Comprehensive energy system using double-fused-salt heat storage and supercritical carbon dioxide energy release

Abstract

The invention discloses a comprehensive energy system using double-fused-salt heat storage and supercritical carbon dioxide energy release, which comprises an S-CO2 Brayton power cycle subsystem and a double-fused-salt heat storage subsystem, the double-fused-salt heat storage subsystem is coupled with the S-CO2 Brayton power cycle subsystem, the system can solve the problem of single energy storage form, and the energy storage efficiency is improved. The system has the characteristics of high operability, high peak regulation capability and high energy storage and release efficiency.

Description

Technical Field

[0001] This invention belongs to the field of energy storage technology and relates to an integrated energy system that uses dual molten salt thermal storage and supercritical carbon dioxide energy release. Background Technology

[0002] Currently, traditional thermal power plants mainly use the Rankine cycle for power generation. As an alternative, the supercritical carbon dioxide (S-CO2) Brayton cycle offers higher cycle efficiency. In practical applications, the S-CO2 Brayton cycle can be well integrated with nuclear reactors, waste heat from ship hulls, internal combustion engine exhaust, and solar energy. Regarding energy storage, currently operational and under-construction power plants worldwide primarily utilize molten salt thermal storage. Numerous research institutions have analyzed and summarized the application of high-temperature thermal energy storage systems in solar thermal power generation, developing a wide range of efficient and economical thermal storage system solutions. In addition, widely used energy storage technologies include pumped hydro storage and compressed air storage, both characterized by low cost and large capacity. Pumped hydro storage is currently the most mature large-scale energy storage technology, accounting for 93% of my country's installed energy storage capacity. However, it is limited by geographical factors and has high site requirements. Compressed air storage offers large capacity and high efficiency, and its site selection is more flexible than pumped hydro storage, making it a promising technology direction for future large-scale energy storage.

[0003] Previous research has focused on improving the performance of thermal energy storage systems by designing and optimizing aspects such as cycle layout, working fluid selection, and operating parameters. However, the selection of energy storage methods has been relatively limited. Traditional molten salt thermal energy storage systems suffer from problems such as molten salt solidification and heat loss. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an integrated energy system that uses dual molten salt thermal storage and supercritical carbon dioxide energy release. This system can solve the problem of single energy storage form and has the characteristics of strong operability, strong peak-shaving capability and high energy storage and release efficiency.

[0005] To achieve the above objectives, the present invention discloses an integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release, comprising an S-CO2 Brayton power cycle subsystem and a dual molten salt thermal storage subsystem, wherein the dual molten salt thermal storage subsystem is coupled to the S-CO2 Brayton power cycle subsystem.

[0006] Furthermore, the dual molten salt thermal storage subsystem includes a fluoride molten salt cold tank, a molten salt-main steam heat exchanger, a first electric heater, a fluoride molten salt hot tank, a first molten salt-SCO2 heat exchanger, a first molten salt precooler, an evaporator, a Hitec molten salt cold tank, a molten salt-reheat steam heat exchanger, a second electric heater, a Hitec molten salt hot tank, a second high-temperature pump, a second molten salt-SCO2 heat exchanger, a second molten salt precooler, and deoxygenated water pipelines;

[0007] The outlet of the fluoride molten salt cold tank is connected to the inlet of the fluoride molten salt cold tank in sequence via the tube side of the molten salt-main steam heat exchanger, the first electric heater, the fluoride molten salt hot tank, the primary side of the first molten salt-SCO2 heat exchanger, the tube side of the first molten salt precooler, and the shell side of the evaporator.

[0008] The outlet of the Hitec molten salt cold tank is connected to the inlet of the Hitec molten salt cold tank via the tube side of the molten salt-reheat steam heat exchanger, the second electric heater, the Hitec molten salt hot tank, the second high-temperature pump, the primary side of the second molten salt-SCO2 heat exchanger, and the tube side of the second molten salt precooler.

[0009] The deoxygenated water pipeline is connected to the S-CO2 Brayton power cycle subsystem via the shell side of the second molten salt precooler, the tube side of the evaporator, and the shell side of the first molten salt precooler.

