Decoupling type liquid air energy storage cold-electricity-gas triple generation device and method

Abstract

The invention discloses a decoupling type liquid air energy storage cold-electricity-gas triple co-generation device and method, and belongs to the technical field of heat exchange equipment. The device comprises a liquid air storage tank, a temperature difference power generation module, a heater, an expansion generator and a multi-stream heat exchanger, and liquid air in the liquid air storage tank is conveyed to the temperature difference power generation module through a low-temperature pump; the heated gas-liquid mixture is heated by a heater and then enters an expansion power generator for power generation; exhaust gas of the expansion generator enters the multi-stream heat exchanger, and dry and clean air circulated between the multi-stream heat exchanger and the thermoelectric power generation module for multiple times is conveyed to a user. Liquid air evaporation and gasification high-grade cold energy is obtained through temperature difference power generation, low-grade cold energy obtained after liquid air gasification is fully utilized to supply cold to users through the temperature difference power generation module and a multi-stream air flow channel heat exchange design in the multi-stream heat exchanger, gradient utilization of cooling capacity is achieved, cold, power and gas triple generation can be achieved, and the energy consumption is reduced. And various energy consumption requirements of users are met, and the energy recovery efficiency is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat exchange equipment, and particularly relates to a decoupled liquid air energy storage cold-electricity-gas combined supply device and method. Background Art

[0002] Liquid air energy storage technology is a new cryogenic energy storage technology with air as the energy storage medium. It can be used to solve the intermittency problems of renewable energy (such as wind energy and solar energy) in remote areas, islands, etc. By storing and releasing energy, the utilization rate of renewable energy can be improved. Liquid air energy storage has the characteristics of high energy storage density, strong scalability, flexible site selection, environmental friendliness, high safety, and long system life, and has received extensive attention.

[0003] In small-scale application scenarios, if a coupled liquid air energy storage independent power station scheme is adopted, the round-trip efficiency of valley electricity-peak electricity alone is relatively low. If only limited to improving the energy storage power generation and round-trip conversion efficiency, the system structure is more complex, the initial investment is higher, and the levelized cost of energy storage (LCOE) increases. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a decoupled liquid air energy storage cold-electricity-gas combined supply device and method.

[0005] To achieve the above object, the technical solutions adopted by the present invention are as follows: A decoupled liquid air energy storage cold-electricity-gas combined supply device includes a liquid air storage tank, a thermoelectric generation module, a heater, an expansion generator, and a multi-stream heat exchanger. The liquid air in the liquid air storage tank is transported to the thermoelectric generation module through a cryogenic pump. The gas-liquid mixture output by the thermoelectric generation module is heated by the heater and then enters the expansion generator for power generation. The return air of the expansion generator enters the multi-stream heat exchanger and is circulated multiple times between the multi-stream heat exchanger and the thermoelectric generation module, and the dry and clean air formed is transported to users.

[0006] Further, a heat exchanger is provided between the thermoelectric generation module and the heater. The low-temperature zone output end of the thermoelectric generation module is connected to the medium inlet of the heat exchanger, and the medium outlet of the heat exchanger is connected to the inlet of the heater. The return air of the expansion generator is connected to the air inlet of the heat exchanger, and the air outlet of the heat exchanger is connected to the multi-stream heat exchanger.

[0007] Further, the return water pipe of the user is connected to the multi-stream heat exchanger and enters the water supply pipeline of the user after being cooled by the multi-stream heat exchanger.

[0008] Further, the thermoelectric power generation module includes a low-temperature region, a high-temperature region, and a power generation layer therebetween. The power generation layer is provided with a thermoelectric power generation component. The low-temperature region is provided with a low-temperature flow channel A, and the high-temperature region is provided with a high-temperature flow channel A in which multiple flow streams are arranged in parallel. The number of flow streams of the high-temperature flow channel A is N≥2, which are respectively the first high-temperature flow channel A, the second high-temperature flow channel A... the Nth high-temperature flow channel A; the multiple flow streams of the high-temperature flow channel A are correspondingly connected to multiple inlets and outlets of the multi-stream heat exchanger.

