ORC and CO2 energy storage system coupled with solar energy

Abstract

The utility model discloses an ORC and CO2 energy storage system coupled with solar energy, an energy storage stage CO2 working medium loop and an energy storage stage heat storage medium loop jointly form an energy storage stage of the CO2 energy storage system, and an energy release stage CO2 working medium loop, an energy release stage heat storage medium loop, a solar heating subsystem and an ORC waste heat recovery subsystem jointly form an energy release stage of the CO2 energy storage system. According to the ORC and CO2 energy storage system coupling solar energy, CO2 is used as an operation working medium, and water is used as a heat storage medium. Compared with a compressed air energy storage technology, a CO2 energy storage system has higher energy storage density, and due to the addition of solar energy and an ORC system, the system output work is improved, the system efficiency is further improved, and meanwhile, the purposes of reducing energy waste and reducing environmental pollution are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to an ORC and CO2 energy storage system coupled with solar energy. Background Art

[0002] With the rapid consumption of fossil energy and the increasing environmental pollution problems, the development of new renewable energy sources represented by solar energy and hydropower has been rapidly valued by countries around the world. Making full use of renewable energy has become an important way to achieve carbon peak and carbon neutrality. At present, the main utilization form of renewable energy is power generation. However, the environmental dependence, intermittency and instability of renewable energy during energy supply have always been criticized problems. Applying it to large-scale power generation may have a huge impact on the power grid. At this time, the importance of energy storage systems becomes increasingly prominent. Energy storage technology can store electrical energy during the low electricity consumption period and release it during the high electricity consumption period, achieving the effect of peak shaving and valley filling to make up for the deficiency during the intermittent period of renewable energy. Energy storage technology plays a crucial role in the large-scale application of renewable energy.

[0003] At present, the energy storage technology widely used on a large scale is pumped storage technology. However, it has high investment costs, low economic feasibility, and is greatly affected by geographical environment, with limited application scenarios. Compared with pumped storage technology, compressed air energy storage technology does not have the above problems and has the potential for large-scale application. Among them, advanced compressed air energy storage technology can store and utilize thermal energy through a heat storage device without using fossil fuels. Although compressed air energy storage technology has strong adaptability, due to the limitation of working medium, its energy storage density is relatively low. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an ORC and CO2 energy storage system coupled with solar energy to solve the problems that the current energy storage technology is greatly affected by the environment and has a relatively low energy storage density.

[0005] To achieve the above purpose, the utility model provides an ORC and CO2 energy storage system coupled with solar energy. The system includes a first stop valve, a low-pressure tank, a first compressor, a first intercooler, a second compressor, a second intercooler, a third compressor, a third intercooler, a high-pressure tank, a second stop valve, a first reheater, a regenerator, a solar heater, a first expander, a second reheater, a second expander, a third reheater, a third expander, a first radiator, a low-temperature tank, a cold water pump, a high-temperature tank, a hot water pump, a second radiator, a first heat conduction oil pump, a heat conduction oil tank, a solar collector, a second heat conduction oil pump, an evaporator, a fourth expander, a condenser, and a fourth compressor;

[0006] During the energy storage stage, the connection mode of the CO2 circuit is as follows: the right side of the first shut-off valve is connected to the left side of the low-pressure tank, the left side of the first shut-off valve is connected to the left side of the first compressor, the right side of the first compressor is connected to the lower left side of the first intercooler, the upper left side of the first intercooler is connected to the left side of the second compressor, the second compressor is connected to the lower left side of the second intercooler, the upper left side of the second intercooler is connected to the left side of the third compressor, the right side of the third compressor is connected to the lower left side of the third intercooler, and the upper left side of the third intercooler is connected to the left side of the high-pressure tank;

[0007] During the energy storage stage, the connection mode of the heat storage medium circuit is as follows: the left side of the low-temperature tank is connected to the right side of the cold water pump, and the left side of the cold water pump is respectively connected to the upper right side of the first intercooler, the upper right side of the second intercooler, and the upper right side of the third intercooler. The left side of the high-temperature tank is respectively connected to the lower right side of the first intercooler, the lower right side of the second intercooler, and the lower right side of the third intercooler;

