An energy storage system based on thermo-chemical energy storage and rankine cycle and a method of operation

Abstract

The present application relates to the technical field of energy storage, and relates to an energy storage system based on thermochemical energy storage and Rankine cycle and an operation method. The energy storage system comprises a storage device, an energy storage device, an energy release device and a power generation device. The energy storage device comprises a calcium carbonate rotary calcining kiln, a first heat exchanger network and an electric heater, and the structural components are sequentially connected. The electric heater is used to convert excess electricity into heat energy, the calcium carbonate decomposition reaction is carried out in the calcium carbonate rotary calcining kiln, the heat energy is converted into chemical energy stored in calcium oxide, the energy release device is used to convert the chemical energy stored in calcium oxide into heat energy, the heat energy is converted into electricity by the power generation device, and the electricity demand of the terminal user is met. The energy storage system provided by the present application can realize the conversion, transmission and storage of different energies, has high energy conversion efficiency, can effectively reduce the coal consumption in the energy conversion process, and meets the energy saving and carbon reduction and flexibility reconstruction requirements of coal-fired power plants.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy storage technology, in particular to an energy storage system based on thermo-chemical energy storage and Rankine cycle and a running method thereof. BACKGROUND

[0002] Energy storage technology is a key technology to improve the reliability and stability of renewable energy, however, due to the dual constraints of natural resources and short-time energy storage equipment technology, the current energy storage technology can only meet the real-time balance of load and immediate use, but the time of renewable energy enrichment is opposite to the load, resulting in more acute long-period supply and demand contradiction.

[0003] Developing the mode of "new energy + energy storage + thermal power generation", and strengthening the coupling and complementation of coal-fired generating units and renewable energy, are important trends to promote energy saving and carbon reduction and flexibility reconstruction of coal-fired power plants. However, the energy storage technology used in the existing coal-fired power plant reconstruction process mainly uses sensible heat and latent heat energy storage technology, and these reconstruction methods have some deficiencies, such as solid sensible heat storage can only store energy for a short time and has small heat storage capacity; the molten salt used in high-temperature molten salt energy storage has low thermal conductivity and specific heat capacity, and is highly corrosive, which has high requirements for the corrosion resistance of the corresponding heat storage device materials, limiting the depth and economy of energy saving and carbon reduction and flexibility reconstruction of coal-fired power plants.

[0004] Therefore, the existing energy storage technology cannot meet the long-period supply and demand contradiction of renewable power and the energy saving and carbon reduction and flexibility reconstruction requirements of coal-fired power plants. SUMMARY

[0005] The present application provides an energy storage system based on thermo-chemical energy storage and Rankine cycle, which effectively realizes the conversion, transmission and storage of electric energy-thermal energy-chemical energy-electric energy, has high energy conversion efficiency in the energy conversion and transmission process, can realize the function of carbon element capture, reduce coal consumption in the energy conversion process, meet the energy saving and carbon reduction and flexibility reconstruction requirements of coal-fired power plants, and improve the safety and flexibility of new power systems mainly based on renewable energy.

[0006] The present application also provides a running method of the energy storage system based on thermo-chemical energy storage and Rankine cycle.

[0007] According to the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the first aspect of the present application, the energy storage system comprises:

[0008] a storage device;

[0009] The energy storage device comprises a calcium carbonate rotary calcining kiln, a first heat exchanger network and an electric heater; a calcium carbonate inlet of the calcium carbonate rotary calcining kiln is communicated with a calcium carbonate outlet of the first heat exchanger network, a calcium oxide outlet of the calcium carbonate rotary calcining kiln is communicated with a calcium oxide inlet of the first heat exchanger network, and a carbon dioxide outlet of the calcium carbonate rotary calcining kiln is communicated with a carbon dioxide inlet of the first heat exchanger network; the carbon dioxide outlet, the calcium carbonate inlet and the calcium oxide outlet of the first heat exchanger network are all communicated with the storage device; the electric heater is arranged in the calcium carbonate rotary calcining kiln, the electric heater is electrically communicated with a power grid, and the electric heater is used for heating and decomposing calcium carbonate, so that electric energy is converted into chemical energy and stored in calcium oxide.

[0010] The energy release device is communicated with the storage device, and is used for converting chemical energy in the calcium oxide into thermal energy.

[0011] The power generation device is communicated with the energy release device, and is used for converting thermal energy generated by the energy release device into electric energy.

[0012] According to the energy storage system based on thermochemical energy storage and Rankine cycle provided by the application, the storage device comprises:

[0013] The carbon dioxide compressor set is communicated with the carbon dioxide outlet of the first heat exchanger network.

[0014] The carbon dioxide storage tank is communicated with the carbon dioxide outlet of the carbon dioxide compressor set.

[0015] According to the energy storage system based on thermochemical energy storage and Rankine cycle provided by the application, the storage device further comprises:

[0016] The calcium carbonate storage tank is communicated with the calcium carbonate inlet of the first heat exchanger network.

[0017] The calcium oxide storage tank is communicated with the calcium oxide outlet of the first heat exchanger network.

[0018] According to the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the application, the energy releasing device comprises a second heat exchanger network, a carbon dioxide emission source and a carbonation reaction fluidized bed; the calcium oxide inlet of the second heat exchanger network is communicated with the calcium oxide outlet of the calcium oxide storage tank, the calcium carbonate outlet of the second heat exchanger network is communicated with the calcium carbonate inlet of the calcium carbonate storage tank, and the carbon-containing flue gas inlet of the second heat exchanger network is communicated with the carbon dioxide emission source; the calcium oxide outlet of the second heat exchanger network is communicated with the calcium oxide inlet of the carbonation reaction fluidized bed, the carbon-containing flue gas outlet of the second heat exchanger network is communicated with the carbon-containing flue gas inlet of the carbonation reaction fluidized bed, and the calcium carbonate inlet of the second heat exchanger network is communicated with the calcium carbonate outlet of the carbonation reaction fluidized bed; the decarburized flue gas inlet of the second heat exchanger network is communicated with the decarburized flue gas outlet of the carbonation reaction fluidized bed, and the decarburized flue gas outlet of the second heat exchanger network is communicated with the atmosphere.

