A thermoelectric power generation method utilizing waste heat, a thermoacoustic engine utilizing waste heat, and a thermoelectric power generation system utilizing a thermoacoustic engine.

Abstract

To provide a thermoelectric power generation method using waste heat, a thermoacoustic engine using waste heat, and a thermoelectric power generation system using a thermoacoustic engine, which can convert heat transfer into electricity by utilizing waste heat as a work source without the need to install equipment to dissipate cooling water and without using electricity such as heaters. [Solution] A thermoelectric power generation method utilizing waste heat, comprising a thermoacoustic engine (100) that takes heat as input and extracts sound waves, and a thermoacoustic cooler (200) that takes sound waves as input and generates a temperature difference, wherein one waste heat is supplied to the thermoacoustic engine (100) as a work source to extract sound waves, the extracted sound waves are input to the thermoacoustic cooler (200) to generate a coolant, and the other waste heat is introduced together with the generated coolant into a thermoelectric power generation module (40) to generate electricity by the Seebeck effect.

Description

Technical Field

[0001] The present invention relates to a thermoelectric power generation method using waste heat, a thermoacoustic engine using waste heat, and a thermoelectric power generation system using a thermoacoustic engine. Specifically, it is not necessary to provide equipment for radiating cooling water such as a cooling tower or a chiller, etc., and it does not use electric power or alternative refrigerants, etc. By using waste heat as a work source, it relates to a thermoelectric power generation method using waste heat that can convert the transfer of heat into electric power, a thermoacoustic engine using waste heat, and a thermoelectric power generation system using a thermoacoustic engine.

Background Art

[0002] According to the "Investigation of the Actual Situation of Exhaust Heat in Industrial Fields" (Non-Patent Document 1) published by NEDO (National Institute of Advanced Industrial Science and Technology) in March 2019, the total amount of exhaust gas heat of 15 industries with a large amount of heat utilization is 743 petajoules (PJ) / y, and 565 PJ / y, which accounts for 76% of it, is the exhaust gas heat amount below 200°C. It is stated that if this unused heat below 2°C can be effectively utilized, it can greatly contribute to the reduction of energy consumption in the domestic industrial fields.

[0003] Unused heat includes heat directly discarded from production equipment such as heat carried by exhaust gas and drainage, heat radiated from high-temperature equipment or products, heat discarded after heat recovery, heat discarded from exhaust gas treatment devices, heat discarded from cooling equipment, etc.

[0004] As a method for effectively utilizing mainly unused heat below 200°C, a method of generating electric power from heat using binary power generation or an organic Rankine cycle (ORC) is known. This method is to heat a medium (alternative refrigerant) with a low boiling point by a heating source to evaporate it and rotate a turbine with its vapor to generate electricity. This method has the disadvantages that the device is large and expensive, and since rotating machinery such as a working medium pump and a generator is used, maintenance is required and the running cost is high.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Patent No. 6649464 [Non-patent literature]

[0006] [Non-Patent Document 1] "Survey on the Actual State of Waste Heat in the Industrial Sector," March 2019: NEDO (New Energy and Industrial Technology Development Organization) [Non-Patent Document 2] Cryogenic Engineering, Vol. 43, No. 12, "Double-loop Stirling Cooler - 1. Workflow Measurement -" (Biwa) [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Focusing on the shortcomings of conventional methods, there is a need for a method that does not require large-scale equipment, does not use rotating machinery such as working fluid pumps or generators, does not require maintenance, and has low running costs. As a method to satisfy these requirements, the inventor focused on thermoelectric power generation technology utilizing thermoacoustic phenomena. Since thermoelectric power generation technology is a technology that converts heat transfer into electricity, power generation stops when a state of thermal equilibrium is reached where the temperatures of the high-temperature side and the low-temperature side are equal.

[0008] Especially on the low-temperature side (cooling side), using a liquid such as water, which has a higher thermal conductivity than a gas, will provide a more stable cooling effect, but there may be cases where a water source is not available nearby. In that case, it is necessary to add equipment to dissipate the heat from the cooling water, such as cooling towers or chillers, but this increases equipment costs. To avoid the increased burden, air cooling is sometimes used, but this does not guarantee sufficient heat dissipation, making it easy for thermal equilibrium to occur and preventing power generation. Furthermore, installing equipment to dissipate heat from the cooling water would consume energy, which presents another problem.