[0008] The above-mentioned CO2 working medium circuit and heat storage medium circuit during the energy storage stage together constitute the energy storage stage of the CO2 energy storage system;

[0009] During the energy release stage, the connection mode of the CO2 working medium circuit is as follows: the right side of the high-pressure tank is connected to the left side of the second shut-off valve, the right side of the second shut-off valve is connected to the lower right side of the first reheater, the upper right side of the first reheater is connected to the lower side of the regenerator, the upper side of the regenerator is connected to the lower right side of the solar heater. The upper right side of the solar heater is connected to the left side of the first expander, the right side of the first expander is connected to the right side of the regenerator, the left side of the regenerator is connected to the lower right side of the second reheater, the upper right side of the second reheater is connected, the upper right side of the second reheater is connected to the left side of the second expander, the right side of the second expander is connected to the lower right side of the third reheater, the upper right side of the third reheater is connected to the left side of the third expander, the right side of the third expander is connected to the right side of the first radiator, and the left side of the first radiator is connected to the right side of the low-pressure tank;

[0010] During the energy release stage, the connection mode of the heat storage medium circuit is as follows: the right side of the high-temperature tank is connected to the left side of the hot water pump, the right side of the hot water pump is respectively connected to the upper left side of the first reheater, the upper left side of the second reheater, and the upper left side of the third reheater. The right side of the low-temperature tank is connected to the left side of the second radiator, and the right side of the second radiator is respectively connected to the lower left side of the first reheater, the upper left side of the evaporator, and the lower left side of the third reheater. The upper right side of the evaporator is connected to the lower left side of the second reheater;

[0011] The connection mode of the solar heating subsystem is as follows: the lower left side of the solar heater is connected to the right side of the first heat conduction oil pump, the left side of the first heat conduction oil pump is connected to the lower right side of the heat conduction oil tank, the upper right side of the heat conduction oil tank is connected to the upper left side of the solar heater, the lower side of the solar collector is connected to the left side of the second heat conduction oil pump, the right side of the second heat conduction oil pump is connected to the lower left side of the heat conduction oil tank, and the upper left side of the heat conduction oil tank is connected to the upper side of the solar collector;

[0012] The connection mode of the ORC waste heat recovery subsystem is as follows: the lower right side of the evaporator is connected to the upper side of the fourth expander, the lower side of the fourth expander is connected to the right side of the condenser, the left side of the condenser is connected to the lower side of the fourth compressor, and the upper side of the fourth compressor is connected to the lower left side of the evaporator;

[0013] The energy release stage of the CO2 energy storage system is jointly composed of the CO2 working medium circuit in the energy release stage, the heat storage medium circuit in the energy release stage, the solar heating subsystem, and the ORC waste heat recovery subsystem.

[0014] Preferably, in the above-mentioned ORC and CO2 energy storage system coupled with solar energy, the right sides of the high-temperature tank, low-temperature tank, high-pressure tank, and low-pressure tank are closed, the hot water pump, the second radiator, the second stop valve, and the first radiator are opened, the first reheater, the second reheater, the third reheater, the regenerator, the first expander, the second expander, the third expander, the solar heater, the first heat conduction oil pump, the heat conduction oil tank, the solar collector, the second heat conduction oil pump, the evaporator, the fourth expander, the condenser, and the fourth compressor are opened; the first stop valve is closed, the first compressor, the second compressor, the third compressor, the first intercooler, the second intercooler, and the third intercooler are closed, the left sides of the low-pressure tank, high-pressure tank, high-temperature tank, and low-temperature tank are opened, and the cold water pump is closed, forming the daytime energy release cycle of the CO2 energy storage system.

[0015] Preferably, in the above-mentioned ORC and CO2 energy storage system coupled with solar energy, the first stop valve is opened, the first compressor, the second compressor, the third compressor, the first intercooler, the second intercooler, and the third intercooler are opened, the left sides of the low-pressure tank, high-pressure tank, high-temperature tank, and low-temperature tank are opened, and the cold water pump is opened; the right sides of the high-temperature tank, low-temperature tank, high-pressure tank, and low-pressure tank are closed, the hot water pump, the second radiator, the second stop valve, and the first radiator are closed, the first reheater, the second reheater, the third reheater, the regenerator, the first expander, the second expander, the third expander, the solar heater, the first heat conduction oil pump, the heat conduction oil tank, the solar collector, the second heat conduction oil pump, the evaporator, the fourth expander, the condenser, and the fourth compressor are closed, forming the nighttime energy storage cycle of the CO2 energy storage system.

