Heat storage coupling energy storage system

Abstract

The utility model provides a heat storage coupling energy storage system which can reduce energy waste. The heat storage and energy storage coupled system comprises a heat storage and steam supply device, and the heat storage and steam supply device comprises a cold tank used for storing a cold-state heat storage medium, a hot tank used for storing a hot-state heat storage medium and a heater used for secondarily heating the heat storage medium so as to further increase the temperature of the heat storage medium to the use temperature upper limit of the heat storage medium; the energy storage power generation device comprises a first storage used for storing an energy storage medium in a first state, a second storage used for storing an energy storage medium in a second state, an energy storage and heat storage module and an energy release and heat absorption module.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to a thermal storage coupled energy storage system. Background Art

[0002] As new energy sources such as wind and light continue to replace traditional non-renewable energy sources such as coal, oil and gas, industrial enterprises are facing a green transformation in the way they use energy, of which energy storage is one of the key links.

[0003] Thermal energy and electric energy are the two main types of energy in high-energy-consuming industries. Thermal energy is usually used in the form of steam in various processes in industrial production, and its usage and cost are often very huge. In order to reduce the cost of steam use, thermal storage steam supply technology has been promoted among industrial users. For example, molten salt thermal storage electric boilers replace natural gas boilers and use valley electricity to store heat. However, the cost of thermal storage equipment is high. Compared with the centralized steam supply of thermal power plants, the return on investment of thermal storage steam supply is not good, and the direct conversion of high-grade molten salt thermal storage into low-grade industrial steam is also a waste of energy. Electric energy storage technology has also begun to be used by industrial users. For example, compressed liquefied carbon dioxide energy storage technology has inherent safety properties and has both energy storage and waste heat utilization functions. It has been successfully applied to cement plants. However, the compression heat generated by the compression process of the compressed liquefied carbon dioxide energy storage system is at a low temperature. When the heat is used in the power generation process, the turbine expander is difficult to play the advantages of high efficiency and large capacity, and the energy storage efficiency of the system is low. Utility Model Content

[0004] In view of this, the embodiments of the present utility model are dedicated to providing a thermal storage coupled energy storage system, which can promote energy efficiency improvement and reduce energy waste.

[0005] According to one aspect of the utility model, a thermal storage coupled energy storage system provided by an embodiment of the utility model comprises: a thermal storage steam supply device, the thermal storage steam supply device comprising: a cold tank for storing cold thermal storage medium, a hot tank for storing hot thermal storage medium, a heater for secondary heating the thermal storage medium to further increase the temperature of the thermal storage medium to its upper limit of use temperature, and a steam generator for producing industrial steam; an energy storage power generation device, the energy storage power generation device comprising: a first reservoir for storing energy storage medium in a first state, a second reservoir for storing energy storage medium in a second state, an energy storage thermal storage module, and an energy release and heat absorption module; wherein the inlet of the energy storage thermal storage module is connected to the outlet of the first reservoir, and the energy storage thermal storage module is connected to the outlet of the first reservoir. The outlet of the module is connected to the inlet of the second reservoir, the outlet of the cold tank is connected to the inlet of the heat storage medium of the energy storage heat storage module, the outlet of the heat storage medium of the energy storage heat storage module is connected to the inlet of the heater, the outlet of the heater is connected to the inlet of the hot tank, the outlet of the hot tank is connected to the inlet of the heat storage medium of the energy releasing heat absorption module, the inlet of the energy releasing heat absorption module is connected to the outlet of the second reservoir, the outlet of the heat storage medium of the energy releasing heat absorption module is connected to the inlet of the first reservoir, the intermediate energy storage medium outlet of the energy releasing heat absorption module is connected to the energy storage medium inlet of the steam generator, and the energy storage medium outlet of the steam generator is connected to the intermediate energy storage medium inlet of the energy releasing heat absorption module;

[0006] The energy storage and heat storage module is configured to: compress the energy storage medium in the first state and liquefy it, convert it into the second state, and generate a first heat, the first heat heats the cold heat storage medium output by the cold tank, the heated heat storage medium passes through the heat storage medium outlet of the energy storage and heat storage module to the inlet of the heater and enters the heater for secondary heating, and the heat storage medium after secondary heating is stored in the hot tank;

[0007] The energy-releasing heat-absorbing module is configured to receive the hot heat storage medium output by the hot tank, and utilize the heat of the hot heat storage medium to heat the second-state energy storage medium output by the second reservoir, which is then expanded to generate electricity, and converted to the first state, so as to store the energy storage medium in the first state in the first reservoir, and at the same time utilize the residual heat of the energy storage medium after partial expansion and power generation to heat the steam generator to produce industrial steam.

