A supercritical co2 brayton cycle power generation system coupled with manganese-based thermochemical energy storage and a method of operating the same

Abstract

The application belongs to the field of supercritical carbon dioxide cycle power generation, and discloses a supercritical CO2 Brayton cycle power generation system coupled with a manganese-based thermochemical energy storage and an operation method thereof, which comprises a thermochemical cycle subsystem; the thermochemical cycle subsystem comprises a high-temperature manganese-based thermochemical reactor; a first path of a shell side gas outlet of the high-temperature manganese-based thermochemical reactor is connected with an inlet of a solid particle heat storage tank, a first path of an outlet of the solid particle heat storage tank is connected with an inlet of a high-pressure oxygen storage tank, an outlet of the high-pressure oxygen storage tank is connected with an oxygen inlet of a gas mixing chamber, a mixed gas outlet of the gas mixing chamber is connected with an inlet of the solid particle heat storage tank; a second path of the shell side gas outlet is connected with a second path of the outlet of the solid particle heat storage tank after being combined, and then connected to a shell side gas inlet; circulating working medium of a Brayton cycle power generation subsystem flows through a heat exchange pipeline of the high-temperature manganese-based thermochemical reactor and exchanges heat with manganese-based oxide energy storage materials; and the application effectively improves the comprehensive operation performance and energy utilization efficiency of the system.

Description

Technical Field

[0001] This invention belongs to the field of supercritical carbon dioxide cycle power generation technology, and specifically relates to a supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage and its operation method. Background Technology

[0002] Thermochemical energy storage technology is an energy storage technology that utilizes the reversible chemical reaction of materials to achieve the storage and release of thermal energy. It has the advantages of high energy storage density, low heat loss, and long-term storage, and is a key research direction in the field of renewable energy consumption. Among them, manganese-based oxide thermochemical energy storage system has been gradually applied to various engineering scenarios such as supporting energy storage for large-scale new energy power plants, centralized energy supply in industrial parks, and peak shaving and frequency regulation of power grids, due to its good reaction reversibility, abundant raw material reserves, low cost, and suitability for high-temperature energy storage scenarios.

[0003] However, most existing manganese-based oxide thermochemical energy storage systems adopt a single operating architecture, which generally suffers from large heat loss, inability to achieve cascade utilization of thermal energy, and poor operational flexibility in practical engineering applications, which seriously restricts the energy efficiency and service life of the system.

[0004] Specifically, existing energy storage systems rely on intermediate heat exchangers for heat transfer, resulting in significant heat loss and usable energy loss during the heat exchange process, drastically reducing the overall thermal efficiency of the system. Secondly, during the energy storage reaction stage, manganese-based oxides react to generate high-temperature oxygen, which carries a large amount of sensible heat. However, most existing systems directly discharge this oxygen or only perform simple, crude heat recovery, wasting a large amount of high-quality thermal energy and failing to achieve tiered and layered utilization of thermal energy, resulting in low overall energy utilization. Simultaneously, the system's energy release and power generation stage suffers from significant operational condition adaptation defects. Under normal operating conditions, room-temperature reaction gases must be directly introduced into the high-temperature reactor to participate in the reduction and energy release reaction. The significant temperature difference between ambient gas and the high-temperature reactor creates intense thermal stress on the manganese-based energy storage material inside the reactor. This repeated temperature fluctuations over time continuously damage the microcrystalline structure of the energy storage material, leading to rapid degradation of its activity and reduced reversibility of the reaction. This directly shortens the lifespan of the energy storage material and the entire system, significantly increasing equipment maintenance and replacement costs, and reducing the stability and reliability of the system. Furthermore, a single, independent energy storage system has a fixed operating mode and a narrow range of operational adjustments, making it unable to flexibly adjust its operating status according to dynamic changes in grid load and energy demand. This results in extremely poor system flexibility, making it difficult to adapt to complex and ever-changing real-world engineering applications. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention provides a supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage and its operation method, in order to solve the technical problems that existing energy storage systems all adopt a single operating architecture, which generally suffer from large heat loss, inability to achieve cascade utilization of thermal energy, and poor operational flexibility in practical engineering applications.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage, comprising a thermochemical cycle subsystem and a Brayton cycle power generation system; The thermochemical cycle subsystem includes a high-temperature manganese-based thermochemical reactor, a solid particle heat storage tank, a high-pressure oxygen storage tank, and a mixing chamber. The high-temperature manganese-based thermochemical reactor is equipped with heat exchange pipes and filled with manganese-based oxide energy storage material. The manganese-based oxide energy storage material undergoes an endothermic reduction reaction to produce high-temperature oxygen. The first gas outlet of the shell side of the high-temperature manganese-based thermochemical reactor is connected to the inlet of the solid particle heat storage tank. The first outlet of the solid particle heat storage tank is connected to the inlet of the high-pressure oxygen storage tank. The outlet of the high-pressure oxygen storage tank is connected to the oxygen inlet of the mixing chamber. The mixed gas outlet of the mixing chamber is connected to the inlet of the solid particle heat storage tank. The second gas outlet of the shell side of the high-temperature manganese-based thermochemical reactor is combined with the second outlet of the solid particle heat storage tank and then connected to the shell side gas inlet of the high-temperature manganese-based thermochemical reactor. The working fluid of the Brayton cycle power generation system flows through the heat exchange pipes of the high-temperature manganese-based thermochemical reactor and exchanges heat with the manganese-based oxide energy storage material.

[0007] Furthermore, the thermochemical cycle subsystem also includes a first heat exchanger, which is located between the outlet of the solid particle heat storage tank and the inlet of the high-pressure oxygen storage tank. The outlet of the solid particle heat storage tank is connected to the hot side inlet of the first heat exchanger, and the hot side outlet of the first heat exchanger is connected to the inlet of the high-pressure oxygen storage tank.

[0008] Furthermore, the thermochemical cycle subsystem also includes an oxygen compressor, which is located between the outlet of the solid particle heat storage tank and the inlet of the high-pressure oxygen storage tank.

[0009] Furthermore, it also includes an air compressor, which is located at the air inlet of the mixing chamber.

[0010] Furthermore, it also includes a renewable energy power generation system; the high-temperature manganese-based thermochemical reactor is also equipped with an electric heater, the power supply of which is connected to the renewable energy power generation system.

[0011] Furthermore, the Brayton cycle power generation system includes a turbine, a regenerator, a compressor, and a generator; The heat exchange pipe outlet of the high-temperature manganese-based thermochemical reactor is connected to the turbine inlet, the turbine outlet is connected to the hot-side inlet of the regenerator, the hot-side outlet of the regenerator is connected to the compressor inlet, the compressor outlet is connected to the cold-side inlet of the regenerator, and the cold-side outlet of the regenerator is connected to the heat exchange pipe inlet of the high-temperature manganese-based thermochemical reactor; the turbine is connected to the generator.