[0019] According to the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the application, the power generation device comprises:

[0020] The endothermic device, the first steam turbine, the second steam turbine, the third steam turbine, the generator, the regenerator group and the boiler are arranged inside the carbonation reaction fluidized bed, the water vapor inlet of the endothermic device is communicated with the first outlet of the first steam turbine, and the water vapor outlet of the endothermic device is communicated with the water vapor inlet of the second steam turbine; the first outlet of the second steam turbine is communicated with the water vapor inlet of the third steam turbine, and the first outlet of the third steam turbine is communicated with the first inlet of the regenerator group; the rotating shafts of the first steam turbine, the second steam turbine and the third steam turbine are connected with the rotating shaft of the generator; the outlet of the regenerator group is communicated with the water vapor inlet of the boiler, and the water vapor outlet of the boiler is communicated with the water vapor inlet of the first steam turbine.

[0021] According to the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the application, the regenerator group comprises a first regenerator and a second regenerator; the first inlet of the first regenerator is communicated with the first outlet of the third steam turbine, the outlet of the first regenerator is communicated with the first inlet of the second regenerator, and the outlet of the second regenerator is communicated with the water vapor inlet of the boiler.

[0022] According to the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the application, the second outlet of the first steam turbine and the second outlet of the second steam turbine are both communicated with the second inlet of the second regenerator, and the third outlet of the second steam turbine and the second outlet of the third steam turbine are both communicated with the second inlet of the first regenerator.

[0023] The energy storage system based on thermo-chemical energy storage and Rankine cycle further comprises:

[0024] a condenser, a water vapor inlet of the condenser being communicated with a first outlet of the third steam turbine;

[0025] a water pump, a water inlet of the water pump being communicated with a water outlet of the condenser, and a water outlet of the water pump being communicated with a first inlet of the first regenerator.

[0026] The operation method of the energy storage system based on thermo-chemical energy storage and Rankine cycle according to the second aspect of the present application is based on any one of the energy storage systems based on thermo-chemical energy storage and Rankine cycle described above, and the operation method comprises:

[0027] The calcium carbonate input into the calcium carbonate rotary calcining kiln is heated and decomposed by the electric heater using the excess power of the power grid, so that the electric energy is converted into chemical energy and stored in the calcium oxide obtained by decomposition;

[0028] The calcium carbonate is preheated by the first heat exchanger network using the residual heat carried by the calcium oxide obtained by decomposition and the carbon dioxide gas, and the preheated calcium carbonate is introduced into the calcium carbonate rotary calcining kiln;

[0029] The carbon dioxide and calcium oxide particles that have completed preheating are stored by the storage device.

[0030] The operation method of the energy storage system based on thermo-chemical energy storage and Rankine cycle according to the present application further comprises:

[0031] The carbonation reaction fluidized bed is used to make the calcium oxide and the carbon-containing flue gas undergo a carbonation reaction to generate calcium carbonate and convert chemical energy into heat energy;

[0032] The calcium oxide and the carbon-containing flue gas are preheated by the second heat exchanger network using the residual heat carried by the generated calcium carbonate;

[0033] The boiler is used to heat water vapor or a mixture of water vapor and water to obtain superheated water vapor, and the superheated water vapor is input into the first steam turbine to drive the generator to generate electricity;

[0034] The heat absorber is used to reheat the water vapor output by the first steam turbine using the heat released by the carbonation reaction, and the reheated water vapor is sequentially input into the second steam turbine and the third steam turbine to make the second steam turbine and the third steam turbine drive the generator to generate electricity;

[0035] The condenser is used to condense the water vapor output by the third steam turbine to obtain condensed water;

[0036] The condensed water is pumped by a water pump to the first regenerator and the second regenerator for preheating, and the water vapor or the mixture of water vapor and water obtained after preheating is delivered to the boiler for heating.

[0037] The one or more technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0038] According to the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the embodiment of the present application, the excess power is converted into heat energy by the electric heater, the calcium carbonate is heated in the calcium carbonate rotary calcining kiln to make the calcium carbonate decompose, so that the heat energy is converted into chemical energy suitable for long-term storage and stored in calcium oxide; when the terminal user has power demand, the chemical energy stored in the calcium oxide is converted into heat energy by the energy release device, and then the heat energy is converted into electric energy by the power generation device, so that the energy conversion is realized to meet the demand of the terminal user. The energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the present application realizes the conversion, transmission and storage among electric energy-heat energy-chemical energy-electric energy, and the energy conversion efficiency is high in the process of energy conversion and transmission. Meanwhile, under the action of the energy release system, carbon capture can be realized, and the coal consumption in the energy conversion process is reduced, so that the energy saving and carbon reduction and flexibility reconstruction requirements of the coal-fired power plant are met, and the safety and flexibility of the new power system mainly based on renewable energy are improved.

[0039] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following description and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0041] Figure 1 is a structural schematic diagram of the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the embodiment of the present application;

[0042] Figure 2 is a connection structure schematic diagram of the energy storage device and the storage device provided by the embodiment of the present application;

[0043] Figure 3 is a connection structure schematic diagram of the energy release device and the power generation device provided by the embodiment of the present application;

[0044] Figure 4 is a flow chart of the operation method of the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the embodiment of the present application.

[0045] Reference signs:

[0046] 1, power grid; 2, electric heater; 3, calcium carbonate rotary calcining kiln; 4, first heat exchanger network; 5, carbon dioxide compressor unit; 6, carbon dioxide storage tank; 7, calcium carbonate storage tank; 8, calcium oxide storage tank; 9, second heat exchanger network; 10, carbon dioxide emission source; 11, carbonation reaction fluidized bed; 12, heat absorber; 13, first steam turbine; 14, second steam turbine; 15, third steam turbine; 16, generator; 17, condenser; 18, water pump; 19, first regenerator; 20, second regenerator; 21, boiler. DETAILED DESCRIPTION

[0047] The embodiments of the present application will be further described below in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0048] In the description of the embodiments of the present application, it should be noted that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0049] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0050] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature is "over", "above" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only means that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only means that the first feature is lower in horizontal height than the second feature.

[0051] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0052] The following will be described in conjunction with Figures 1 to 3 The embodiments of the present application provide a thermal chemical energy storage and Rankine cycle based energy storage system.

[0053] Figure 1 The structure schematic diagram of the thermal chemical energy storage and Rankine cycle based energy storage system provided by the embodiments of the present application is illustrated as follows, Figure 1 As shown in the figure, the thermal chemical energy storage and Rankine cycle based energy storage system includes a storage device, an energy storage device, an energy release device and a power generation device. The energy storage device includes a calcium carbonate rotary calcining kiln 3, a first heat exchanger network 4 and an electric heater 2.

