Thermoelectric power generation method using waste heat, thermoacoustic mechanism, and thermoelectric power generation system using thermoacoustic mechanism

Abstract

The present application provides a waste heat thermoelectric power generation method, a thermoacoustic mechanism, and a waste heat thermoelectric power generation system, which do not need to set a device for dissipating heat of a coolant, do not use power of a heater or the like, use waste heat as a work source, and thus can convert heat movement into electric power. The waste heat thermoelectric power generation method is characterized by comprising a thermoacoustic engine (100) that inputs heat and outputs sound waves, and a thermoacoustic cooler (200) that inputs the sound waves to generate a temperature difference, wherein one kind of waste heat is supplied to the thermoacoustic engine (100) as the work source and the sound waves are output, the output sound waves are input to the thermoacoustic cooler (200) to generate a cooling liquid, another kind of waste heat is introduced into a thermoelectric power generation module (40) together with the generated cooling liquid, and electric power is generated by using the Seebeck effect.

Description

Technical Field

[0001] This invention relates to a thermoelectric power generation method, a thermoacoustic mechanism, and a thermoelectric power generation system utilizing a thermoacoustic mechanism, specifically to a thermoelectric power generation method, a thermoacoustic mechanism, and a thermoelectric power generation system utilizing waste heat that does not require cooling towers, coolers, or other equipment to dissipate heat from the coolant, does not use electricity, and replaces Freon, etc., by using waste heat as a power source, thereby converting the movement of heat into electricity. Background Technology

[0002] According to the "Survey on the Actual Situation of Heat Dissipation in Industrial Sectors" (Non-Patent Document 1) published by NEDO (New Energy and Industrial Technology Development Organization, National Research and Development Corporation) in March 2019, the following is recorded: The total heat dissipation from the fifteen industries with the highest heat utilization is 743 petajoules (PJ) / year, of which 565 PJ / year, corresponding to 76%, is heat dissipation from exhaust gases at temperatures below 200°C. If this unused heat below 200°C can be effectively utilized, it will make a significant contribution to reducing energy consumption in the domestic industrial sector.

[0003] Unused heat includes heat from exhaust and drainage, heat released from high-temperature equipment or manufacturing, heat directly discarded from production equipment, heat discarded after heat recovery, heat discarded from exhaust treatment devices, and heat discarded from cooling equipment.

[0004] As a primary means of effectively utilizing unused heat below 200°C, methods for generating electricity from heat using dual-cycle power generation and the Organic Rankine Cycle (ORC) are known. This method utilizes a heat source to heat a medium with a low boiling point (instead of Freon) to evaporate it, and uses the vapor to rotate a turbine to generate electricity.

[0005] This method involves large and expensive equipment that uses rotating machinery such as working medium pumps and generators, which presents challenges in terms of maintenance and high operating costs.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Invention No. 6649464

[0009] Non-patent literature

[0010] Non-patent literature 1: "Real-world survey of heat dissipation in industrial sectors", March 2019: NEDO (New Energy and Industrial Technology Development Organization, National Research and Development Corporation)

[0011] Non-Patent Document 2: Cryogenic Engineering Volume 43 No. 12 "Flower type スターリングクーラー - 1. Work flow measurement - (Double circuit type Stirling refrigerator - 1. Work flow measurement -)" (Pipa)

[0012] Focusing on past difficulties, the aim is to develop a device that is small in size, does not use rotating machinery such as working medium pumps or generators, requires no maintenance, and has low operating costs.

[0013] As a means to meet this requirement, the inventors are interested in thermoelectric power generation technology utilizing the thermoacoustic effect. Thermoelectric power generation technology is a technology that converts the movement of heat into electricity; therefore, power generation stops when a thermal equilibrium state is reached where the temperature on the high-temperature side is equal to the temperature on the low-temperature side.

[0014] In particular, for the low-temperature side (cooling side), using liquids such as water, which have a higher thermal conductivity than gases, can achieve a stable cooling effect, but there are also situations where there is no water source nearby.

