Low-temperature phase change Rankine cycle energy storage power generation system

Abstract

The utility model discloses a low-temperature phase change Rankine cycle energy storage and power generation system, which integrates energy storage, power generation and heat pump functions, and innovatively integrates three subsystems of energy storage and charging, organic Rankine cycle power generation and heat pump cycle. Efficient storage and conversion of low-temperature heat energy are achieved through the compression and expansion all-in-one machine, the overheating heat exchanger, the supercooling heat exchanger, the storage tank, the pump and other core assemblies. The energy storage charging and power generation system shares a cycle working medium and heat storage medium circulation system, working modes are flexibly switched, heat energy can be stored in a charging mode, and the heat energy can be released in a power generation mode to drive Rankine cycle power generation. The heat management capacity of the system is further enhanced through heat pump circulation, and the overall energy efficiency is improved. The system is compact in design and comprehensive in function, and a new scheme is provided for efficient utilization and energy storage of renewable energy sources.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy storage, and particularly relates to a low-temperature phase-change Rankine cycle energy storage power generation system. Background Technique

[0002] With the continuous growth of global energy demand and the increasing awareness of environmental protection, the development of efficient and clean energy storage and conversion technologies has become particularly important. Traditional energy systems face problems such as resource depletion and environmental pollution. Although renewable energy sources such as solar energy and geothermal energy are clean and pollution-free, their supply is intermittent and unstable, making it difficult to achieve continuous and stable power supply. Therefore, researching technologies that can efficiently store and flexibly release thermal energy has become the key to solving this problem.

[0003] The low-temperature phase-change Rankine cycle energy storage power generation system emerged precisely under this background. This system integrates three subsystems: energy storage charging, organic Rankine cycle power generation, and heat pump cycle, realizing the efficient storage, conversion, and utilization of low-temperature thermal energy. This system can not only convert intermittent renewable energy into storable thermal energy but also release thermal energy to drive Rankine cycle power generation when needed, thereby providing stable and reliable power supply for users. At the same time, the introduction of the heat pump cycle further enhances the thermal management ability of the system and improves the overall energy efficiency. Summary of the Invention

[0004] The utility model provides a low-temperature phase-change Rankine cycle energy storage power generation system, which integrates the functions of energy storage, power generation, and heat pump, and innovatively combines three subsystems: energy storage charging, organic Rankine cycle power generation, and heat pump cycle.

[0005] Specifically described as follows: A low-temperature phase-change Rankine cycle energy storage power generation system includes an energy storage charging system, an organic Rankine cycle power generation system, a heat pump cycle system, and a control system;

[0006] The energy storage charging system includes a cold storage tank, a compression-expansion integrated machine with compression and expansion functions, a superheat heat exchanger, a heat storage tank, a subcooling heat exchanger, a low-temperature tank, a high-temperature tank, a working fluid tank, a working fluid pump / hydraulic power generation integrated machine, a first circulation pump, and the connecting pipes between them; the cold storage tank, the compression-expansion integrated machine, the superheat heat exchanger, the heat storage tank, the subcooling heat exchanger, the working fluid tank, and the working fluid pump / hydraulic power generation integrated machine are connected by pipes in the above order to form a closed-loop circuit, which constitutes the circulating working fluid circulation system of the energy storage charging system; the high-temperature tank, the superheat heat exchanger, the subcooling heat exchanger tank, the low-temperature tank, and the first circulation pump are connected end to end in sequence to form the heat storage medium circulation system of the energy storage charging system;

[0007] The organic Rankine cycle power generation system includes a cold storage tank, a compression-expansion integrated machine with compression and expansion functions, a superheat heat exchanger, a heat storage tank, a subcooling heat exchanger, a low-temperature tank, a high-temperature tank, a working fluid tank, a working fluid pump / hydraulic power generation integrated machine, a second circulation pump, and the connecting pipes between them; the cold storage tank, the compression-expansion integrated machine, the superheat heat exchanger, the heat storage tank, the subcooling heat exchanger, the working fluid pump / hydraulic power generation integrated machine, and the working fluid tank are connected by pipes in the above order to form a closed loop, which constitutes the circulating working fluid circulation system of the organic Rankine cycle power generation system; the second circulation pump, the high-temperature tank, the superheat heat exchanger, the subcooling heat exchanger, and the low-temperature tank are connected end to end in sequence to form the heat storage medium circulation system of the organic Rankine cycle power generation system.