[0009] Further, the multi-stream heat exchanger includes a high-temperature flow channel B and multiple low-temperature flow channels B arranged in parallel. The multiple low-temperature flow channels B are arranged in parallel with multiple flow streams; the number of flow streams of the low-temperature flow channel B is N + 1, which are respectively the first low-temperature flow channel B, the second low-temperature flow channel B... the (N + 1)th low-temperature flow channel B; the N flow streams of the high-temperature flow channel A are correspondingly connected to the inlets and outlets of the low-temperature flow channel B to form a gas path for circulating cooling, and the output end of the gas path is connected to the user; The return water pipe of the user is connected to the input end of the high-temperature flow channel B, and the output end of the high-temperature flow channel B is connected to the water supply pipeline of the user through a water pump.

[0010] Further, the connection sequence of the high-temperature flow channel A of the thermoelectric power generation module and the low-temperature flow channel B of the multi-stream heat exchanger is as follows: The air outlet of the heat exchanger is connected to the input end of the first low-temperature flow channel B, the output end of the first low-temperature flow channel B is connected to the input end of the first high-temperature flow channel A, the output end of the first high-temperature flow channel A is connected to the input end of the second low-temperature flow channel B, the output end of the second low-temperature flow channel B is connected to the input end of the second high-temperature flow channel A, the output end of the second high-temperature flow channel A is connected to the input end of the third low-temperature flow channel B, the output end of the third low-temperature flow channel B is connected to the input end of the fourth high-temperature flow channel A,... the output end of the Nth low-temperature flow channel B is connected to the input end of the Nth high-temperature flow channel A, the output end of the Nth high-temperature flow channel A is connected to the input end of the (N + 1)th low-temperature flow channel B, and the output end of the (N + 1)th low-temperature flow channel B is connected to the user.

[0011] Further, the direct current generated by the thermoelectric power generation module and the alternating current generated by the expansion generator are both transmitted to the electrical equipment of the user.

[0012] The present invention also provides a decoupled liquid air energy storage cold-electricity-gas combined supply method, including the following steps: Assemble the above-mentioned decoupled liquid air energy storage cold-electricity-gas combined supply device; During the low electricity consumption period, store the excess electricity in the liquid air storage tank in the form of liquid air; Start the cryogenic pump to transport the liquid air in the liquid air storage tank to the low-temperature side of the thermoelectric generation module. The liquid air outputting high-grade cold energy undergoes a liquid-vapor phase change process in the thermoelectric generation module, and then enters the heat exchanger to output low-grade cold energy, and the air temperature at the outlet of the heat exchanger medium increases; the thermoelectric generation module generates direct current by using the temperature difference for power generation; The air output from the heat exchanger medium is reheated to a high temperature by the heater and then enters the expansion generator for expansion power generation to generate alternating current; The return air output from the expansion generator enters the heat exchanger to absorb low-grade cold energy, and then enters the low-temperature flow channel B of the multi-stream heat exchanger to exchange heat with the user's circulating water and release cold energy and the temperature increases; then it enters the high-temperature area of the thermoelectric generation module to obtain cold energy, and then flows back to the low-temperature flow channel B of the multi-stream heat exchanger to continue cooling the user's circulating water; the return air circulates N times between the low-temperature flow channel B of the multi-stream heat exchanger and the high-temperature area of the thermoelectric generation module, and then is supplied to the user as dry and clean air for air conditioning; The direct current generated by the thermoelectric generation module and the alternating current generated by the expansion generator are supplied for the user to use; The return water of the user flows through the high-temperature flow channel B of the multi-stream heat exchanger, exchanges heat with the multi-stream return air in the low-temperature flow channel B, is cooled and then pressurized by the water pump to supply the user with cold water.

[0013] Compared with the prior art, the technical progress achieved by the present invention lies in: In the present invention, by flowing the liquid air and the return air through the thermoelectric generation module, using the temperature difference between the two for power generation to supply direct current, and after the air is heated, it enters the expansion generator to supply alternating current, and the exhaust gas after power generation circulates between the thermoelectric generation module and the multi-stream heat exchanger, realizing the recovery and supply of cold energy, and providing dry air for the user after the cooling is completed, realizing combined cooling, power and gas supply. The present invention obtains the high-grade cold energy of the evaporation and gasification of liquid air through thermoelectric generation, and through the heat exchange design of the multi-stream air flow channels inside the thermoelectric generation module and the multi-stream heat exchanger, makes full use of the lower-grade cold energy after the evaporation and gasification of liquid air to supply cold to the user, realizing the cascade utilization of cold energy; the dry and clean cold air after the cascade recovery and utilization of cold energy is supplied to the user to realize air conditioning. Using the present invention can meet the various energy consumption needs of users, and the energy recovery efficiency is significantly improved. Description of the Drawings

[0014] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention.