[0012] Furthermore, the turbine, compressor, and generator are arranged coaxially.

[0013] Furthermore, the Brayton cycle power generation system also includes a second heat exchanger, which is located between the hot-side outlet of the regenerator and the inlet of the compressor. The hot-side outlet of the regenerator is connected to the hot-side inlet of the second heat exchanger, and the hot-side outlet of the second heat exchanger is connected to the inlet of the compressor.

[0014] This invention also provides an operation method for a supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage, including energy storage operating conditions and rated power generation operating conditions. Energy storage operating conditions include: The manganese-based oxide energy storage material in the high-temperature manganese-based thermochemical reactor is heated to cause an endothermic reduction reaction to generate high-temperature oxygen. After the high-temperature oxygen flows through the solid particle heat storage tank, the sensible heat it carries is stored in the solid particle heat storage tank to form cooled oxygen, which is then passed into a high-pressure oxygen storage tank for storage. Rated power generation conditions include: In the mixing chamber, air is mixed with oxygen from the high-pressure oxygen storage tank to form room-temperature oxygen-enriched gas. The room-temperature oxygen-enriched gas flows through the solid particle heat storage tank to absorb the sensible heat stored therein, forming preheated oxygen-enriched gas. The preheated oxygen-enriched gas enters the high-temperature manganese-based thermochemical reactor, triggering an exothermic oxidation reaction of the manganese-based oxide energy storage material and forming high-temperature air after the reaction. The high-temperature air after the reaction is mixed with the preheated oxygen-enriched gas and then re-enters the high-temperature manganese-based thermochemical reactor. After the cold circulating working fluid flows through the heat exchange pipes of the high-temperature manganese-based thermochemical reactor, it absorbs the heat generated by the manganese-based oxide energy storage material, forming a hot circulating working fluid, which then re-enters the Brayton cycle power generation system.

[0015] Furthermore, it also includes peak-shaving operating conditions; peak-shaving operating conditions include: By maintaining the total gas mass flow rate of the high-temperature manganese-based thermochemical reactor constant or making slight adjustments, reducing the oxygen supply in the mixing chamber and increasing the air supply in the mixing chamber, the proportion of oxygen in the oxygen-enriched gas and the oxygen partial pressure in the high-temperature manganese-based thermochemical reactor are reduced. This weakens the exothermic oxidation reaction rate of the manganese-based oxide energy storage material, reduces the heat absorption of the cold circulating working fluid, and achieves a reduction in the output of the Brayton cycle power generation system.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage provided by this invention integrates a manganese-based thermochemical cycle subsystem with a Brayton cycle power generation system, effectively improving the overall system performance and energy utilization efficiency. Specifically, by directly introducing the working fluid of the Brayton cycle power generation system into the heat exchange pipe of the high-temperature manganese-based thermochemical reactor and directly exchanging heat with the manganese-based oxide energy storage material, an intermediate heat exchanger is eliminated, effectively reducing heat dissipation and usable energy loss during indirect heat exchange and significantly improving the system's heat transfer efficiency. The high-temperature oxygen generated during the energy storage stage enters the solid particle heat storage tank through the shell-side gas outlet, effectively storing the large amount of sensible heat it carries in the solid particle medium, thus realizing the recovery of the sensible heat of the high-temperature oxygen. This cascaded utilization method avoids the direct waste of high-quality thermal energy through emissions. Furthermore, the heat stored in the solid particle thermal storage tank can be used to preheat the reaction gas entering the reactor after being mixed in the mixing chamber during the energy release stage. This ensures that the reaction gas is raised to the preset temperature before entering the reactor, effectively eliminating the severe temperature difference shock caused by room temperature gas directly entering the high-temperature reactor. This significantly reduces the microcrystalline structure damage and activity decay of manganese-based oxide energy storage materials caused by cyclic thermal stress, and significantly extends the cycle life of the energy storage materials and the system. At the same time, the system can flexibly adjust the operating parameters and operating modes of each stage of energy storage, energy release, and power generation according to the dynamic changes in external grid load fluctuations and energy demand, significantly enhancing the system's operational flexibility and adaptability in complex engineering scenarios.

[0017] The operation method of the supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage provided by the present invention has all the advantages of the supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application 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 application. 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 a supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage provided by the present invention.

[0020] Among them, 1 is a renewable energy power generation system, 2 is a high-temperature manganese-based thermochemical reactor, 3 is a solid particle heat storage tank, 4 is a first heat exchanger, 5 is an oxygen compressor, 6 is a high-pressure oxygen storage tank, 7 is an air compressor, 8 is a mixing chamber, 9 is a turbine, 10 is a regenerator, 11 is a second heat exchanger, 12 is a compressor, 13 is a generator, 14 is a first valve, 15 is a second valve, 16 is a third valve, 17 is a fourth valve, 18 is a fifth valve, 19 is a sixth valve, 20 is a seventh valve, 21 is an eighth valve, 22 is a ninth valve, 23 is a tenth valve, and 24 is an eleventh valve. Detailed Implementation

[0021] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0022] This invention provides a supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage, comprising a thermochemical cycle subsystem and a Brayton cycle power generation system. The thermochemical cycle subsystem includes a high-temperature manganese-based thermochemical reactor 2, a solid particle heat storage tank 3, a high-pressure oxygen storage tank 6, and a mixing chamber 8. The high-temperature manganese-based thermochemical reactor 2 is equipped with heat exchange pipes and filled with manganese-based oxide energy storage material. The manganese-based oxide energy storage material undergoes an endothermic reduction reaction to generate high-temperature oxygen. The first gas outlet on the shell side of the high-temperature manganese-based thermochemical reactor 2 is connected to the solid particle heat storage tank 3. The inlet of the solid particle heat storage tank 3 is connected to the outlet of the high-pressure oxygen storage tank 6, the outlet of the high-pressure oxygen storage tank 6 is connected to the oxygen inlet of the mixing chamber 8, and the mixed gas outlet of the mixing chamber 8 is connected to the inlet of the solid particle heat storage tank 3. The second outlet of the shell side gas of the high-temperature manganese-based thermochemical reactor 2 is combined with the second outlet of the solid particle heat storage tank 3 and then connected to the shell side gas inlet of the high-temperature manganese-based thermochemical reactor 2. The circulating working fluid of the Brayton cycle power generation system flows through the heat exchange pipe of the high-temperature manganese-based thermochemical reactor 2 and exchanges heat with the manganese-based oxide energy storage material.