[0008] In one embodiment, the energy storage heat storage module includes: a gas compression module, the inlet of the gas compression module is connected to the outlet of the first reservoir, and the gas compression module is configured to compress the energy storage medium in the first state into compressed gas; a heat storage heat exchanger, the inlet of the heat storage heat exchanger is connected to the outlet of the gas compression module, the heat storage medium inlet of the heat storage heat exchanger is connected to the inlet of the heater, and the heat storage medium outlet of the heat storage heat exchanger is connected to the inlet of the heater, wherein the heat storage medium inlet of the heat storage heat exchanger is the heat storage medium inlet of the energy storage heat storage module, and the heat storage medium outlet of the heat storage heat exchanger is the heat storage medium outlet of the energy storage heat storage module; a first regenerator, the first regenerator is connected in series with the gas compression module, and the first inlet of the first regenerator is connected to the outlet of the heat storage heat exchanger; and a condenser, the outlet of the condenser is connected to the inlet of the second reservoir, and the inlet of the condenser is connected to the first outlet of the first regenerator.

[0009] In one embodiment, the gas compression module includes: a first compressor, the inlet of the first compressor is connected to the outlet of the first reservoir, and the outlet of the first compressor is connected to the second inlet of the first regenerator; a second compressor, the inlet of the second compressor is connected to the second outlet of the first regenerator, and the outlet of the second compressor is connected to the inlet of the heat storage heat exchanger.

[0010] In one embodiment, the energy-releasing heat absorption module includes: a vaporizer, which is connected to the outlet of the second reservoir; a second regenerator, a first inlet of the second regenerator is connected to the outlet of the vaporizer; a heat-releasing heat exchanger, whose inlet is connected to the first outlet of the second regenerator, whose heat storage medium outlet of the heat-releasing heat exchanger is connected to the inlet of the cold tank, and whose heat storage medium inlet of the heat-releasing heat exchanger is connected to the outlet of the hot tank; a first expander, whose inlet is connected to the outlet of the heat-releasing heat exchanger, and whose outlet is connected to the second inlet of the second regenerator; and a second expander, whose inlet is connected to the second outlet of the second regenerator, and whose outlet is connected to the inlet of the first reservoir.

[0011] In one embodiment, the air inlet of the steam generator is connected to the outlet of the first expansion machine, the air outlet of the steam generator is connected to the second inlet of the second regenerator, and the outlet of the first expansion machine is connected to the second inlet of the second regenerator through the steam generator; wherein, the outlet of the first expansion machine is the intermediate energy storage medium outlet of the energy releasing and heat absorbing module, the second inlet of the second regenerator is the intermediate energy storage medium inlet of the energy releasing and heat absorbing module, the energy storage medium inlet of the steam generator is the air inlet of the steam generator, and the energy storage medium outlet of the steam generator is the air outlet of the steam generator.

[0012] In one embodiment, the energy storage medium includes carbon dioxide.

[0013] In one embodiment, the first state of the carbon dioxide is a thermodynamic state of a gas-liquid-solid coexistence point.

[0014] In one embodiment, the second state of the carbon dioxide is a thermodynamic state of a liquid phase at room temperature.

[0015] In one embodiment, the pressure in the second state is 5-10 MPa.

[0016] In one embodiment, the thermal storage medium includes molten salt.

[0017] The thermal storage coupled energy storage system provided by the embodiment of the utility model couples the thermal storage steam supply with the energy storage power generation, and shares the thermal storage medium and its storage tank, thereby achieving the purpose of reducing the equipment investment cost of the thermal storage steam supply device. The thermal storage steam supply device utilizes the medium-temperature heat released by the energy storage power generation device to produce steam, and the energy storage power generation device utilizes the high-temperature heat provided by the thermal storage steam supply device, which greatly improves the power generation capacity and thermal efficiency, reduces the energy grade loss, gives full play to the performance of the thermal storage steam supply device and the energy storage power generation device, and realizes energy temperature matching and cascade utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shown is a schematic structural diagram of a thermal storage coupled energy storage system provided by an exemplary embodiment of the present application.

[0019] Figure 2 Shown is a schematic structural diagram of a thermal storage coupled energy storage system provided by another exemplary embodiment of the present application.

[0020] Explanation of the reference numerals: 1. heat storage steam supply device; 201. energy storage heat storage module; 202. energy release heat absorption module; 203. gas compression module; 11. cold tank; 12. hot tank; 13. heater; 14. steam generator; 15. first pipeline; 16. second pipeline; 2. energy storage power generation device; 21. first reservoir; 22. first compressor; 23. first regenerator; 24. second compressor; 25. heat storage heat exchanger; 26. condenser; 27. second reservoir; 28. vaporizer; 29. ​​second regenerator; 30. heat release heat exchanger; 31. first expander; 32. second expander; 33. third pipeline; 34. fourth pipeline; 41. steam supply pipeline; 42. water supply pipeline. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] In addition, in the exemplary embodiments, because the same reference numerals denote the same components having the same structure or the same steps of the same method, if one embodiment is described exemplarily, only the structures or methods different from the described embodiments are described in other exemplary embodiments. When a component is described as being "connected" to another component, the one component may be "directly connected" to the other component, or "electrically connected" to the other component through a third component. In addition, unless explicitly described to the contrary, the term "include" and its corresponding terms should be understood to include only the components described, and should not be understood to exclude any other components.