[0009] Patent Document 1, which aims to generate electricity efficiently using waste heat, discloses a power generation system using thermoelectric power generation and states that it can be applied to a wide range of systems, such as thermoacoustic power generation. However, it does not disclose any specific details, nor does it disclose any means to solve the above problem.

[0010] The inventors focused on a thermoacoustic engine and a thermoacoustic cooler as a thermoacoustic engine, and found that by supplying waste heat as a work source to the thermoacoustic engine to extract sound waves, and then inputting the extracted sound waves into the thermoacoustic cooler to generate a coolant, cooling equipment is unnecessary, and the above major problem can be solved. Furthermore, it was discovered that waste heat can be used to reduce costs when manufacturing the coolant. Non-patent document 2 discloses a double-loop type thermoacoustic cooler that uses a heater as a heat source to convert energy from heat to sound waves in a prime mover loop and a cooler loop to convert energy from sound waves to heat. However, using a heater as a heat source has the disadvantage of significantly increasing costs.

[0011] Therefore, the object of the present invention is to provide a thermoelectric power generation method using waste heat, a thermoacoustic engine using waste heat, and a thermoelectric power generation system using a thermoacoustic engine, which can convert heat transfer into electricity by utilizing waste heat as a work source without the need to install equipment to dissipate cooling water and without using electricity such as heaters.

[0012] Another objective of the present invention is to provide a thermoelectric power generation method utilizing waste heat, a thermoacoustic engine utilizing waste heat, and a thermoelectric power generation system utilizing a thermoacoustic engine, which achieve stable operation of thermoelectric power generation while also achieving clean energy recovery.

[0013] Furthermore, another objective of the present invention is to provide a thermoelectric power generation system using a thermoacoustic engine that can keep energy costs low because it uses at least two waste heat sources as work sources.

[0014] Furthermore, other problems of the present invention will become clear from the following description. [Means for solving the problem]

[0015] The above problems are solved by the following inventions. 1. The system comprises a thermoacoustic engine (100) that takes heat as input and extracts sound waves, and a thermoacoustic cooler (200) that takes the sound waves as input and generates a temperature difference. One waste heat is supplied to the thermoacoustic engine (100) as a work source to extract sound waves. The extracted sound waves are input to the thermoacoustic cooler (200) to generate a cooling liquid. A thermoelectric power generation method utilizing waste heat, characterized in that another waste heat is introduced into the thermoelectric power generation module (40) together with the generated coolant, and electricity is generated by the Seebeck effect. 2. A thermoacoustic engine loop (10) consisting of a loop-shaped pipe equipped with the aforementioned thermoacoustic engine (100), A thermoacoustic cooler loop (20), which consists of a loop-shaped pipe equipped with the aforementioned thermoacoustic cooler (200), is connected by a waveguide (30) filled with gas inside. By supplying one source of waste heat to the thermoacoustic engine (100) to generate sound waves, and then supplying them to the thermoacoustic cooler (200) via the waveguide, a coolant is generated. The thermoelectric power generation method using waste heat according to claim 1, characterized in that another waste heat is introduced into the thermoelectric power generation module (40) together with the generated coolant, and electricity is generated by the Seebeck effect. 3. A thermoacoustic engine (100) that takes heat as input and extracts sound waves, and a thermoacoustic cooler (200) that takes the sound waves as input and generates a temperature difference, are connected via a waveguide (30) that transmits sound waves. The thermoacoustic engine (100) comprises a heat accumulator (101) having pores and connected at both ends to the waveguide (30), and a low-temperature side heat exchanger (102) and a high-temperature side heat exchanger (103) arranged to sandwich both sides of the heat accumulator (101), At least one waste heat is input to the high-temperature side heat exchanger (103) as a work source, a temperature difference is provided on both sides of the heat accumulator (201), the gas inside the heat accumulator (101) expands when moving to the high-temperature side and contracts when moving to the low-temperature side, repeating expansion and contraction to generate sound waves. The thermoacoustic cooler (200) that receives the sound waves generated by the thermoacoustic engine (100) via the waveguide (30) performs heat exchange associated with the expansion and compression of the gas near the pore wall surface of the heat accumulator (201), generates 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 generates a coolant for thermoelectric power generation from the low-temperature side heat exchanger (203). A thermoacoustic engine using waste heat, characterized in that. 4. The thermoacoustic engine using waste heat according to item 3 above, characterized by comprising a coolant tank (204) for storing the coolant. 5. The thermoacoustic engine using waste heat according to item 3 above, characterized in that the inside of the waveguide (30) is filled with one or more gases composed of helium, argon or air. 6. The thermoacoustic engine using waste heat according to any one of items 3 to 5 above, and A thermoelectric power generation system using a thermoacoustic engine, characterized in that waste heat is passed through the high-temperature side of the thermoelectric power generation module unit (40), and the coolant generated by the thermoacoustic cooler (200) is passed through the low-temperature side, and electric power is generated by the Seebeck effect. 7. The thermoelectric power generation system using the thermoacoustic engine according to item 6 above, characterized in that the coolant exiting the low-temperature side of the thermoelectric power generation module unit (40) is cooled by passing through the low-temperature side heat exchanger (203) after passing through the high-temperature side heat exchanger (202) of the thermoacoustic cooler (200). 8. In the thermoacoustic cooler (200), when the high-temperature side is adjusted to +α °C, the low-temperature side is adjusted to -α °C, and ΔT is adjusted to 2α °C, and the high-temperature side is kept at room temperature, by maintaining ΔT = 2α °C, a coolant reaching (room temperature - 2α) °C is generated on the low-temperature side. A thermoelectric power generation system using the thermoacoustic engine according to item 6 above, characterized in that. 9. The thermoelectric power generation system using a thermoacoustic engine according to claim 6, characterized in that the cooled coolant is stored in a coolant tank. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a thermoelectric power generation method using waste heat, a thermoacoustic engine using waste heat, and a thermoelectric power generation system using a thermoacoustic engine, which can convert heat transfer into electricity by utilizing waste heat as a work source without the need to install equipment to dissipate heat from cooling water and without using electricity such as heaters.

