A multifunctional Carnot battery system and its control method

Abstract

This disclosure provides a multifunctional Carnot battery system and control method, wherein the Brayton cycle heat pump unit includes: a compressor outlet connected in sequence to an air-molten salt heat exchanger group, a hot-side flow channel of an air-to-air heat exchanger, a hot-side flow channel of an air-to-water heat exchanger, an expander, a cold-side flow channel of an air-to-air heat exchanger, and an inlet returning to the compressor; a dual-salt heat storage unit thermally coupled to the air-molten salt heat exchanger group for storing heat generated by the Brayton cycle heat pump unit that is higher than the target temperature threshold; a steam Rankine cycle unit thermally coupled to the dual-salt heat storage unit for generating steam and driving power generation using the high-temperature heat energy released by the dual-salt heat storage unit; and a heating unit coupled to the cold-side flow channel of the air-to-water heat exchanger for storing heat from the waste heat generated by the Brayton cycle heat pump unit that is lower than the target temperature threshold after heat exchange by the dual-salt heat storage unit, and supplying heat to external heating equipment.

Description

Technical Field

[0001] This disclosure relates to the field of Carnot battery technology, and in particular to a multifunctional Carnot battery system and control method. Background Technology

[0002] As chemical energy sources continue to deplete and new energy power generation continues to develop rapidly, traditional thermal power plants are gradually transitioning to new energy power generation methods. However, the unstable nature of new energy sources leads to significant instability in power generation, which in turn causes instability in the power supply system.

[0003] The Carnot battery is a new type of energy storage technology that consists of three parts: electricity to heat, heat storage, and heat to electricity. It can convert excess electrical energy into heat energy for storage, and when renewable energy generation is insufficient or there is a peak in electricity demand, the stored heat energy can be converted back into electrical energy to feed back to the grid, thereby effectively smoothing out fluctuations in renewable energy output and improving the stability and reliability of the power system.

[0004] However, current Carnot batteries focus on power peak shaving, resulting in a single function. Summary of the Invention

[0005] This disclosure provides a multifunctional Carnot battery system and control method, which aims to solve the problem of Carnot batteries having only one function.

[0006] In a first aspect, this disclosure provides a multifunctional Carnot battery system, which may include: a Brayton cycle heat pump unit, a dual-salt thermal storage unit, a vapor Rankine cycle unit, and a heating unit. The Brayton cycle heat pump unit includes: a compressor, an air-molten salt heat exchanger assembly, an air-to-air heat exchanger, an air-to-water heat exchanger, and an expander. The outlet of the compressor is sequentially connected to the air-molten salt heat exchanger assembly, the hot-side flow channel of the air-to-air heat exchanger, the hot-side flow channel of the air-to-water heat exchanger, the expander, the cold-side flow channel of the air-to-air heat exchanger, and returns to the inlet of the compressor. The dual-salt thermal storage unit is thermally coupled to the air-molten salt heat exchanger assembly to store heat generated by the Brayton cycle heat pump unit that exceeds the target temperature threshold. The steam Rankine cycle unit is thermally coupled to the dual-salt thermal storage unit to generate steam using the high-temperature heat energy released by the dual-salt thermal storage unit and to drive power generation. The heating unit is coupled to the cold-side flow channel of the air-water heat exchanger to store heat generated by the Brayton cycle heat pump unit that is below the target temperature threshold from the waste heat after heat exchange by the dual-salt thermal storage unit and to supply heat to external heating equipment.

[0007] In some embodiments, the heating unit is also coupled to the steam Rankine cycle unit for storing the heat of the steam in the steam Rankine cycle unit and supplying heat to the external heating equipment.

[0008] In some embodiments, the heating unit includes: a first circulation subunit and a second circulation subunit that are independent of each other; the first circulation subunit includes: a first water pump and a hot water storage tank, wherein the circulating medium at the cold side outlet of the air-water heat exchanger passes sequentially through the first water pump and the hot water storage tank and returns to the cold side inlet of the air-water heat exchanger, forming a closed heat storage circulation loop; the second circulation subunit includes: a second water pump, a heat network-water heat exchanger and a heat network pipeline, wherein the circulating medium at the outlet of the hot water storage tank passes sequentially through the second water pump and the heat network-water heat exchanger and returns to the inlet of the hot water storage tank, forming a closed heat release circulation loop, wherein the heat release target is the heat network pipeline, and the heat network pipeline is connected to the external heating equipment.

[0009] In some embodiments, the air-molten salt heat exchanger assembly includes: a first air-molten salt heat exchanger and a second air-molten salt heat exchanger, with the compressor outlet sequentially connected to the first air-molten salt heat exchanger, the second air-molten salt heat exchanger, and the air-to-air heat exchanger; the dual-salt thermal storage unit includes: a solar salt molten salt high-temperature thermal storage tank, a solar salt molten salt low-temperature thermal storage tank, a Hitec salt molten salt high-temperature thermal storage tank, and a Hitec salt molten salt low-temperature thermal storage tank; the steam Rankine cycle unit includes: a preheater, an evaporator, and a superheater connected in sequence; wherein, the first air-molten salt heat exchanger, the solar salt molten salt high-temperature thermal storage tank, and the solar salt molten salt low-temperature thermal storage tank constitute a first circulation loop, which flows sequentially through the superheater and the evaporator; the second air-molten salt heat exchanger, the Hitec salt molten salt high-temperature thermal storage tank, and the Hitec salt molten salt low-temperature thermal storage tank constitute a second circulation loop, which flows through the preheater.

[0010] In some embodiments, the steam Rankine cycle unit further includes: a high-pressure cylinder of a steam turbine, an intermediate-pressure cylinder of a steam turbine, a low-pressure cylinder of a steam turbine, a rotor, a generator, a reheater, a condenser, and an extraction pipe. The high-pressure cylinder, the intermediate-pressure cylinder, and the low-pressure cylinder are coaxially mounted on the rotor. The rotor drives the generator to generate electricity. The first circulation loop also flows through a reheater arranged parallel to the superheater. The steam outlet of the superheater is sequentially connected to the high-pressure cylinder of the steam turbine, the reheater, and the... The intermediate-pressure cylinder of the steam turbine is connected to the preheater. The exhaust port of the intermediate-pressure cylinder is also connected to the inlet of the low-pressure cylinder of the steam turbine and the inlet of the extraction pipe. The exhaust port of the low-pressure cylinder is connected to the inlet of the condenser and the inlet of the preheater in sequence. The extraction pipe is connected to the condenser. The heating unit also includes a heat network-steam heat exchanger, which is thermally coupled to the extraction pipe to obtain heat from the extraction pipe and release heat to the heat network pipeline.

[0011] In some embodiments, the temperature range of the solar molten salt high-temperature thermal storage tank is 556-560℃; the temperature range of the solar molten salt low-temperature thermal storage tank is 358-362℃; the temperature range of the Hitec molten salt high-temperature thermal storage tank is 358-362℃; and the temperature range of the Hitec molten salt low-temperature thermal storage tank is 288-292℃.

[0012] In some embodiments, the multifunctional Carnot battery system may further include: a steam supply unit for supplying steam to external steam-using equipment; wherein the steam supply unit is thermally coupled to the dual-salt thermal storage unit and adjusts the temperature of the steam in the steam supply unit by the heat provided by the dual-salt thermal storage unit; and / or, the steam supply unit is thermally coupled to the steam Rankine cycle unit and obtains the high-temperature steam generated in the steam Rankine cycle unit.