[0054] The carbon dioxide outlet, the calcium carbonate inlet and the calcium oxide outlet of the first heat exchanger network 4 are in communication with the storage device, and the calcium carbonate solid particles of the storage device are input into the first heat exchanger network 4 through the calcium carbonate inlet of the first heat exchanger network 4. The first heat exchanger network 4 recovers the heat of the high-temperature products flowing out from the outlet of the calcium carbonate rotary calcining kiln 3, and preheats the calcium carbonate solid particles by using the heat of the recovered high-temperature products. Specifically, the high-temperature products include high-temperature calcium oxide solid particles and high-temperature carbon dioxide gas.

[0055] The calcium carbonate inlet of the calcium carbonate rotary calcining kiln 3 is communicated with the calcium carbonate outlet of the first heat exchanger network 4, and the preheated calcium carbonate solid particles are input into the calcium carbonate rotary calcining kiln 3 through the calcium carbonate inlet of the calcium carbonate rotary calcining kiln 3. The decomposition reaction of the calcium carbonate solid particles occurs in the calcium carbonate rotary calcining kiln 3, and the reaction temperature of the decomposition reaction is 800-900 DEG C. The calcium carbonate is decomposed to generate calcium oxide solid particles and carbon dioxide gas.

[0056] The calcium carbonate outlet of the calcium carbonate rotary calcining kiln 3 is communicated with the calcium carbonate inlet of the first heat exchanger network 4, and the calcium carbonate solid particles carrying residual heat are input into the first heat exchanger network 4 through the calcium carbonate inlet of the first heat exchanger network 4. The carbon dioxide outlet of the calcium carbonate rotary calcining kiln 3 is communicated with the carbon dioxide inlet of the first heat exchanger network 4, and the carbon dioxide gas carrying residual heat is input into the first heat exchanger network 4 through the carbon dioxide inlet of the first heat exchanger network 4.

[0057] The electric heater 2 is arranged in the calcium carbonate rotary calcining kiln 3, and the electric heater 2 is electrically communicated with the power grid 1. The electric heater 2 converts the excess power of the power grid 1 into heat energy, and the decomposition reaction of the calcium carbonate occurs after the calcium carbonate absorbs the converted heat energy. The electric heater 2 is used for heating and decomposing the calcium carbonate, so that the electric energy is converted into chemical energy and stored in the calcium oxide.

[0058] The energy releasing device is communicated with the storage device, and the energy releasing device is used for converting the chemical energy in the calcium oxide into heat energy. The power generation device is communicated with the energy releasing device, and the power generation device is used for converting the heat energy generated by the energy releasing device into electric energy.

[0059] According to the energy storage system based on thermochemical energy storage and Rankine cycle provided by the embodiment of the present application, the excess power of the power grid 1 is converted into heat energy under the working of the electric heater 2, and through the decomposition reaction of the calcium carbonate occurring in the calcium carbonate rotary calcining kiln 3, the heat energy is converted into chemical energy suitable for long-term storage and stored in the calcium oxide. When the terminal user proposes the power demand, the chemical energy stored in the calcium oxide is converted into heat energy through the energy releasing device, and then the heat energy is converted into electric energy through the power generation device, so that the energy conversion is realized and the terminal user demand is met.

[0060] In the embodiment of the present application, the first heat exchanger network 4 is composed of a group of fluid-solid heat exchangers, a group of fluid-fluid heat exchangers and connecting pipelines thereof, and the specific pipeline composition can be designed based on the mass heat capacity and temperature of the import and export materials by using the pinch point analysis method. The structure of the calcium carbonate rotary calcining kiln 3 is sequentially composed of an insulation layer, a high-pressure resistant shell, an electric heating layer and a calcium carbonate particle calcining furnace body from outside to inside, and the electric heater 2 is arranged in the electric heating layer.

[0061] It should be noted that the first heat exchanger network 4 and the calcium carbonate rotary calcining kiln 3 are both existing devices, and the specific structures of the two are not introduced in detail here.

[0062] In the embodiment of the present application, Figure 2 The connection structure of the energy storage device and the storage device provided by the embodiment of the present application is illustrated as follows: Figure 1 and Figure 2 As shown in the figures, the storage device comprises a carbon dioxide compressor set 5 and a carbon dioxide storage tank 6. The carbon dioxide inlet of the carbon dioxide compressor set 5 is in communication with the carbon dioxide outlet of the first heat exchanger network 4, and the carbon dioxide storage tank 6 is in communication with the carbon dioxide outlet of the carbon dioxide compressor set 5. After the reaction waste heat is fully transferred to the calcium carbonate solid particles, the carbon dioxide gas flows out of the carbon dioxide outlet of the first heat exchanger network 4, is input into the carbon dioxide compressor set 5, and is compressed to a supercritical state by the carbon dioxide compressor set 5. The carbon dioxide gas in the supercritical state flows out of the carbon dioxide outlet of the carbon dioxide compressor set 5 and is stored in the carbon dioxide storage tank 6.

[0063] In the embodiment of the present application, as shown in the figures, Figure 1 and Figure 2 The storage device further comprises a calcium carbonate storage tank 7 and a calcium oxide storage tank 8. The calcium carbonate outlet of the calcium carbonate storage tank 7 is in communication with the calcium carbonate inlet of the first heat exchanger network 4, and the calcium carbonate storage tank 7 provides the first heat exchanger network 4 with calcium carbonate solid particles. The calcium oxide inlet of the calcium oxide storage tank 8 is in communication with the calcium oxide outlet of the first heat exchanger network 4. After the reaction waste heat is fully transferred to the calcium carbonate solid particles, the calcium oxide solid particles are input into the calcium oxide storage tank 8 through the calcium oxide outlet of the first heat exchanger network 4 and the calcium oxide inlet of the calcium oxide storage tank 8, and the storage of the calcium oxide solid particles is completed.

[0064] It should be noted that the calcium carbonate storage tank 7 and the calcium oxide storage tank 8 are both sealed storage.