[0023] In the above embodiments, a solid particle heat storage tank is used as a capture unit for the sensible heat of high-temperature oxygen. The high-quality heat energy carried by the high-temperature oxygen generated by the reduction of manganese-based oxide energy storage material is stored in the particle medium. The cooled oxygen is then introduced into the subsequent oxygen storage and mixing process, so that the sensible heat of oxygen that was originally directly discarded or crudely recovered is converted into an adjustable heat storage resource. This realizes the cascade utilization of heat energy from high-temperature sensible heat, particle heat storage and subsequent working fluid heat exchange, effectively avoiding the degradation of usable energy quality and large-area heat loss caused by the transfer of heat through a single heat exchanger.

[0024] On the other hand, the mixing chamber mixes the ambient temperature reaction gas with the oxygen output from the high-pressure oxygen storage tank, and preheats the reaction gas after it has been mixed by the heat stored in the solid particle heat storage tank. This increases the initial temperature of the gas entering the reactor and effectively reduces the temperature difference between the reaction gas and the manganese-based oxide energy storage material inside the reactor. Thus, while ensuring the energy release response speed of the system, it effectively extends the cycle life of the energy storage medium and the reactor body.

[0025] Meanwhile, the system allows for flexible adjustment of oxygen circulation volume, mixed gas ratio, and heat extraction method of particle heat storage tank according to external load requirements, enabling the Brayton cycle to maintain efficient and stable circulation parameters within a wide load range. This effectively overcomes the inherent defects of traditional single-architecture operation mode being fixed and having poor adjustment capabilities, thereby improving the overall heat-to-electric conversion efficiency of the system while effectively balancing the long-term reliability and operational flexibility of the equipment.

[0026] The following specific embodiments further explain the supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage provided by the present invention: Example 1 As attached Figure 1 As shown, this embodiment 1 provides a supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage, including a renewable energy power generation system 1, a thermochemical cycle subsystem, and a Brayton cycle power generation system; the renewable energy power generation system 1 is used to provide electrical energy input to the thermochemical cycle subsystem; the thermochemical cycle subsystem is used to realize the cyclic allocation of thermochemical energy storage and energy storage medium, serving as the energy storage side of the system; the Brayton cycle power generation system is used to convert the released thermochemical energy storage into electrical energy output, serving as the power generation side of the system; wherein, the thermochemical cycle subsystem and the Brayton cycle power generation system achieve heat energy transfer and coupling integration through the heat exchange pipe inside the high-temperature manganese-based thermochemical reactor 2 in the thermochemical cycle subsystem.

[0027] Specifically, the renewable energy power generation system 1 is connected to the power supply terminal of the electric heater inside the high-temperature manganese-based thermochemical reactor 2; explanatoryly, the renewable energy power generation system 1 refers to a system that generates electricity using renewable energy sources, such as wind power and solar energy; optionally, the renewable energy power generation system 1 is a wind turbine generator or a photovoltaic power generation array; explanatoryly, when the renewable energy power generation system 1 has sufficient power generation or when there is wind or solar curtailment, the renewable energy power generation system 1 supplies power to the electric heater inside the high-temperature manganese-based thermochemical reactor 2; the electric heater converts electrical energy into heat energy, heating the manganese-based oxide energy storage material inside the reactor in the form of high heat flux density, driving the endothermic reduction reaction; by directly connecting the renewable energy power generation system 1 to the electric heater, the direct conversion and storage from renewable energy electricity to high-temperature thermochemical energy is realized, avoiding the intermediate links of power grid connection and dispatch, and improving the renewable energy absorption capacity.

[0028] In this embodiment 1, the thermochemical cycle subsystem includes a high-temperature manganese-based thermochemical reactor 2, a solid particle heat storage tank 3, a first heat exchanger 4, an oxygen compressor 5, a high-pressure oxygen storage tank 6, an air compressor 7, a mixing chamber 8, a first valve 14, a second valve 15, a third valve 16, a fourth valve 17, a fifth valve 18, a sixth valve 19, a seventh valve 20, an eighth valve 21, and a ninth valve 22.

[0029] The high-temperature manganese-based thermochemical reactor 2 is equipped with heat exchange pipes and filled with manganese-based oxide energy storage material; specifically, the high-temperature manganese-based thermochemical reactor 2 is equipped with a manganese-based material reaction chamber, and the manganese-based material reaction chamber is equipped with heat exchange pipes; the manganese-based oxide energy storage material is filled in the manganese-based material reaction chamber; wherein, after the manganese-based oxide energy storage material undergoes an endothermic reduction reaction, it generates high-temperature oxygen.

[0030] Explained, the high-temperature manganese-based thermochemical reactor 2 is a device for high-temperature thermochemical energy storage and release. Its interior is filled with manganese-based oxide energy storage material as the high-temperature energy storage medium. When heated to a high temperature, the manganese-based oxide energy storage material undergoes an endothermic reduction reaction. The products of this reaction include low-valence manganese oxides and high-temperature oxygen, with thermal energy stored in the form of sensible heat and chemical energy. The shell-side space of the high-temperature manganese-based thermochemical reactor 2 serves as a reaction chamber for manganese-based materials, accommodating the manganese-based oxide energy storage material and acting as a passageway for oxygen and air. The reactor 2 also contains heat exchange pipes for circulating the working fluid of the Brayton cycle power generation system during power generation, absorbing the heat released by the manganese-based oxide energy storage material in the exothermic oxidation reaction and transferring the heat to the working fluid of the Brayton cycle power generation system.

[0031] Optionally, the manganese-based oxide energy storage material is manganese trioxide (Mn2O3) / manganese trioxide (Mn3O4), which has the advantages of high reaction temperature, good cycle stability, wide availability of raw materials and low cost. Specifically, Mn2O3 and Mn3O4 are a pair of reversible thermochemical reactions. In the energy storage stage (endothermic direction), Mn2O3 undergoes thermal decomposition at high temperature (900-1000℃) to generate Mn3O4 and oxygen. This reaction is an endothermic reduction reaction, storing the electrical energy input from the renewable energy power generation system 1 in Mn3O4 in the form of chemical energy. In the energy release stage (exothermic direction), Mn3O4 undergoes an oxidation reaction with oxygen in the introduced reaction gas to regenerate Mn2O3. This reaction is an exothermic oxidation reaction, releasing the stored chemical heat.