[0008] The heat pump cycle system includes a cold storage tank, a compression-expansion integrated machine with compression and expansion functions, a radiator, a working fluid tank, a working fluid pump / hydraulic power generation integrated machine, and the connecting pipes between them; the cold storage tank, the compression-expansion integrated machine, the radiator, the working fluid tank, and the working fluid pump / hydraulic power generation integrated machine are connected by pipes in the above order to form a closed loop, which constitutes the heat pump cycle system.

[0009] Further, the control system includes a stop valve between the cold storage tank and the compression-expansion integrated machine, a solenoid valve connected in parallel between the compression-expansion integrated machine and the superheat heat exchanger, a solenoid valve / solenoid valve between the superheat heat exchanger and the heat storage tank / high-temperature tank, a stop valve between the heat storage tank and the subcooling heat exchanger, a solenoid valve / stop valve / solenoid valve / solenoid valve between the subcooling heat exchanger and the top inlet of the working fluid tank / radiator / low-temperature tank / outlet at the bottom of the working fluid tank, a solenoid valve between the subcooling heat exchanger and the working fluid pump / hydraulic power generation integrated machine, a solenoid valve and a stop valve / solenoid valve between the outlet at the bottom of the working fluid tank and the cold storage tank / expansion valve, a stop valve between the expansion valve and the cold storage tank, a solenoid valve between the top inlet of the working fluid tank and the cold storage tank, and a solenoid valve between the radiator and the compression-expansion integrated machine.

[0010] Further, the cold storage tank is filled with a cold storage medium, and heat exchange tubes are arranged around the cold storage medium. The external connection inlet and outlet of the cold storage tank are communicated with the internal heat exchange tubes.

[0011] Further, the heat storage tank is filled with a heat storage medium, and heat exchange tubes are arranged around the heat storage medium; the external connection inlet and outlet of the heat storage tank are communicated with the internal heat exchange tubes.

[0012] Further, the energy storage and charging system includes a cold storage tank, a compression-expansion integrated machine with compression and expansion functions, a superheat heat exchanger, a heat storage tank, a subcooling heat exchanger, a low-temperature tank, a high-temperature tank, a working fluid tank, an expansion valve, a first circulation pump, and the connecting pipes between them; the cold storage tank, the compression-expansion integrated machine, the superheat heat exchanger, the heat storage tank, the subcooling heat exchanger, the working fluid tank, and the expansion valve are connected by pipes in the above order to form a closed loop, which constitutes the circulating working fluid system of the energy storage and charging system; the high-temperature tank, the superheat heat exchanger, the subcooling heat exchanger tank, the low-temperature tank, and the first circulation pump are connected end to end in sequence to form the heat storage medium circulation system of the energy storage and charging system.

[0013] Further, the heat pump cycle system includes a cold storage tank, a compression-expansion integrated machine with compression and expansion functions, a radiator, a working fluid tank, an expansion valve, and the connecting pipes between them; the cold storage tank, the compression-expansion integrated machine, the radiator, the working fluid tank, and the expansion valve are connected by pipes in the above order to form a closed loop, which constitutes the heat pump cycle system.

[0014] Further, the working fluid pump / hydraulic power generation integrated machine is a device that integrates the technologies of a working fluid pump and hydraulic power generation.

[0015] The utility model has the following advantages compared with the prior art: 1) High-efficiency energy storage and conversion: The system adopts the low-temperature phase change Rankine cycle technology, which can efficiently store and convert thermal energy into electrical energy. The energy storage efficiency and power generation efficiency are both better than those of traditional energy storage systems, realizing the efficient utilization of energy; 2) Flexible switching and stable operation: The energy storage and charging system and the organic Rankine cycle power generation system share the circulating working fluid and the heat storage medium circulation system. Through the precise adjustment of the control system, the working mode can be flexibly switched to achieve seamless connection between energy storage and power generation, ensuring the stable operation of the system; 3) Integrated and modular design: The system adopts an integrated design, and the subsystems are highly coordinated with each other. At the same time, the modular design makes the system easy to expand and maintain, reducing the operation and maintenance costs; 4) Strong heat management ability: The introduction of the heat pump cycle system enhances the heat management ability of the system, can effectively adjust the internal temperature of the system, improve the overall energy efficiency, and extend the service life of the equipment; 5) Environmental protection and energy saving: The system mainly uses low-temperature thermal energy for energy storage and power generation, without generating pollutant emissions, conforming to the environmental protection concept of green and low-carbon, and is one of the important directions for future energy development. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Attached Figure 1 is a schematic structural principle diagram of the energy storage power generation system of the present invention.