[0065] According to the energy storage system of the embodiment of the present application, after the calcium carbonate solid particles are preheated in the first heat exchanger network 4, they enter the calcium carbonate rotary calcining kiln 3, and at the same time, the excess power of the power grid 1 is converted into heat energy by the electric heater 2. After absorbing the heat generated by the electric heater 2, the calcium carbonate solid particles decompose to generate calcium oxide solid particles and carbon dioxide gas, thereby realizing the conversion of heat energy into chemical energy suitable for long-term storage. The calcium oxide solid particles and the carbon dioxide gas carrying a large amount of heat enter the first heat exchanger network 4 to release and transfer the heat. The carbon dioxide gas after completing the heat transfer is transported to the carbon dioxide storage tank 6 after being compressed to a supercritical state, and the calcium oxide solid particles after completing the heat transfer are transported back to the calcium oxide storage tank 8 through the calcium oxide outlet of the first heat exchanger network 4 and the calcium oxide inlet of the calcium oxide storage tank 8, thereby completing the thermochemical energy storage process.

[0066] According to the demand scenario of power grid 1 surplus power consumption, the energy storage device is started, the surplus power of power grid 1 is converted into high-grade heat energy through the electric heater 2, and finally the high-grade heat energy is converted into suitable chemical energy through the decomposition reaction of calcium carbonate and stored in calcium oxide solid particles. As a thermochemical energy storage material, calcium oxide solid particles have the advantages of safety, non-toxicity and wide source, and have high energy storage density, long energy storage period and can realize long-term energy storage.

[0067] In the embodiments of the present application, Figure 3 The connection structure schematic diagram of the energy releasing device and the power generation device provided by the embodiments of the present application is illustrated as follows, Figure 1 and Figure 3 The energy releasing device includes a second heat exchanger network 9, a carbon dioxide emission source 10 and a carbonation reaction fluidized bed 11.

[0068] The calcium oxide inlet of the second heat exchanger network 9 is in communication with the calcium oxide outlet of the calcium oxide storage tank 8, and the normal-temperature calcium oxide solid particles in the calcium oxide storage tank 8 are input into the second heat exchanger network 9 through the calcium oxide inlet of the second heat exchanger network 9. The carbon-containing flue gas inlet of the second heat exchanger network 9 is in communication with the carbon dioxide emission source 10, and the carbon-containing flue gas emitted by the carbon dioxide emission source 10 is input into the second heat exchanger network 9 from the carbon-containing flue gas inlet of the second heat exchanger network 9. In this embodiment, the carbon dioxide emission source 10 is a carbon dioxide emission plant, which can be a coal-fired power plant, a steel plant or a cement plant, etc. The second heat exchanger network 9 recovers the heat of the high-temperature products output from the outlet of the carbonation reaction fluidized bed 11, and uses the heat of the recovered high-temperature products to complete the preheating of the calcium oxide solid particles and the carbon-containing flue gas. Specifically, the high-temperature products at the outlet of the carbonation reaction fluidized bed 11 include high-temperature calcium carbonate solid particles and decarburized flue gas.

[0069] The calcium oxide outlet of the second heat exchanger network 9 is in communication with the calcium oxide inlet of the carbonation reaction fluidized bed 11, and the preheated calcium oxide solid particles are input into the carbonation reaction fluidized bed 11 through the calcium oxide inlet of the carbonation reaction fluidized bed 11; the carbon-containing flue gas outlet of the second heat exchanger network 9 is in communication with the carbon-containing flue gas inlet of the carbonation reaction fluidized bed 11, and the preheated carbon-containing flue gas is input into the carbonation reaction fluidized bed 11 through the carbon-containing flue gas inlet of the carbonation reaction fluidized bed 11. In the carbonation reaction fluidized bed 11, the calcium oxide solid particles and the carbon dioxide in the carbon-containing flue gas undergo carbonation reaction and generate high-temperature calcium carbonate solid particles, and the reaction temperature of the carbonation reaction is 600-650℃. A large amount of heat is released during the carbonation reaction process, thereby realizing the conversion of the chemical energy stored in the calcium oxide into heat energy. At the same time, the carbon elements in the carbon-containing flue gas are captured in the calcium carbonate solid particles through the carbonation reaction, the carbon-containing flue gas is converted into decarburized flue gas, and the capture of the carbon elements in the carbon-containing flue gas is completed, thereby reducing the carbon emission of the releasing device.

[0070] The calcium carbonate inlet of the second heat exchanger network 9 is in communication with the calcium carbonate outlet of the carbonation reaction fluidized bed 11, and the high-temperature calcium carbonate solid particles generated by the carbonation reaction enter the second heat exchanger network 9 through the calcium carbonate inlet of the second heat exchanger network 9. In the second heat exchanger network 9, the high-temperature calcium carbonate solid particles release heat to achieve preheating of the calcium oxide solid particles and the carbon-containing flue gas. The calcium carbonate outlet of the second heat exchanger network 9 is in communication with the calcium carbonate inlet of the calcium carbonate storage tank 7, and the calcium carbonate solid particles completing heat transfer are transported from the calcium carbonate inlet of the calcium carbonate storage tank 7 to the calcium carbonate storage tank 7.

[0071] The decarburized flue gas inlet of the second heat exchanger network 9 is in communication with the decarburized flue gas outlet of the carbonation reaction fluidized bed 11, and the decarburized flue gas carrying heat energy enters the second heat exchanger network 9 through the decarburized flue gas inlet of the second heat exchanger network 9. In the second heat exchanger network 9, the decarburized flue gas releases heat to achieve preheating of the calcium oxide solid particles and the carbon-containing flue gas. The decarburized flue gas outlet of the second heat exchanger network 9 is in communication with the atmosphere, and the decarburized flue gas completing heat transfer is discharged from the decarburized flue gas outlet of the second heat exchanger network 9, thereby reducing carbon emissions of the carbon dioxide emission source 10.

[0072] In the embodiment of the present application, the second heat exchanger network 9 is composed of a group of fluid-solid heat exchangers, a group of fluid-fluid heat exchangers, and connecting pipelines thereof. The specific pipeline composition can be designed based on the mass heat capacity and temperature of the inlet and outlet materials by using pinch analysis method. The structure of the carbonation reaction fluidized bed 11 includes a heat insulation layer, a shell, a furnace body, a heat absorber 12, and inlet and outlet ports.

[0073] It should be noted that, in the inlet and outlet ports, the carbon-containing flue gas inlet of the carbonation reaction fluidized bed 11 is located below the calcium oxide inlet of the carbonation reaction fluidized bed 11, so that in the carbonation reaction fluidized bed 11, the calcium oxide solid particles are in a fluidized state under the action of the carbon-containing flue gas, achieving sufficient reaction of the calcium oxide solid particles and the carbon dioxide, and at the same time, completing sufficient heat and mass transfer.