[0016] Therefore, the present utility model adopts a CO2 energy storage system coupled with solar energy in the above structure, using CO2 as the working medium and water as the heat storage medium. Compared with compressed air energy storage technology, the CO2 energy storage system has a higher energy storage density. Moreover, due to the addition of solar energy and the ORC system, the output work of the system is increased, the system efficiency is further improved, and at the same time, the purpose of reducing energy waste and environmental pollution is achieved. The system includes an energy storage stage and an energy release stage. The energy release stage further includes a solar heating subsystem and an ORC waste heat recovery subsystem. By opening and closing valves, the conversion between the night energy storage and the day energy release stages of the CO2 energy storage system is realized, enabling the system to achieve efficient energy storage.

[0017] In the energy storage stage, an intercooler is provided between the first compressor, the second compressor, and the third compressor. When the CO2 pressure is constant, the temperature of the working medium entering the compressor is reduced, the power consumption during the compression process of the compressor is reduced, and when the output work of the system remains unchanged, the input work of the system is reduced, improving the system performance; in the energy release stage, a recuperator is added before the first expander to use the high temperature of the working medium at the outlet of the first expander to increase the temperature of the working medium at the outlet of the first reheater. At the same time, a solar heater is added between the recuperator and the first expander, and the high-temperature heat transfer oil of the solar subsystem is used to further heat the temperature of the working medium at the inlet of the first expander to increase the output work of the first expander; due to the addition of the solar subsystem, the temperature of the working medium entering the second reheater is still relatively high, and finally, there is still relatively high waste heat on the heat storage medium side of the second reheater. An ORC waste heat recovery subsystem is added to the heat storage medium side after the second reheater to recover this part of the waste heat for power generation to increase the output work of the system and further improve the performance of the CO2 energy storage system;

[0018] Adopting a three-stage compression and three-stage expansion form for energy storage, compared with other invented CO2 energy storage systems, the present utility model has a higher energy storage pressure, a larger energy storage density, and a larger energy storage capacity; due to the coupling of the solar subsystem and the ORC waste heat recovery system, the system has a higher output work, less energy waste, and at the same time, the utilization rate of renewable energy is increased, achieving the purpose of energy conservation and environmental protection.

[0019] The technical solution of the present utility model will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of a CO2 energy storage system coupling solar energy and ORC of the present utility model. Detailed Embodiment

[0021] The technical solution of the present utility model will be further described below through the drawings and embodiments.

[0022] Unless otherwise defined, the technical terms or scientific terms used in this utility model shall have the ordinary meanings understood by those with ordinary skills in the field to which this utility model belongs. The "first", "second" and similar words used in this utility model do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0023] The system components and their connection modes in the energy storage stage are as follows: the right side of the first cut-off valve 1 is connected to the left side of the low-pressure tank 2, the left side of the first cut-off valve 1 is connected to the left side of the first compressor 3, the right side of the first compressor 3 is connected to the lower left side of the first intercooler 4, the upper left side of the first intercooler 4 is connected to the left side of the second compressor 5, the second compressor 5 is connected to the lower left side of the second intercooler 6, the upper left side of the second intercooler 6 is connected to the left side of the third compressor 7, the right side of the third compressor 7 is connected to the lower left side of the third intercooler 8, and the upper left side of the third intercooler 8 is connected to the left side of the high-pressure tank 9, forming a CO2 circuit in the energy storage stage.

[0024] The left side of the low-temperature tank 20 is connected to the right side of the cold water pump 21. The left side of the cold water pump 21 is respectively connected to the upper right side of the first intercooler 4, the upper right side of the second intercooler 6, and the upper right side of the third intercooler 8. The left side of the high-temperature tank 22 is respectively connected to the lower right side of the first intercooler 4, the lower right side of the second intercooler 6, and the lower right side of the third intercooler 8, forming a heat storage medium circuit in the energy storage stage.