[0018] Attached Figure 2 is a schematic diagram of the energy storage charging process of the energy storage power generation system of the present invention Figure 1 .

[0019] Attached Figure 3 is a schematic diagram of the energy storage charging process of the energy storage power generation system of the present invention Figure 2 .

[0020] Attached Figure 4 is a schematic diagram of the organic Rankine cycle power generation process of the energy storage power generation system of the present invention.

[0021] Attached Figure 5 is a schematic diagram of the heat pump cycle process of the energy storage power generation system of the present invention Figure 1 .

[0022] Attached Figure 6 is a schematic diagram of the heat pump cycle process of the energy storage power generation system of the present invention Figure 2 .

[0023] The meanings represented by the serial numbers in the above figures are as follows: 1 cold storage tank; 2 compression-expansion integrated machine; 3 superheat heat exchanger; 4 heat storage tank; 5 subcooling heat exchanger; 6 low-temperature tank; 7 high-temperature tank; 8 radiator; 9 radiator fan; 10 working fluid tank; 11 working fluid pump / hydraulic power generation integrated machine; 12 first circulation pump; 13 second circulation pump; 14-18 stop valves; 19-30 solenoid valves; 31 expansion valve. Specific embodiments

[0024] To make the purpose, technical solutions and advantages of the present invention clearer, the following will describe the technical solutions of the present invention in detail.

[0025] Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments.

[0026] Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present utility model. To facilitate better understanding of the embodiments, the following provides multiple embodiments or implementation methods to illustrate the relevant devices, modules, and functions of the present utility model.

[0027] To enable the readers of this embodiment to quickly understand the implementation manner of the present utility model, the working principle of the present utility model is described below.

[0028] As shown in the attached Figure 1 figure, a low-temperature phase-change Rankine cycle energy storage power generation system includes an energy storage charging system, an organic Rankine cycle power generation system, a heat pump cycle system, and a control system.

[0029] Please refer to Figure 2 figure, the energy storage charging system includes a cold storage tank 1, a compression-expansion integrated machine 2 with compression and expansion functions, a superheat heat exchanger 3, a heat storage tank 4, a subcooling heat exchanger 5, a low-temperature tank 6, a high-temperature tank 7, a working fluid tank 10, a working fluid pump / hydraulic power generation integrated machine 11, a first circulation pump 12, a second circulation pump 13, and the connecting pipes therebetween. The cold storage tank 1 is filled with a cold storage medium, and heat exchange pipes are arranged around the cold storage medium; the heat storage tank 4 is filled with a heat storage medium, and heat exchange pipes are arranged around the heat storage medium; the outlet of the heat exchange pipe in the cold storage tank 1 is communicated with the inlet of the compression-expansion integrated machine 2; the two ends of the circulating working fluid channel of the superheat heat exchanger 3 are respectively communicated with the outlet of the compression-expansion integrated machine 2 and the inlet of the heat exchange pipe in the heat storage tank 4, the outlet of the heat exchange pipe in the heat storage tank 4 is communicated with one end of the circulating working fluid channel of the subcooling heat exchanger 5, the other end of the circulating working fluid channel of the subcooling heat exchanger 5 is communicated with the top inlet of the working fluid tank 10, and the working fluid pump / hydraulic power generation integrated machine 11 is installed between the bottom outlet of the working fluid tank 10 and the inlet of the heat exchange pipe in the cold storage tank 1; the first circulation pump 12 is arranged near the bottom in the low-temperature tank 6 so that the first circulation pump 12 can pump all the heat storage medium in the low-temperature tank 6; the outlet of the first circulation pump 12 is connected to the outside of the low-temperature tank 6 through a pipe and is connected to the inlet of the heat storage medium channel of the subcooling heat exchanger 5; the outlet of the heat storage medium channel of the subcooling heat exchanger 5 is communicated with the inlet of the heat storage medium channel of the superheat heat exchanger 3; the outlet of the heat storage medium channel of the superheat heat exchanger 3 is connected to the inlet of the high-temperature tank 7 through a pipe.