[0074] It should also be noted that the second heat exchanger network 9 and the carbonation reaction fluidized bed 11 are both existing devices, and the specific structures thereof will not be described in detail here.

[0075] According to the energy storage system of the embodiment of the present application, the calcium oxide solid particles and the carbon-containing flue gas are preheated by the second heat exchanger network 9 and then enter the carbonation reaction fluidized bed 11, the carbonation reaction between the calcium oxide and the carbon dioxide in the carbon-containing flue gas generates calcium carbonate and releases a large amount of heat, thereby realizing the conversion of the chemical energy stored in the calcium oxide into heat energy. The high-temperature calcium carbonate solid particles and the decarburized flue gas enter the second heat exchanger network 9 to release and transfer heat, the normal-temperature decarburized flue gas completing heat transfer is discharged from the decarburized flue gas outlet of the second heat exchanger network 9, and the normal-temperature calcium carbonate solid particles completing heat transfer are transported from the calcium carbonate inlet of the calcium carbonate storage tank 7 to the calcium carbonate storage tank 7, thereby completing the thermochemical energy release cycle process.

[0076] In the embodiment of the present application, as shown in Figure 1 and Figure 3 , the power generation device comprises a heat absorber 12, a first steam turbine 13, a second steam turbine 14, a third steam turbine 15, a generator 16, a regenerative heater group, and a boiler 21.

[0077] The outlet of the regenerative heater group is in communication with the water vapor inlet of the boiler 21, and the water vapor or the mixture of water vapor and water at the outlet of the regenerative heater group is input into the boiler 21 through the water vapor inlet of the boiler 21, and the water vapor and water are heated by the boiler 21 to form high-temperature and high-pressure superheated steam. The water vapor outlet of the boiler 21 is in communication with the water vapor inlet of the first steam turbine 13, and the high-temperature and high-pressure superheated steam enters the first steam turbine 13 through the water vapor outlet of the boiler 21 and the water vapor inlet of the first steam turbine 13 to expand and do work, thereby realizing the conversion of heat energy into mechanical energy. In the present embodiment, the first steam turbine 13 is a steam turbine high-pressure cylinder.

[0078] The heat absorber 12 is arranged inside the carbonation reaction fluidized bed 11, and the heat absorber 12 can absorb the heat energy generated by the carbonation reaction of calcium oxide. The water vapor inlet of the heat absorber 12 is in communication with the first outlet of the first steam turbine 13, and the water vapor flowing out of the first outlet of the first steam turbine 13 has a temperature of 390-410°C, and the water vapor is input into the heat absorber 12 through the water vapor inlet of the heat absorber 12. The water vapor input into the heat absorber 12 absorbs a large amount of heat generated by the carbonation reaction, thereby increasing the temperature of the water vapor to 600-630°C, thereby realizing the reheating of the water vapor by the heat energy generated by the carbonation reaction of calcium oxide. In the present embodiment, the reheating of the water vapor refers to the second heating of the water vapor by the heat energy generated by the carbonation reaction of calcium oxide, thereby realizing the transfer of the heat energy generated by the carbonation reaction of calcium oxide and further improving the heat transfer efficiency of the Rankine cycle. At the same time, the reheating of the water vapor by the heat absorber 12 using the heat energy generated by the carbonation reaction of calcium oxide makes it unnecessary to provide the heat required for the reheating of the water vapor in the Rankine cycle by the boiler 21 consuming coal to generate heat, thereby effectively reducing the coal consumption of the boiler 21 and further reducing the carbon emission of the energy release device.

[0079] The water vapor outlet of the heat absorber 12 is communicated with the water vapor inlet of the second steam turbine 14, and the water vapor after reheat enters the second steam turbine 14 through the water vapor inlet of the second steam turbine 14 to expand and do work. In the embodiment, the second steam turbine 14 is a medium-pressure cylinder of a steam turbine.

[0080] The first outlet of the second steam turbine 14 is communicated with the water vapor inlet of the third steam turbine 15, and the water vapor flowing out of the first outlet of the second steam turbine 14 is further input into the third steam turbine 15 to expand and do work. In the embodiment, the third steam turbine 15 is a low-pressure cylinder of a steam turbine. The first outlet of the third steam turbine 15 is communicated with the first inlet of the regenerator set, and the low-temperature and low-pressure water vapor of the first outlet of the third steam turbine 15 is input into the regenerator set through the first inlet of the regenerator set. The low-temperature and low-pressure water vapor is preheated and heated by the regenerator set, and the water vapor or the mixture of water vapor and water after preheating and heating is input into the boiler 21 through the water vapor inlet of the boiler 21.

[0081] The rotating shafts of the first steam turbine 13, the second steam turbine 14 and the third steam turbine 15 are connected with the rotating shaft of the generator 16, and the expansion and work processes of the first steam turbine 13, the second steam turbine 14 and the third steam turbine 15 drive the generator 16 to generate electricity, so as to realize the conversion of mechanical energy into electrical energy, and further meet the electricity demand of the end user.

[0082] In the embodiment of the present application, as shown in Figure 1 and Figure 3 The regenerator set includes a first regenerator 19 and a second regenerator 20. The first inlet of the first regenerator 19 is communicated with the first outlet of the third steam turbine 15, and the outlet of the first regenerator 19 is communicated with the first inlet of the second regenerator 20. The low-temperature and low-pressure water vapor output by the third steam turbine 15 is input into the first regenerator 19 through the first inlet of the first regenerator 19, and the water vapor or the mixture of water vapor and water after first preheating in the first regenerator 19 is input into the second regenerator 20 through the first inlet of the second regenerator 20. The water vapor or the mixture of water vapor and water is second preheated in the second regenerator 20. In the embodiment, the first regenerator 19 is a multi-stage low-pressure regenerator, and the second regenerator 20 is a multi-stage high-pressure regenerator. The outlet of the second regenerator 20 is communicated with the water vapor inlet of the boiler 21, and the water vapor or the mixture of water vapor and water after two times of preheating and heating is input into the boiler 21 through the outlet of the second regenerator 20 and the water vapor inlet of the boiler 21. The water vapor or the mixture of water vapor and water is heated in the boiler 21, so that the water vapor or the mixture of water vapor and water absorbs heat to be converted into high-temperature and high-pressure superheated water vapor.