[0017] Furthermore, according to the present invention, it is possible to provide a thermoelectric power generation method using waste heat, a thermoacoustic engine using waste heat, and a thermoelectric power generation system using a thermoacoustic engine, which achieve stable operation of thermoelectric power generation while recovering clean energy. [Brief explanation of the drawing]

[0018] [Figure 1] Block flow diagram showing one embodiment of the thermoelectric power generation system of the present invention. [Figure 2] Schematic cross-sectional view showing an embodiment of a heat storage device. [Modes for carrying out the invention]

[0019] Preferred embodiments of the present invention will be described below. The present invention relates to an electric power generation method, a thermoacoustic engine utilizing waste heat, and a thermoelectric power generation system utilizing a thermoacoustic engine, which is a thermoelectric power generation system that uses a thermoacoustic engine capable of converting heat transfer into electricity by utilizing waste heat as a work source.

[0020] This invention demonstrates the effectiveness of utilizing unused heat (industrial waste heat below 300°C that is otherwise discarded).

[0021] The thermoelectric power generation method of the present invention involves supplying one waste heat source to a thermoacoustic engine to extract sound waves, inputting the extracted sound waves into a thermoacoustic cooler to generate a coolant, and introducing the other waste heat source together with the generated coolant into a thermoelectric power generation module to generate electricity through the Seebeck effect. In other words, this method is a power generation technique that converts thermal energy into electrical energy by creating a potential difference by bringing one junction of a thermoelectric power generation module into contact with a high heat source and the other with a low heat source, and utilizing the Seebeck effect (the reverse of the Peltier effect).

[0022] A thermoacoustic engine is a technology that utilizes thermoacoustic phenomena to enable heat engines that extract work from heat input via sound waves, or heat pumps (cooling and heating) that draw heat from sound waves.

[0023] Thermoelectric power generation is a technology that converts heat transfer into electricity, so power generation stops when thermal equilibrium is reached, where the temperatures of the high-temperature side and the low-temperature side are equal. In particular, a more stable cooling effect can be obtained by using a liquid such as water, which has a higher thermal conductivity than a gas, on the low-temperature side (cooling side). If there is no water source nearby, air cooling may be used to avoid additional burdens such as the need to add equipment to dissipate the cooling water, such as a cooling tower, but in this case, sufficient heat dissipation cannot be ensured, and thermal equilibrium is likely to occur.