[0030] Please refer to Figure 3As shown, the energy storage and charging system includes a cold storage tank 1, a compression-expansion integrated machine 2 with compression and expansion functions, a superheat heat exchanger 3, a heat storage tank 4, a subcooling heat exchanger 5, a low-temperature tank 6, a high-temperature tank 7, a working fluid tank 10, an expansion valve 31, a first circulation pump 12, and the connecting pipes between them. The cold storage tank 1 is filled with a cold storage medium, and heat exchange pipes are arranged around the cold storage medium; the heat storage tank 4 is filled with a heat storage medium, and heat exchange pipes are arranged around the heat storage medium; the outlet of the heat exchange pipes in the cold storage tank 1 is communicated with the inlet of the compression-expansion integrated machine 2; both ends of the circulating working fluid channel of the superheat heat exchanger 3 are respectively communicated with the outlet of the compression-expansion integrated machine 2 and the inlet of the heat exchange pipes in the heat storage tank 4, the outlet of the heat exchange pipes in the heat storage tank 4 is communicated with one end of the circulating working fluid channel of the subcooling heat exchanger 5, and the other end of the circulating working fluid channel of the subcooling heat exchanger 5 is communicated with the top inlet of the working fluid tank 10; the expansion valve 31 is installed between the bottom outlet of the working fluid tank 10 and the inlet of the heat exchange pipes in the cold storage tank 1; the first circulation pump 12 is arranged near the bottom in the low-temperature tank 6 so that the first circulation pump 12 can extract all the heat storage medium in the low-temperature tank 6; the outlet of the first circulation pump 12 is connected to the outside of the low-temperature tank 6 through a pipe and is connected to the inlet of the heat storage medium channel of the subcooling heat exchanger 5; the outlet of the heat storage medium channel of the subcooling heat exchanger 5 is communicated with the inlet of the heat storage medium channel of the superheat heat exchanger 3; the outlet of the heat storage medium channel of the superheat heat exchanger 3 is communicated with the inlet of the high-temperature tank 7 through a pipe.

[0031] Please refer to Figure 4As shown in the figure, the organic Rankine cycle power generation system includes: a cold storage tank 1, a compression-expansion integrated machine 2 with compression and expansion functions, a superheat heat exchanger 3, a heat storage tank 4, a subcooling heat exchanger 5, a low-temperature storage tank 6, a high-temperature storage tank 7, a working fluid storage tank 10, a working fluid pump / hydraulic power generation integrated machine 11, a second circulation pump 13, and the connecting pipes therebetween. The cold storage tank 1 is filled with a cold storage medium, and heat exchange pipes are arranged around the cold storage medium; the heat storage tank 4 is filled with a heat storage medium, and heat exchange pipes are arranged around the heat storage medium; the outlet of the heat exchange pipes in the cold storage tank 1 is communicated with the top inlet of the working fluid storage tank 10, the compression-expansion integrated machine 2 is installed at the bottom outlet of the working fluid storage tank 10 and communicated with one end of the circulating working fluid passage of the subcooling heat exchanger 5, and the other end of the circulating working fluid passage of the subcooling heat exchanger 5 is communicated with the inlet of the heat exchange pipes in the heat storage tank 4; the two ends of the circulating working fluid passage of the superheat heat exchanger 3 are respectively communicated with the outlet of the heat exchange pipes in the heat storage tank 4 and the inlet of the compression-expansion integrated machine 2; the outlet of the compression-expansion integrated machine 2 is communicated with the inlet of the heat exchange pipes in the cold storage tank 1. The second circulation pump 13 is arranged near the bottom in the high-temperature storage tank 7 so that the second circulation pump 13 can extract all the heat storage medium in the high-temperature storage tank 7; the outlet of the second circulation pump 13 is connected to the outside of the high-temperature storage tank 7 through a pipe and communicated with the inlet of the heat storage medium passage of the superheat heat exchanger 3; the outlet of the heat storage medium passage of the superheat heat exchanger 3 is communicated with the inlet of the heat storage medium passage of the subcooling heat exchanger 5 through a pipe, and the outlet of the heat storage medium passage of the subcooling heat exchanger 5 is communicated with the inlet of the low-temperature storage tank 7.