[0013] In some embodiments, the steam supply unit includes: a steam supply water tank, a steam supply pump, a first deaerator, a heating-molten salt heat exchanger, and a heating header connected in sequence. The heating-molten salt heat exchanger is thermally coupled to the dual-salt heat storage unit to adjust the temperature of the steam in the heating header through the heat provided by the dual-salt heat storage unit. The heating header is thermally coupled to the steam Rankine cycle unit and obtains the high-temperature steam generated in the steam Rankine cycle unit. The heating header is used to supply steam to an external steam network.

[0014] Secondly, this disclosure provides a multifunctional Carnot battery control method, applied to the system described in any one of the first aspects, comprising: during a first power consumption period, controlling the operation of the Brayton cycle heat pump unit, the operation of the dual-salt heat storage unit, and the shutdown of the steam Rankine cycle unit, wherein the dual-salt heat storage unit stores heat generated by the Brayton cycle heat pump unit exceeding a target temperature threshold, and the heating unit stores heat generated by the Brayton cycle heat pump unit below the target temperature threshold, and when there is a heating demand, controlling the heating unit to supply heat to external heating equipment; during a second power consumption period, controlling the shutdown of the Brayton cycle heat pump unit, the operation of the dual-salt heat storage unit, and the operation of the steam Rankine cycle unit, wherein the dual-salt heat storage unit releases the heat stored during the first power consumption period, causing the steam Rankine cycle unit to generate steam and generate electricity; wherein the power consumption during the first power consumption period is less than the power consumption during the second power consumption period.

[0015] In some embodiments, during the first power consumption period, the dual-salt thermal storage unit is controlled to supply heat to the steam supply unit; and / or, during the second power consumption period, the steam Rankine cycle unit is controlled to supply heat to the heating unit and / or supply steam to the steam supply unit.

[0016] Through the above technical solution, the multifunctional Carnot battery system and control method disclosed herein can include: a Brayton cycle heat pump unit, a dual-salt thermal storage unit, a steam Rankine cycle unit, and a heating unit. The Brayton cycle heat pump unit generates heat energy when energized, while the dual-salt thermal storage unit stores heat energy at temperatures above a target temperature threshold and releases this heat energy when renewable energy supply is insufficient. This heat energy is then converted into electrical energy by the steam Rankine cycle unit, thus contributing to a stable power supply. Simultaneously, the heating unit stores heat energy at temperatures below the target temperature threshold and releases it to external heating equipment during heating seasons and other scenarios requiring heating. Therefore, this multifunctional Carnot battery system not only possesses the ability to stabilize the power system but also provides heating functionality, effectively expanding the system's functionality and comprehensive application value.

[0017] The above description is only an overview of the technical solution of this disclosure. In order to better understand the technical means of this disclosure and to implement it in accordance with the contents of the specification, the preferred embodiments of this disclosure are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the structure of the multifunctional Carnot battery system provided in this disclosure. Figure 1 ; Figure 2 A schematic diagram of the structure of the multifunctional Carnot battery system provided in this disclosure. Figure 2 ; Figure 3 This is a partial schematic diagram of the heating unit of the multifunctional Carnot battery system provided in this disclosure; Figure 4 A schematic diagram of the structure of the multifunctional Carnot battery system provided in this disclosure. Figure 3 ; Figure 5 A schematic diagram of the structure of the multifunctional Carnot battery system provided in this disclosure. Figure 4 ; Figure 6 This is a control schematic diagram of the multifunctional Carnot battery control method provided in this disclosure. Figure 1 ; Figure 7 This is a control schematic diagram of the multifunctional Carnot battery control method provided in this disclosure. Figure 2 .

[0020] Explanation of reference numerals in the attached figures: 10. Multifunctional Carnot Battery System; 11. Brayton Cycle Heat Pump Unit; 111. Compressor; 112. Air-Molten Salt Heat Exchanger Assembly; 1121. First Air-Molten Salt Heat Exchanger; 1122. Second Air-Molten Salt Heat Exchanger; 113. Air-Air Heat Exchanger; 114. Air-Water Heat Exchanger; 115. Expander; 116. Ninth Valve; 13. Dual-Salt Thermal Storage Unit; 131. Solar Salt Molten Salt High-Temperature Thermal Storage Tank; 132. Solar Salt Molten Salt Low-Temperature Thermal Storage Tank 133. High-temperature thermal storage tank with Hitec molten salt; 134. Low-temperature thermal storage tank with Hitec molten salt; 135. First circulation pump; 136. Third valve; 137. Fourth valve; 138. Second circulation pump; 139. Fifth valve; 140. Sixth valve; 15. Steam Rankine cycle unit; 151. Preheater; 152. Evaporator; 153. Superheater; 154. High-pressure cylinder of steam turbine; 155. Intermediate-pressure cylinder of steam turbine; 156. Low-pressure cylinder of steam turbine 157. Cylinder; 158. Rotor; 159. Generator; 160. Reheater; 161. Condenser; 162. Extraction pipe; 163. Seventh valve; 164. Eighth valve; 165. Second deaerator; 166. Third water pump; 167. High-pressure heating group; 168. Condensate pump; 179. Low-pressure heating group; 170. Heating unit; 171. First circulation subunit; 1711. First water pump; 1712. Hot water storage tank; 1713. First valve; 172. 1721. Second circulation subunit; 1722. Second water pump; 1723. Heat network-water heat exchanger; 1724. Heat network pipeline; 1725. Second valve; 173. Heat network-steam heat exchanger; 174. Tenth valve; 19. Steam supply unit; 191. Steam supply water tank; 192. Steam supply pump; 193. First deaerator; 194. Heating-molten salt heat exchanger; 195. Heating header; 196. Eleventh valve; 197. Twelfth valve; 198. Thirteenth valve. Detailed Implementation

[0021] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0022] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0023] It should be noted that, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0024] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.

[0025] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure depending on the specific circumstances. When a particular device is described as being located between a first device and a second device, an intermediary device may or may not be present between the particular device and the first or second device.

[0026] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0027] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0028] As chemical energy sources continue to deplete and new energy power generation continues to develop rapidly, traditional thermal power plants are gradually transitioning to new energy power generation methods. However, the unstable nature of new energy sources leads to significant instability in power generation, which in turn causes instability in the power supply system.

[0029] The Carnot battery is a new type of energy storage technology that consists of three parts: electricity to heat, heat storage, and heat to electricity. It can convert excess electrical energy into heat energy for storage, and when renewable energy generation is insufficient or there is a peak in electricity demand, the stored heat energy can be converted back into electrical energy to feed back to the grid, thereby effectively smoothing out fluctuations in renewable energy output and improving the stability and reliability of the power system.

[0030] However, current Carnot batteries focus on power peak shaving, resulting in a single function.

[0031] The inventors of this disclosure have discovered that a multifunctional Carnot battery system and control method can be designed. This system can include: a Brayton cycle heat pump unit, a dual-salt thermal storage unit, a steam Rankine cycle unit, and a heating unit. The Brayton cycle heat pump unit can convert surplus low-cost electrical energy into heat energy when the power supply exceeds the power consumption. The dual-salt thermal storage unit can store the converted heat energy above a target temperature threshold and release the heat energy when renewable energy sources are insufficient. The released heat energy can then be converted into electrical energy through the steam Rankine cycle unit, thus stabilizing the power supply of the electrical system. Simultaneously, the heating unit can store the converted heat energy below the target temperature threshold and release the heat energy to external heating equipment during the heating season or when heating is required. Thus, the multifunctional Carnot battery system not only has the function of stabilizing the power system but also provides heating, enriching the system's functionality and improving the utilization rate of the heat energy converted by the Brayton cycle heat pump unit.