[0015] In this situation, additional cooling towers, coolers, and other equipment are needed to dissipate heat from the coolant, but this increases equipment costs. To avoid this additional burden, air cooling is sometimes used, but this cannot guarantee sufficient heat dissipation and can easily lead to a thermal equilibrium state, thus preventing power generation.

[0016] In addition, if equipment is installed to dissipate heat from the coolant, there is also the issue of energy consumption.

[0017] Patent Document 1, which aims to generate electricity efficiently by utilizing heat dissipation, discloses a power generation system based on thermoelectric power generation. As an application scope, it discloses the main idea that it can realize a wide range of applications such as thermoacoustic power generation systems, but it does not disclose any specific content or any means to solve the above problems. Summary of the Invention

[0018] The inventors have developed a thermoacoustic engine and a thermoacoustic cooler as thermoacoustic mechanisms. By supplying waste heat to the thermoacoustic engine as a power source and outputting sound waves, and then inputting the output sound waves into the thermoacoustic cooler to generate coolant, the aforementioned large-scale problems can be solved without the need for cooling equipment.

[0019] Furthermore, it was discovered that waste heat can be utilized to reduce costs during the manufacture of this coolant. Non-Patent Document 2 discloses a dual-loop thermoacoustic refrigerator that uses a heater as a heat source, which includes a prime mover circuit that converts heat into sound waves and a refrigerator circuit that converts sound waves into heat. However, it has the disadvantage that if a heater is used as the heat source, the cost increases significantly.

[0020] Therefore, the problem of the present invention is to provide a thermoelectric power generation method, a thermoacoustic mechanism, and a thermoelectric power generation system that utilize waste heat to generate electricity without the need for a device to dissipate heat from the coolant, without using electricity from heaters or the like, and using waste heat as a power source.

[0021] Furthermore, another problem with the present invention is to provide a waste heat-utilizing thermoelectric power generation method, a waste heat-utilizing thermoacoustic mechanism, and a waste heat-utilizing thermoacoustic mechanism-utilizing thermoelectric power generation system that achieves clean energy recovery while realizing stable operation of thermoelectric power generation.

[0022] Furthermore, another problem with the present invention is to provide a thermoelectric power generation system that uses at least two waste heat sources as power sources, thereby enabling lower energy costs through a thermoacoustic mechanism.

[0023] Furthermore, other problems with the present invention will become clear from the following description.

[0024] The above problems are solved by the following inventions.

[0025] 1. A thermoelectric power generation method utilizing waste heat, characterized in that it comprises: a thermoacoustic engine (100) that inputs heat and outputs sound waves; and a thermoacoustic cooler (200) that inputs the sound waves to generate a temperature difference, supplies one type of waste heat as a power source to the thermoacoustic engine (100) and outputs sound waves, inputs the output sound waves to the thermoacoustic cooler (200) to generate coolant, and introduces another type of waste heat together with the generated coolant into a thermoelectric power generation module (40) to generate electricity using the Seebeck effect.

[0026] 2. The thermoelectric power generation method using waste heat as described in 1 above is characterized in that a thermoacoustic engine circuit (10) and a thermoacoustic cooler circuit (20) are connected by a waveguide (30) filled with gas inside. The thermoacoustic engine circuit (10) includes the thermoacoustic engine (100) and is composed of loop-shaped piping. The thermoacoustic cooler circuit (20) includes the thermoacoustic cooler (200) and is composed of loop-shaped piping. One type of waste heat is supplied to the thermoacoustic engine (100) as a power source, and sound waves are supplied to the thermoacoustic cooler (200) via the waveguide, thereby generating a coolant. Another type of waste heat is introduced together with the generated coolant into the thermoelectric power generation module (40) to generate electricity using the Seebeck effect.