[0025] The working mode of the energy storage stage of the CO2 energy storage system coupling solar energy and ORC:

[0026] During the energy storage stage, the first shut-off valve 1 is opened, the first compressor 3, the second compressor 5, the third compressor 7, the first intercooler 4, the second intercooler 6, the third intercooler 8 are opened, the left sides of the low-pressure tank 2, the high-pressure tank 9, the high-temperature tank 22, and the low-temperature tank 20 are opened, and the cold water pump 21 is opened; the right sides of the high-temperature tank 22, the low-temperature tank 20, the high-pressure tank 9, and the low-pressure tank 2 are closed, the hot water pump 23, the second radiator 24, the second shut-off valve 10, and the first radiator 19 are closed, and the first reheater 11, the second reheater 15, the third reheater 17, the recuperator 12, the first expander 14, the second expander 16, the third expander 18, the solar heater 13, the first heat-conducting oil pump 25, the heat-conducting oil tank 26, the solar collector 27, the second heat-conducting oil pump 28, the evaporator 29, the fourth expander 30, the condenser 31, and the fourth compressor 32 are closed.

[0027] During night energy storage, the first shut-off valve 1 is opened, and the low-pressure CO2 in the low-pressure tank 2 enters the first expander 3, where it is compressed into a high-temperature and high-pressure state. Then it enters the first intercooler 4 for cooling and becomes a normal-temperature and high-pressure state. Then it enters the second compressor 5 for compression, and so on, until it flows out of the third intercooler 8 and becomes normal-temperature and high-pressure CO2. Finally, it enters the high-pressure tank 9 for storage; at the same time, the water on the heat storage medium side of each intercooler absorbs the heat of CO2 and becomes high-temperature water, and finally enters the high-temperature tank for storage, and the energy storage stage ends.

[0028] The system components and their indirect connection methods during the energy release stage are as follows: the right side of the high-pressure tank 9 is connected to the left side of the second shut-off valve 10, the right side of the second shut-off valve 10 is connected to the lower right side of the first reheater 11, the upper right side of the first reheater 11 is connected to the lower side of the recuperator 12, the upper side of the recuperator 12 is connected to the lower right side of the solar heater 13, the upper right side of the solar heater 13 is connected to the left side of the first expander 14, the right side of the first expander 14 is connected to the right side of the recuperator 12, the left side of the recuperator 12 is connected to the lower right side of the second reheater 15, the upper right side of the second reheater 15 is connected, the upper right side of the second reheater 15 is connected to the left side of the second expander 16, the right side of the second expander 16 is connected to the lower right side of the third reheater 17, the upper right side of the third reheater 17 is connected to the left side of the third expander 18, the right side of the third expander 18 is connected to the right side of the first radiator 19, and the left side of the first radiator 19 is connected to the right side of the low-pressure tank 2, forming the CO2 working medium circuit during the energy release stage;

[0029] The right side of the high-temperature tank 22 is connected to the left side of the hot water pump 23. The right side of the hot water pump 23 is respectively connected to the upper left side of the first reheater 11, the upper left side of the second reheater 15, and the upper left side of the third reheater 17. The right side of the low-temperature tank 20 is connected to the left side of the second radiator 24. The right side of the second radiator 24 is respectively connected to the lower left side of the first reheater 11, the upper left side of the evaporator 29, and the lower left side of the low-three reheater 15. The upper right side of the evaporator 29 is connected to the lower left side of the second reheater 15, forming a heat storage medium circuit in the energy release stage;

[0030] The lower left side of the solar heater 13 is connected to the right side of the first heat conduction oil pump 25. The left side of the first heat conduction oil pump 25 is connected to the lower right side of the heat conduction oil tank 26. The upper right side of the heat conduction oil tank 26 is connected to the upper left side of the solar heater 13. The lower side of the solar collector 27 is connected to the left side of the second heat conduction oil pump 28. The right side of the second heat conduction oil pump 28 is connected to the lower left side of the heat conduction oil tank 26. The upper left side of the heat conduction oil tank 26 is connected to the upper side of the solar collector 27, forming a solar heating subsystem;

[0031] The lower right side of the evaporator 29 is connected to the upper side of the fourth expander 30. The lower side of the fourth expander 30 is connected to the right side of the condenser 31. The left side of the condenser 31 is connected to the lower side of the fourth compressor 32. The upper side of the fourth compressor 32 is connected to the lower left side of the evaporator 29, forming an ORC waste heat recovery subsystem.