[0032] First aspect This disclosure provides a multifunctional Carnot battery system 10, see [link to relevant documentation]. Figure 1As shown, the multifunctional Carnot battery system 10 may include: a Brayton cycle heat pump unit 11, a dual-salt thermal storage unit 13, a steam Rankine cycle unit 15, and a heating unit 17. The Brayton cycle heat pump unit 11 may include: a compressor 111, an air-molten salt heat exchanger assembly 112, an air-to-air heat exchanger 113, an air-to-water heat exchanger 114, and an expander 115. The outlet of the compressor 111 is sequentially connected to the hot side flow channel of the air-to-molten salt heat exchanger assembly 112, the hot side flow channel of the air-to-air heat exchanger 113, the hot side flow channel of the air-to-water heat exchanger 114, the expander 115, the cold side of the air-to-air heat exchanger 113, and... The heat is returned to the inlet of compressor 111; the dual-salt heat storage unit 13 is thermally coupled to the air-molten salt heat exchanger group 112 to store the heat generated by the Brayton cycle heat pump unit 11 that is higher than the target temperature threshold; the steam Rankine cycle unit 15 is thermally coupled to the dual-salt heat storage unit 13 to generate steam using the high-temperature heat energy released by the dual-salt heat storage unit 13 and drive power generation; the heating unit 17 is coupled to the cold side flow channel of the air-water heat exchanger 114 to store the heat generated by the Brayton cycle heat pump unit 11 that is lower than the target temperature threshold from the waste heat after heat exchange by the dual-salt heat storage unit 13, and to supply heat to the external heating equipment.

[0033] In the Brayton cycle heat pump unit 11, air is used as the working fluid in the cycle. It passes sequentially through the compressor 111, the hot side of the air-molten salt heat exchanger group 112, the hot side of the air-air heat exchanger 113, and the hot side of the air-water heat exchanger 114. Then, it enters the expansion turbine through the inlet of the expander 115. Finally, the working fluid passes through the cold side of the air-air heat exchanger 113 and re-enters the compressor 111 for circulation. During this process, the compressor 111 compresses and heats the air to form high-temperature and high-pressure air and generates a large amount of heat. The portion of this heat that is released in the air-molten salt heat exchanger group 112 with a temperature greater than the target temperature threshold (such as 290°C) is given to the dual-salt heat storage unit 13, and the portion that is released in the air-water heat exchanger 114 with a temperature less than the target temperature threshold is given to the heating unit 17. After entering the expander 115, the air does work to cool down and drives the external power generation equipment to generate electricity. The electrical energy that drives the compressor 111 can be low-priced electricity during off-peak periods when the supply exceeds the demand, or abandoned electricity; the compressor 111 can be a centrifugal compressor 111, etc., and the expander 115 can be a vortex expander 115, etc.

[0034] The dual-salt thermal storage unit 13 can exchange the heat generated in the Brayton cycle heat pump unit 11 that is greater than the target temperature threshold with itself through the air-molten salt heat exchanger group 112. Alternatively, it can directly convert low-priced electricity or waste electricity into heat energy and supply it to the dual-salt thermal storage unit 13 through electric heaters (such as resistance heating, electric heating rods, etc.) that are close to or connected to the dual-salt thermal storage unit 13, so as to realize the storage of high-temperature heat energy by the molten salt in the dual-salt thermal storage unit 13.

[0035] In the steam Rankine cycle unit 15, the water inside absorbs heat and turns into steam when the heat energy released by the dual-salt thermal storage unit 13 is released. The steam can drive the steam turbine to work. The mechanical energy generated by the steam turbine can be provided to the shaft of the generator 158 to generate electricity. The steam that has passed through the steam turbine can be condensed and pressurized again to restore it to water for the next power generation cycle.

[0036] The heating unit 17 can transfer heat from the waste heat generated in the Brayton cycle heat pump unit 11 that is less than the target temperature threshold after being exchanged by the dual-salt heat storage unit 13 to itself through the air-water heat exchanger 114, and then supply heat to the external heating equipment.

[0037] A control method for the multi-functional Carnot battery system 10 may include: a first power consumption period, which is a low-power period (e.g., nighttime, when electricity prices are low, hereinafter referred to as low-price electricity), during which the low-price electricity acts on the compressor 111, causing the Brayton cycle heat pump unit 11 to generate heat, which is then sequentially supplied to the dual-salt thermal storage unit 13 and the heating unit 17 for temperature-decreasing storage. The heat stored in the dual-salt thermal storage unit 13 can be released to the steam Rankine cycle unit 15 during peak power consumption periods (e.g., the second power consumption period) to generate electricity. The heat stored in the heating unit 17 can be released to external heating equipment (e.g., user-side heaters) during the heating season. In the second power consumption period, which is a peak power consumption period (e.g., daytime, when electricity prices are high), the dual-salt thermal storage unit 13 releases the heat stored in the first power consumption period, causing the steam Rankine cycle unit 15 to generate steam and generate electricity.

[0038] In this embodiment, the multifunctional Carnot battery system 10 may include: a Brayton cycle heat pump unit 11, a dual-salt thermal storage unit 13, a steam Rankine cycle unit 15, and a heating unit 17. The Brayton cycle heat pump unit 11 can convert surplus low-cost electrical energy into heat energy when the power supply exceeds the power consumption. The dual-salt thermal storage unit 13 can store the heat energy above the target temperature threshold and release the heat energy when new energy sources are insufficient. The released heat energy can then be converted into electrical energy through the steam Rankine cycle unit 15 to stabilize the power supply of the power system. At the same time, the heating unit 17 can store the heat energy below the target temperature threshold and release the heat energy to external heating equipment when heating is needed, such as during the heating season. Thus, the multifunctional Carnot battery system 10 not only has the function of stabilizing the power system but also has the function of heating, which enriches the functions of the system. At the same time, it reduces the heat loss generated by the Brayton cycle heat pump unit 11, thereby increasing the overall efficiency of the multifunctional Carnot battery system 10. In addition, the multifunctional Carnot battery system 10 has no chemical degradation during use, is safe and has a long service life, and has no carbon emissions. Compared with coal power, it is more environmentally friendly and more in line with the national development strategy.

[0039] Since Carnot batteries do not rely on specific resource geographical conditions (such as reservoirs or caves), they are suitable for large-scale modular deployment in new energy industrial parks. They can be used in conjunction with photovoltaic, thermal, and wind power generation to drive the compressor 111, and are also applicable to the retrofitting of abandoned power plants. For example, the multi-functional Carnot battery system 10 can be applied to the retrofitting of abandoned thermal power plants. The power generation portion of the steam Rankine cycle unit 15 can utilize the power generation portion of the abandoned thermal power plant, thereby reducing the cost of the multi-functional Carnot battery system 10. Simultaneously, the thermal power generation of the original thermal power plant and the Brayton cycle heat pump unit 11 can jointly serve as a heat source. After storing heat through the dual-salt thermal storage unit 13, the heat is generated by the steam Rankine cycle unit 15, thus reducing the use and emissions of chemical resources such as coal.

[0040] In some embodiments, see Figure 2 and Figure 4 As shown, the heating unit 17 is also coupled to the steam Rankine cycle unit 15 to store the heat of the steam in the steam Rankine cycle unit 15 and to supply heat to the external heating equipment.

[0041] In other words, the heat from the heating unit 17 can be provided directly by the Brayton cycle heat pump unit 11 (as in the first power consumption period) or by steam from the steam Rankine cycle unit 15 (as in the second power consumption period), thus ensuring the stability and continuity of heating.