[0027] 3. A thermoacoustic mechanism utilizing waste heat, characterized in that a thermoacoustic engine (100) that inputs heat and outputs sound waves and a thermoacoustic cooler (200) that inputs the sound waves to generate a temperature difference are connected via a waveguide (30) that transmits sound waves, the thermoacoustic engine (100) comprising: a heat accumulator (101) having both ends connected to the waveguide (30) and having fine holes; and a low-temperature side heat exchanger (102) and a high-temperature side heat exchanger (103) arranged such that the two sides of the heat accumulator (101) are sandwiched in the middle, at least one waste heat is input to the high-temperature side heat exchanger (103) as a power source, and the heat accumulator (201) generates a temperature difference by inputting the sound waves into the heat accumulator (201). A temperature difference is set on both sides of the heat accumulator (101). When the gas inside the heat accumulator (101) moves to the high temperature side, it expands and contracts when it moves to the low temperature side. The expansion and contraction are repeated to generate sound waves. The thermoacoustic cooler (200) receives the sound waves generated by the thermoacoustic engine (100) through the waveguide (30). Heat exchange accompanied by gas expansion and compression is carried out near the fine hole wall of the heat accumulator (201). A temperature difference is generated between the high temperature side heat exchanger (202) and the low temperature side heat exchanger (203) at both ends of the heat accumulator (201). Cooling liquid for thermoelectric power generation is generated from the low temperature side heat exchanger (203).

[0028] 4. The thermoacoustic mechanism utilizing waste heat according to the aforementioned 3, characterized in that the thermoacoustic mechanism utilizing waste heat includes a coolant tank (204) for storing the coolant.

[0029] 5. The thermoacoustic mechanism utilizing waste heat as described in 3 above, characterized in that the interior of the waveguide (30) is filled with one or more gases composed of helium, argon or air.

[0030] 6. A thermoelectric power generation system utilizing a thermoacoustic mechanism, characterized in that the thermoacoustic mechanism is a waste heat thermoacoustic mechanism as described in any one of the preceding 3 to 5, wherein the waste heat flows through the high-temperature side of the thermoelectric power generation module (40), and the coolant generated by the thermoacoustic cooler (200) flows through the low-temperature side of the thermoelectric power generation module (40), thereby generating electricity using the Seebeck effect.

[0031] 7. The thermoelectric power generation system utilizing the thermoacoustic mechanism described above 6 is characterized in that the coolant flowing out from the low-temperature side of the thermoelectric power generation module (40) is cooled by flowing through the low-temperature side heat exchanger (202) of the thermoacoustic cooler (200) and then through the low-temperature side heat exchanger (203).

[0032] 8. The thermoelectric power generation system utilizing the thermoacoustic mechanism according to the aforementioned 6, characterized in that, in the thermoacoustic cooler (200), the high temperature side is adjusted to +α℃, the low temperature side is adjusted to -α℃, and ΔT is adjusted to 2α℃. While keeping the high temperature side at room temperature, by maintaining ΔT = 2α℃, a coolant reaching (room temperature - 2α)℃ is generated on the low temperature side.

[0033] 9. The thermoelectric power generation system utilizing a thermoacoustic mechanism as described in claim 6 above, characterized in that the cooled coolant is stored in a coolant tank.

[0034] Invention Effects

[0035] According to the present invention, a thermoelectric power generation method utilizing waste heat is provided, which eliminates the need for a device to dissipate heat from the coolant and does not use electricity from heaters or the like, but uses waste heat as a power source, thereby converting the movement of heat into electricity; a thermoacoustic mechanism utilizing waste heat is also provided; and a thermoelectric power generation system utilizing the thermoacoustic mechanism is provided.

[0036] Furthermore, according to the present invention, a waste heat-utilizing thermoelectric power generation method, a waste heat-utilizing thermoacoustic mechanism, and a waste heat-utilizing thermoacoustic mechanism are provided, which achieve clean energy recovery while realizing stable operation of thermoelectric power generation. Attached Figure Description

[0037] Figure 1 This is a block flowchart illustrating one embodiment of the thermoelectric power generation system of the present invention.

[0038] Figure 2 This is a schematic cross-sectional view showing an embodiment of the heat accumulator.