[0024] In this invention, even in environments without a cooling source such as water, it is possible to achieve stable operation of thermoelectric power generation while also achieving clean energy recovery by combining it with a thermoacoustic cooler that operates as a refrigerator using waste heat as a work source, without using electricity or fluorocarbons, and without requiring cooling water equipment such as cooling towers or chillers, even in environments without a cooling source such as water.

[0025] Furthermore, this invention enables the construction of a thermoelectric power generation system using a thermoacoustic engine that utilizes at least two waste heat sources as work sources. Thermoelectric power generation technology is highly versatile as a device because it can generate electricity by arranging the device to come into contact with various heat sources. Moreover, this invention allows for increasing power output by simply increasing the number of units installed, making it easier to balance cost and power generation, and facilitating expansion.

[0026] Furthermore, this invention does not require an external liquid cooling source and generates cooling water from waste heat using a thermoacoustic cooler (cooler), achieving stable power generation. Since both the thermoacoustic cooler and the thermoelectric power generation module have no moving parts in the main body, maintenance costs and running costs can be reduced.

[0027] Next, an embodiment of the thermoelectric power generation method and thermoelectric power generation system of the present invention will be described based on Figure 1.

[0028] (Source of work) This embodiment is an example of using two waste heat sources as work sources: high-temperature waste heat (1) supplied to a thermoacoustic engine to generate coolant (cooling water), and high-temperature waste heat (2) supplied to a thermoelectric power generation module to generate electricity. High-temperature waste heat (1) and high-temperature waste heat (2) may be the same type of waste heat or different types of waste heat. For example, if the high-temperature waste heat generated from a waste incinerator (A), which is not shown in the diagram, is used as high-temperature waste heat (1) and high-temperature waste heat (2), it is the same waste heat. However, if the waste heat generated from incinerator (A) is used as high-temperature waste heat (1) and the waste heat generated from incinerator (B) is used as high-temperature waste heat (2), they are different types of waste heat. In both cases, these are examples of using two types of waste heat as work sources. The waste heat may be waste heat generated from two or more sources, but when used in the system of the present invention, it is preferable that the system is configured to use high-temperature waste heat (1) supplied to a thermoacoustic engine to generate a coolant and high-temperature waste heat (2) supplied to a thermoelectric power generation module to generate electricity as work sources.

[0029] (Unused heat) Unused heat includes heat directly discarded from production facilities, such as heat contained in exhaust gases and wastewater, heat radiated from high-temperature equipment or products, heat discarded after heat recovery, heat discarded from exhaust gas treatment equipment, and heat discarded from cooling equipment. In the system of the present invention, it is preferable that the waste heat includes unused heat such as industrial waste heat that is discarded at a temperature of 300°C or lower, as described above. The high-temperature waste heat (1) supplied to the thermoacoustic engine to generate coolant and the high-temperature waste heat (2) supplied to the thermoelectric power generation module to generate electricity may both be unused heat, or only one of them may be unused heat and the other the remaining one being high-temperature waste heat. In the present invention, it is preferable to collect and separate the waste heat generated from multiple waste heat generation points and use it as the high-temperature waste heat (1) and high-temperature waste heat (2) described above.

[0030] (W-loop) In Figure 1, the thermoacoustic engine that generates the coolant is explained using a W (double) loop type as an example. As shown in the figure, the W-loop type consists of a thermoacoustic engine loop 10 made of loop-shaped piping, a thermoacoustic cooler loop 20 made of loop-shaped piping, and a waveguide 30 connecting the thermoacoustic engine loop 10 and the thermoacoustic cooler loop 20. The piping constituting the thermoacoustic engine loop 10 and the thermoacoustic cooler loop 20 has the same configuration as the waveguide 30, communicates with the waveguide 30, and is filled with gas. The gas filled inside will be described later. By configuring such a W-loop, it became possible to functionally separate the two types of waste heat. This is a unique method of the present invention. In examples using heaters, such as Non-Patent Document 2, there is no need for functional separation. The thermoacoustic engine loop 10 is equipped with a thermoacoustic engine 100, which is a device that takes heat as input and extracts work as sound waves. The thermoacoustic cooler loop 20 is also equipped with a thermoacoustic cooler 200, which is a device that generates a temperature difference by inputting sound waves.