[0015] In the drawings: Figure 1 is a structural schematic diagram of a decoupled liquid air energy storage combined cooling, power and gas supply device provided by an embodiment of the present invention; In the figure: 1. Liquid air storage tank; 2. Cryogenic pump; 3. Thermoelectric generation module, 3-1. Power generation layer, 3-2. Low-temperature zone, 3-3. High-temperature zone; 4. Heat exchanger; 5. Heater; 6. Expansion generator; 7. Multi-stream heat exchanger, 7-1. High-temperature flow channel B, 7-2. Low-temperature flow channel B; 8. Water pump; 9. User. Specific embodiments

[0016] The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below with reference to the accompanying drawings.

[0017] As Figure 1 shown, a decoupled liquid air energy storage cold-electricity-gas combined supply device provided by an embodiment of the present invention includes a liquid air storage tank 1, a thermoelectric generation module 3, a heat exchanger 4, a heater 5, an expansion generator 6, and a multi-stream heat exchanger 7. The liquid air in the liquid air storage tank 1 is transported to the thermoelectric generation module 3 through a cryogenic pump 2. The output end of the low-temperature zone of the thermoelectric generation module 3 is connected to the medium inlet of the heat exchanger 4, and the medium outlet of the heat exchanger 4 is connected to the inlet of the heater 5; the air output by the heat exchanger 4 is heated by the heater 5 and then enters the expansion generator 6 for power generation; the return air of the expansion generator 6 is connected to the air inlet of the heat exchanger 4, and the air outlet of the heat exchanger 4 is connected to the multi-stream heat exchanger 7. The air circulates between the multi-stream heat exchanger 7 and the thermoelectric generation module 3 for multiple times and then forms dry and clean air to be transported to the user 9 to adjust the air. The thermoelectric generation module 3 generates direct current by using the temperature difference between the liquid air and the return air, and the expansion generator supplies alternating current. Both the generated direct current and alternating current are transported to the electrical equipment of the user.

[0018] Further optimizing the above solution, the return water pipe of the user 9 is connected to the multi-stream heat exchanger 7, and after circulating and cooling through the multi-stream heat exchanger 7, it enters the water supply pipeline of the user 9 to provide cold water for the user. This solution has the advantages of simple structure and high energy recovery efficiency. The high-grade evaporation latent heat of the liquid air is used for thermoelectric generation, and the low-grade sensible heat is used for circulating cooling to realize the cascade utilization of cooling capacity. The present invention can simultaneously provide cold water, clean air, and power supply for users, realizing cold-electricity-gas combined supply and meeting the various energy consumption needs of users.

[0019] In a specific embodiment of the present invention, as Figure 1As shown in the figure, the thermoelectric power generation module 3 includes a low-temperature area 3-2, a high-temperature area 3-3, and a power generation layer 3-1 therebetween. The power generation layer 3-1 is provided with a thermoelectric power generation component. The low-temperature area 3-2 is provided with a low-temperature flow channel A, and the high-temperature area 3-3 is provided with a high-temperature flow channel A in which multiple flow streams are arranged in parallel. Moreover, the multiple flow streams of the high-temperature flow channel A are all connected in parallel to the power generation layer 3-1. Power generation is achieved through the temperature difference formed on both sides of the power generation layer 3-1 between the multiple flow streams of the high-temperature flow channel A and the low-temperature area 3-2. The number of flow streams of the high-temperature flow channel A is N≥2, which are respectively the first high-temperature flow channel A, the second high-temperature flow channel A... the Nth high-temperature flow channel A. Among them, the thermoelectric power generation component is formed by connecting a plurality of semiconductor thermoelectric power generation chips in parallel or in series.

[0020] Among them, the multi-stream heat exchanger 7 includes a high-temperature flow channel B7-1 and multiple low-temperature flow channels B7-2 arranged in parallel. The multiple low-temperature flow channels B7-2 are arranged in parallel with multiple flow streams. The return water pipe of the user 9 is connected to the input end of the high-temperature flow channel B7-1, and the output end of the high-temperature flow channel B7-1 is connected to the water supply pipeline of the user 9 through a water pump 8.