[0032] The shell-side gas outlet of the high-temperature manganese-based thermochemical reactor 2 is divided into two paths, and the first valve 14 is located at the shell-side gas outlet. The first path of the shell-side gas outlet is connected to the first end of the second valve 15, and the second path of the shell-side gas outlet is connected to the first end of the ninth valve 22. The second end of the second valve 15 is connected to the inlet of the solid particle heat storage tank 3, and the outlet of the solid particle heat storage tank 3 is divided into two paths. The first path of the outlet of the solid particle heat storage tank 3 is connected to the first end of the third valve 16, and the second path of the outlet of the solid particle heat storage tank 3 is connected to the first end of the eighth valve 21. The second end of the third valve 16 is connected to the hot-side inlet of the first heat exchanger 4, and the second end of the eighth valve 21 and the second end of the ninth valve 22 are combined and connected to the shell-side gas inlet of the high-temperature manganese-based thermochemical reactor 2.

[0033] The hot-side outlet of the second heat exchanger 4 is connected to the inlet of the oxygen compressor 5. The outlet of the oxygen compressor 5 is connected to the first end of the fourth valve 17. The outlet of the fourth valve 17 is connected to the inlet of the high-pressure oxygen storage tank 6. The outlet of the high-pressure oxygen storage tank 6 is connected to the inlet of the fifth valve 18. The outlet of the fifth valve 18 is connected to the oxygen inlet of the mixing chamber 8. The inlet of the air compressor 7 is connected to the inlet of the sixth valve 19. The outlet of the sixth valve 19 is connected to the air inlet of the mixing chamber 8. The mixed gas outlet of the mixing chamber 8 is connected to the inlet of the solid particle heat storage tank 3.

[0034] Explanatoryly, the first gas outlet of the shell side of the high-temperature manganese-based thermochemical reactor 2 is connected to the inlet of the solid particle heat storage tank 3. Under energy storage conditions, the high-temperature oxygen generated by the endothermic reduction reaction of the manganese-based oxide energy storage material in the high-temperature manganese-based thermochemical reactor 2 is discharged from the shell side gas outlet and introduced into the solid particle heat storage tank 3 through the first gas outlet of the shell side. The solid particle heat storage tank 3 is filled with heat storage particles, such as alumina balls or ceramic balls. When the high-temperature oxygen passes through the heat storage particle bed of the solid particle heat storage tank 3, it transfers and stores a large amount of sensible heat carried by it in the heat storage particles through direct gas-solid contact heat exchange, thereby realizing the effective recovery and storage of the sensible heat of the high-temperature oxygen. The temperature of the high-temperature oxygen itself drops significantly after passing through the bed and is discharged from the first outlet of the solid particle heat storage tank 3.

[0035] Secondly, the outlet of the solid particle heat storage tank 3 is connected to the inlet of the high-pressure oxygen storage tank 6. The oxygen, after being cooled by heat exchange in the solid particle heat storage tank 3, is discharged from the outlet of the solid particle heat storage tank 3, processed by the first heat exchanger 4 and the oxygen compressor 5, and then stored in the high-pressure oxygen storage tank 6. The outlet of the high-pressure oxygen storage tank 6 is connected to the oxygen inlet of the mixing chamber 8 to provide the stored high-purity oxygen to the mixing chamber 8 during power generation.

[0036] The mixing chamber 8 is used to uniformly mix air with oxygen from the high-pressure oxygen storage tank 6. The mixed gas outlet of the mixing chamber 8 is connected to the inlet of the solid particle heat storage tank 3. Under rated power generation conditions, the air compressor 7 compresses ambient air and sends it into the mixing chamber 8. At the same time, the high-pressure oxygen storage tank 6 releases stored oxygen into the mixing chamber 8. The compressed air and oxygen are mixed in the mixing chamber 8 in a set ratio to form oxygen-enriched gas at room temperature. The oxygen-enriched gas at room temperature is discharged from the mixed gas outlet of the mixing chamber 8 and enters the inlet of the solid particle heat storage tank 3. When the oxygen-enriched gas at room temperature flows through the solid particle heat storage tank 3, it absorbs the sensible heat stored by the heat storage particles during the energy storage stage and its own temperature is preheated to form preheated oxygen-enriched gas. The preheated oxygen-enriched gas then enters the shell side of the high-temperature manganese-based thermochemical reactor 3 to participate in and trigger the exothermic oxidation reaction of the manganese-based oxide energy storage material. Among them, the sensible heat of the high-temperature oxygen stored in the solid particle heat storage tank 3 during the energy storage stage is effectively recovered and used to preheat the cold reaction gas, realizing the internal recycling of thermal energy.

[0037] Furthermore, the second gas outlet of the shell side of the high-temperature manganese-based thermochemical reactor 2 is combined with the second outlet of the solid particle heat storage tank 3 and connected to the shell side gas inlet of the high-temperature manganese-based thermochemical reactor 2. Under rated power generation conditions, after the manganese-based oxide energy storage material in the high-temperature manganese-based thermochemical reactor 3 undergoes an exothermic oxidation reaction, the reaction product is regenerated Mn2O3. At the same time, the high-temperature air (mainly nitrogen and residual oxygen) after the reaction in the reactor is discharged from the second gas outlet of the shell side. At this time, the high-temperature air after the reaction still has a high temperature. The second outlet of the solid particle heat storage tank 3 is used for... The preheated oxygen-enriched gas is output; the high-temperature air discharged from the second outlet of the shell side gas outlet and the preheated oxygen-enriched gas output from the second outlet of the solid particle heat storage tank 3 are combined and mixed in the pipeline, and then re-enter the shell side gas inlet of the high-temperature manganese-based thermochemical reactor 3. This mixing of the high-temperature air after reaction with the preheated oxygen-enriched gas before re-entering the reactor can effectively increase the temperature of the gas entering the reactor, which helps to maintain the temperature level of the bed inside the reactor. At the same time, the gas recirculation increases the gas flow rate in the reactor, which is beneficial to improving the fluidization state and heat transfer effect of the bed.

[0038] A first heat exchanger 4 is positioned between the outlet of the solid particle heat storage tank 3 and the inlet of the high-pressure oxygen storage tank 6. The cold-side inlet of the first heat exchanger 4 is connected to a first heat exchange medium source, and the cold-side outlet of the second heat exchanger 4 is connected to a heat user. The first heat exchange medium source provides the first heat exchange medium to the cold side of the first heat exchanger 4. After being cooled by heat exchange in the solid particle heat storage tank 3, the oxygen is discharged from the outlet of the solid particle heat storage tank 3, forming medium-temperature oxygen. The temperature of the medium-temperature oxygen is typically still higher than ambient temperature (e.g., 300-500℃). The medium-temperature oxygen first enters the heat exchanger of the first heat exchanger 4. The oxygen enters through the side inlet. Inside the first heat exchanger 4, the remaining heat is released to the first heat exchange medium flowing through the cold side, and its own temperature is further reduced to room temperature. It is then discharged from the hot side outlet of the first heat exchanger 4 and subsequently enters the high-pressure oxygen storage tank 6 for storage. By setting up the first heat exchanger 4, the oxygen entering the high-pressure oxygen storage tank 6 is further cooled to room temperature, allowing the high-pressure oxygen storage tank 6 to operate under room temperature conditions. This reduces the temperature resistance requirements of the high-pressure oxygen storage tank 6 material and the safety risks. At the same time, the heat recovered by the first heat exchange medium can be used for other auxiliary purposes, such as preheating boiler feedwater or heating, thereby effectively improving the heat utilization efficiency of the system.