[0031] (Thermoacoustic engines and thermoacoustic coolers) The thermoacoustic engine 100 consists of a heat accumulator 101 having pores, and a low-temperature side heat exchanger 102 and a high-temperature side heat exchanger 103 arranged to sandwich the heat accumulator 101. The thermoacoustic cooler 200 consists of a heat accumulator 201 having pores, and a high-temperature side heat exchanger 202 and a low-temperature side heat exchanger 203 arranged to sandwich the heat accumulator 201.

[0032] (heat storage) Based on Figure 2, we will explain the heat storage device. The heat accumulator 101 is installed in the thermoacoustic engine 100, and the heat accumulator 201 is installed in the thermoacoustic cooler 200 (see Figure 1). The drawing shows a structure in which a heat accumulator 101 is provided in the thermoacoustic engine 100.

[0033] In Figure 2, a low-temperature heat exchanger 102 is provided on one side (left side in the drawing) of the heat accumulator 101, and a high-temperature heat exchanger 103 is provided on the other side (right side in the drawing), with the low-temperature heat exchanger 102 and the high-temperature heat exchanger 103 flanking the heat accumulator 101 from both sides. Sub-waveguides 302 and 301 are provided on the outside of the low-temperature heat exchanger 102 and the high-temperature heat exchanger 103, respectively.

[0034] The low-temperature heat exchanger 102 and the high-temperature heat exchanger 103 are not particularly limited, but for example, tube-type ones can be used. In that case, multiple heat exchange tubes may be arranged horizontally, with one end opening to the sub-waveguide side and the other end opening to the heat accumulator side. Cooling liquid is introduced around the outer circumference of the multiple heat exchange tubes in the low-temperature heat exchanger 102, and high-temperature waste heat is introduced in the high-temperature heat exchanger 103.

[0035] The heat accumulator only needs to have pores, but it may also have a structure in which ceramic or SUS meshes are stacked in a honeycomb shape, for example. Preferably, the pores are continuous, and it is preferable that the structure allows for repeated expansion and contraction of the gas inside. Furthermore, it is preferable that the thermoacoustic engine including the heat accumulator, the thermoacoustic cooler, and the waveguide connected thereto have a structure that can pressurize the gas-filled interior. Examples of gases used inside include, but are not limited to, hydrogen, helium, argon, nitrogen, and air.

[0036] (waveguide) As shown in Figure 1, the thermoacoustic engine loop 10, consisting of the thermoacoustic engine 100, and the thermoacoustic cooler loop 20, consisting of the thermoacoustic cooler 200, are connected by a main wave tube 30. The interior is filled with one of the following gases, as described above: hydrogen, helium, argon, or air. The gas inside is preferably one with high thermal conductivity, and higher pressure is preferable as it leads to higher efficiency. However, considering not only thermal conductivity but also ease of handling and cost of acquisition, argon, for example, is preferred. Furthermore, if the internal gas pressure exceeds 1 MPa, it becomes necessary to increase the pressure resistance of the waveguide enclosing the gas, and the installation of qualified personnel for handling will also be required. From the perspective of the potential increase in manufacturing costs, maintenance costs, and other expenses, it is preferable that the internal gas pressure be less than 1 MPa. In this embodiment, it is also preferable to arrange five waveguides containing, for example, a gas at 200 kPa in parallel. This makes it possible to achieve an effect equivalent to that of using a gas at a higher pressure.

[0037] In the thermoacoustic engine 100, the high-temperature heat exchanger 103 is connected to the main waveguide 30 via a secondary waveguide 301, and the low-temperature heat exchanger 102 is connected to the main waveguide 30 via a secondary waveguide 302. In the thermoacoustic cooler 200, the high-temperature side heat exchanger 202 is connected to the main waveguide 30 via a secondary waveguide 303, and the low-temperature side heat exchanger 203 is connected to the main waveguide 30 via a secondary waveguide 304.