[0042] In some embodiments, see Figure 1 , Figure 2 and Figure 5 As shown, the heating unit 17 may include: a first circulation subunit 171 and a second circulation subunit 172 that are independent of each other; the first circulation subunit 171 includes: a first water pump 1711 and a hot water storage tank 1712. The circulating medium from the cold side outlet of the air-water heat exchanger 114 passes through the first water pump 1711 and the hot water storage tank 1712 in sequence and then returns to the cold side inlet of the air-water heat exchanger 114, forming a closed heat storage circulation loop; the second circulation subunit 172 includes: a second water pump 1721, a heat network-water heat exchanger 1722 and a heat network pipeline 1723. The circulating medium from the outlet of the hot water storage tank 1712 passes through the second water pump 1721 and the heat network-water heat exchanger 1722 in sequence and then returns to the inlet of the hot water storage tank 1712, forming a closed heat release circulation loop, and the heat release object is the heat network pipeline 1723, which is connected to the external heating equipment.

[0043] In the first circulation subunit 171, the circulation medium can be water. Driven by the first water pump 1711, the water circulates between the hot water storage tank 1712 and the cold side of the air-water heat exchanger 114. The water flowing to the air-water heat exchanger 114 can absorb the heat transferred from the hot side of the air-water heat exchanger 114 and store it in the hot water storage tank 1712, thus accumulating thermal energy. The first circulation subunit 171 can also be equipped with a first valve 1713, which is used to control the opening and closing of the circulation medium in the circulation subunit. The hot water storage tank 1712 can be provided with a first opening and a second opening. The first opening located at the upper position is connected to the first water pump 1711, and the second opening located at the lower position is connected to the cold side inlet of the air-water heat exchanger 114. In this way, the gravitational potential energy of the water in the hot water storage tank 1712 assists the flow of the circulation medium, thereby reducing the power consumption of the first water pump 1711.

[0044] In the second circulation subunit 172, the circulation medium can be water. Driven by the second water pump 1721, the water circulates between the hot water storage tank 1712 and the hot side of the heat network-water heat exchanger 1722. The water flowing to the hot water storage tank 1712 can absorb the heat from the hot water storage tank 1712 (such as the heat stored in the hot water storage tank 1712 during the circulation process through the first circulation subunit 171), and after flowing to the hot side of the heat network-water heat exchanger 1722, it exchanges heat to its cold side and transfers it to the heat network pipeline 1723. The heat network pipeline 1723 is connected to the external heating equipment so as to provide heating to the external heating equipment. The second circulation subunit 172 can also be equipped with a second valve 1724, which is used to control the on / off of the circulation medium in the circulation subunit.

[0045] Here, when the second circulation subunit 172 is running, the first circulation subunit 171 can be in a circulation state or a stopped state. When the first circulation subunit 171 is in a circulation state, the heat source obtained by the second circulation subunit 172 can be the heat energy input by the first circulation subunit 171 to the hot water storage tank 1712 in real time. When the first circulation subunit 171 is in a stopped state, the second circulation subunit 172 can obtain the previously stored heat from the hot water storage tank 1712 to realize the retrieval of historical heat energy.

[0046] In this embodiment, the heating unit 17 achieves efficient storage and on-demand release of thermal energy by placing the heat storage function and the heat release function in the independent first circulation subunit 171 and the second circulation subunit 172, respectively. At the same time, the first circulation subunit 171 can store heat using the low-temperature heat of the Brayton cycle heat pump unit 11 during the non-heating season or the first period of electricity consumption (low load stage). When the heating season arrives, the stored heat is released to the heating network system through the second circulation subunit 172 to meet the heating demand, improve the flexibility of system operation, and also help to match the time inconsistency between heat source and heat load, thereby improving the overall energy utilization efficiency.

[0047] In some embodiments, see Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the air-molten salt heat exchanger assembly 112 includes: a first air-molten salt heat exchanger 1121 and a second air-molten salt heat exchanger 1122. The outlet of the compressor 111 is sequentially connected to the first air-molten salt heat exchanger 1121, the second air-molten salt heat exchanger 1122, and an air-to-air heat exchanger 113. The dual-salt thermal storage unit 13 may include: a solar salt molten salt high-temperature thermal storage tank 131, a solar salt molten salt low-temperature thermal storage tank 132, a Hitec salt molten salt high-temperature thermal storage tank 133, and a Hitec salt molten salt low-temperature thermal storage tank 134; steam The Rankine cycle unit 15 includes a preheater 151, an evaporator 152, and a superheater 153 connected in sequence; wherein, a first air-molten salt heat exchanger 1121, a solar salt molten salt high-temperature heat storage tank 131, and a solar salt molten salt low-temperature heat storage tank 132 constitute a first circulation loop, which flows through the superheater 153 and the evaporator 152 in sequence; a second air-molten salt heat exchanger 1122, a Hitec salt molten salt high-temperature heat storage tank 133, and a Hitec salt molten salt low-temperature heat storage tank 134 constitute a second circulation loop, which flows through the preheater 151.

[0048] Sun salt molten salt, which can be composed of 60% sodium nitrate ( ) and 40% potassium nitrate ( This mixed molten salt, composed of 7% sodium nitrate, exhibits good thermal stability and is suitable for medium- to high-temperature thermal storage within a temperature range of approximately 290°C to 565°C. Hitec molten salt can be composed of 7% sodium nitrate (… ), 40% sodium nitrite ( ) and 53% potassium nitrate ( The mixed molten salt, formed by mixing these components, has a low melting point and is suitable for a temperature range of approximately 150°C to 500°C, making it ideal for medium- and low-temperature thermal storage. The preheater 151 heats the circulating medium (e.g., water) within the steam Rankine cycle unit 15 to near saturation temperature; the evaporator 152 completely vaporizes the water preheated in the preheater 151 into saturated steam; and the superheater 153 further heats the saturated steam after the evaporator 152 into superheated steam to improve the thermal efficiency of the steam Rankine cycle unit 15.

[0049] The high-temperature, high-pressure air discharged from the compressor 111 first enters the first air-molten salt heat exchanger 1121, where the first gradient heat is transferred to the first circulation loop. Then it enters the second air-molten salt heat exchanger 1122, where the second gradient heat (less than or equal to the first gradient heat) is transferred to the first circulation loop. Subsequently, at the air-water heat exchanger 114, the third gradient heat (less than or equal to the second gradient heat) is transferred to the first circulation subunit 171.

[0050] In the first circulation loop, solar salt molten salt is pumped out from the solar salt molten salt low-temperature storage tank 132, flows through the first air-molten salt heat exchanger 1121 and is heated by high-temperature air before entering the solar salt molten salt high-temperature storage tank 131 for storage. The first circulation loop may include a first circulation pump 135, a third valve 136, and a fourth valve 137. The first circulation pump 135 provides driving force to the solar salt molten salt low-temperature storage tank 132, so that the solar salt molten salt inside has a pumping force. The third valve 136 controls the on / off connection between the solar salt molten salt low-temperature storage tank 132 and the first circulation pump 135. The fourth valve 137 controls whether the solar salt molten salt high-temperature storage tank 131 transfers heat with the steam Rankine cycle unit 15. For example, when power generation is required, the fourth valve 137 is opened, and the high-temperature solar salt molten salt flows out from the solar salt molten salt high-temperature storage tank 131, flows through the heater 153 and the evaporator 152 in sequence, transfers heat to the water / steam working fluid, cools down itself, and returns to the solar salt molten salt low-temperature storage tank 132 to complete the cycle.