[0021] The number of flow streams of the low-temperature flow channel B7-2 is N + 1, which are respectively the first low-temperature flow channel B, the second low-temperature flow channel B... the (N + 1)th low-temperature flow channel B from top to bottom. The N flow streams of the high-temperature flow channel A are connected to the inlets and outlets of the low-temperature flow channel B7-2 correspondingly to form a gas path for circulating cooling, so as to circulate and cool the air. Finally, the output end of the gas path is connected to the user 9 to provide the user with dry and clean low-temperature air, realizing temperature and humidity adjustment.

[0022] During specific production, the connection sequence of the high-temperature flow channel A of the thermoelectric power generation module 3 and the low-temperature flow channel B of the multi-stream heat exchanger 7 is as follows: The air outlet of the heat exchanger 4 is connected to the input end of the first low-temperature flow channel B. The output end of the first low-temperature flow channel B is connected to the input end of the first high-temperature flow channel A. The output end of the first high-temperature flow channel A is connected to the input end of the second low-temperature flow channel B. The output end of the second low-temperature flow channel B is connected to the input end of the second high-temperature flow channel A. The output end of the second high-temperature flow channel A is connected to the input end of the third low-temperature flow channel B. The output end of the third low-temperature flow channel B is connected to the input end of the fourth high-temperature flow channel A,... The output end of the Nth low-temperature flow channel B is connected to the input end of the Nth high-temperature flow channel A. The output end of the Nth high-temperature flow channel A is connected to the input end of the (N + 1)th low-temperature flow channel B, and the output end of the (N + 1)th low-temperature flow channel B is connected to the user 9. Figure 1 In the illustrated embodiment, N is taken as 4, that is, there are 4 high-temperature flow channels A and 5 low-temperature flow channels B.

[0023] The exhaust gas after expansion power generation serves as a circulating fluid (return air), and successively passes through the low-temperature flow channel B of the multi-stream heat exchanger 7 and the high-temperature flow channel A of the thermoelectric generation module 3. In the high-temperature flow channel A, the cold energy released during the thermoelectric generation process can be recovered, and in the low-temperature flow channel B, the cold energy absorbed by the air can be used to cool the user's return water. After cooling, the water is pumped to supply cold water to the user, and through multiple cycles, the energy matching is achieved to supply cold energy to the user.

[0024] Since the components of the air discharged after the liquid air power generation cycle are N2, O2, and Ar, without water vapor and carbon dioxide, it is a clean and dry gas, and additional benefits can be generated through reasonable utilization. The air after expansion power generation is circulated between the thermoelectric generation module 3 and the multi-stream heat exchanger 7 to achieve reasonable distribution of energy in the heat exchange process. The dry and clean cold air after cascaded cold energy recovery and utilization is supplied to the user for air conditioning.

[0025] The present invention also provides a decoupled liquid air energy storage cold-electricity-gas combined supply method, including the following steps: Assemble the above-mentioned decoupled liquid air energy storage cold-electricity-gas combined supply device; During the off-peak electricity consumption period, the excess electricity generated by renewable energy is stored in the liquid air storage tank in the form of liquid air. The pressure of the liquid air storage tank is 0.8 MPa, and the temperature is about -180 °C. Liquid air has ultra-low temperature and high-grade cold energy.

[0026] Start the cryogenic pump to transport the liquid air in the liquid air storage tank to the low-temperature side of the thermoelectric generation module. The liquid air outputting high-grade cold energy undergoes a liquid-gas phase change process in the thermoelectric generation module, and then enters the heat exchanger to output low-grade cold energy, and the air temperature at the medium outlet of the heat exchanger increases; the thermoelectric generation module generates direct current by using the temperature difference. The air output from the heat exchanger medium is reheated to a high temperature by the heater and then enters the expansion generator to generate alternating current. The return air output from the expansion generator enters the heat exchanger to absorb low-grade cold energy, and then enters the low-temperature flow channel B of the multi-stream heat exchanger to exchange heat with the circulating water of the user and release cold energy to increase the temperature; then it enters the high-temperature area of the thermoelectric generation module to obtain cold energy, and then flows back to the low-temperature flow channel B of the multi-stream heat exchanger to continue cooling the circulating water of the user; the return air circulates N times between the low-temperature flow channel B of the multi-stream heat exchanger and the high-temperature area of the thermoelectric generation module, and then is supplied to the user as dry and clean air for air conditioning. The direct current generated by the thermoelectric generation module and the alternating current generated by the expansion generator are used by the user. The return water of the user flows through the high-temperature flow channel B of the multi-stream heat exchanger, exchanges heat with the multi-stream return air in the low-temperature flow channel B, is cooled and then pressurized by the water pump to supply cold water to the user.