[0039] Explanation of reference numerals in the attached figures

[0040] 3: Waste heat piping; 4: Waste heat piping; 10: Thermoacoustic engine circuit; 100: Thermoacoustic engine; 101: Heat accumulator; 102: Low-temperature side heat exchanger; 103: High-temperature side heat exchanger; 20: Thermoacoustic cooler circuit; 200: Thermoacoustic cooler; 201: Heat accumulator; 202: High-temperature side heat exchanger; 203: Low-temperature side heat exchanger; 204: Coolant tank; 210, 211, 212, 213, 214, 215: Coolant piping; 30: Waveguide (main waveguide); 301: Secondary waveguide; 302: Secondary waveguide; 303: Secondary waveguide; 304: Secondary waveguide; 40: Thermoelectric power generation module; 40a: High-temperature side; 40b: Low-temperature side. Detailed Implementation

[0041] Hereinafter, preferred embodiments of the present invention will be described. The electric power generation method of the present invention, the thermoacoustic mechanism utilizing waste heat, and the thermoelectric power generation system utilizing the thermoacoustic mechanism are thermoelectric power generation systems that use waste heat as a power source, thereby converting the movement of heat into electricity.

[0042] This invention enables the effective utilization of unused heat (discarded industrial waste heat below 300°C).

[0043] In the thermoelectric power generation method of the present invention, a waste heat is supplied to a thermoacoustic engine as a power source and outputs sound waves. The output sound waves are input to a thermoacoustic cooler to generate coolant. Another waste heat is introduced together with the generated coolant into a thermoelectric power generation module to generate electricity using the Seebeck effect.

[0044] That is, the method is as follows: one side of the junction of the thermoelectric power generation module is brought into contact with a high heat source, and the other side of the junction of the thermoelectric power generation module is brought into contact with a low heat source to generate a potential difference, and the Seebeck effect (the inverse of the Peltier effect) is used to convert thermal energy into electrical energy.

[0045] A thermoacoustic mechanism is a thermal mechanism that utilizes the thermoacoustic effect to output work from heat input via sound waves, and a heat pump (cooling / heating) technology that extracts heat by inputting sound waves.

[0046] Thermoelectric power generation technology converts the movement of heat into electricity. Therefore, power generation stops when the temperature on the high-temperature side equals the temperature on the low-temperature side, reaching thermal equilibrium. In particular, for the low-temperature side (cooling side), using liquids such as water, which have a higher thermal conductivity than gases, provides a stable cooling effect. When there is no nearby water source, air cooling is sometimes used to avoid adding extra burdens such as cooling towers to dissipate heat from the coolant. However, this cannot guarantee sufficient heat dissipation and easily leads to a thermal equilibrium state.

[0047] In this invention, even in environments without cooling sources such as water, there is no need for cooling towers, coolers, or other coolant equipment, and no use of electricity or Freon. It is combined with a thermoacoustic cooler that uses waste heat as a power source to function as a refrigeration unit, thereby achieving stable operation of thermoelectric power generation while realizing clean energy recovery.

[0048] Furthermore, this invention enables the construction of a thermoelectric power generation system using a thermoacoustic mechanism that utilizes at least two waste heat sources. Moreover, thermoelectric power generation technology generates electricity by being configured to contact various heat sources, thus offering high versatility as a device. Furthermore, to achieve high output, this invention can be implemented by increasing the number of configurations, thus easily achieving a balance between cost and power generation, and facilitating expansion.

[0049] Furthermore, this invention eliminates the need for an external liquid cooling source, generating stable power from waste heat through a thermoacoustic cooler (cooler) to produce a coolant. The thermoacoustic cooler / thermoelectric power generation module has no moving parts on its main body, thus reducing maintenance and operating costs.

[0050] Next, based on Figure 1 An embodiment of the thermoelectric power generation method and thermoelectric power generation system of the present invention will be described.

[0051] (Source of work)

[0052] This scheme is an example of using two types of waste heat as work sources: high-temperature waste heat (1) supplied to the thermoacoustic mechanism to generate coolant (coolant) and high-temperature waste heat (2) supplied to the thermoelectric power generation module to generate electricity.