[0032] Please refer to Figure 5 As shown in the figure, the heat pump cycle system includes a cold storage tank 1, a compression-expansion integrated machine 2 with compression and expansion functions, a radiator 8, a radiator fan 9, a working fluid storage tank 10, a working fluid pump / hydraulic power generation integrated machine 11, and the connecting pipes therebetween. The cold storage tank 1 is filled with a cold storage medium, and heat exchange pipes are arranged around the cold storage medium; the heat exchange pipes in the cold storage tank 1, the compression-expansion integrated machine 2, the radiator 8, the working fluid storage tank 10, and the working fluid pump / hydraulic power generation integrated machine 11 are connected in the above order through pipes to form a closed loop, which constitutes the heat pump cycle system. The top end of the working fluid storage tank 10 is communicated with the outlet of the radiator 8, and the bottom end of the working fluid storage tank 10 is communicated with the inlet of the working fluid pump / hydraulic power generation integrated machine 11.

[0033] Please refer to Figure 6As shown, the heat pump cycle system includes a cold storage tank 1, a compression-expansion integrated machine 2 with compression and expansion functions, a radiator 8, a radiator fan 9, a working fluid tank 10, an expansion valve 31, and the connecting pipes therebetween. The cold storage tank 1 is filled with a cold storage medium, and heat exchange pipes are arranged around the cold storage medium; the heat exchange pipes in the cold storage tank 1, the compression-expansion integrated machine 2, the radiator 8, the working fluid tank 10, and the expansion valve 31 are connected by pipes in the above order to form a closed loop, which constitutes the heat pump cycle system. The top of the working fluid tank 10 is communicated with the outlet of the radiator 8, and the bottom of the working fluid tank 10 is communicated with the inlet of the expansion valve 31. The radiator fan 9 is installed beside the radiator 8, and by generating an air flow, it accelerates the air flow on the surface of the radiator 8 to improve the heat dissipation efficiency.

[0034] Please refer to Figure 1 As shown, the control system includes a stop valve 14 between the cold storage tank 1 and the compression-expansion integrated machine 2, a solenoid valve 29 and a solenoid valve 30 connected in parallel between the compression-expansion integrated machine 2 and the superheat heat exchanger 3, a solenoid valve 27 / solenoid valve 26 between the superheat heat exchanger 3 and the heat storage tank 4 / high-temperature tank 7, a stop valve 18 between the heat storage tank 4 and the subcooling heat exchanger 5, a solenoid valve 24 / stop valve 17 / solenoid valve 25 / solenoid valve 23 and solenoid valve 22 between the subcooling heat exchanger 5 and the top inlet of the working fluid tank 10 / radiator 8 / low-temperature tank 6 / bottom outlet of the working fluid tank 10, a solenoid valve 23 and solenoid valve 21 between the subcooling heat exchanger 5 and the working fluid pump / hydraulic power generation integrated machine 11, a solenoid valve 20 and stop valve 15 / solenoid valve 20 between the bottom outlet of the working fluid tank 10 and the cold storage tank 1 / expansion valve 31, a stop valve 16 between the expansion valve 31 and the cold storage tank 1, a solenoid valve 19 between the top inlet of the working fluid tank 10 and the cold storage tank 1, and a solenoid valve 28 and solenoid valve 29 / solenoid valve 30 between the radiator 8 and the compression-expansion integrated machine 2.

[0035] The above-mentioned working fluid pump / hydraulic power generation integrated machine 11 is a device that integrates the technologies of a working fluid pump and hydraulic power generation.

[0036] The circulating working fluid is Freon, propane, ammonia, carbon dioxide, etc.

[0037] The heat storage medium is water, heat-conducting oil, ethylene glycol, an aqueous solution of low-melting-point chloride (such as calcium chloride).

[0038] The cold storage medium is water, ice, ethylene glycol, an aqueous solution of low-melting-point chloride (such as calcium chloride), etc.

[0039] The heat storage medium is a liquid heat storage medium (such as water, heat-conducting oil).

[0040] Under the action of the control system, the working cycle of the utility model is divided into an energy storage charging process, an organic Rankine cycle power generation process, and a heat pump cycle process.