[0083] In the embodiment of the present application, the second outlet of the first steam turbine 13 and the second outlet of the second steam turbine 14 are both communicated with the second inlet of the second regenerator 20, the water vapor flowing out of the second outlet of the first steam turbine 13 has completed the expansion work on the first steam turbine 13, the water vapor flowing out of the second outlet of the second steam turbine 14 has completed the expansion work on the second steam turbine 14, and the heat source of the second regenerator 20 is provided by the water vapor flowing out of the second outlet of the first steam turbine 13 and the water vapor flowing out of the second outlet of the second steam turbine 14. The third outlet of the second steam turbine 14 and the second outlet of the third steam turbine 15 are both communicated with the second inlet of the first regenerator 19, the water vapor flowing out of the third outlet of the second steam turbine 14 has completed the expansion work on the second steam turbine 14, the water vapor flowing out of the second outlet of the third steam turbine 15 has completed the expansion work on the third steam turbine 15, and the heat source of the first regenerator 19 is provided by the water vapor flowing out of the third outlet of the second steam turbine 14 and the water vapor flowing out of the second outlet of the third steam turbine 15.

[0084] In the embodiment of the present application, the power generation device further comprises a condenser 17 and a water pump 18. The water vapor inlet of the condenser 17 is communicated with the first outlet of the third steam turbine 15, the water inlet of the water pump 18 is communicated with the water outlet of the condenser 17, and the water outlet of the water pump 18 is communicated with the first inlet of the first regenerator 19. The low-temperature and low-pressure water vapor output by the first outlet of the third steam turbine 15 enters the condenser 17, and the water vapor is condensed into liquid water under the action of the condenser 17, and then the condensed water is pumped to the first regenerator 19 under the action of the water pump 18. By arranging the condenser 17 and the water pump 18 between the third steam turbine 15 and the first regenerator 19, the flow efficiency of the water vapor or the liquid water in the power generation device is improved.

[0085] According to the energy storage system provided by the embodiment of the present application, water vapor is condensed into liquid water under the action of the condenser 17, and the condensed liquid water is pumped to the first regenerator 19 and the second regenerator 20 by the water pump 18 for preheating and temperature rising, and under the action of the first regenerator 19 and the second regenerator 20, the liquid water is all or partially converted into water vapor. The water vapor or the mixture of water vapor and water flowing out of the outlet of the second regenerator 20 enters the boiler 21 and is further heated into high-temperature and high-pressure superheated water vapor, and the high-temperature and high-pressure superheated water vapor is input into the first steam turbine 13 through the water vapor outlet of the boiler 21 and the water vapor inlet of the first steam turbine 13 to expand and do work. The water vapor flowing out of the first steam turbine 13 absorbs the heat generated by the carbonation reaction through the heat absorber 12 to realize the reheating of the water vapor. The water vapor flowing out of the heat absorber 12 is sequentially input into the second steam turbine 14 and the third steam turbine 15 to drive the second steam turbine 14 and the third steam turbine 15 to expand and do work, and the expansion and work of the first steam turbine 13, the second steam turbine 14 and the third steam turbine 15 drive the generator 16 to generate electricity. The low-temperature and low-pressure water vapor flowing out of the first outlet of the third steam turbine 15 is further input into the condenser 17 to be condensed into liquid water, so as to complete the steam Rankine cycle.

[0086] When the demand scenario of energy saving and carbon reduction and flexibility reconstruction of the coal-fired power plant occurs, the energy release subsystem is started, the calcium oxide solid particles and the carbon dioxide gas in the flue gas discharged by the plant react, so as to realize carbon capture under the action of the energy release device, and convert the chemical energy in the calcium oxide solid particles into high-grade heat energy, thereby assisting the coal-fired unit to be reheated and driving the power generation.

[0087] It should be noted that during the operation of the energy storage system, due to high-temperature sintering, crushing or elutriation, etc., the reactivity and mechanical properties of part of the calcium carbonate solid particles are reduced, and the inventory of the calcium carbonate solid particles is reduced. In order to maintain the long-term stability of the thermochemical energy storage and energy release cycle, fresh calcium carbonate solid particles can be supplied to the carbonation reaction each time, so that they enter the carbonation reaction fluidized bed 11 together with the original calcium carbonate solid particles to participate in the carbonation reaction, or fresh calcium carbonate solid particles can be supplied to the calcium carbonate storage tank 7. At the same time, part of the old calcium carbonate solid particles in the calcium carbonate storage tank 7 are periodically eliminated.

[0088] The energy storage system based on thermochemical energy storage and Rankine cycle provided by the present application can effectively realize the conversion, transmission and storage between electric energy-thermal energy-chemical energy-electric energy by using calcium oxide and calcium carbonate as the thermochemical energy storage material, which is safe, non-toxic, has high energy storage density and long energy storage period, has high energy conversion efficiency in the process of energy conversion and transmission, can realize carbon element capture under the action of the energy release device, and can reduce the coal consumption in the energy conversion process, thereby meeting the energy saving and carbon reduction and flexibility reconstruction demand of the coal-fired power plant, and improving the safety and flexibility of the new power system mainly based on renewable energy.

[0089] The operation method of the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the present application is described below. Figure 4 The operation method of the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the present application is described below. Figure 4 The flow chart of the operation method of the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the present application is illustrated as follows. Figure 4 The operation method of the energy storage system based on thermo-chemical energy storage and Rankine cycle provided by the present application is described below.

[0090] In step 100, the calcium carbonate input into the calcium carbonate rotary calciner 3 is heated and decomposed by the electric heater 2 using the excess power of the power grid 1, so that the electric energy is converted into chemical energy and stored in the calcium oxide obtained by decomposition.

[0091] When the demand scenario of excess power consumption of the power grid 1 occurs, the electric heater 2 converts the excess power of the power grid 1 into heat energy, and under the action of the heat energy provided by the electric heater 2, the calcium carbonate in the calcium carbonate rotary calciner 3 is heated and decomposed, and the calcium carbonate decomposition generates high-temperature calcium oxide solid particles and high-temperature carbon dioxide gas, realizing the conversion of energy into chemical energy suitable for long-term storage.