[0053] High-temperature waste heat (1) and high-temperature waste heat (2) can be the same waste heat or different waste heat.

[0054] For example, using high-temperature waste heat generated from a waste incinerator (A) (not shown) as high-temperature waste heat (1) and high-temperature waste heat (2) are the same waste heat. Furthermore, using waste heat generated from incinerator (A) as high-temperature waste heat (1) and waste heat generated from incinerator (B) as high-temperature waste heat (2) are different waste heat. Both cases are examples of using two types of waste heat as a source of work.

[0055] Waste heat can be generated from two or more sources, but in the case of the system of the present invention, it is preferred to configure high-temperature waste heat (1) supplied to the thermoacoustic mechanism to generate coolant and high-temperature waste heat (2) supplied to the thermoelectric power generation module to generate electricity as work sources.

[0056] (Unutilized heat)

[0057] Unused heat includes heat from exhaust and drainage, heat released from high-temperature equipment or manufacturing, heat directly discarded from production equipment, heat discarded after heat recovery, heat discarded from exhaust treatment devices, and heat discarded from cooling equipment.

[0058] In the system of the present invention, the waste heat preferably includes discarded industrial waste heat below 300°C, i.e., unused heat as described above.

[0059] Either the high-temperature waste heat (1) supplied to the above-mentioned thermoacoustic mechanism to generate coolant and the high-temperature waste heat (2) supplied to the thermoelectric power generation module to generate electricity can be unused heat, or only one of them can be unused heat and the other can be high-temperature waste heat.

[0060] In this invention, it is preferable to collect and classify waste heat generated from multiple waste heat sources for use as the aforementioned high-temperature waste heat (1) and high-temperature waste heat (2).

[0061] (W loop)

[0062] exist Figure 1 In this paper, the thermoacoustic mechanism for generating coolant is illustrated using the W (double) loop type as an example.

[0063] As shown in the figure, the W-type circuit consists of a thermoacoustic engine circuit 10, a thermoacoustic cooler circuit 20, and a waveguide 30. The thermoacoustic engine circuit 10 is composed of loop-shaped piping, the thermoacoustic cooler circuit 20 is composed of loop-shaped piping, and the waveguide 30 connects the thermoacoustic engine circuit 10 and the thermoacoustic cooler circuit 20.

[0064] The piping constituting the thermoacoustic engine circuit 10 and the thermoacoustic cooler circuit 20 has the same structure as the waveguide 30, is connected to the waveguide 30, and is filled with gas inside. The gas filled inside will be described later.

[0065] By constructing such a W-loop, the functional division of the two types of waste heat is achieved. This is a unique method of the present invention. In the example using a heater such as Non-Patent Document 2, there is no requirement for functional division.

[0066] The thermoacoustic engine circuit 10 includes a device that inputs heat and outputs work as sound waves, namely a thermoacoustic engine 100.

[0067] In addition, the thermoacoustic cooler circuit 20 includes a device for generating a temperature difference by inputting sound waves, namely the thermoacoustic cooler 200.

[0068] (Thermoacoustic engine and thermoacoustic cooler)

[0069] The thermoacoustic engine 100 consists of a heat accumulator 101 with fine holes and a low-temperature side heat exchanger 102 and a high-temperature side heat exchanger 103 arranged in such a way that the heat accumulator 101 is sandwiched in the middle.

[0070] The thermoacoustic cooler 200 consists of a heat accumulator 201 with fine holes and a high-temperature side heat exchanger 202 and a low-temperature side heat exchanger 203 arranged in such a way that the heat accumulator 201 is sandwiched in the middle.

[0071] (Heat accumulator)

[0072] based on Figure 2 The heat accumulators are described below. Heat accumulator 101 is located in the thermoacoustic engine 100, and heat accumulator 201 is located in the thermoacoustic cooler 200 (see reference). Figure 1 The accompanying drawings show the configuration of a heat accumulator 101 provided in the thermoacoustic engine 100.