[0027] In the embodiment of the present invention, the high-grade latent heat of vaporization of liquid air is used for thermoelectric power generation, and the low-grade sensible heat is used for cooling, realizing the cascade utilization of cold energy. At the same time, the exhaust gas after expansion power generation is used as the circulating fluid to recover the cold energy released during the thermoelectric power generation process. Through multiple cycles, the energy is matched to supply cold energy to users. The dry and clean cold air after the cascade recovery and utilization of cold energy is supplied to users for air conditioning, ultimately realizing the combined supply of cold, electricity, and gas to meet the various energy consumption needs of users.

[0028] The structure of the present invention is simple and has a high energy recovery rate, especially suitable for small-scale application scenarios. By thermoelectric power generation, the high-grade cold energy of the evaporation and gasification of liquid air is obtained. While efficiently generating direct current power with a large temperature difference for users, the exergy loss of the ultra-low temperature - ordinary cold heat exchange is also reduced. Through the heat exchange design of the multi-stream air channels inside the thermoelectric power generation module and the multi-stream heat exchanger, the lower-grade cold energy after the evaporation and gasification of liquid air is fully utilized to supply cold to users. The reheated air is used for expansion power generation to supply alternating current to users. The dry and clean cold air after the cascade recovery and utilization of cold energy is supplied to users for air conditioning. The decoupled liquid air energy storage cold - electricity - gas combined supply system can meet the various energy consumption needs of users, and the energy recovery efficiency is significantly improved.

[0029] The present invention has the following specific advantages: 1. The present invention uses thermoelectric power generation to generate direct current and generates alternating current through reheating and expansion, which can meet the various electricity consumption needs of users.

[0030] 2. The present invention uses thermoelectric power generation and the heat exchange design of the multi-stream air channels inside to realize the cascade utilization of the ultra-low temperature cold energy of liquid air, reduce the exergy loss of the ultra-low temperature - ordinary cold heat exchange, and obtain a high cold - electricity combined supply energy recovery efficiency.

[0031] 3. The present invention supplies the dry and clean cold air discharged at the end of the liquid air power generation process to users for air conditioning, obtaining additional benefits, which can further improve the economic benefits of the decoupled liquid air energy storage.

[0032] 4. The present invention provides a feasible method and solution for realizing the decoupled liquid air energy storage cold - electricity - gas combined supply.

[0033] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A decoupled liquid air energy storage cold-electricity-gas combined supply device, characterized in that: It includes a liquid air storage tank, a thermoelectric generation module, a heater, an expansion generator and a multi-stream heat exchanger. The liquid air in the liquid air storage tank is transported to the thermoelectric generation module by a cryogenic pump. The gas-liquid mixture output by the thermoelectric generation module enters the expansion generator for power generation after being heated by the heater. The return air of the expansion generator enters the multi-stream heat exchanger and is circulated between the multi-stream heat exchanger and the thermoelectric generation module for multiple times before being transported to the user.

2. The decoupled liquid air energy storage cold-electricity-gas triple supply device according to claim 1, characterized in that: A heat exchanger is provided between the thermoelectric generation module and the heater. The low-temperature zone output end of the thermoelectric generation module is connected to the medium inlet of the heat exchanger, and the medium outlet of the heat exchanger is connected to the inlet of the heater. The return air of the expansion generator is connected to the air inlet of the heat exchanger, and the air outlet of the heat exchanger is connected to the multi-stream heat exchanger.

3. The decoupled liquid air energy storage cold-electricity-gas trigeneration device according to claim 2, wherein: The return water pipe of the user is connected to the multi-stream heat exchanger and enters the water supply pipeline of the user after being cooled by the multi-stream heat exchanger.