[0038] (Generation of sound waves) High-temperature waste heat (1) is input to the high-temperature side heat exchanger 103 of the thermoacoustic engine 100 from the waste heat pipe 3, and cooling water is introduced to the low-temperature side heat exchanger 102 from the coolant tank 204 via the cooling water pipe 210. This creates a temperature difference between the high-temperature side heat exchanger 103 and the low-temperature side heat exchanger 102. When the low-temperature side heat exchanger 102 is kept near room temperature, the gas inside the heat regenerator 101 moves to the high-temperature side and expands, and moves to the low-temperature side and contracts. As this expansion and contraction repeats, thermoacoustic self-excited oscillation occurs when the critical temperature difference is exceeded, generating sound waves (pressure oscillations). The waste heat input to the high-temperature side heat exchanger 103 of the thermoacoustic engine 100 is used up and becomes low-temperature waste heat, which is then released through the waste heat pipe 5. The cooling water supplied to the low-temperature side heat exchanger 102 of the thermoacoustic engine 100 is returned to the coolant tank 204 via the cooling water piping 211.

[0039] (Sound wave propagation) Sound waves generated by the thermoacoustic engine 100 propagate through the lead wave tube 30 and reach the thermoacoustic cooler 200, where heat exchange (Carnot cycle) occurs near the pore walls of the heat accumulator 201 due to gas expansion and compression.

[0040] (Coolant generation) The heat exchange described above generates a temperature difference between the heat exchangers 202 and 203 at both ends of the heat storage unit 201. Specifically, the cooling water used in the thermoelectric power generation module section 40 (described later) is sent to the high-temperature side heat exchanger 202 of the thermoacoustic cooler 200 via the cooling water piping 213. The cooling water that has passed through the high-temperature side heat exchanger 202 is introduced to the low-temperature side heat exchanger 203 via the cooling water piping 214. At this time, by utilizing the sound wave energy generated by the thermoacoustic engine 100, the system attempts to maintain the temperature difference between the high-temperature side heat exchanger 202 and the low-temperature side heat exchanger 203 by the amount of sound wave energy, thus cooling the cooling water that passes through the low-temperature side heat exchanger 203. The cooling water that has passed through the low-temperature side heat exchanger 203 is returned to the coolant tank 204 via the cooling water piping 215. For example, if the high temperature side is +50°C and the low temperature side is -50°C, then ΔT is 100°C. If the high temperature side is kept at room temperature of 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. In other words, in the thermoacoustic cooler 200, when the temperature is +α°C on the high-temperature side and -α°C on the low-temperature side, ΔT is 2α°C. If the high-temperature side is at room temperature (room temperature being 20°C), then by maintaining ΔT 2α°C, a coolant is generated on the low-temperature side that reaches (20°C (room temperature) - 2α)°C.

[0041] (Thermoelectric power generation) Next, the power generation system in the thermoelectric power generation module 40 will be described. The thermoelectric power generation module 40 converts heat into electricity by using the Seebeck effect to make one side hot and the other side cold. In this embodiment, high-temperature waste heat (2) is passed through the waste heat pipe 4 to the high-temperature side 40a, and coolant (cooling water) generated by the thermoacoustic cooler 200 and stored in the coolant tank 204 is passed through the cooling water pipe 212 to the low-temperature side 40b. This creates a temperature difference between the high-temperature side 40a and the low-temperature side 40b, and electricity is generated by the Seebeck effect. The waste heat that has passed through the high-temperature side 40a of the thermoelectric power generation module section 40 becomes low-temperature and is released as low-temperature waste heat through the waste heat pipe 6. The cooling water exiting the low-temperature side 40b of the thermoelectric power generation module 40 passes through the high-temperature side heat exchanger 202 of the thermoacoustic cooler 200, and then passes through the low-temperature side heat exchanger 203 to be cooled.