[0051] In the second circulation loop, Hitec molten salt is pumped out from Hitec molten salt low-temperature heat storage tank 134, heated by medium-temperature air in the second air-molten salt heat exchanger 1122, and then stored in Hitec molten salt high-temperature heat storage tank 133. The second circulation loop may include a second circulation pump 138, a fifth valve 139, and a sixth valve 140. The second circulation pump 138 provides driving force to the Hitec molten salt cryogenic storage tank 134, enabling the Hitec molten salt within it to have a pumping force. The fifth valve 139 controls the connection between the Hitec molten salt cryogenic storage tank 134 and the second circulation pump 138. The sixth valve 140 controls whether the solar molten salt high-temperature storage tank 131 transfers heat with the steam Rankine cycle unit 15. For example, when power generation or heat release is required, the sixth valve 140 opens, and the high-temperature Hitec molten salt flows out from the Hitec molten salt high-temperature storage tank 133, flows through the preheater 151, and is used to preheat the water medium in the steam Rankine cycle unit 15 or release heat to other structures (such as the steam supply unit 19 mentioned below). After cooling, it returns to the Hitec molten salt cryogenic storage tank 134.

[0052] In this embodiment, the high-temperature section (first gradient) heat (from the compressed air of the compressor 111) generated by the Brayton cycle heat pump unit 11 is provided by high thermal stability solar salt, which is used to generate superheated steam in the steam Rankine cycle unit 15; the medium-temperature section (second gradient) heat is recovered by low melting point Hitec salt, which is used to heat the water medium in the steam Rankine cycle unit 15 or to release heat to other structures, thereby achieving gradient-level heat storage, reducing heat loss and improving energy utilization efficiency. At the same time, it avoids the problem of "using high-temperature molten salt in low-temperature section" or failure of low-temperature molten salt in high-temperature section, and achieves precise temperature matching between heat source and heat storage medium.

[0053] In some embodiments, see Figure 1 , Figure 2 , Figure 4 and Figure 5As shown, the steam Rankine cycle unit 15 may further include: a high-pressure cylinder 154, an intermediate-pressure cylinder 155, a low-pressure cylinder 156, a rotor 157, a generator 158, a reheater 159, a condenser 160, and an extraction pipe 161. The high-pressure cylinder 154, intermediate-pressure cylinder 155, and low-pressure cylinder 156 are coaxially mounted on the rotor 157. The rotor 157 drives the generator 158 to generate electricity. The first circulation loop also flows through the reheater 159, which is arranged parallel to the superheater 153. The steam outlet of the superheater 153 is sequentially connected to the high-pressure cylinder 154, the intermediate-pressure cylinder 155, the low-pressure cylinder 156, the generator 158, the reheater 159, the condenser 160, and the extraction pipe 161. The heating unit 17 is connected to the heat exchanger 159, the intermediate pressure cylinder 155 of the steam turbine, and the preheater 151. The exhaust port of the intermediate pressure cylinder 155 of the steam turbine is also connected to the inlet of the low pressure cylinder 156 of the steam turbine and the inlet of the extraction pipe 161. The exhaust port of the low pressure cylinder 156 of the steam turbine is connected to the inlet of the condenser 160 and the inlet of the preheater 151 in sequence. The extraction pipe 161 is connected to the condenser 160. The heating unit 17 may also include a heat network-steam heat exchanger 173, which is thermally coupled to the extraction pipe 161 to obtain heat from the extraction pipe 161 and release heat to the heat network pipeline 1723.

[0054] The high-pressure cylinder 154, intermediate-pressure cylinder 155, and low-pressure cylinder 156 of the steam turbine are coaxially mounted on the rotor 157 to form a multi-stage expansion and power-generating mechanism. The generator 158 can be directly driven by the rotor 157 to convert mechanical energy into electrical energy. The solar salt molten salt high-temperature heat storage tank 131 can be connected to the superheater 153 and the reheater 159 through a distributor to simultaneously distribute the heat in the solar salt molten salt high-temperature heat storage tank 131 to the superheater 153 and the reheater 159. After the two portions of solar salt merge, they both enter the evaporator 152, and then sequentially enter the solar salt molten salt low-temperature heat storage tank 132, the first air-molten salt heat exchanger 1121, and finally into the solar salt molten salt high-temperature heat storage tank 131. The reheater 159 is used to reheat the steam output from the high-pressure cylinder 154 of the steam turbine. The condenser 160 is used to condense the exhaust steam from the low-pressure cylinder 156 of the steam turbine into condensate and supply it to the preheater 151. The extraction pipe 161 draws out part of the steam from the exhaust port of the intermediate-pressure cylinder 155 of the steam turbine for heat exchange with the heat network-steam heat exchanger 173, and then supplies heat to the heating unit 17 through the heat network pipeline 1723.

[0055] The high-temperature, high-pressure superheated steam output from superheater 153 first enters the high-pressure cylinder 154 of the turbine for expansion and work, then enters the reheater 159 for secondary heating by solar salt molten salt, and is then sent to the intermediate-pressure cylinder 155 of the turbine for further work. The exhaust steam from the intermediate-pressure cylinder 155 is divided into three paths: one path enters the low-pressure cylinder 156 of the turbine for further expansion and work, one path is led out through the extraction pipe 161 to the heat network-steam heat exchanger 173 for heating, and one path enters the preheater 151 for steam Rankine cycle. The exhaust steam from the low-pressure cylinder 156 and the extraction pipe 161 enters the condenser 160 for condensation into saturated condensate, which is then transported to the preheater 151 for steam Rankine cycle. Here, after passing through superheater 153, the steam sequentially passes through the high-pressure cylinder 154, intermediate-pressure cylinder 155, and low-pressure cylinder 156 of the turbine for expansion and work, driving the generator 158 to generate electricity.

[0056] In this embodiment, during the heating season, the multifunctional Carnot battery system 10 can provide real-time heating through the low-temperature heat circulating in the Brayton cycle heat pump unit 11 using the first cycle subunit 171 and the second cycle subunit 172. It can also provide heating through the heat previously stored in the hot water storage tank 1712 in the first cycle subunit 171, or through steam extraction from the steam Rankine cycle unit 15 via the extraction pipe 161. One or more of these three methods can be flexibly selected. Furthermore, the condensate from the exhaust steam from the turbine low-pressure cylinder 156 and the extraction pipe 161 is heated in the preheater 151 by the second cycle loop (Hitec molten salt loop) and then flows sequentially through the evaporator 152 and the superheater 153, completing the heating, vaporization, and superheating process of the Rankine cycle working fluid, thus achieving working fluid recovery and recycling.

[0057] It should be noted that the connection between the extraction pipe 161 and the high-pressure cylinder 154 of the steam turbine will significantly reduce the steam flow into the subsequent intermediate and low-pressure cylinders, greatly reducing the work capacity of the intermediate and low-pressure cylinders and affecting the stability of power generation. The connection between the extraction pipe 161 and the low-pressure cylinder 156 of the steam turbine will cause risks such as water hammer in the extraction pipe 161 and corrosion or scaling of the heat exchanger 173 due to the steam being close to the saturated wet steam zone. In contrast, the intermediate-pressure cylinder 155 of the steam turbine usually still contains dry saturated or slightly superheated steam with stable quality, which is suitable for external supply.