4. The decoupled liquid air energy storage combined cooling, heat and power supply device according to claim 3, characterized in that: The thermoelectric generation module includes a low-temperature zone, a high-temperature zone and a power generation layer therebetween. The power generation layer is provided with thermoelectric generation components. The low-temperature zone is provided with a low-temperature flow channel A, and the high-temperature zone is provided with a high-temperature flow channel A with multiple streams arranged in parallel. The number of streams of the high-temperature flow channel A is N≥2, which are the first high-temperature flow channel A, the second high-temperature flow channel A... the Nth high-temperature flow channel A respectively. The multi-stream high-temperature flow channel A is correspondingly connected to multiple inlets and outlets of the multi-stream heat exchanger.

5. A decoupled liquid air energy storage cold-electricity-gas combined supply device according to claim 4, characterized in that: The multi-stream heat exchanger includes a high-temperature flow channel B and multiple low-temperature flow channels B arranged in parallel. The multiple low-temperature flow channels B are arranged with multiple streams in parallel. The number of streams of the low-temperature flow channel B is N + 1, which are the first low-temperature flow channel B, the second low-temperature flow channel B... the (N + 1)th low-temperature flow channel B respectively. The N-stream high-temperature flow channel A is correspondingly connected to the inlets and outlets of the low-temperature flow channel B to form a gas path for circulating cooling, and the output end of the gas path is connected to the user. The return water pipe of the user is connected to the input end of the high-temperature flow channel B, and the output end of the high-temperature flow channel B is connected to the water supply pipeline of the user through a water pump.

6. The decoupled liquid air energy storage cold-electricity-gas triple supply device according to claim 5, wherein: The connection sequence of the high-temperature flow channel A of the thermoelectric generation module and the low-temperature flow channel B of the multi-stream heat exchanger is as follows: The air outlet of the heat exchanger is connected to the input end of the first low-temperature flow channel B. The output end of the first low-temperature flow channel B is connected to the input end of the first high-temperature flow channel A. The output end of the first high-temperature flow channel A is connected to the input end of the second low-temperature flow channel B. The output end of the second low-temperature flow channel B is connected to the input end of the second high-temperature flow channel A. The output end of the second high-temperature flow channel A is connected to the input end of the third low-temperature flow channel B. The output end of the third low-temperature flow channel B is connected to the input end of the fourth high-temperature flow channel A... The output end of the Nth low-temperature flow channel B is connected to the input end of the Nth high-temperature flow channel A. The output end of the Nth high-temperature flow channel A is connected to the input end of the (N + 1)th low-temperature flow channel B. The output end of the (N + 1)th low-temperature flow channel B is connected to the user.

7. The decoupled liquid air energy storage cold-electricity-gas combined supply device according to claim 1, characterized in that: The direct current generated by the thermoelectric generation module and the alternating current generated by the expansion generator are both transported to the electrical equipment of the user.

8. A decoupled liquid air energy storage cold-electricity-gas combined heat, power and cooling supply method, characterized in that, It includes the following steps: Assemble the decoupled liquid air energy storage cold-electricity-gas combined heat and power supply device as claimed in claim 6. During the low electricity consumption period, the excess electricity is stored in the liquid air storage tank in the form of liquid air; Start the cryogenic pump to transport the liquid air in the liquid air storage tank to the low-temperature side of the thermoelectric generation module. The liquid air output with high-grade cold energy undergoes a liquid-gas phase change process in the thermoelectric generation module, and then enters the heat exchanger to output low-grade cold energy, and the air temperature at the medium outlet of the heat exchanger rises; the thermoelectric generation module generates direct current by using the temperature difference for power generation; The air output from the heat exchanger medium is reheated to a high temperature by the heater and then enters the expansion generator to expand and generate alternating current; The return air output from the expansion generator enters the heat exchanger to absorb low-grade cold energy, and then enters the low-temperature flow channel B of the multi-stream heat exchanger to exchange heat with the circulating water of the user and release cold energy and the temperature rises; then it enters the high-temperature area of the thermoelectric generation module to obtain cold energy, and then flows back to the low-temperature flow channel B of the multi-stream heat exchanger to continue cooling the circulating water of the user; the return air circulates N times between the low-temperature flow channel B of the multi-stream heat exchanger and the high-temperature area of the thermoelectric generation module, and then is supplied to the user as dry and clean air for air conditioning; The direct current generated by the thermoelectric generation module and the alternating current generated by the expansion generator are supplied for the user to use; The return water of the user flows through the high-temperature flow channel B of the multi-stream heat exchanger, exchanges heat with the multi-stream return air in the low-temperature flow channel B, and the return water is cooled and then pressurized by the water pump to supply cold water to the user.

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