[0032] The working mode of the energy release stage of the CO2 energy storage system coupling solar energy and ORC:

[0033] During the operation of the energy release stage, the right sides of the high-temperature tank 22, the low-temperature tank 20, the high-pressure tank 9, and the low-pressure tank 2 are closed. The hot water pump 23, the second radiator 24, the second stop valve 10, and the first radiator 19 are opened. The first reheater 11, the second reheater 15, the third reheater 17, the recuperator 12, the first expander 14, the second expander 16, the third expander 18, the solar heater 13, the first heat conduction oil pump 25, the heat conduction oil tank 26, the solar collector 27, the second heat conduction oil pump 28, the evaporator 29, the fourth expander 30, the condenser 31, and the fourth compressor 32 are opened. The first stop valve 1 is closed. The first compressor 3, the second compressor 5, the third compressor 7, the first intercooler 4, the second intercooler 6, and the third intercooler 8 are closed. The left sides of the low-pressure tank 2, the high-pressure tank 9, the high-temperature tank 22, and the low-temperature tank 20 are opened. The cold water pump 21 is closed.

[0034] During the daytime when energy is released, the second cut-off valve 10 opens, and the normal-temperature and high-pressure CO2 in the high-pressure tank 9 enters the first reheater 11, absorbs the high-temperature water from the high-temperature tank 22, returns to the high-temperature and high-pressure state, and enters the expander to do work. Among them, before the first expander 14, a solar heating system is added. The high-temperature and high-pressure CO2 flowing out of the regenerator 12 is further heated by the high-temperature heat-conducting oil in the solar heater 13, and then enters the first expander 14 to do work, improving the quality of the working medium at the inlet of the first expander and increasing the system output work. After that, the CO2 still has a relatively high temperature after doing work. First, it enters the regenerator 12 to heat the CO2 flowing out of the first reheater 11, and then enters the second reheater 15 to absorb heat, and so on. Finally, it flows out of the third expander 18 and becomes normal-temperature and normal-pressure CO2. Then it enters the first radiator 19 to be cooled to the ambient temperature, and finally enters the low-pressure tank for storage; at the same time, the high-temperature water flowing out of the high-temperature tank 22 releases heat to the CO2 in each reheater and becomes normal temperature, and then enters the second radiator 24 to be cooled to the ambient temperature, and finally enters the low-temperature tank 20 for storage.

[0035] Among them, due to the addition of solar energy, the CO2 entering the second reheater 15 still has a relatively high temperature, which ultimately leads to the high-temperature water flowing out of the second reheater still having relatively high waste heat. This part of the waste heat will be recovered by the ORC waste heat recovery subsystem. The working process is as follows: The water flowing out of the second reheater 15 first enters the evaporator 29 to release heat to the working medium R245fa of the ORC waste heat recovery subsystem. The heated R245fa working medium becomes a high-temperature and high-pressure gas and enters the fourth expander 30 to do work. After doing work, it becomes a low-temperature and low-pressure state, and then enters the condenser for cooling, becomes a liquid, then enters the fourth compressor 30 to become a high-pressure liquid, and then enters the evaporator 29 for heating, and so on to complete the waste heat recovery process. This process reduces the waste of system preheating, further improves the system performance, realizes the efficient storage and utilization of energy, and achieves the purpose of energy conservation and environmental protection.