[0073] exist Figure 2 In the heat storage device 101, a low-temperature heat exchanger 102 is provided on one side (left side in the attached drawing), and a high-temperature heat exchanger 103 is provided on the other side (right side in the attached drawing). The low-temperature heat exchanger 102 and the high-temperature heat exchanger 103 are arranged to sandwich the heat storage device 101 from both sides. A secondary waveguide 302 and a secondary waveguide 301 are provided on the outer side of each of the low-temperature heat exchanger 102 and the high-temperature heat exchanger 103.

[0074] The low-temperature heat exchanger 102 and the high-temperature heat exchanger 103 are not particularly limited; for example, tubular heat exchangers can be used. In this case, it can also be a configuration in which multiple heat exchange tubes are arranged horizontally, with one end open on the secondary waveguide side and the other end open on the heat accumulator side. Coolant is introduced into the low-temperature heat exchanger 102 around the outer periphery of the multiple heat exchange tubes, and high-temperature waste heat is introduced into the high-temperature heat exchanger 103.

[0075] The heat accumulator only needs to have fine pores; for example, it can be constructed by stacking layers of ceramic or SUS in a honeycomb pattern. The pores are preferably continuous, and a structure that allows for repeated expansion and contraction of the internal gas is preferred. Furthermore, it is preferable to include a thermoacoustic engine, a thermoacoustic cooler, and waveguides connected to them, to create a structure capable of pressurizing the gas-filled interior. Examples of gases used for the interior include, but are not limited to, hydrogen, helium, argon, nitrogen, and air.

[0076] (waveguide)

[0077] like Figure 1 As shown, the thermoacoustic engine circuit 10, consisting of the thermoacoustic engine 100, and the thermoacoustic cooler circuit 20, consisting of the thermoacoustic cooler 200, are connected via a main waveguide 30. The interior is filled with any one of hydrogen, helium, argon, or air as described above. The internal gas is preferably a gas with high thermal conductivity, and higher pressure results in higher efficiency, which is therefore preferred. However, from the viewpoint of not only thermal conductivity but also ease of handling and cost of acquisition, argon is preferred, for example.

[0078] Furthermore, if the internal gas pressure exceeds 1 MPa, the pressure resistance of the waveguide containing the gas needs to be improved, and qualified personnel are required to handle it. This may increase manufacturing and maintenance costs. From this perspective, it is preferable to have a pressure less than 1 MPa.

[0079] In this embodiment, it is also a preferred option to arrange five rows of waveguides containing 200 kPa of gas side by side. As a result, it can achieve the same effect as using high-pressure gas.

[0080] In the thermoacoustic engine 100, the high-temperature side heat exchanger 103 is connected to the main waveguide 30 via the secondary waveguide 301, and the low-temperature side heat exchanger 102 is connected to the main waveguide 30 via the secondary waveguide 302. In the thermoacoustic cooler 200, the high-temperature side heat exchanger 202 is connected to the main waveguide 30 via the secondary waveguide 303, and the low-temperature side heat exchanger 203 is connected to the main waveguide 30 via the secondary waveguide 304.

[0081] (The generation of sound waves)

[0082] High-temperature waste heat (1) is input from waste heat pipe 3 to high-temperature side heat exchanger 103 of thermoacoustic engine 100, and coolant is introduced from coolant tank 204 to low-temperature side heat exchanger 102 via coolant pipe 210.

[0083] Thus, a temperature difference between the high-temperature side and the low-temperature side can be formed in the high-temperature side heat exchanger 103 and the low-temperature side heat exchanger 102. Furthermore, when the low-temperature side heat exchanger 102 is kept near room temperature, the gas inside the heat accumulator 101 moves and expands towards the high-temperature side, and contracts when it moves towards the low-temperature side, repeatedly expanding and contracting. As a result, when the critical temperature difference is exceeded, thermoacoustic self-excited vibration is generated, producing sound waves (pressure vibration).