[0042] (Coolant regeneration) The coolant, heated by the power generated by the thermoelectric power generation module 40, exits the low-temperature side 40b, passes through the high-temperature side heat exchanger 202 of the thermoacoustic cooler 200, and is then cooled via the low-temperature side heat exchanger 203. This regenerated coolant is stored in the coolant tank 204 via the cooling water piping 215 and can be transferred back to the thermoelectric power generation module 40 for reuse. [Explanation of Symbols]

[0043] 3. Waste heat piping 4. Waste heat piping 10 Thermoacoustic Engine Loop 100 Thermoacoustic Engine 101 Heat storage 102 Low temperature side heat exchanger 103 High temperature side heat exchanger 20 Thermoacoustic Cooler Loop 200 Thermoacoustic Cooler 201 Heat storage device 202 High temperature side heat exchanger 203 Low temperature side heat exchanger 204 Coolant Tank 210, 211, 212, 213, 214, 215 Cooling water piping 30 Waveguide (main waveguide) 301 Sub-waveguide 302 Sub-waveguide 303 Sub-waveguide 304 Sub-waveguide 40 Thermoelectric power generation module section 40a High temperature side 40b Low temperature side

Claims

1. The system comprises a thermoacoustic engine (100) that takes heat as input and extracts sound waves, and a thermoacoustic cooler (200) that takes the sound waves as input and generates a temperature difference. One waste heat is supplied to the thermoacoustic engine (100) as a work source to extract sound waves. The extracted sound waves are input to the thermoacoustic cooler (200) to generate a cooling liquid. A thermoelectric power generation method utilizing waste heat, characterized in that another waste heat is introduced into the thermoelectric power generation module (40) together with the generated coolant, and electricity is generated by the Seebeck effect.

2. A thermoacoustic engine loop (10) consisting of a loop-shaped pipe equipped with the thermoacoustic engine (100), A thermoacoustic cooler loop (20), which consists of a loop-shaped pipe equipped with the aforementioned thermoacoustic cooler (200), is connected by a waveguide (30) filled with gas inside. By supplying one source of waste heat to the thermoacoustic engine (100) to generate sound waves, and then supplying them to the thermoacoustic cooler (200) via the waveguide, a coolant is generated. The thermoelectric power generation method using waste heat according to claim 1, characterized in that another waste heat is introduced into the thermoelectric power generation module (40) together with the generated coolant, and electricity is generated by the Seebeck effect.

3. A thermoacoustic engine (100) that takes heat as input and extracts sound waves, and a thermoacoustic cooler (200) that takes the sound waves as input and generates a temperature difference, are connected via a waveguide (30) that transmits sound waves. The thermoacoustic engine (100) comprises a heat accumulator (101) having pores and connected at both ends to the waveguide (30), and a low-temperature side heat exchanger (102) and a high-temperature side heat exchanger (103) arranged to sandwich both sides of the heat accumulator (101), At least one waste heat source is input to the high-temperature side heat exchanger (103) as a work source, a temperature difference is created on both sides of the heat accumulator (201), and when the gas inside the heat accumulator (101) moves to the high-temperature side it expands and when it moves to the low-temperature side it contracts, and the repeated expansion and contraction generates sound waves. A thermoacoustic engine utilizing waste heat, characterized in that the thermoacoustic cooler (200), which receives sound waves generated by the thermoacoustic engine (100) via the waveguide (30), performs heat exchange due to gas expansion and compression near the pore wall surface 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. A thermoacoustic engine utilizing waste heat according to claim 3, characterized in that it comprises a coolant tank (204) for storing the coolant.

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

6. A thermoacoustic engine utilizing waste heat as described in any of claims 3 to 5, A thermoelectric power generation system utilizing a thermoacoustic engine, characterized in that it generates electricity by the Seebeck effect by passing waste heat through the high-temperature side of the thermoelectric power generation module (40) and passing a coolant generated by the thermoacoustic cooler (200) through the low-temperature side.

7. The thermoelectric power generation system using a thermoacoustic engine according to claim 6, characterized in that the coolant exiting the low-temperature side of the thermoelectric power generation module (40) passes through the high-temperature side heat exchanger (202) of the thermoacoustic cooler (200) and is then cooled by passing through the low-temperature side heat exchanger (203).

8. The thermoelectric power generation system using a thermoacoustic engine according to claim 6, characterized in that, in the thermoacoustic cooler (200), when the high temperature side is adjusted to +α°C, the low temperature side to -α°C, and ΔT to 2α°C, and the high temperature side is kept at room temperature, by maintaining ΔT = 2α°C, a coolant that reaches (room temperature - 2α)°C is generated on the low temperature side.

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

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