[0092] In step 200, the calcium carbonate is preheated by the first heat exchanger network 4 using the residual heat carried by the calcium oxide and carbon dioxide gas obtained by decomposition, and the preheated calcium carbonate is introduced into the calcium carbonate rotary calciner 3.

[0093] The high-temperature calcium oxide and high-temperature carbon dioxide input into the first heat exchanger network 4 release heat and transfer heat, and the heat released by the high-temperature calcium oxide and high-temperature carbon dioxide preheats the calcium carbonate in the first heat exchanger network 4, and the calcium carbonate solid particles complete preheating in the first heat exchanger network 4 and then enter the calcium carbonate rotary calciner 3.

[0094] In step 300, the preheated carbon dioxide and calcium oxide particles are stored in the storage device.

[0095] The carbon dioxide gas after completing heat transfer is transported to the carbon dioxide storage tank 6 after being compressed to a supercritical state, and the calcium oxide solid particles after completing heat transfer are transported back to the calcium oxide storage tank 8 through the calcium oxide outlet of the first heat exchanger network 4 and the calcium oxide inlet of the calcium oxide storage tank 8.

[0096] In the embodiment of the present application, the operation method of the energy storage system further includes the following steps:

[0097] In step 400, the calcium oxide reacts with the carbon-containing flue gas in the carbonation reaction fluidized bed 11 to generate calcium carbonate and convert chemical energy into heat energy.

[0098] The preheated calcium oxide and the carbon-containing flue gas are input into the carbonation reaction fluidized bed 11. In the carbonation reaction fluidized bed 11, the carbonation reaction occurs between the calcium oxide solid particles and the carbon dioxide in the carbon-containing flue gas to generate high-temperature calcium carbonate solid particles and release a large amount of heat, thereby converting the chemical energy stored in the calcium oxide into heat energy. At the same time, the carbon elements in the carbon-containing flue gas are captured in the calcium carbonate solid particles through the carbonation reaction, and the carbon-containing flue gas is converted into decarbonized flue gas, thereby completing the capture of carbon elements in the carbon-containing flue gas.

[0099] In step 500, the second heat exchanger network 9 is used to preheat the calcium oxide and the carbon-containing flue gas by using the residual heat carried by the generated calcium carbonate.

[0100] When the energy saving and carbon reduction and flexibility reconstruction of the coal-fired power plant are required, the calcium oxide and the carbon-containing flue gas are input into the second heat exchanger network 9, and the second heat exchanger network 9 is used to preheat the calcium oxide solid particles and the carbon-containing flue gas by using the heat of the calcium carbonate.

[0101] In step 600, the water vapor or the mixture of water vapor and water is heated by the boiler 21 to obtain superheated steam, and the superheated steam is input into the first steam turbine 13 to drive the generator 16 to generate electricity.

[0102] After the preheating and temperature rising of the condensed water by the first regenerator 19 and the second regenerator 20, the preheated water vapor or the mixture of water vapor and water is obtained, and the preheated water vapor or the mixture of water vapor and water is further heated by the boiler 21 to obtain high-temperature and high-pressure superheated steam. The superheated steam is input into the first steam turbine 13 to expand and do work, thereby driving the generator 16 to generate electricity.

[0103] In step 700, the water vapor output from the first steam turbine 13 is reheated by the heat absorber 12 using the heat released by the carbonation reaction, and the reheated water vapor is sequentially input into the second steam turbine 14 and the third steam turbine 15 to drive the generator 16 to generate electricity.

[0104] The water vapor flowing out of the first steam turbine 13 is input into the heat absorber 12 from the water vapor inlet of the heat absorber 12. The water vapor absorbs the heat generated by the carbonation reaction to be reheated, and the temperature of the water vapor is raised to 600-630°C. The reheated water vapor is sequentially input into the second steam turbine 14 and the third steam turbine 15, and the first steam turbine 13 and the second steam turbine 14 are expanded and do work, thereby driving the generator 16 to generate electricity.

[0105] In step 800, the water vapor output from the third steam turbine 15 is condensed by the condenser 17 to obtain condensed water.

[0106] The low-temperature and low-pressure water vapor flowing out of the first outlet of the third steam turbine 15 is input into the condenser 17, and the water vapor is condensed into liquid water under the action of the condenser 17.

[0107] At step 900, the condensed water is pumped by the water pump 18 to the first regenerator 19 and the second regenerator 20 for preheating, and the water vapor or the mixture of water vapor and water obtained after preheating is delivered to the boiler 21 for heating.

[0108] The condensed water is input into the water pump 18 from the water inlet of the water pump 18, and the condensed water is pumped by the water pump 18 to the first regenerator 19 and the second regenerator 20 for preheating, and the water vapor or the mixture of water vapor and water flowing out of the outlet of the second regenerator 20 is input into the boiler 21 and is further heated into high-temperature and high-pressure superheated water vapor.

[0109] The operation method of the energy storage system based on thermochemical energy storage and Rankine cycle provided by the application can realize the conversion, transmission and storage among electric energy, thermal energy and chemical energy, and the energy conversion efficiency is high during the energy conversion and transmission process. Meanwhile, the chemical energy of calcium oxide can be converted from the excess power of the power grid 1 through the decomposition reaction of calcium carbonate during the low power consumption period, so as to realize the conversion of electric energy into chemical energy suitable for long-term storage. The chemical energy in the calcium oxide can be converted into electric energy through the carbonation reaction of calcium oxide during the peak power consumption period, so as to meet the demand of the terminal user during the peak power consumption period. Meanwhile, the carbon element can be captured under the action of the energy release system, and the coal consumption during the energy conversion process is reduced, so as to meet the energy saving and carbon reduction and flexibility reconstruction demand of the coal-fired power plant, and improve the safety and flexibility of the new type of power system mainly based on renewable energy.

[0110] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

Claims

1. An energy storage system based on thermo-chemical energy storage and a Rankine cycle, characterized in that, include: Storage devices; Energy storage equipment, including a rotary kiln for calcium carbonate calcination, a first heat exchanger network, and an electric heater; The calcium carbonate inlet of the rotary calcium carbonate calcining kiln is connected to the calcium carbonate outlet of the first heat exchanger network, the calcium oxide outlet of the rotary calcium carbonate calcining kiln is connected to the calcium oxide inlet of the first heat exchanger network, and the carbon dioxide outlet of the rotary calcium carbonate calcining kiln is connected to the carbon dioxide inlet of the first heat exchanger network; the carbon dioxide outlet, calcium carbonate inlet, and calcium oxide outlet of the first heat exchanger network are all connected to the storage device; the electric heater is installed inside the rotary calcium carbonate calcining kiln, the electric heater is electrically connected to the power grid, and the electric heater is used to heat and decompose the calcium carbonate, so that electrical energy is converted into chemical energy and stored in the calcium oxide. An energy-releasing device, which is connected to the storage device, is used to convert the chemical energy in calcium oxide into thermal energy. A power generation device, which is connected to the energy release device, is used to convert the heat energy generated by the energy release device into electrical energy.