[0058] In some embodiments, see Figure 1 , Figure 2 , Figure 4 and Figure 5As shown, the steam Rankine cycle unit 15 may further include: a seventh valve 162, an eighth valve 163, a second deaerator 164, a third water pump 165, a high-pressure heating group 166, a condensate pump 167, and a low-pressure heating group 168; the seventh valve 162 is located between the superheater 153 and the high-pressure cylinder 154 of the steam turbine to control the steam flow between them; the eighth valve 163 is located between the reheater 159 and the intermediate-pressure cylinder 155 of the steam turbine to control the steam flow between them. The second deaerator 164, the third water pump 165, and the high-pressure heating group 166 are sequentially arranged between the intermediate pressure cylinder 155 and the preheater 151 of the steam turbine to achieve deep deaeration, pressurization, and high-temperature regenerative heating of the working fluid; the condensate pump 167 and the low-pressure heating group 168 are sequentially arranged between the condenser 160 and the second deaerator 164 to pressurize and transport the condensate output from the condenser 160 to the second deaerator 164 for deep deaeration, pressurization, and high-temperature regenerative heating.

[0059] Here, the saturated condensate generated by the condenser 160 is first pressurized by the condensate pump 167, and then flows through the low-pressure heating group 168 (composed of multiple low-pressure heaters) for the first heating. After being deoxygenated by the second deaerator 164, the condensate is then heated a second time to the saturation temperature using steam extracted from the intermediate-pressure cylinder 155 of the turbine. This causes non-condensable gases such as oxygen and carbon dioxide dissolved in the water to be released and discharged, thereby significantly reducing the corrosion risk of downstream equipment (such as boilers and pipelines). Then, the third water pump 165 further pressurizes the condensate and makes it flow through the high-pressure heating group 166. The high-pressure heating group 166 (composed of several high-pressure heaters) regenerates the feedwater at high temperature, bringing it close to or reaching the temperature required at the inlet of the evaporator 152, which greatly improves the efficiency of the Rankine cycle.

[0060] In this embodiment, a complete regenerative feedwater system is constructed by condensate pump 167, low-pressure heating group 168, second deaerator 164, third water pump 165, and high-pressure heating group 166. This system can effectively remove dissolved oxygen and reduce system corrosion. At the same time, it recovers waste heat from the low-pressure cylinder 156 and intermediate-pressure cylinder 155 of the turbine in a gradient stage, significantly improving thermal efficiency. The regenerative feedwater system, in conjunction with the seventh valve 162 and the eighth valve 163, enhances the controllability and safety of the system under varying operating conditions, start-up, shutdown, and fault conditions.

[0061] In some embodiments, the temperature range of the solar molten salt high-temperature thermal storage tank 131 is 556-560℃; the temperature range of the solar molten salt low-temperature thermal storage tank 132 is 358-362℃; the temperature range of the Hitec molten salt high-temperature thermal storage tank 133 is 358-362℃; and the temperature range of the Hitec molten salt low-temperature thermal storage tank 134 is 288-292℃.

[0062] The solar salt molten salt high-temperature storage tank 131 contains solar salt at a temperature of 556-560℃ (e.g., 558℃), the solar salt molten salt low-temperature storage tank 132 contains solar salt at a temperature of 358-362℃ (e.g., 360℃), the Hitec salt molten salt high-temperature storage tank 133 contains Hitec salt at a temperature of 358-362℃ (e.g., 360℃), and the Hitec salt molten salt low-temperature storage tank 134 contains Hitec salt at a temperature of 288-292℃ (e.g., 290℃).

[0063] In this embodiment, after passing through the dual-salt heat storage unit 13, the temperature is controlled above 288°C so that more heat can be reserved for the heating unit 17 to meet the heating demand.

[0064] In some embodiments, see Figure 4 and Figure 5 As shown, the multifunctional Carnot battery system 10 also includes: a steam supply unit 19 for supplying steam to external steam-using equipment; wherein the steam supply unit 19 is thermally coupled to the dual-salt heat storage unit 13, and adjusts the temperature of the steam in the steam supply unit 19 by the heat provided by the dual-salt heat storage unit 13; and / or, the steam supply unit 19 is thermally coupled to the steam Rankine cycle unit 15, and obtains the high-temperature steam generated in the steam Rankine cycle unit 15.

[0065] In other words, the multifunctional Carnot battery system 10 also has a steam supply function, such as providing process steam that meets the temperature and pressure requirements to industrial steam users, sterilization equipment, food processing equipment, etc., so as to further enrich the functions of the multifunctional Carnot battery system 10. The supplied steam can come from the steam with heat in the steam Rankine cycle unit 15, or from steam from other sources, while the dual salt heat storage unit 13 can provide heat to increase the heat of the steam.

[0066] In this embodiment, by integrating a steam supply unit 19 into the multifunctional Carnot battery system 10, the multifunctional Carnot battery system 10 achieves multi-energy combined supply of electricity-heat-power, electricity-heat-heating, and electricity-heat-steam, so as to simultaneously meet the needs of multiple terminal energy sources such as electricity, heating, and industrial steam. It is especially suitable for scenarios with complex needs for high-quality thermal energy, such as industrial parks and regional integrated energy stations, and significantly improves the comprehensive utilization efficiency of primary energy and the economic efficiency of the system.

[0067] In some embodiments, see Figure 4 and Figure 5As shown, the steam supply unit 19 may include: a steam supply water tank 191, a steam supply pump 192, a first deaerator 193, a heating-molten salt heat exchanger 194, and a heating header 195 connected in sequence. The heating-molten salt heat exchanger 194 is thermally coupled to the dual-salt heat storage unit 13 to adjust the temperature of the steam in the heating header 195 through the heat provided by the dual-salt heat storage unit 13. The heating header 195 is thermally coupled to the steam Rankine cycle unit 15 and obtains the high-temperature steam generated in the steam Rankine cycle unit 15. The heating header 195 is used to supply steam to the external steam network.

[0068] The steam supply water tank 191 stores water as the water source for the steam supply unit 19. The steam supply pump 192 pressurizes the water in the steam supply water tank 191 to the pressure required for steam supply, ensuring the stable operation of subsequent heat exchange and vaporization processes. The first deaerator 193 thermally deoxygenates the pressurized feedwater, removing dissolved oxygen, carbon dioxide, and other non-condensable gases to prevent oxygen corrosion or acid corrosion in subsequent equipment (especially high-temperature heat exchangers). The heating-molten salt heat exchanger 194 serves as a heat exchange device; its hot side is connected to the dual-salt heat storage unit 13, and its cold side is supplied with feedwater deoxygenated by the first deaerator 193, allowing it to exchange heat from the hot side. The heating header 195 serves as a steam collection and distribution hub. On the one hand, it receives steam generated from the heating-molten salt heat exchanger 194. On the other hand, it can directly connect to the high-temperature steam of the steam Rankine cycle unit 15 (such as the inlet or outlet of the reheater 159). Finally, the heating header 195 outputs the mixed or independent steam to the external steam network to supply industrial or process users.

[0069] In this embodiment, industrial steam can be supplied by exchanging heat from the Hitec molten salt high-temperature thermal storage tank 133 with the water in the steam supply tank 191 during energy storage in the Brayton cycle heat pump unit 11, or by supplying industrial steam from the inlet or outlet of the reheater 159 during power generation in the steam Rankine cycle unit 15. This design breaks through the functional limitations of traditional Carnot battery systems, broadens its application scope in the industrial field, and enables the Carnot battery system to provide steam for industrial production in addition to electricity storage and release, meeting industrial steam demand and realizing diversified energy utilization.

[0070] In some embodiments, see Figure 5 As shown, the outlet of the extraction pipe 161 is connected to the condenser 160, and can also be connected in parallel to the steam and water supply tank 191 to supply water to the steam and water supply tank 191.