[0039] The oxygen compressor 5 is positioned between the hot-side outlet of the first heat exchanger 4 and the inlet of the high-pressure oxygen storage tank 6. The oxygen, after being cooled to room temperature by the solid particle heat storage tank 3 and the first heat exchanger 4, typically has a pressure close to atmospheric pressure. The oxygen compressor compresses and pressurizes the room-temperature, low-pressure oxygen to reach the high-pressure storage pressure required by the high-pressure oxygen storage tank. The pressurized oxygen is then introduced into the high-pressure oxygen storage tank 6 for sealed storage, which significantly reduces the required volume of the oxygen storage tank and lowers the equipment footprint and investment costs.

[0040] An air compressor 7 is installed at the air inlet of the mixing chamber 8. Under rated power generation conditions, the air compressor 7 starts, compresses and pressurizes ambient air, and sends it into the mixing chamber 8 as the source of air components in the mixed gas. By installing the air compressor 7, a continuous source of compressed air is provided to the mixing chamber 8. Optionally, by adjusting the intake air volume of the air compressor 7 or adjusting the opening of the sixth valve 19 installed on its outlet pipe, the air flow rate entering the mixing chamber 8 can be controlled, thereby coordinating with the oxygen flow rate released by the high-pressure oxygen storage tank 6 to achieve precise adjustment of the oxygen ratio in the mixed gas.

[0041] In this embodiment 1, the Brayton cycle power generation system includes a turbine 9, a regenerator 10, a second heat exchanger 11, a compressor 12, a generator 13, a tenth valve 23, and an eleventh valve 24.

[0042] The outlet of the heat exchange pipe of the high-temperature manganese-based thermochemical reactor 2 is connected to the first end of the tenth valve 23, and the second end of the tenth valve 23 is connected to the inlet of the turbine 9; the outlet of the turbine 9 is connected to the hot-side inlet of the regenerator 10, the hot-side outlet of the regenerator 10 is connected to the hot-side inlet of the second heat exchanger 11, the hot-side outlet of the second heat exchanger 11 is connected to the inlet of the compressor 12, and the outlet of the compressor 12 is connected to the cold-side inlet of the regenerator 10; the cold-side outlet of the regenerator 10 is connected to the first end of the eleventh valve 24, and the second end of the eleventh valve 24 is connected to the inlet of the heat exchange pipe of the high-temperature manganese-based thermochemical reactor 2; the turbine 9 is connected to the generator 13.

[0043] Specifically, when the working fluid of the Brayton cycle power generation system flows through the heat exchange pipe of the high-temperature manganese-based thermochemical reactor 2, it is heated to a preset high-temperature and high-pressure state and discharged from the outlet of the heat exchange pipe into the turbine 9. The high-temperature and high-pressure working fluid expands and does work in the turbine 9, converting the internal energy and pressure energy of the working fluid into the rotor mechanical energy of the turbine 9. The rotor of the turbine 9 drives the generator 13 connected to it to rotate and generate electricity. The low-pressure and low-temperature working fluid after doing work is discharged from the outlet of the turbine 9 and enters the hot side inlet of the regenerator 10. In the regenerator 10, the remaining heat is transferred to the low-temperature and high-pressure working fluid flowing through the cold side, and its own temperature is further reduced.

[0044] Specifically, supercritical carbon dioxide is used as the working fluid in the Brayton cycle, and it flows through the heat exchange pipes inside the high-temperature manganese-based thermochemical reactor 2 during the cycle. Under rated power generation conditions, the cold supercritical carbon dioxide enters the heat exchange pipes and exchanges heat with the manganese-based oxide energy storage material through the pipe wall, absorbing the chemical heat and sensible heat released by the energy storage material in the exothermic oxidation reaction, forming a hot supercritical carbon dioxide working fluid. The hot supercritical carbon dioxide working fluid then enters the turbine 9 to expand and do work, driving the generator 13 to generate electricity, realizing the thermal energy coupling and transfer between the thermochemical energy storage subsystem and the Brayton cycle power generation system.

[0045] The working fluid discharged from the hot side outlet of the regenerator 10 passes through the second heat exchanger 11 and enters the inlet of the compressor 12. After being compressed to a high pressure by the compressor 12, it is discharged from the outlet of the compressor 12 and enters the cold side inlet of the regenerator 10. In the regenerator 10, it absorbs the heat released by the hot side working fluid. After the temperature rises, it is discharged from the cold side outlet of the regenerator 10 and re-enters the heat exchange pipe inlet of the high-temperature manganese-based thermochemical reactor 2, completing the closed Brayton cycle. In this way, by setting up the regenerator 10, the waste heat in the working fluid discharged from the turbine 9 can be recovered to preheat the high-pressure working fluid at the outlet of the compressor 12, reducing the need for external heat source supplementation and significantly improving the thermal efficiency of the cycle.

[0046] A second heat exchanger 11 is disposed between the hot-side outlet of the regenerator 10 and the inlet of the compressor 12. The cold-side inlet of the second heat exchanger 11 is connected to a second heat exchange medium source, and the cold-side outlet of the second heat exchanger 11 is connected to a heat user. The second heat exchange medium source provides the second heat exchange medium into the second heat exchanger 11. The circulating working fluid, after being initially cooled by the hot side of the regenerator 10, is discharged from the hot-side outlet of the regenerator 10 and enters the hot-side inlet of the second heat exchanger 11. In the second heat exchanger 11, it is cooled by the second heat exchange medium to the temperature required for the inlet of the compressor 12, and then discharged from the hot-side outlet of the second heat exchanger 11 and enters the inlet of the compressor 12. By setting the second heat exchanger 11 to cool the circulating working fluid to the temperature required for the inlet of the compressor 12, the compression power consumption of the compressor 12 can be effectively reduced, thereby improving the net power generation efficiency of the entire Brayton cycle.