[0010] Furthermore, the outlet of the fluoride molten salt cold tank is connected to the inlet of the fluoride molten salt cold tank in sequence via the first cryogenic pump, the tube side of the molten salt-main steam heat exchanger, the first electric heater, the fluoride molten salt hot tank, the first high temperature pump, the primary side of the first molten salt-SCO2 heat exchanger, the tube side of the first molten salt precooler, and the shell side of the evaporator.

[0011] Furthermore, the outlet of the Hitec molten salt cold tank is connected to the inlet of the Hitec molten salt cold tank via the second cryogenic pump, the tube side of the molten salt-reheat steam heat exchanger, the second electric heater, the Hitec molten salt hot tank, the second high-temperature pump, the primary side of the second molten salt-SCO2 heat exchanger, and the tube side of the second molten salt precooler.

[0012] Furthermore, the molten salt in the fluoride molten salt hot tank, Hitec molten salt hot tank, fluoride molten salt cold tank, and Hitec molten salt cold tank is either a fluoride system molten salt LiNaK fluorides or a binary nitrate Hitec.

[0013] Furthermore, both the first and second electric heaters are powered by new energy sources.

[0014] Furthermore, the S-CO2 Brayton power cycle subsystem includes a turbine, a third valve, a regenerator, a compressor, a high-pressure CO2 storage tank, a main CO2 turbine, a low-pressure CO2 storage tank, a secondary CO2 turbine, and a first valve;

[0015] The turbine outlet is divided into two paths. One path is connected to the third valve, and the other path is connected to the inlet of the CO2 main turbine via the primary side of the regenerator, the compressor, the high-pressure CO2 storage tank, the secondary side of the regenerator, and the secondary side of the first molten salt-SCO2 heat exchanger. The CO2 main turbine outlet is divided into two paths. One path is connected to the primary side inlet of the regenerator via the low-pressure CO2 storage tank, and the other path is divided into two paths via the secondary side of the second molten salt-SCO2 heat exchanger. One path is connected to the inlet of the CO2 auxiliary turbine, and the other path is connected to the turbine inlet via the first valve. The outlet of the CO2 auxiliary turbine is connected to the primary side inlet of the regenerator, and the shell side of the first molten salt precooler is connected to the turbine inlet.

[0016] Furthermore, the turbine outlet is connected to the inlet of the CO2 main turbine via the fourth valve, the primary side of the regenerator, the first cooler, the compressor, the second cooler, the CO2 high-pressure storage tank, the secondary side of the regenerator, and the secondary side of the first molten salt-SCO2 heat exchanger.

[0017] Furthermore, the outlet of the CO2 main turbine is divided into two paths, one of which is connected to the primary side inlet of the regenerator via the fifth valve, the third cooler, the CO2 low-pressure storage tank, and the sixth valve.

[0018] The shell side of the first molten salt precooler is connected to the turbine inlet via a second valve.

[0019] Furthermore, the compressor and turbine are arranged coaxially;

[0020] The main CO2 turbine, auxiliary CO2 turbine, and generator are arranged coaxially.

[0021] The present invention has the following beneficial effects:

[0022] In specific operation, the integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release described in this invention couples the dual molten salt thermal storage subsystem with the S-CO2 Brayton power cycle subsystem. This combines the supercritical carbon dioxide Brayton cycle and dual molten salt energy storage and release with the utilization of new energy power to improve the energy conversion efficiency of thermal power units during energy storage and release, deeply utilize new energy power, improve the peak-shaving effect of thermal power units, and enhance the operational flexibility of thermal power units. It features strong operability, strong peak-shaving capability, and high energy storage and release efficiency. Attached Figure Description

[0023] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 This is a structural diagram of the dual molten salt thermal storage subsystem in this invention;

[0025] Figure 2 This is a structural diagram of the S-CO2 Brayton power cycle subsystem.