[0041] The working principle of the energy storage charging process is as follows: Please refer to Figure 1 and Figure 2 As shown, start the stop valves 14, 15, 18, solenoid valves 21, 22, 24, 26, 27, and 30. The remaining stop valves, solenoid valves, and expansion valve 31 are closed. Turn on the compression function of the compression-expansion integrated machine 2 and the hydraulic power generation function of the working fluid pump / hydraulic power generation integrated machine 11. The circulating working fluid exchanges heat with the cold storage medium in the heat exchange tubes of the cold storage tank 1. The circulating working fluid is heated up, and the cold storage medium is cooled down. The heated circulating working fluid enters the compression-expansion integrated machine 2 and is compressed into a superheated high-temperature and high-pressure gaseous circulating working fluid. The superheated high-temperature and high-pressure gaseous circulating working fluid enters the circulating working fluid channel of the superheat heat exchanger 3 to exchange heat with the heat storage medium. The superheated high-temperature and high-pressure gaseous circulating working fluid realizes the first temperature drop. Then, the circulating working fluid after the first temperature drop enters the heat exchange tubes of the heat storage tank 4 to exchange heat with the heat storage medium in the heat storage tank 4. The heat storage medium in the heat storage tank 4 absorbs the heat of the circulating working fluid after the first temperature drop and stores it in the heat storage tank 4. At the same time, the circulating working fluid after the first temperature drop completes the second temperature drop. The circulating working fluid after the second temperature drop enters the circulating working fluid channel of the subcooling heat exchanger 5 to exchange heat with the heat storage medium. After the third temperature drop of the circulating working fluid after the second temperature drop, it directly enters the working fluid tank 10. The circulating working fluid that has undergone three temperature drops and comes out of the working fluid tank 10 directly enters the working fluid pump / hydraulic power generation integrated machine 11 for power generation to realize energy recovery and then is discharged, completing the circulating process of the circulating working fluid in the energy storage charging process. At the same time, driven by the first circulating pump 12, the low-temperature heat storage medium in the low-temperature tank 6 enters the heat storage medium channel of the subcooling heat exchanger 5 to conduct the first countercurrent heat exchange with the circulating working fluid in the circulating working fluid channel of the subcooling heat exchanger 5. The low-temperature heat storage medium absorbs heat for the first time and becomes a medium-temperature heat storage medium. Then, the medium-temperature heat storage medium enters the heat storage medium channel of the superheat heat exchanger 3 to conduct the second countercurrent heat exchange with the superheated circulating working fluid in the circulating working fluid channel of the superheat heat exchanger 3. The medium-temperature heat storage medium absorbs heat for the second time and becomes a high-temperature heat storage medium, which is finally stored in the high-temperature tank 7 for power generation use; the above-mentioned cycle of the working fluid completes the entire process of energy storage charging.

[0042] Please refer to Figure 3 the energy storage charging process shown. Compared with Figure 2 shown, the working fluid pump / hydraulic power generation integrated machine 11 is replaced by an expansion valve 31. The circulating working fluid that has undergone three temperature drops and comes out of the working fluid tank 10 directly enters the expansion valve 31 for expansion throttling and pressure reduction. The operation of other components is the same as Figure 2 that.

[0043] The working principle of the organic Rankine cycle power generation process is as follows: Please refer to Figure 1 and Figure 4 As shown, start the stop valve 14, stop valve 18, solenoid valve 19, solenoid valve 20, solenoid valve 21, solenoid valve 23, solenoid valve 25, solenoid valve 27, and solenoid valve 29. The remaining stop valves, solenoid valves, and expansion valve 31 are closed. Activate the expansion function of the compression-expansion integrated machine 2 and the working fluid pump function of the working fluid pump / hydraulic power generation integrated machine 11. The working fluid pump / hydraulic power generation integrated machine 11 sucks in the low-temperature liquid circulating working fluid from the working fluid storage tank 10. Through the change in the pump chamber volume brought about by its movement, the low-temperature liquid circulating working fluid is compressed into a low-temperature and high-pressure liquid circulating working fluid and enters the circulating medium channel of the subcooling heat exchanger 5, where it is preheated by the heat storage medium in the heat storage medium channel of the subcooling heat exchanger 5. The preheated circulating working fluid enters the heat exchange tubes of the heat storage tank 4 and absorbs the heat stored in the heat storage medium in the heat storage tank 4 during the energy storage charging process, undergoes a phase change, and becomes a high-pressure gaseous circulating working fluid. Subsequently, the high-pressure gaseous circulating working fluid enters the circulating medium channel of the superheat heat exchanger 3 and is reheated by the heat storage medium in the heat storage medium channel of the superheat heat exchanger 3 to become a high-temperature and high-pressure superheated gaseous circulating working fluid. Finally, the high-temperature and high-pressure superheated gaseous circulating working fluid drives the compression-expansion integrated machine 2 to generate electricity. After the circulating working fluid has done work through the compression-expansion integrated machine 2, it enters the heat exchange tubes in the cold storage tank 1, where it is quickly cooled by the cold storage medium in the cold storage tank 1 and becomes a low-temperature liquid circulating working fluid, which is stored in the working fluid storage tank 10 for the next cycle of power generation. This cycle repeats continuously to complete the continuous power supply. In this cycle, driven by the second circulating pump 13, the heat storage medium that absorbs the heat of the superheated circulating medium compressed during the energy storage charging process enters the heat storage medium channel of the superheat heat exchanger 3 from the high-temperature storage tank 7 and conducts the first countercurrent heat exchange with the circulating working fluid in the circulating working fluid channel of the superheat heat exchanger 3. The heat storage medium undergoes the first temperature reduction and becomes a medium-temperature heat storage medium water. Then, the medium-temperature heat storage medium enters the heat storage medium channel of the subcooling heat exchanger 5 to preheat the circulating working fluid in the circulating working fluid channel of the subcooling heat exchanger 5. The medium-temperature heat storage medium water undergoes the second temperature reduction and becomes a low-temperature heat storage medium, which is finally stored in the low-temperature storage tank 7.