[0036] The overall implementation and operation mode of the present utility model is as follows: During night energy storage, the system drives each compressor to do work by absorbing the excess electric energy of the power plant, compresses the CO2 at normal temperature and pressure in the low-pressure tank 2 to a high-temperature and high-pressure state, and then is cooled to a high-pressure and normal-temperature state by the normal-temperature water in each intercooler and enters the high-pressure tank 9 for storage. The heated high-temperature water enters the high-temperature tank for storage, and the energy storage process is completed. During day energy release, the high-pressure and normal-temperature CO2 in the high-pressure tank 9 enters each reheater and is heated by the high-temperature water flowing out of the high-temperature tank 22 to return to a high-temperature and high-pressure state, and then enters the expander to expand and do work. Among them, a solar heating subsystem is added in front of the first compressor 14 to further improve the quality of the working medium entering the first compressor 14, increase the output work of the expander, and improve the system performance; an ORC waste heat recovery subsystem is added at the water side outlet of the second reheater 15 to absorb and utilize the high-temperature waste heat in the hot water, reduce the waste of system waste heat, further improve the system performance, improve the energy utilization rate, reduce environmental pollution, and realize the efficient storage and utilization of energy.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model and are not intended to limit them. Although the present utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present utility model, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present utility model.

Claims

1. A solar-coupled ORC and CO2 energy storage system, characterized in that: The system comprises a first stop valve (1), a low-pressure tank (2), a first compressor (3), a first intercooler (4), a second compressor (5), a second intercooler (6), a third compressor (7), a third intercooler (8), a high-pressure tank (9), a second stop valve (10), a first reheater (11), a regenerator (12), a solar heater (13), a first expander (14), a second reheater (15), a second expander (16), a third reheater (17), a third expander (18), a first radiator (19), a low-temperature tank (20), a cold water pump (21), a high-temperature tank (22), a hot water pump (23), a second radiator (24), a first thermal oil pump (25), a thermal oil tank (26), a solar collector (27), a second thermal oil pump (28), an evaporator (29), a fourth expander (30), a condenser (31), and a fourth compressor (32); The connection mode of the CO2 circuit in the energy storage stage is as follows: the right side of the first stop valve (1) is connected to the left side of the low-pressure tank (2), the left side of the first stop valve (1) is connected to the left side of the first compressor (3), the right side of the first compressor (3) is connected to the lower left side of the first intercooler (4), the upper left side of the first intercooler (4) is connected to the left side of the second compressor (5), the second compressor (5) is connected to the lower left side of the second intercooler (6), the upper left side of the second intercooler (6) is connected to the left side of the third compressor (7), the right side of the third compressor (7) is connected to the lower left side of the third intercooler (8), and the upper left side of the third intercooler (8) is connected to the left side of the high-pressure tank (9); The connection mode of the heat storage medium circuit in the energy storage stage is as follows: the left side of the low temperature tank (20) is connected to the right side of the cold water pump (21), the left side of the cold water pump (21) is respectively connected to the upper right side of the first intercooler (4), the upper right side of the second intercooler (6), and the upper right side of the third intercooler (8), and the left side of the high temperature tank (22) is respectively connected to the lower right side of the first intercooler (4), the lower right side of the second intercooler (6), and the lower right side of the third intercooler (8); The above-mentioned CO2 working medium circuit in the energy storage stage and the heat storage medium circuit in the energy storage stage together constitute the energy storage stage of the CO2 energy storage system; The connection mode of the CO2 working medium circuit in the energy release stage is as follows: the right side of the high-pressure tank (9) is connected to the left side of the second stop valve (10), the right side of the second stop valve (10) is connected to the lower right side of the first reheater (11), the upper right side of the first reheater (11) is connected to the lower side of the regenerator (12), the upper side of the regenerator (12) is connected to the lower right side of the solar heater (13), the upper right side of the solar heater (13) is connected to the left side of the first expander (14), the right side of the first expander (14) is connected to the regenerator (12), and the upper right side of the solar heater (13) is connected to the left side of the first expander (14). The left side of the regenerator (12) is connected to the right side of the second reheater (15), the left side of the regenerator (12) is connected to the lower right side of the second reheater (15), the upper right side of the second reheater (15) is connected to the left side of the second expander (16), the right side of the second expander (16) is connected to the lower right side of the third reheater (17), the upper right side of the third reheater (17) is connected to the left side of the third expander (18), the right side of the third expander (18) is connected to the right side of the first radiator (19), and the left side of the first radiator (19) is connected to the right side of the low-pressure tank (2); The connection mode of the heat storage medium circuit in the energy release stage is as follows: the right side of the high temperature tank (22) is connected to the left side of the hot water pump (23), the right side of the hot water pump (23) is respectively connected to the upper left side of the first reheater (11), the upper left side of the second reheater (15), and the upper left side of the third reheater (17), the right side of the low temperature tank (20) is connected to the left side of the second radiator (24), the right side of the second radiator (24) is respectively connected to the lower left side of the first reheater (11), the upper left side of the evaporator (29), and the lower left side of the third reheater (15), and the upper right side of the evaporator (29) is connected to the lower left side of the second reheater (15); The solar heating subsystem is connected in the following manner: the lower left side of the solar heater (13) is connected to the right side of the first thermal oil pump (25), the left side of the first thermal oil pump (25) is connected to the lower right side of the thermal oil tank (26), the upper right side of the thermal oil tank (26) is connected to the upper left side of the solar heater (13), the lower side of the solar collector (27) is connected to the left side of the second thermal oil pump (28), the right side of the second thermal oil pump (28) is connected to the lower left side of the thermal oil tank (26), and the upper left side of the thermal oil tank (26) is connected to the upper side of the solar collector (27); The connection mode of the ORC waste heat recovery subsystem is as follows: the lower right side of the evaporator (29) is connected to the upper side of the fourth expander (30), the lower side of the fourth expander (30) is connected to the right side of the condenser (31), the left side of the condenser (31) is connected to the lower side of the fourth compressor (32), and the upper side of the fourth compressor (32) is connected to the lower left side of the evaporator (29); The CO2 working fluid circuit in the energy release stage, the heat storage medium circuit in the energy release stage, the solar heating subsystem and the ORC waste heat recovery subsystem together constitute the energy release stage of the CO2 energy storage system.