[0071] In some embodiments, see Figures 5-7 As shown, the multi-functional Carnot battery system 10 includes: The Brayton cycle heat pump unit 11 includes: a compressor 111, a first air-molten salt heat exchanger 1121, a second air-molten salt heat exchanger 1122, an air-to-air heat exchanger 113, an air-to-water heat exchanger 114, an expander 115, and a ninth valve 116. The dual-salt thermal storage unit 13 includes: a solar salt molten salt high-temperature thermal storage tank 131 (558℃), a solar salt molten salt low-temperature thermal storage tank 132 (360℃), a Hitec salt molten salt high-temperature thermal storage tank 133 (360℃), a Hitec salt molten salt low-temperature thermal storage tank 134 (290℃), a first circulation pump 135, a third valve 136, a fourth valve 137, a second circulation pump 138, a fifth valve 139, and a sixth valve 140; The steam Rankine cycle unit 15 includes: a preheater 151, an evaporator 152, a superheater 153, a high-pressure cylinder of a steam turbine 154, an intermediate-pressure cylinder of a steam turbine 155, a low-pressure cylinder of a steam turbine 156, a rotor 157, a generator 158, a reheater 159, a condenser 160, an extraction pipe 161, a seventh valve 162, an eighth valve 163, a second deaerator 164, a third water pump 165, a high-pressure heating group 166, a condensate pump 167, and a low-pressure heating group 168. Heating unit 17 includes: a first circulation subunit 171 and a second circulation subunit 172. The first circulation subunit 171 includes: a first water pump 1711, a hot water storage tank 1712 and a first valve 1713; the second circulation subunit 172 includes: a second water pump 1721, a heating network-water heat exchanger 1722, a heating network pipeline 1723, a second valve 1724, a heating network-steam heat exchanger 173 and a tenth valve 174. Steam supply unit 19 includes: steam supply water tank 191, steam supply pump 192, first deaerator 193, heating-molten salt heat exchanger 194, heating header 195, eleventh valve 196, twelfth valve 197 and thirteenth valve 198, and steam supply water tank 191 is connected to the outlet of extraction steam pipe 161. During the first electricity consumption period, the Brayton cycle heat pump unit 11 and the dual-salt heat storage unit 13 are operated, while the steam Rankine cycle unit 15 is stopped. The dual-salt heat storage unit 13 stores heat generated by the Brayton cycle heat pump unit 11 that exceeds the target temperature threshold, and the heating unit 17 stores heat generated by the Brayton cycle heat pump unit 11 that is below the target temperature threshold. When there is a heating demand, the heating unit 17 is controlled to supply heat to external heating equipment and can also provide heat to the steam supply unit 19. The ninth valve 116, the third valve 136, the fifth valve 139, the first valve 1713, the second valve 1724, the tenth valve 174, and the eleventh valve 196 are controlled to open, while the fourth valve 137, the sixth valve 140, the seventh valve 162, the eighth valve 163, the twelfth valve 197, the thirteenth valve 198, and the valve on the extraction pipe 161 are controlled to close. During the second power consumption period, the Brayton cycle heat pump unit 11 is stopped, the dual-salt thermal storage unit 13 is operated, and the steam Rankine cycle unit 15 is operated. The dual-salt thermal storage unit 13 releases the heat stored during the first power consumption period, causing the steam Rankine cycle unit 15 to generate steam and generate electricity. When there is a heating demand, the extraction pipe 161 is controlled to supply heat to the external heating equipment. At the same time, the inlet and / or outlet of the reheater 159 can supply steam to the steam supply unit 19. Among them, the fourth valve 137, the sixth valve 140, the seventh valve 162, the eighth valve 163, the tenth valve 174, the twelfth valve 197, and the thirteenth valve 198 are controlled to open, and the ninth valve 116, the third valve 136, the fifth valve 139, the first valve 1713, the second valve 1724, the tenth valve 174, and the eleventh valve 196 are controlled to close. The electricity consumption in the first electricity consumption period is less than that in the second electricity consumption period.

[0072] Second aspect This disclosure provides a multifunctional Carnot battery control method, applicable to any system according to the first aspect, see [link]. Figures 5 to 7 As shown, the control method may include: During the first period of electricity use, the Brayton cycle heat pump unit 11 is operated, the dual-salt heat storage unit 13 is operated, and the steam Rankine cycle unit 15 is stopped. The dual-salt heat storage unit 13 stores the heat generated by the Brayton cycle heat pump unit 11 that is greater than the target temperature threshold, and the heating unit 17 stores the heat generated by the Brayton cycle heat pump unit 11 that is less than the target temperature threshold. When there is a heating demand, the heating unit 17 is controlled to supply heat to the external heating equipment. During the second electricity consumption period, the Brayton cycle heat pump unit 11 is stopped, the dual-salt heat storage unit 13 is operated, and the steam Rankine cycle unit 15 is operated. The dual-salt heat storage unit 13 releases the heat stored in the first electricity consumption period, so that the steam Rankine cycle unit 15 generates steam and generates electricity. The electricity consumption in the first electricity consumption period is less than that in the second electricity consumption period.

[0073] The first electricity consumption period is during off-peak electricity demand (such as at night). During this period, low-priced electricity can be used to power compressor 111. Compressor 111 pressurizes low-temperature, low-pressure air into high-temperature, high-pressure gas. The high-temperature, high-pressure air first provides heat above the target temperature threshold to the dual-salt heat storage unit 13 through the air-molten salt heat exchanger group 112, so that the dual-salt heat storage unit 13 can store heat above the target temperature threshold. Then, it provides heat below the target temperature threshold to the heating unit 17 through the air-water heat exchanger 114, so as to provide heat to external heating equipment (such as heaters on the user side) during the heating season. At the same time, heat can be provided to the steam supply unit 19 through the dual-salt heat storage unit 13.

[0074] The second electricity consumption period is the peak electricity consumption period of the power grid (such as during the day). During this period, the heat stored in the dual-salt thermal storage unit 13 can be provided to the steam Rankine cycle unit 15 to generate electricity through the generator 158. At the same time, the steam Rankine cycle unit 15 can provide heat to the heating unit 17 and provide heat and / or steam to the steam supply unit 19.

[0075] In this embodiment, the system of the present invention can flexibly switch operating modes according to the peak and valley conditions of the power grid. During periods of low power grid demand, it utilizes low-priced electricity for energy storage, converting excess electrical energy into heat energy for storage, thus reducing the power supply pressure on the grid. During periods of high power grid demand, it releases the stored heat energy to generate electricity, supplementing the grid and alleviating power shortages. This effective peak-shaving function enhances the stability and reliability of the power grid operation, helps improve the overall power system's capacity to absorb new energy generation, and promotes the large-scale application and development of renewable energy. Furthermore, by rationally utilizing the heat in various parts of the system, more heat energy is effectively utilized while consuming the same amount of electricity, increasing the coefficient of performance (COP) on the heat pump side. For example, in industrial steam supply and heating processes, it fully utilizes previously wasted low-temperature heat, improving the energy conversion efficiency of the entire heat pump system, thereby reducing system energy consumption and enhancing the economic benefits of energy utilization.

[0076] In some embodiments, during a first power consumption period, the dual-salt thermal storage unit 13 is controlled to supply heat to the steam supply unit 19; and / or, during a second power consumption period, the steam Rankine cycle unit 15 is controlled to supply heat to the heating unit 17 and / or to the steam supply unit 19. This allows for flexible application of the multifunctional Carnot battery system 10.

[0077] In some embodiments, when the Brayton cycle heat pump unit 11 stops circulating, the dual-salt heat storage unit 13 stops storing heat, and the steam Rankine cycle unit 15 stops operating, heat can be supplied to the steam supply unit 19 by controlling the dual-salt heat storage unit 13 to release heat. In this way, continuous steam supply to the steam supply unit 19 can be achieved under different conditions.