2. The thermochemical energy storage and Rankine cycle based energy storage system of claim 1, wherein, The storage device includes: A carbon dioxide compressor unit, wherein the carbon dioxide inlet of the carbon dioxide compressor unit is connected to the carbon dioxide outlet of the first heat exchanger network; A carbon dioxide storage tank, which is connected to the carbon dioxide outlet of the carbon dioxide compressor unit.

3. The thermochemical energy storage and Rankine cycle based energy storage system according to claim 1 or 2, characterized in that, The storage device also includes: A calcium carbonate storage tank, wherein the calcium carbonate outlet of the calcium carbonate storage tank is connected to the calcium carbonate inlet of the first heat exchanger network; A calcium oxide storage tank, wherein the calcium oxide inlet of the calcium oxide storage tank is connected to the calcium oxide outlet of the first heat exchanger network.

4. The thermochemical energy storage and Rankine cycle based energy storage system of claim 3, wherein, The energy release device includes a second heat exchanger network, a carbon dioxide emission source, and a carbonation reaction fluidized bed. The calcium oxide inlet of the second heat exchanger network is connected to the calcium oxide outlet of the calcium oxide storage tank; the calcium carbonate outlet of the second heat exchanger network is connected to the calcium carbonate inlet of the calcium carbonate storage tank; the carbon-containing flue gas inlet of the second heat exchanger network is connected to the carbon dioxide emission source; the calcium oxide outlet of the second heat exchanger network is connected to the calcium oxide inlet of the carbonation reaction fluidized bed; the carbon-containing flue gas outlet of the second heat exchanger network is connected to the carbon-containing flue gas inlet of the carbonation reaction fluidized bed; the calcium carbonate inlet of the second heat exchanger network is connected to the calcium carbonate outlet of the carbonation reaction fluidized bed; the decarbonated flue gas inlet of the second heat exchanger network is connected to the decarbonated flue gas outlet of the carbonation reaction fluidized bed; and the decarbonated flue gas outlet of the second heat exchanger network is connected to the atmosphere.

5. The thermochemical energy storage and Rankine cycle based energy storage system of claim 4, wherein, The power generation equipment includes: The heat absorber, the first steam turbine, the second steam turbine, the third steam turbine, the generator, the regenerator set and the boiler; the heat absorber is arranged in the carbonation reaction fluidized bed, the water vapor inlet of the heat absorber is communicated with the first outlet of the first steam turbine, the water vapor outlet of the heat absorber is communicated with the water vapor inlet of the second steam turbine; the first outlet of the second steam turbine is communicated with the water vapor inlet of the third steam turbine, the first outlet of the third steam turbine is communicated with the first inlet of the regenerator set; the rotating shaft of the first steam turbine, the rotating shaft of the second steam turbine and the rotating shaft of the third steam turbine are connected with the rotating shaft of the generator; the outlet of the regenerator set is communicated with the water vapor inlet of the boiler, and the water vapor outlet of the boiler is communicated with the water vapor inlet of the first steam turbine.

6. The thermochemical energy storage and Rankine cycle based energy storage system of claim 5, wherein, The regenerator set comprises a first regenerator and a second regenerator; the first inlet of the first regenerator is communicated with the first outlet of the third steam turbine, the outlet of the first regenerator is communicated with the first inlet of the second regenerator, and the outlet of the second regenerator is communicated with the water vapor inlet of the boiler.

7. The thermochemical energy storage and Rankine cycle based energy storage system of claim 6, wherein, The second outlet of the first steam turbine and the second outlet of the second steam turbine are both communicated with the second inlet of the second regenerator, and the third outlet of the second steam turbine and the second outlet of the third steam turbine are both communicated with the second inlet of the first regenerator.

8. - Thermal chemical energy storage and Rankine cycle based energy storage system according to claim 6 or 7, characterized in that, The power generation device further comprises: a condenser, the water vapor inlet of the condenser being communicated with the first outlet of the third steam turbine; a water pump, the water inlet of the water pump being communicated with the water outlet of the condenser, and the water outlet of the water pump being communicated with the first inlet of the first regenerator.

9. A method of operating an energy storage system based on thermochemical energy storage and a Rankine cycle, characterized in that, The operation method is based on the thermal chemical energy storage and Rankine cycle-based energy storage system of claim 8, and the operation method comprises: heating and decomposing calcium carbonate input into a calcium carbonate rotary calciner by an electric heater using excess power of a power grid, so that electric energy is converted into chemical energy and stored in decomposed calcium oxide; preheating calcium carbonate by a first heat exchanger network using residual heat carried by the decomposed calcium oxide and carbon dioxide gas, and introducing the preheated calcium carbonate into the calcium carbonate rotary calciner; storing the preheated carbon dioxide and calcium oxide particles by a storage device.

10. A method of operating a thermal-chemical energy storage and Rankine cycle based energy storage system according to claim 9, characterized in that, The operation method further comprises: generating calcium carbonate and converting chemical energy into heat energy by carbonation reaction of calcium oxide and carbon-containing flue gas in a carbonation reaction fluidized bed; preheating calcium oxide and carbon-containing flue gas by a second heat exchanger network using residual heat carried by the generated calcium carbonate; heating water vapor or a mixture of water vapor and water by a boiler to obtain superheated water vapor, and inputting the superheated water vapor into a first steam turbine to drive a generator to generate electricity; reheating water vapor output by the first steam turbine by a heat absorber using heat released by the carbonation reaction, and sequentially inputting the reheated water vapor into a second steam turbine and a third steam turbine to drive the second steam turbine and the third steam turbine to generate electricity; condensing water vapor output by the third steam turbine by a condenser to obtain condensed water; The condensed water is pumped by a water pump to the first and second regenerators for preheating, and the water vapor or mixture of water vapor and water obtained after preheating is delivered to the boiler for heating.

Images