[0084] The waste heat input to the high-temperature side heat exchanger 103 of the thermoacoustic engine 100 is used to become low temperature and is released as low temperature waste heat through the waste heat piping 5.

[0085] The coolant supplied to the cryogenic heat exchanger 102 of the thermoacoustic engine 100 returns to the coolant tank 204 via coolant piping 211.

[0086] (The propagation of sound waves)

[0087] The sound waves generated by the thermoacoustic engine 100 propagate to the main waveguide 30, and when they reach the thermoacoustic cooler 200, heat exchange (Carnot cycle) with gas expansion / compression occurs near the pore wall of the heat accumulator 201.

[0088] (The generation of coolant)

[0089] The aforementioned heat exchange creates a temperature difference between the heat exchangers 202 and 203 at both ends of the heat accumulator 201. Specifically, the coolant used in the thermoelectric power generation module 40 (described later) is sent to the high-temperature side heat exchanger 202 of the thermoacoustic cooler 200 via coolant piping 213. The coolant flowing through the high-temperature side heat exchanger 202 is introduced into the low-temperature side heat exchanger 203 via coolant piping 214. At this time, by utilizing the sound wave energy generated in the thermoacoustic engine 100, the temperature difference between the high-temperature side heat exchanger 202 and the low-temperature side heat exchanger 203 is maintained according to the amount of sound wave energy, thus cooling the coolant flowing through the low-temperature side heat exchanger 203. The coolant flowing through the low-temperature side heat exchanger 203 returns to the coolant tank 204 via coolant piping 215.

[0090] For example, with a high-temperature side of +50°C and a low-temperature side of -50°C, ΔT is 100°C. If the high-temperature side is kept at room temperature (20°C), then ΔT of 100°C is maintained, and the low-temperature side reaches -80°C. In this way, coolant is generated in the thermoacoustic cooler 200.

[0091] That is, in the thermoacoustic cooler 200, with the high temperature side at +α℃ and the low temperature side at -α℃, ΔT is 2α℃. When the high temperature side is set to the ambient temperature of 20℃, by maintaining ΔT2α℃, the low temperature side generates a coolant at (20℃ (ambient temperature) - 2α)℃.

[0092] (Thermoelectric power generation)

[0093] Next, the power generation system in the thermoelectric power generation module 40 will be described.

[0094] The thermoelectric power generation module 40 utilizes the Seebeck effect, setting one side to a high temperature and the other side to a low temperature, thereby converting it into electricity.

[0095] In this embodiment, high-temperature waste heat (2) is flowed from the waste heat pipe 4 through the high-temperature side 40a, and on the low-temperature side 40b, the coolant (coolant) generated in the thermoacoustic cooler 200 and stored in the coolant tank 204 is flowed through the coolant pipe 212 through the low-temperature side 40b, thereby generating a temperature difference between the high-temperature side 40a and the low-temperature side 40b, and generating electricity through the Seebeck effect.

[0096] Waste heat flowing from the high-temperature side 40a of the thermoelectric power generation module 40 is converted into low-temperature waste heat and released as low-temperature waste heat through the waste heat piping 6. The coolant flowing from the low-temperature side 40b of the thermoelectric power generation module 40 is cooled after passing through the high-temperature side heat exchanger 202 of the thermoacoustic cooler 200 and then through the low-temperature side heat exchanger 203.

[0097] (Regeneration of coolant)

[0098] The coolant, heated by the power generation of the thermoelectric power generation module 40 and flowing out from the low-temperature side 40b, is cooled by the low-temperature side heat exchanger 203 after passing through the high-temperature side heat exchanger 202 of the thermoacoustic cooler 200. The regenerated coolant is stored in the coolant tank 204 via the coolant piping 215 and can be transferred back to the thermoelectric power generation module 40 for reuse.

Claims

1. A method for generating electricity using waste heat, characterized in that, It includes: a thermoacoustic engine (100) that inputs heat and outputs sound waves; and a thermoacoustic cooler (200) that inputs the sound waves to generate a temperature difference. Waste heat is supplied to the thermoacoustic engine (100) as a power source and outputs sound waves. The output sound waves are input into the thermoacoustic cooler (200) to generate coolant. Another type of waste heat is introduced together with the generated coolant into the thermoelectric power generation module (40) to generate electricity using the Seebeck effect.