[0026] Among them, 1 is a fluoride molten salt cold tank, 2 is an evaporator, 3 is a first molten salt precooler, 4 is a first molten salt-SCO2 heat exchanger, 5 is a first high-temperature pump, 6 is a fluoride molten salt hot tank, 7 is a first electric heater, 8 is a molten salt-main steam heat exchanger, 9 is a first low-temperature pump, 10 is a Hitec molten salt cold tank, 11 is a second molten salt precooler, 12 is a second molten salt-SCO2 heat exchanger, 13 is a second high-temperature pump, 14 is a Hitec molten salt hot tank, and 15 is a second electric heater. 16 is a molten salt-reheat steam heat exchanger, 17 is a second cryogenic pump, 18 is a CO2 main turbine, 19 is a CO2 auxiliary turbine, 20 is a turbine, 21 is a compressor, 22 is a first cooler, 23 is a second cooler, 24 is a CO2 high-pressure storage tank, 25 is a regenerator, 26 is a CO2 low-pressure storage tank, 27 is a third cooler, 28 is a first valve, 29 is a second valve, 30 is a third valve, 31 is a fourth valve, 32 is a fifth valve, and 33 is a sixth valve. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0029] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0030] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0031] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0032] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0035] Example 1

[0036] refer to Figure 1 and Figure 2 The integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release described in this invention includes an S-CO2 Brayton power cycle subsystem and a dual molten salt thermal storage subsystem, wherein the dual molten salt thermal storage subsystem is coupled to the S-CO2 Brayton power cycle subsystem.

[0037] Example 2

[0038] refer to Figure 1 and Figure 2 Furthermore, to improve this application, the integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release described in this invention includes an S-CO2 Brayton power cycle subsystem and a dual molten salt thermal storage subsystem. The dual molten salt thermal storage subsystem is coupled to the S-CO2 Brayton power cycle subsystem. The dual molten salt thermal storage subsystem includes a fluoride molten salt cold tank 1, an evaporator 2, a first molten salt precooler 3, a first molten salt-SCO2 heat exchanger 4, a first high-temperature pump 5, a fluoride molten salt hot tank 6, a first electric heater 7, a molten salt-main steam heat exchanger 8, a first low-temperature pump 9, a Hitec molten salt cold tank 10, and a second molten salt precooler. The system includes: a second molten salt-SCO2 heat exchanger 11, a second high-temperature pump 13, a Hitec molten salt hot tank 14, a second electric heater 15, a molten salt-reheat steam heat exchanger 16, and a second low-temperature pump 17; the S-CO2 Brayton power cycle subsystem includes a CO2 main turbine 18, a CO2 auxiliary turbine 19, a turbine 20, a compressor 21, a first cooler 22, a second cooler 23, a CO2 high-pressure storage tank 24, a regenerator 25, a CO2 low-pressure storage tank 26, a third cooler 27, a first valve 28, a second valve 29, a third valve 30, a fourth valve 31, a fifth valve 32, and a sixth valve 33;

[0039] The outlet of the fluoride molten salt cold tank 1 is connected to the inlet of the fluoride molten salt cold tank 1 in sequence via the first cryogenic pump 9, the tube side of the molten salt-main steam heat exchanger 8, the first electric heater 7, the fluoride molten salt hot tank 6, the first high temperature pump 5, the primary side of the first molten salt-SCO2 heat exchanger 4, the tube side of the first molten salt precooler 3, and the shell side of the evaporator 2.

[0040] The outlet of the Hitec molten salt cold tank 10 is connected to the inlet of the Hitec molten salt cold tank 10 via the second cryogenic pump 17, the tube side of the molten salt-reheat steam heat exchanger 16, the second electric heater 15, the Hitec molten salt hot tank 14, the second high temperature pump 13, the primary side of the second molten salt-SCO2 heat exchanger 12, and the tube side of the second molten salt precooler 11.

[0041] The deoxygenated water pipeline is connected to the inlet of turbine 20 via the shell side of the second molten salt precooler 11, the tube side of the evaporator 2, and the shell side of the first molten salt precooler 3.

[0042] The outlet of turbine 20 is divided into two paths. One path connects to the third valve 30, and the other path connects to the inlet of the main CO2 turbine 18 via the fourth valve 31, the primary side of regenerator 25, the first cooler 22, compressor 21, second cooler 23, CO2 high-pressure storage tank 24, the secondary side of regenerator 25, and the secondary side of the first molten salt-SCO2 heat exchanger 4. The outlet of the main CO2 turbine 18 is also divided into two paths, one of which connects to the fifth valve 32 and the third cooler 27. The CO2 low-pressure storage tank 26 and the sixth valve 33 are connected to the primary side inlet of the regenerator 25. Another path is split into two paths after passing through the secondary side of the second molten salt-SCO2 heat exchanger 12. One path is connected to the inlet of the CO2 auxiliary turbine 19, and the other path is connected to the inlet of the turbine 20 through the first valve 28. The outlet of the CO2 auxiliary turbine 19 is connected to the primary side inlet of the regenerator 25. The shell side of the first molten salt precooler 3 is connected to the inlet of the turbine 20 through the second valve 29.