[0047] In one possible implementation, the turbine 9, compressor 12, and generator 13 are arranged coaxially; specifically, the turbine 9, compressor 12, and generator 13 are mounted on the same rotating shaft; the mechanical energy generated by the expansion of the turbine 9 is directly transmitted to the compressor 12 through the same rotating shaft to drive the rotation of the compressor 12, and to the generator 13 to generate electricity, which has the advantages of compact structure, high transmission efficiency, and small equipment footprint; after the mechanical energy output by the turbine 9 satisfies the power consumption of the compressor 12, the remaining power drives the generator 13 to generate electricity, reducing energy loss in intermediate transmission links.

[0048] The supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage described in Example 1 integrates manganese-based thermochemical energy storage with the supercritical CO2 Brayton cycle. It utilizes the high-temperature reversible reaction of manganese-based oxide energy storage materials to provide a heat source for the supercritical CO2 Brayton cycle, combining the advantages of high chemical energy storage density and high supercritical CO2 cycle efficiency. Secondly, through the graded storage and recovery of sensible heat and chemical energy, it achieves cascaded utilization of thermal energy and avoids thermal stress impact on materials. Based on the chemically controlled non-destructive load change technology, it achieves non-destructive, precise, and dynamic adjustment of generator output.

[0049] Example 2 This embodiment 2 provides an operation method for the manganese-calcium cascade thermochemical energy storage and high-purity oxygen cogeneration system described in embodiment 1 above, including energy storage operation mode, rated power generation operation mode and peak shaving operation mode.

[0050] Energy storage operating conditions are as follows: The manganese-based oxide energy storage material in the high-temperature manganese-based thermochemical reactor 2 is heated to undergo an endothermic reduction reaction to generate high-temperature oxygen. After the high-temperature oxygen flows through the solid particle heat storage tank 3, the sensible heat it carries is stored in the solid particle heat storage tank 3 to form cooled oxygen, which is then passed into the high-pressure oxygen storage tank 6 for storage.

[0051] Explanatoryly, energy storage is employed during periods of abundant renewable energy generation, such as windy or sunny periods, to convert renewable energy electricity into thermochemical energy for storage.

[0052] In practical implementation, the renewable energy power generation system 1 supplies power to the electric heater installed inside the high-temperature manganese-based thermochemical reactor 2. The electric heater generates a high heat flux density heat source of over 950°C, which heats the Mn2O3 filled inside the reactor. When the temperature of the main material in the reactor rises to 900-1000°C, Mn2O3 begins to undergo a large-scale endothermic reduction reaction. The process of the endothermic reduction reaction is as follows:

[0053] In this process, electrical energy is first converted into heat energy, which is then stored in the reaction products Mn3O4 and oxygen in the form of sensible heat and chemical energy. At the same time, the high-temperature oxygen produced by the reaction is discharged from the gas outlet on the side of the reactor shell.

[0054] After the high-temperature oxygen flows through the solid particle heat storage tank 3, the sensible heat it carries is stored in the solid particle heat storage tank 3. After being cooled by the first heat exchanger 4 and compressed by the oxygen compressor 5, the cooled oxygen is introduced into the high-pressure oxygen storage tank 6, realizing the recovery and storage of the sensible heat of the high-temperature oxygen, as well as the final storage of oxygen.

[0055] In practice, the first valve 14 and the second valve 15 are opened, and the high-temperature O2 generated by the decomposition of Mn2O3 (above 900°C) is discharged and then introduced into the solid particle heat storage tank 3 through the first gas outlet on the shell side. The high-temperature O2 passes through the heat storage particle bed inside the solid particle heat storage tank 3, and through direct gas-solid contact heat exchange, a large amount of sensible heat carried by it is transferred and stored in the solid particles, and the temperature of the high-temperature O2 itself is greatly reduced. Then, the third valve 16 is opened, and the cooled O2 is reduced to room temperature through the first heat exchanger 4. The oxygen compressor 5 is started, the fourth valve 17 is opened, and the room temperature low-pressure O2 is compressed to a high-pressure state and introduced into the high-pressure oxygen storage tank 6 for sealed storage.

[0056] In this process, electrical energy is converted into sensible heat and chemical energy of manganese-based oxide energy storage material and sensible heat of heat storage particles in solid particle heat storage tank 3, realizing graded energy storage. The graded storage of sensible heat and chemical energy not only recovers the waste heat of high-temperature oxygen, but also avoids the direct emission and waste of heat.

[0057] The rated power generation conditions are as follows: In the mixing chamber 8, air is mixed with oxygen from the high-pressure oxygen storage tank 6 to form room-temperature oxygen-enriched gas. The room-temperature oxygen-enriched gas flows through the solid particle heat storage tank 3 to absorb the sensible heat stored therein, forming preheated oxygen-enriched gas. The preheated oxygen-enriched gas enters the high-temperature manganese-based thermochemical reactor 2, triggering an exothermic oxidation reaction of the manganese-based oxide energy storage material, and forming high-temperature air after the reaction. The high-temperature air after the reaction mixes with the preheated oxygen-enriched gas and re-enters the high-temperature manganese-based thermochemical reactor 2. The cold circulating working fluid flows through the heat exchange pipe of the high-temperature manganese-based thermochemical reactor 2, absorbs the heat generated by the manganese-based oxide energy storage material, forms a hot circulating working fluid, and re-enters the Brayton cycle power generation system.

[0058] Explanatoryly, the rated power generation condition is the main operating mode of the system for outputting electrical energy, which is activated when there is a demand for electricity from the grid.

[0059] In practice, the air compressor 7 is turned on, and the fifth valve 18 and the sixth valve 19 are opened simultaneously. Room temperature air and high-purity oxygen from the high-pressure oxygen storage tank are sent into the mixing chamber 8 according to the set ratio (higher oxygen content). After the air and oxygen are mixed evenly in the mixing chamber 8, room temperature oxygen-enriched gas is formed. The oxygen content in the room temperature oxygen-enriched gas is higher than the natural oxygen content in the air, so as to improve the rate and intensity of the subsequent oxidation reaction.

[0060] Next, the second valve 15 and the third valve 16 are closed, and the seventh valve 20 and the eighth valve 21 are opened. The room-temperature oxygen-enriched gas is first introduced into the solid particle heat storage tank 3, which is in a high-temperature heat storage state. When the room-temperature oxygen-enriched gas passes through the heat storage particle bed, it absorbs the sensible heat stored by the heat storage particles in the energy storage stage through direct gas-solid contact heat exchange, and its own temperature is preheated to above 700°C, forming preheated high-temperature oxygen-enriched gas. Through the preheating process, the cold reaction gas has been heated to a higher temperature before entering the high-temperature manganese-based thermochemical reactor 2, eliminating the thermal stress impact on the material caused by the direct injection of cold reaction gas into the high-temperature manganese-based thermochemical reactor 2, and effectively extending the service life of the energy storage material.