2. The method for generating electricity using waste heat according to claim 1, characterized in that, The thermoacoustic engine circuit (10) and the thermoacoustic cooler circuit (20) are connected by a gas-filled waveguide (30). The thermoacoustic engine circuit (10) includes the thermoacoustic engine (100) and is composed of loop-shaped piping. The thermoacoustic cooler circuit (20) includes the thermoacoustic cooler (200) and is composed of loop-shaped piping. Waste heat is supplied to the thermoacoustic engine (100) as a power source, and sound waves are supplied to the thermoacoustic cooler (200) via the waveguide, thereby generating coolant. Another type of waste heat is introduced together with the generated coolant into the thermoelectric power generation module (40) to generate electricity using the Seebeck effect.

3. A thermoacoustic mechanism utilizing waste heat, characterized in that, A thermoacoustic motor (100) that inputs heat and outputs sound waves and a thermoacoustic cooler (200) that inputs the sound waves to generate a temperature difference are connected via a waveguide (30) that transmits sound waves. The thermoacoustic engine (100) includes: a heat accumulator (101) with its two ends connected to the waveguide (30) and having fine holes; and a low-temperature side heat exchanger (102) and a high-temperature side heat exchanger (103) arranged such that the two sides of the heat accumulator (101) are sandwiched in the middle. At least one type of waste heat is input into the high-temperature heat exchanger (103) as a power source. A temperature difference is set on both sides of the heat accumulator (201). The gas inside the heat accumulator (101) expands when it moves to the high-temperature side and contracts when it moves to the low-temperature side. This repeated expansion and contraction generates sound waves. The thermoacoustic cooler (200), which receives sound waves generated by the thermoacoustic engine (100) via the waveguide (30), performs heat exchange with gas expansion and compression near the pore wall of the heat accumulator (201), generating a temperature difference between the high-temperature side heat exchanger (202) and the low-temperature side heat exchanger (203) at both ends of the heat accumulator (201), and generating a coolant for thermoelectric power generation from the low-temperature side heat exchanger (203).

4. The thermoacoustic mechanism utilizing waste heat according to claim 3, characterized in that, The thermoacoustic mechanism utilizing waste heat includes a coolant tank (204) for storing the coolant.

5. The thermoacoustic mechanism utilizing waste heat according to claim 3, characterized in that, The waveguide (30) is filled with one or more gases consisting of helium, argon or air.

6. A thermoelectric power generation system utilizing a thermoacoustic mechanism, characterized in that, The thermoacoustic mechanism is a waste heat thermoacoustic mechanism as described in any one of claims 3 to 5. Waste heat is passed through the high-temperature side of the thermoelectric power generation module (40), and coolant generated by the thermoacoustic cooler (200) is passed through the low-temperature side of the thermoelectric power generation module (40), thereby generating electricity using the Seebeck effect.

7. The thermoelectric power generation system utilizing a thermoacoustic mechanism according to claim 6, characterized in that, The coolant flowing out from the low-temperature side of the thermoelectric power generation module (40) is cooled by flowing through the low-temperature side heat exchanger (202) of the thermoacoustic cooler (200) and then through the low-temperature side heat exchanger (203).

8. The thermoelectric power generation system utilizing a thermoacoustic mechanism according to claim 6, characterized in that, In the thermoacoustic cooler (200), the high temperature side is adjusted to +α℃, the low temperature side is adjusted to -α℃, and ΔT is adjusted to 2α℃. While keeping the high temperature side at room temperature, by maintaining ΔT = 2α℃, a coolant reaching (room temperature - 2α)℃ is generated on the low temperature side.

9. The thermoelectric power generation system utilizing a thermoacoustic mechanism according to claim 6, characterized in that, The cooled coolant is stored in a coolant tank.

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