[0043] The molten salts used in this invention are fluoride-based molten salt LiNaK fluorides and binary nitrate Hitec. Binary nitrate Hitec is a mature and widely used material, and it does not easily solidify. Hitec has a solidification temperature of 142℃, and when its physicochemical properties are stable, its maximum operating temperature can reach 540℃. Fluoride-based molten salt LiNaK fluorides can be matched with high-parameter thermal power units with main and reheat steam temperatures of 565℃ and above. When its physicochemical properties are stable, its maximum operating temperature can reach above 700℃, and its solidification temperature is 454℃. A total of four storage tanks are arranged: a fluoride molten salt hot tank 6, a Hitec molten salt hot tank 14, a fluoride molten salt cold tank 1, and a Hitec molten salt cold tank 10. A tiered heat storage and release strategy is adopted, combined with the use of waste renewable energy, which can better utilize renewable energy and extracted steam heat, and broaden the temperature range for heat storage and release. This effectively utilizes the sensible and latent heat of steam, improving system efficiency.

[0044] refer to Figure 1When the power grid requires thermal power units to reduce peak loads, the load is reduced by extracting steam for heat storage. The stored energy is stored in the molten salt tanks of the integrated energy system. Specifically, the molten salt at 480-500℃ output from the fluoride molten salt cold tank 1 is sent to the molten salt-main steam heat exchanger 8 via the first cryogenic pump 9, absorbing heat from the main steam extraction of the thermal power unit, raising its temperature to 550-560℃. Then, using renewable energy, the fluoride molten salt is heated to 670-700℃ via the first electric heater 7. The molten salt at 160-180℃ output from the Hitec molten salt cold tank 10 is pumped to the molten salt-reheat steam heat exchanger 16 via the second cryogenic pump 17, absorbing heat from the reheat steam extraction of the thermal power unit, raising its temperature to 450-480℃. Then, using renewable energy, the Hitec molten salt is heated to 500-540℃ via the second electric heater 15. During heat release, the 670-700℃ molten salt output from the fluoride molten salt hot tank 6 is pumped by the first high-temperature pump 5 to the first molten salt-SCO2 heat exchanger 4 for primary heat release, with a temperature of 550-560℃ after heat release. It then enters the first molten salt precooler 3 for secondary heat release, with a temperature of 520-530℃ after heat release. Next, it enters the evaporator 2, with a temperature of 480-500℃ after heat release, and finally returns to the fluoride molten salt cold tank 1. The 500-540℃ molten salt output from the Hitec molten salt hot tank 14 is pumped by the second high-temperature pump 13 to the second molten salt-SCO2 heat exchanger 12 for primary heat release, with a temperature of 300-330℃ after heat release. It then enters the second molten salt precooler 11 for secondary heat release, with a temperature of 160-180℃ after heat release, and finally returns to the Hitec molten salt cold tank 10. Figure 1 In this process, deoxygenated water is drawn from the deaerator of the thermal power unit to absorb a large amount of waste heat released by fluoride molten salt and Hitec molten salt. The deoxygenated water with a pressure of 0.9-1.0 MPa and a temperature of 140-170℃ first enters the second molten salt precooler 11 to absorb the waste heat released by Hitec molten salt, reaching a state close to saturated water. Then it enters the evaporator 2 to absorb the high-temperature waste heat of fluoride molten salt and become saturated steam with a pressure of 0.6-0.9 MPa. Then it enters the first molten salt precooler 3 to continue to absorb the high-temperature waste heat of fluoride molten salt and become superheated steam with a temperature of 280-300℃.