2. A solar-coupled ORC and CO2 energy storage system according to claim 1, characterized in that: The right side of the high temperature tank (22), the right side of the low temperature tank (20), the right side of the high pressure tank (9), and the right side of the low pressure tank (2) are closed; the hot water pump (23), the second radiator (24), the second stop valve (10), and the first radiator (19) are opened; the first reheater (11), the second reheater (15), the third reheater (17), the regenerator (12), the first expander (14), the second expander (16), the third expander (18), the solar heater (13), the first thermal oil pump (25), the thermal oil tank (26), and the solar collector ( 27), the second thermal oil pump (28), the evaporator (29), the fourth expansion machine (30), the condenser (31), and the fourth compressor (32) are turned on; the first stop valve (1) is closed, the first compressor (3), the second compressor (5), the third compressor (7), the first intercooler (4), the second intercooler (6), and the third intercooler (8) are turned off, the left side of the low-pressure tank (2), the left side of the high-pressure tank (9), the left side of the high-temperature tank (22), and the left side of the low-temperature tank (20) are turned on, and the cold water pump (21) is turned off, forming a daily energy release cycle of the CO2 energy storage system.

3. A solar-coupled ORC and CO2 energy storage system according to claim 1, characterized in that: The first stop valve (1) is opened, the first compressor (3), the second compressor (5), the third compressor (7), the first intercooler (4), the second intercooler (6), and the third intercooler (8) are opened, the left side of the low-pressure tank (2), the left side of the high-pressure tank (9), the left side of the high-temperature tank (22), and the left side of the low-temperature tank (20) are opened, and the cold water pump (21) is opened; the right side of the high-temperature tank (22), the right side of the low-temperature tank (20), the right side of the high-pressure tank (9), and the right side of the low-pressure tank (2) are closed, and the hot water pump (23), the second radiator (24), the second stop valve (10), the first A radiator (19) is turned off, and the first reheater (11), the second reheater (15), the third reheater (17), the regenerator (12), the first expander (14), the second expander (16), the third expander (18), the solar heater (13), the first thermal oil pump (25), the thermal oil tank (26), the solar collector (27), the second thermal oil pump (28), the evaporator (29), the fourth expander (30), the condenser (31), and the fourth compressor (32) are turned off, forming a nighttime energy storage cycle of the CO2 energy storage system.

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