[0078] It should be noted that the multifunctional Carnot battery system in the multifunctional Carnot battery control method provided in this disclosure is similar to the multifunctional Carnot battery system embodiments described above, and has similar beneficial effects. For technical details not disclosed in the embodiments of the multifunctional Carnot battery control method of this disclosure, please refer to the description of the multifunctional Carnot battery system embodiments in this disclosure for understanding; they will not be repeated here.

[0079] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0080] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.

Claims

1. A multifunctional Carnot battery system, characterized in that, include: A Brayton cycle heat pump unit includes: a compressor, an air-molten salt heat exchanger assembly, an air-to-air heat exchanger, an air-to-water heat exchanger, and an expander. The outlet of the compressor is sequentially connected to the air-molten salt heat exchanger assembly, the hot-side flow channel of the air-to-air heat exchanger, the hot-side flow channel of the air-to-water heat exchanger, the expander, the cold-side flow channel of the air-to-air heat exchanger, and returns to the inlet of the compressor. The dual-salt thermal storage unit is thermally coupled to the air-molten salt heat exchanger assembly and is used to store the heat generated by the Brayton cycle heat pump unit that exceeds the target temperature threshold. A steam Rankine cycle unit, thermally coupled to the dual-salt thermal storage unit, is used to generate steam using the high-temperature thermal energy released by the dual-salt thermal storage unit and to drive power generation. The heating unit, coupled to the cold-side flow channel of the air-water heat exchanger, is used to store heat below the target temperature threshold from the waste heat generated by the Brayton cycle heat pump unit after heat exchange through the dual-salt heat storage unit, and to supply heat to external heating equipment.

2. The multifunctional Carnot battery system according to claim 1, characterized in that, The heating unit is also coupled to the steam Rankine cycle unit to store the heat of the steam in the steam Rankine cycle unit and to supply heat to the external heating equipment.

3. The multifunctional Carnot battery system according to claim 1 or 2, characterized in that, The heating unit includes: a first circulation subunit and a second circulation subunit that are independent of each other; The first circulation subunit includes: a first water pump and a hot water storage tank. The circulating medium from the cold side outlet of the air-water heat exchanger passes through the first water pump and the hot water storage tank in sequence and then returns to the cold side inlet of the air-water heat exchanger, forming a closed heat storage circulation loop. The second circulation subunit includes: a second water pump, a heat network-water heat exchanger, and a heat network pipeline. The circulating medium from the outlet of the hot water storage tank passes through the second water pump and the heat network-water heat exchanger in sequence and then returns to the inlet of the hot water storage tank, forming a closed heat release circulation loop. The heat release target is the heat network pipeline, which is connected to the external heating equipment.

4. The multifunctional Carnot battery system according to claim 3, characterized in that, The air-molten salt heat exchanger assembly includes: a first air-molten salt heat exchanger and a second air-molten salt heat exchanger, and the outlet of the compressor is sequentially connected to the first air-molten salt heat exchanger, the second air-molten salt heat exchanger and the air-to-air heat exchanger; The dual-salt thermal storage unit includes: a solar salt molten salt high-temperature thermal storage tank, a solar salt molten salt low-temperature thermal storage tank, a Hitec salt molten salt high-temperature thermal storage tank, and a Hitec salt molten salt low-temperature thermal storage tank; The steam Rankine cycle unit includes: a preheater, an evaporator, and a superheater connected in sequence; The first air-molten salt heat exchanger, the solar salt molten salt high-temperature heat storage tank, and the solar salt molten salt low-temperature heat storage tank constitute a first circulation loop, which flows through the superheater and the evaporator in sequence; the second air-molten salt heat exchanger, the Hitec salt molten salt high-temperature heat storage tank, and the Hitec salt molten salt low-temperature heat storage tank constitute a second circulation loop, which flows through the preheater.

5. The multifunctional Carnot battery system according to claim 4, characterized in that, The steam Rankine cycle unit further includes: a high-pressure cylinder of a steam turbine, an intermediate-pressure cylinder of a steam turbine, a low-pressure cylinder of a steam turbine, a rotor, a generator, a reheater, a condenser, and an extraction pipe. The high-pressure cylinder, the intermediate-pressure cylinder, and the low-pressure cylinder are coaxially mounted on the rotor. The rotor drives the generator to generate electricity. The first circulation loop also flows through a reheater arranged parallel to the superheater. The steam outlet of the superheater is sequentially connected to the high-pressure cylinder, the reheater, the intermediate-pressure cylinder, and the preheater. The exhaust port of the intermediate-pressure cylinder is also connected to the inlet of the low-pressure cylinder and the inlet of the extraction pipe. The exhaust port of the low-pressure cylinder is sequentially connected to the inlet of the condenser and the inlet of the preheater. The extraction pipe is connected to the condenser. The heating unit further includes a heat network-steam heat exchanger, which is thermally coupled to the extraction steam pipe to obtain heat from the extraction steam pipe and release heat to the heat network pipeline.

6. The multifunctional Carnot battery system according to claim 4, characterized in that, The temperature range of the solar salt molten salt high-temperature thermal storage tank is 556-560℃; The temperature range of the solar salt molten salt cryogenic storage tank is 358-362℃; The temperature range of the Hitec molten salt high-temperature thermal storage tank is 358-362℃. The temperature range of the Hitec molten salt cryogenic storage tank is 288-292℃.

7. The multifunctional Carnot battery system according to claim 1, characterized in that, Also includes: The steam supply unit is used to supply steam to external steam-consuming equipment; among which... The steam supply unit is thermally coupled to the dual-salt thermal storage unit, and the temperature of the steam in the steam supply unit is adjusted by the heat provided by the dual-salt thermal storage unit; and / or The steam supply unit is thermally coupled to the steam Rankine cycle unit and obtains the high-temperature steam generated in the steam Rankine cycle unit.

8. The multifunctional Carnot battery system according to claim 7, characterized in that, The steam supply unit includes: a steam supply water tank, a steam supply pump, a first deaerator, a heating-molten salt heat exchanger, and a heating header connected in sequence. The heating-molten salt heat exchanger is thermally coupled to the dual-salt heat storage unit to adjust the temperature of the steam in the heating header through the heat provided by the dual-salt heat storage unit. The heating header is thermally coupled to the steam Rankine cycle unit and obtains the high-temperature steam generated in the steam Rankine cycle unit. The heating header is used to supply steam to the external steam network.

9. A multifunctional Carnot battery control method, applied to the system according to any one of claims 1-8, characterized in that, include: During the first period of electricity use, the Brayton cycle heat pump unit and the dual-salt heat storage unit are operated, while the steam Rankine cycle unit is stopped. The dual-salt heat storage unit stores the heat generated by the Brayton cycle heat pump unit that is greater than the target temperature threshold, and the heating unit stores the heat generated by the Brayton cycle heat pump unit that is less than the target temperature threshold. When there is a heating demand, the heating unit is controlled to supply heat to external heating equipment. During the second period of electricity consumption, the Brayton cycle heat pump unit is stopped, the dual-salt thermal storage unit is operated, and the steam Rankine cycle unit is operated. The dual-salt thermal storage unit releases the heat stored during the first period of electricity consumption, causing the steam Rankine cycle unit to generate steam and generate electricity. The electricity consumption during the first electricity consumption period is less than the electricity consumption during the second electricity consumption period.

10. The multifunctional Carnot battery control method according to claim 9, characterized in that, During the first power consumption period, the dual-salt thermal storage unit is controlled to supply heat to the steam supply unit; and / or, During the second period of electricity consumption, the steam Rankine cycle unit is controlled to supply heat to the heating unit and / or steam to the steam supply unit.

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