[0045] refer to Figure 2When the power grid requires increased load, the energy stored in the molten salt heat exchanger in the integrated energy system is released. The heat released from the dual molten salt heat exchangers heats the S-CO2 to form a Brayton power cycle, thereby releasing energy. The specific process is as follows: After the S-CO2 with a pressure of 28-32 MPa is released from the high-pressure CO2 storage tank 24, it enters the first molten salt-SCO2 heat exchanger 4 and is heated to 600-620℃. Then it enters the CO2 main turbine 18 to expand and do work. The CO2 pressure at the outlet of the CO2 main turbine 18 is 16-18 MPa and the temperature is 380-420℃. The CO2 output from the CO2 main turbine 18 enters the second molten salt-SCO2 heat exchanger 12 and is heated to 500-520℃. Then it enters the C The CO2 in the auxiliary turbine 19 expands and does work. The CO2 pressure at the outlet of the auxiliary turbine 19 is 8-9 MPa and the temperature is 120-150℃. The CO2 output from the auxiliary turbine 19 is 90-100℃ after passing through the regenerator 25, and then cooled to 30-40℃ by the first cooler 22. This is higher than the critical state of CO2—7.39 MPa and 31.1℃. At this point, the density is close to that of a liquid and changes greatly with temperature and pressure, which greatly reduces the power consumption of the compressor 21. Then, the low-pressure CO2 is compressed to high-pressure CO2 of 28-32 MPa by the compressor 21, and is cooled to 30-40℃ again by the first cooler 22 before entering the high-pressure CO2 storage tank 24 for storage. The entire energy release process of CO2 is completed.

[0046] In the S-CO2 Brayton power cycle subsystem, the power of compressor 21 is provided by the CO2 diverted from the inlet of CO2 auxiliary turbine 19 to the CO2 turbine to do work. To further utilize energy efficiently and improve the power generation capacity of the S-CO2 Brayton power cycle, after the system is running stably, the second valve 29 can be opened and the first valve 28 can be closed. The superheated steam, which has absorbed heat and turned into 280-300℃, is then introduced into turbine 20 to provide power for compressor 21. The exhaust steam after doing work flows out from the third valve 30 and finally returns to the condenser of the thermal power unit. This allows for the utilization of low-grade energy and improves energy conversion efficiency.

[0047] When the S-CO2 formation Brayton power subsystem stops working, the fifth valve 32 is opened, and the low-pressure CO2 in the system is stored in the low-pressure CO2 storage tank 26 using the residual speed of the turbine 20. The remaining CO2 is stored in the high-pressure CO2 storage tank 24 through the compressor 21, and the entire working process is completed.

[0048] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0049] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0050] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A comprehensive energy system utilizing dual molten salt thermal storage and supercritical carbon dioxide energy release, characterized in that, It includes an S-CO2 Brayton power cycle subsystem and a dual molten salt thermal storage subsystem, wherein the dual molten salt thermal storage subsystem is coupled to the S-CO2 Brayton power cycle subsystem.

2. The integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release according to claim 1, characterized in that, The dual molten salt thermal storage subsystem includes a fluoride molten salt cold tank (1), a molten salt-main steam heat exchanger (8), a first electric heater (7), a fluoride molten salt hot tank (6), a first molten salt-SCO2 heat exchanger (4), a first molten salt precooler (3), an evaporator (2), a Hitec molten salt cold tank (10), a molten salt-reheat steam heat exchanger (16), a second electric heater (15), a Hitec molten salt hot tank (14), a second high-temperature pump (13), a second molten salt-SCO2 heat exchanger (12), a second molten salt precooler (11), and deoxygenated water pipelines; The outlet of the fluoride molten salt cold tank (1) is connected to the inlet of the fluoride molten salt cold tank (1) in sequence via the tube side of the molten salt-main steam heat exchanger (8), the first electric heater (7), the fluoride molten salt hot tank (6), the primary side of the first molten salt-SCO2 heat exchanger (4), the tube side of the first molten salt precooler (3), and the shell side of the evaporator (2); The outlet of the Hitec molten salt cold tank (10) is connected to the inlet of the Hitec molten salt cold tank (10) via the tube side of the molten salt-reheat steam heat exchanger (16), the second electric heater (15), the Hitec molten salt hot tank (14), the second high temperature pump (13), the primary side of the second molten salt-SCO2 heat exchanger (12), and the tube side of the second molten salt precooler (11). The deoxygenated water pipeline is connected to the S-CO2 Brayton power cycle subsystem via the shell side of the second molten salt precooler (11), the tube side of the evaporator (2), and the shell side of the first molten salt precooler (3).

