temperature side heat exchanger, Among the high-temperature side heat exchanger and the low-temperature side heat exchanger, at least one is a movable heat exchanger (30) that is provided movably in the arrangement direction with respect to the housing and is elastically pressed toward the regenerator side, The movable heat exchanger is fixed with a movable introduction pipe (301) for introducing a heat medium into the movable heat exchanger and a movable discharge pipe (302) for discharging the heat medium from the movable heat exchanger to the outside, The housing is formed with a pipe insertion hole (401) that communicates the inside and the outside of the housing along the arrangement direction, The movable introduction pipe and the movable discharge pipe are each slidably inserted into the pipe insertion hole, a thermoacoustic device (1).

2. The thermoacoustic device according to claim 1, wherein the low-temperature side heat exchanger is the movable heat exchanger.

3. It has a through hole penetrating in the arrangement direction and a pressing member (51) that presses the movable heat exchanger toward the regenerator side, The housing is formed with a first fluid communication hole (402) that penetrates in the arrangement direction and communicates the inside of the housing and the inside of the fluid pipe. The first fluid communication hole is formed on the side opposite to the regenerator with respect to the movable heat exchanger in the arrangement direction, and a female screw is formed on the inner peripheral surface (403) of the first fluid communication hole. It has a through hole penetrating in the arrangement direction and has a push screw (52) with a male screw formed on the outer peripheral surface. The push screw is screwed into the female screw formed on the inner peripheral surface of the first fluid communication hole. The push screw is arranged on the side opposite to the movable heat exchanger with respect to the pressing member in the arrangement direction. The push screw presses the pressing member toward the heat accumulator via an elastic member (53). The thermoacoustic device according to claim 1 or 2.

4. The heat accumulator is made of ceramic, and the surface pressure acting between the movable heat exchanger and the heat accumulator is 1 to 20 MPa. The thermoacoustic device according to claim 3.

5. The heat accumulator is made of alumina. The thermoacoustic device according to claim 4.

6. The heat accumulator is made of cordierite. The thermoacoustic device according to claim 4.

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