[0044] When the heat storage medium has met the heat storage temperature requirement, but the cold storage medium in the cold storage tank 1 has not yet dropped to the requirement of the organic Rankine cycle power generation process, or there is a separate refrigeration requirement, start the heat pump cycle process. Please refer to Figure 1 and Figure 5As shown, start the stop valves 14, 15, 17, solenoid valves 21, 22, 24, 28 and 30, and close the remaining stop valves, solenoid valves and expansion valve 31. Turn on the compression function of the compression-expansion unit 2 and the hydraulic power generation function of the working fluid pump / hydraulic power generation unit 11. The circulating working fluid exchanges heat with the cold storage medium in the heat exchange tubes of the cold storage tank 1. The circulating working fluid is heated up and the cold storage medium is cooled down. The heated circulating working fluid enters the compression-expansion unit 2, and the compressed high-temperature and high-pressure gaseous circulating working fluid enters the radiator 8 for air-cooled heat dissipation. The heat-dissipated circulating working fluid directly enters the working fluid storage tank 10, and the circulating working fluid coming out of the working fluid storage tank 10 directly enters the working fluid pump / hydraulic power generation unit 11 for power generation to achieve energy recovery and then is discharged, completing the heat pump cycle process.

[0045] Please refer to Figure 6 the heat pump cycle process shown. Compared with Figure 5 as shown, the working fluid pump / hydraulic power generation unit 11 is replaced by the expansion valve 31. The circulating working fluid coming out of the working fluid storage tank 10 directly enters the expansion valve 31 for expansion throttling and pressure reduction, and the operation of other components is the same as that of Figure 5 the same.

[0046] Both the superheat heat exchanger 3 and the subcooling heat exchanger 5 described above are countercurrent heat exchangers.

[0047] In this specification, the schematic expressions of the above terms do not necessarily refer to the same

[0048] embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0049] It can be understood that the above embodiments are exemplary and should not be construed as limitations on the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A low temperature phase change Rankine cycle energy storage power generation system, characterized in that: Including energy storage charging system, organic Rankine cycle power generation system, heat pump circulation system and control system; The energy storage charging system includes a cold storage tank, a compression-expansion integrated machine with compression and expansion functions, an overheat heat exchanger, a heat storage tank, a subcooling heat exchanger, a low-temperature storage tank, a high-temperature storage tank, a working fluid storage tank, a working fluid pump / hydraulic power generation integrated machine, a first circulating pump, and connecting pipes therebetween; the cold storage tank, the compression-expansion integrated machine, the overheat heat exchanger, the heat storage tank, the subcooling heat exchanger, the working fluid storage tank, the working fluid pump / hydraulic power generation integrated machine are connected in the above order through pipes to form a closed loop to form a circulating working fluid circulation system of the energy storage charging system; the high-temperature storage tank, the overheat heat exchanger, the subcooling heat exchanger tank, the low-temperature storage tank, and the first circulating pump are connected end to end in sequence to form a heat storage medium circulation system of the energy storage charging system; The organic Rankine cycle power generation system includes a cold storage tank, a compression-expansion integrated machine with compression and expansion functions, an overheat heat exchanger, a heat storage tank, a subcooling heat exchanger, a low-temperature storage tank, a high-temperature storage tank, a working fluid storage tank, a working fluid pump / hydraulic power generation integrated machine, a second circulation pump, and connecting pipes therebetween; the cold storage tank, the compression-expansion integrated machine, the overheat heat exchanger, the heat storage tank, the subcooling heat exchanger, the working fluid pump / hydraulic power generation integrated machine, and the working fluid storage tank are connected in the above order through pipes to form a closed loop to form a circulating working fluid circulation system of the organic Rankine cycle power generation system; the second circulation pump, the high-temperature storage tank, the overheat heat exchanger, the subcooling heat exchanger, and the low-temperature storage tank are connected end to end in sequence to form a heat storage medium circulation system of the organic Rankine cycle power generation system; The heat pump circulation system includes a cold storage tank, a compression-expansion integrated machine with compression and expansion functions, a radiator, a working fluid storage tank, a working fluid pump / hydraulic power generation integrated machine and connecting pipes therebetween; the cold storage tank, the compression-expansion integrated machine, the radiator, the working fluid storage tank, the working fluid pump / hydraulic power generation integrated machine are connected in the above order through pipes to form a closed loop to form a heat pump circulation system.