3. The integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release according to claim 2, characterized in that, The outlet of the fluoride molten salt cold tank (1) is connected to the inlet of the fluoride molten salt cold tank (1) in sequence via the first cryogenic pump (9), the tube side of the molten salt-main steam heat exchanger (8), the first electric heater (7), the fluoride molten salt hot tank (6), the first high temperature pump (5), the primary side of the first molten salt-SCO2 heat exchanger (4), the tube side of the first molten salt precooler (3), and the shell side of the evaporator (2).

4. The integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release according to claim 2, characterized in that, The outlet of the Hitec molten salt cold tank (10) is connected to the inlet of the Hitec molten salt cold tank (10) via the second cryogenic pump (17), the tube side of the molten salt-reheat steam heat exchanger (16), the second electric heater (15), the Hitec molten salt hot tank (14), the second high temperature pump (13), the primary side of the second molten salt-SCO2 heat exchanger (12), and the tube side of the second molten salt precooler (11).

5. The integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release according to claim 2, characterized in that, The molten salts in the fluoride molten salt hot tank (6), Hitec molten salt hot tank (14), fluoride molten salt cold tank (1) and Hitec molten salt cold tank (10) are either fluoride system molten salts LiNaK fluorides or binary nitrate Hitec.

6. The integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release according to claim 2, characterized in that, Both the first electric heater (7) and the second electric heater (15) are powered by new energy sources.

7. The integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release according to claim 1, characterized in that, The S-CO2 Brayton power cycle subsystem includes a turbine (20), a third valve (30), a regenerator (25), a compressor (21), a CO2 high-pressure storage tank (24), a CO2 main turbine (18), a CO2 low-pressure storage tank (26), a CO2 auxiliary turbine (19), and a first valve (28). The outlet of turbine (20) is divided into two paths. One path is connected to the third valve (30), and the other path is connected to the inlet of the main CO2 turbine (18) via the primary side of the regenerator (25), compressor (21), CO2 high-pressure storage tank (24), secondary side of the regenerator (25), and secondary side of the first molten salt-SCO2 heat exchanger (4). The outlet of the main CO2 turbine (18) is divided into two paths. One path is connected to the inlet of the main CO2 turbine (18) via the CO2 low-pressure storage tank (26). The primary inlet of the heat exchanger (25) is connected to the secondary side of the second molten salt-SCO2 heat exchanger (12), and the other path is split into two paths after passing through the secondary side of the second molten salt-SCO2 heat exchanger (12). One path is connected to the inlet of the CO2 auxiliary turbine (19), and the other path is connected to the inlet of the turbine (20) through the first valve (28). The outlet of the CO2 auxiliary turbine (19) is connected to the primary inlet of the heat exchanger (25), and the shell side of the first molten salt precooler (3) is connected to the inlet of the turbine (20).

8. The integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release according to claim 7, characterized in that, The outlet of the turbine (20) is connected to the inlet of the CO2 main turbine (18) via the fourth valve (31), the primary side of the regenerator (25), the first cooler (22), the compressor (21), the second cooler (23), the CO2 high-pressure storage tank (24), the secondary side of the regenerator (25), the secondary side of the first molten salt-SCO2 heat exchanger (4).

9. The integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release according to claim 7, characterized in that, The outlet of the CO2 main turbine (18) is divided into two paths. One path is connected to the primary side inlet of the regenerator (25) via the fifth valve (32), the third cooler (27), the CO2 low-pressure storage tank (26) and the sixth valve (33). The shell side of the first molten salt precooler (3) is connected to the inlet of the turbine (20) via the second valve (29).

10. The integrated energy system using dual molten salt thermal storage and supercritical carbon dioxide energy release according to claim 7, characterized in that, The compressor (21) and the turbine (20) are arranged coaxially; The main CO2 turbine (18), the auxiliary CO2 turbine (19), and the generator are arranged coaxially.

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