[0061] Subsequently, the preheated high-temperature oxygen-enriched gas is discharged from the second outlet of the solid particle heat storage tank 3 and enters the shell-side gas inlet of the high-temperature manganese-based thermochemical reactor 2 through the pipeline, where it comes into contact with Mn3O4 inside the reactor. The temperature of the preheated oxygen-enriched gas is above 700℃, which is close to the trigger temperature of the Mn3O4 oxidation reaction (800-850℃), so it can quickly trigger and maintain the exothermic oxidation reaction of Mn3O4. The exothermic oxidation reaction releases a large amount of chemical heat. The high-temperature air formed after the reaction is discharged from the side gas outlet of the high-temperature manganese-based thermochemical reactor 2.

[0062] Afterwards, the first valve 14 and the ninth valve 22 are opened. The high-temperature air after the reaction is discharged from the second gas outlet on the shell side and then mixed with the preheated oxygen-enriched gas from the second outlet of the solid particle heat storage tank 3 in the pipeline. The mixed gas re-enters the shell-side gas inlet of the high-temperature manganese-based thermochemical reactor 2. Through the gas recirculation arrangement, the residual heat carried in the high-temperature air after the reaction is brought back to the reactor. At the same time, the gas flow rate inside the reactor is increased, which improves the temperature uniformity and heat transfer effect of the bed.

[0063] Meanwhile, the cold circulating working fluid flows through the heat exchange pipe of the high-temperature manganese-based thermochemical reactor 2, absorbs the heat generated by the manganese-based oxide energy storage material, forms a hot circulating working fluid, and re-enters the Brayton cycle power generation system. Specifically, under rated power generation conditions, the tenth valve 23 and the eleventh valve 24 are opened, and the cold supercritical carbon dioxide working fluid is discharged from the cold side outlet of the regenerator and enters the inlet of the heat exchange pipe of the high-temperature manganese-based thermochemical reactor 2. When flowing through the reactor inside the heat exchange pipe, it absorbs the chemical heat and sensible heat released by the shell-side manganese-based oxide energy storage material in the exothermic oxidation reaction through the pipe wall, and its own temperature rises to above 650°C, forming a hot supercritical carbon dioxide working fluid. After being discharged from the heat exchange pipe outlet, the hot working fluid enters the turbine inlet, drives the turbine 9 to expand and do work, and drives the generator 13 to generate electricity. After doing work, the working fluid returns to the inlet of the heat exchange pipe of the reactor through the regenerator 10, the second heat exchanger 11, and the compressor 12, completing the closed Brayton cycle.

[0064] When grid load demand decreases and the system needs to reduce power generation output, the system switches to peak-shaving operation mode; peak-shaving operation mode is as follows: Maintaining the total gas mass flow rate of the high-temperature manganese-based thermochemical reactor 2 unchanged or slightly adjusted, reducing the oxygen supply in the mixing chamber 8 and increasing the air supply in the mixing chamber 8, thereby reducing the oxygen ratio in the oxygen-enriched gas and the oxygen partial pressure in the high-temperature manganese-based thermochemical reactor 2, thereby weakening the oxidation exothermic reaction rate of the manganese-based oxide energy storage material, reducing the heat absorption of the cold circulating working fluid, and achieving a reduction in the output of the Brayton cycle power generation system.

[0065] Explanatoryly, the peak-shaving operation aims to achieve lossless, precise, and dynamic reduction of generator output. In specific implementation, firstly, the turbine 9 intake is kept fully open, i.e., the tenth valve 23 is kept fully open to avoid irreversible pressure drop losses caused by throttling regulation. Then, the total gas mass flow rate entering the high-temperature manganese-based thermochemical reactor 2 is maintained or finely adjusted (i.e., the total flow rate of the mixed gas entering the reactor), but the oxygen supply valve of the high-pressure oxygen storage tank 6 is significantly reduced, i.e., the opening of the fifth valve 18 is reduced to decrease the oxygen supply entering the mixing chamber 8. At the same time, the intake volume of the air compressor 7 is increased or the opening of the sixth valve 19 is increased to increase the air supply entering the mixing chamber 8.

[0066] It should be noted that, due to the decrease in oxygen supply and the increase in air supply, the proportion of oxygen in the mixed gas decreases, and the oxygen partial pressure in the high-temperature manganese-based thermochemical reactor 2 decreases sharply accordingly. According to the principle of chemical reaction kinetics, the rate of gas-solid oxidation reaction is directly related to the partial pressure of reactant (O2). The decrease in oxygen partial pressure weakens the rate of Mn3O4 oxidation exothermic reaction and reduces the amount of chemical heat released per unit time. Therefore, the heat absorption of supercritical CO2 working fluid in the heat exchange pipe decreases, the outlet temperature decreases, the work capacity of turbine 9 decreases, and the output of generator 13 is smoothly reduced.

[0067] During this process, since the total gas mass flow rate remains essentially constant, the flow field and heat transfer conditions within the reactor do not change drastically. Furthermore, because the throttling valve regulation method is avoided, no additional throttling pressure drop loss occurs, and the system's operating efficiency is maintained under varying operating conditions. By shifting the power regulation control point from traditional thermal parameter regulation (such as throttling valve regulation) to the chemical kinetic level, and utilizing the direct control effect of oxygen concentration on the reaction rate, lossless and precise regulation of power generation is achieved. When it is necessary to restore rated output, simply increasing the oxygen supply, decreasing the air supply, and increasing the oxygen partial pressure can quickly restore the reaction rate and power generation.

[0068] The supercritical CO2 Brayton cycle power generation system and operation method coupled with manganese-based thermochemical energy storage described in this invention deeply couples manganese-based thermochemical energy storage with the supercritical CO2 Brayton cycle. It utilizes the high-temperature reversible thermochemical reaction of manganese-based oxide energy storage materials to provide a high-grade heat source of over 800°C for the Brayton cycle, combining the advantages of high thermochemical energy storage density and high supercritical carbon dioxide cycle efficiency to construct a high-efficiency power generation system with zero carbon emissions.