2. A low temperature phase change Rankine cycle energy storage power generation system according to claim 1, characterized in that: The control system includes a stop valve between the cold storage tank and the compression-expansion machine, a solenoid valve in parallel between the compression-expansion machine and the superheat heat exchanger, a solenoid valve / solenoid valve between the superheat heat exchanger and the heat storage tank / high-temperature storage tank, a stop valve between the heat storage tank and the subcooling heat exchanger, a solenoid valve / stop valve / solenoid valve / solenoid valve between the subcooling heat exchanger and the top inlet of the working fluid tank / radiator / low-temperature tank / bottom outlet of the working fluid tank, a solenoid valve between the subcooling heat exchanger and the working fluid pump / hydraulic generator, a solenoid valve and a stop valve / solenoid valve between the bottom outlet of the working fluid tank and the cold storage tank / expansion valve, a stop valve between the expansion valve and the cold storage tank, a solenoid valve between the top inlet of the working fluid tank and the cold storage tank, and a solenoid valve between the radiator and the compression-expansion machine.

3. A low temperature phase change Rankine cycle energy storage power generation system according to claim 1, characterized in that: The cold storage tank contains a cold storage medium, and a heat exchange pipe is arranged around the cold storage medium. The cold storage tank has an externally connected inlet and outlet that are connected to the heat exchange pipe inside.

4. A low temperature phase change Rankine cycle energy storage power generation system according to claim 1, characterized in that: The heat storage tank contains a heat storage medium, and a heat exchange pipe is arranged around the heat storage medium; the heat storage tank has an externally connected inlet and outlet that are connected to the heat exchange pipe inside.

5. A low temperature phase change Rankine cycle energy storage power generation system according to claim 1, characterized in that: The energy storage and charging system includes a cold storage tank, a compression-expansion integrated machine with compression and expansion functions, an overheat heat exchanger, a heat storage tank, a subcooling heat exchanger, a low-temperature tank, a high-temperature tank, a working fluid tank, an expansion valve, a first circulation pump, and connecting pipes therebetween; the cold storage tank, the compression-expansion integrated machine, the overheat heat exchanger, the heat storage tank, the subcooling heat exchanger, the working fluid tank, and the expansion valve are connected in the above order through pipes to form a closed loop to form a circulating working fluid circulation system of the energy storage and charging system; the high-temperature tank, the overheat heat exchanger, the subcooling heat exchanger tank, the low-temperature tank, and the first circulation pump are connected end to end in sequence to form a heat storage medium circulation system of the energy storage and charging system.

6. A low temperature phase change Rankine cycle energy storage power generation system according to claim 1, characterized in that: The heat pump circulation system includes a cold storage tank, a compression-expansion integrated machine with compression and expansion functions, a radiator, a working fluid storage tank, an expansion valve, and connecting pipes therebetween; the cold storage tank, the compression-expansion integrated machine, the radiator, the working fluid storage tank, and the expansion valve are connected in the above order through pipes to form a closed loop to form a heat pump circulation system.

7. A low temperature phase change Rankine cycle energy storage power generation system according to claim 1, characterized in that: The working fluid pump / hydraulic power generation integrated machine is a device integrating working fluid pump and hydraulic power generation technology.

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