[0069] In this invention, by designing a graded storage and recovery process for sensible heat and chemical energy, the waste heat of high-temperature pure oxygen is used to preheat the solid particle thermal storage tank, and it is used to preheat the cold reaction gas during power generation, thereby realizing the cascade utilization of thermal energy and effectively recovering the waste heat of high-temperature oxygen. At the same time, the preheated gas eliminates the thermal stress impact on the material caused by the direct injection of cold gas into the high-temperature reactor, thus extending the service life of the energy storage material. In this invention, by changing the control point of power regulation from traditional throttling valve regulation to oxygen partial pressure regulation at the level of chemical reaction kinetics, the total gas mass flow rate entering the reactor is kept constant or only slightly adjusted during peak shaving. By adjusting the oxygen concentration in the mixed gas, the oxidation exothermic reaction rate and heat output of manganese-based oxides are directly controlled, thereby smoothly reducing the power generation. This completely abandons the traditional throttling valve regulation method, avoids irreversible pressure drop losses and sudden drops in system efficiency under varying operating conditions, and achieves lossless, precise, and dynamic reduction of generator output, effectively adapting to the grid's demand for flexible peak shaving of generator sets.

[0070] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage, characterized in that, This includes a thermochemical cycle subsystem and a Brayton cycle electron-generating system; The thermochemical cycle subsystem includes a high-temperature manganese-based thermochemical reactor (2), a solid particle heat storage tank (3), a high-pressure oxygen storage tank (6), and a mixing chamber (8); the high-temperature manganese-based thermochemical reactor (2) is equipped with heat exchange pipes and filled with manganese-based oxide energy storage material; wherein, after the manganese-based oxide energy storage material undergoes an endothermic reduction reaction, it generates high-temperature oxygen; The first gas outlet of the shell side of the high-temperature manganese-based thermochemical reactor (2) is connected to the inlet of the solid particle heat storage tank (3), the first outlet of the solid particle heat storage tank (3) is connected to the inlet of the high-pressure oxygen storage tank (6), the outlet of the high-pressure oxygen storage tank (6) is connected to the oxygen inlet of the mixing chamber (8), and the mixed gas outlet of the mixing chamber (8) is connected to the inlet of the solid particle heat storage tank (3); the second gas outlet of the shell side of the high-temperature manganese-based thermochemical reactor (2) is combined with the second outlet of the solid particle heat storage tank (3) and then connected to the gas inlet of the shell side of the high-temperature manganese-based thermochemical reactor (2); The working fluid of the Brayton cycle power generation system flows through the heat exchange pipe of the high-temperature manganese-based thermochemical reactor (2) and exchanges heat with the manganese-based oxide energy storage material.

2. The supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage according to claim 1, characterized in that, The thermochemical cycle subsystem also includes a first heat exchanger (4), which is located between the outlet of the solid particle heat storage tank (3) and the inlet of the high-pressure oxygen storage tank (6); Among them, the first outlet of the solid particle heat storage tank (3) is connected to the hot side inlet of the first heat exchanger (4), and the hot side outlet of the first heat exchanger (4) is connected to the inlet of the high-pressure oxygen storage tank (6).

3. The supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage according to claim 1, characterized in that, The thermochemical cycle subsystem also includes an oxygen compressor (5), which is located between the outlet of the solid particle heat storage tank (3) and the inlet of the high-pressure oxygen storage tank (6).

4. The supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage according to claim 1, characterized in that, It also includes an air compressor (7), which is located at the air inlet of the mixing chamber (8).

5. A supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage according to claim 1, characterized in that, It also includes a renewable energy power generation system (1); the high-temperature manganese-based thermochemical reactor (2) is also equipped with an electric heater, the power supply of which is connected to the renewable energy power generation system (1).

6. The supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage according to claim 1, characterized in that, The Brayton cycle power generation system includes a turbine (9), a regenerator (10), a compressor (12), and a generator (13). The heat exchange pipe outlet of the high-temperature manganese-based thermochemical reactor (2) is connected to the inlet of the turbine (9), the outlet of the turbine (9) is connected to the hot side inlet of the regenerator (10), the hot side outlet of the regenerator (10) is connected to the inlet of the compressor (12), the outlet of the compressor (12) is connected to the cold side inlet of the regenerator (10), and the cold side outlet of the regenerator (10) is connected to the heat exchange pipe inlet of the high-temperature manganese-based thermochemical reactor (2); the turbine (9) is connected to the generator (13).

7. A supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage according to claim 6, characterized in that, The turbine (9), compressor (12) and generator (13) are arranged coaxially.

8. A supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage according to claim 6, characterized in that, The Brayton cycle power generation system also includes a second heat exchanger (11), which is located between the hot side outlet of the regenerator (10) and the inlet of the compressor (12); The hot side outlet of the regenerator (10) is connected to the hot side inlet of the second heat exchanger (11), and the hot side outlet of the second heat exchanger (11) is connected to the inlet of the compressor (12).

9. The operation method of a supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage as described in any one of claims 1-8, characterized in that, Including energy storage operating conditions and rated power generation operating conditions Energy storage operating conditions include: The manganese-based oxide energy storage material in the high-temperature manganese-based thermochemical reactor (2) is heated to cause an endothermic reduction reaction and generate high-temperature oxygen. After the high-temperature oxygen flows through the solid particle heat storage tank (3), the sensible heat it carries is stored in the solid particle heat storage tank (3) to form cooled oxygen and then passed into the high-pressure oxygen storage tank (6) for storage. Rated power generation conditions include: In the mixing chamber (8), air is mixed with oxygen from the high-pressure oxygen storage tank (6) to form room-temperature oxygen-enriched gas; the room-temperature oxygen-enriched gas flows through the solid particle heat storage tank (3) to absorb the sensible heat stored therein, forming preheated oxygen-enriched gas; the preheated oxygen-enriched gas enters the high-temperature manganese-based thermochemical reactor (2), triggering the manganese-based oxide energy storage material to undergo an exothermic oxidation reaction, and forming high-temperature air after the reaction; the high-temperature air after the reaction is mixed with the preheated oxygen-enriched gas and then re-enters the high-temperature manganese-based thermochemical reactor (2). After the cold circulating working fluid flows through the heat exchange pipe of the high-temperature manganese-based thermochemical reactor (2), it absorbs the heat generated by the manganese-based oxide energy storage material, forms a hot circulating working fluid, and re-enters the Brayton cycle power generation system.

10. The operation method of a supercritical CO2 Brayton cycle power generation system coupled with manganese-based thermochemical energy storage according to claim 9, characterized in that, It also includes peak shaving conditions; Peak shaving conditions include: Maintain the total gas mass flow rate of the high-temperature manganese-based thermochemical reactor (2) unchanged or slightly adjusted, reduce the oxygen supply in the mixing chamber (8) and increase the air supply in the mixing chamber (8) to reduce the oxygen ratio in the oxygen-enriched gas and the oxygen partial pressure in the high-temperature manganese-based thermochemical reactor (2), thereby weakening the oxidation exothermic reaction rate of the manganese-based oxide energy storage material, reducing the heat absorption of the cold circulating working fluid, and realizing the reduction of the output of the Brayton cycle power generation system.

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