[0023] Figure 1 FIG. 1 is a schematic diagram of a heat storage coupled energy storage system provided by an exemplary embodiment of the present application. Figure 1 As shown, the thermal storage coupled energy storage system comprises: a thermal storage steam supply device 1, the thermal storage steam supply device 1 comprises: a cold tank 11 for storing a cold thermal storage medium, a hot tank 12 for storing a hot thermal storage medium, a heater 13 for secondary heating the thermal storage medium to further increase the temperature of the thermal storage medium to its upper limit of use temperature, and a steam generator 14 for producing industrial steam;

[0024] The energy storage power generation device 2 includes: a first reservoir 21 for storing energy storage medium in a first state, a second reservoir 27 for storing energy storage medium in a second state, an energy storage heat storage module 201 and an energy release heat absorption module 202;

[0025] Among them, the inlet of the energy storage heat storage module 201 is connected to the outlet of the first reservoir 21, the outlet of the energy storage heat storage module 201 is connected to the inlet of the second reservoir 27, the outlet of the cold tank 11 is connected to the heat storage medium inlet of the energy storage heat storage module 201, the heat storage medium outlet of the energy storage heat storage module 201 is connected to the inlet of the heater 13, the outlet of the heater 13 is connected to the inlet of the hot tank 12, the outlet of the hot tank 12 is connected to the heat storage medium inlet of the energy release heat absorption module 202, the inlet of the energy release heat absorption module 202 is connected to the outlet of the second reservoir 27, the outlet of the energy release heat absorption module 202 is connected to the inlet of the first reservoir 21, the heat storage medium outlet of the energy release heat absorption module 202 is connected to the cold tank 11, the intermediate energy storage medium outlet of the energy release heat absorption module 202 is connected to the energy storage medium inlet of the steam generator 14, and the energy storage medium outlet of the steam generator 14 is connected to the intermediate energy storage medium inlet of the energy release heat absorption module 202;

[0026] The energy storage and heat storage module 201 is configured to: compress the energy storage medium in the first state and liquefy it, convert it into the second state, and generate the first heat, the first heat heats the cold heat storage medium outputted from the cold tank 11, the heated heat storage medium passes through the heat storage medium outlet of the energy storage and heat storage module 201 to the inlet of the heater 13 and enters the heater 13 for secondary heating, and the secondary heated heat storage medium is stored in the hot tank 12;

[0027] The energy-releasing heat-absorbing module 202 is configured to receive the hot heat storage medium output by the hot tank 12, and utilize the heat of the hot heat storage medium to heat the second-state energy storage medium output by the second reservoir 27, which is then expanded to generate electricity, and is converted to the first state, so as to store the energy storage medium in the first state in the first reservoir 21, and at the same time utilize the residual heat of the energy storage medium after partial expansion and power generation to heat the steam generator 14 to produce industrial steam.

[0028] The heater 13 in the heat storage steam supply device 1 can use valley electricity to heat the heat storage medium for heat storage, and produce industrial steam through the heat release process of the heat storage medium. The heat storage medium can be molten salt, which refers to a mixture of salts that melt at high temperature. The molten salt can be a melt of a single salt or a mixture of multiple different salts. In the energy storage power generation device 2, the energy storage heat storage module 201 is located between the first reservoir 21 and the second reservoir 27. The first reservoir 21, the second reservoir 27, and the energy storage heat storage module 201 form a path for the energy storage medium to flow during the energy storage process. The energy release heat absorption module 202 is located between the second reservoir 27 and the first reservoir 21. The first reservoir 21, the second reservoir 27 and the energy release heat absorption module 202 form a path for the energy storage medium to flow during the energy release process. The energy storage medium can be carbon dioxide. The first state is the thermodynamic state of the gas-liquid-solid coexistence point, and the second state is the thermodynamic state of the liquid phase at room temperature. The energy storage power generation device 2 can use the state transition process and the compression and expansion process of carbon dioxide to store and release energy.

[0029] Figure 2 FIG. 1 is a schematic diagram of a heat storage coupled energy storage system provided by another exemplary embodiment of the present application. Figure 1 and Figure 2 As shown, a first pipeline 15 is provided between the cold tank 11 and the hot tank 12, and the first pipeline 15 is connected in series to transport the heat storage medium from the cold tank 11 to various devices in the hot tank 12. A second pipeline 16 is provided between the hot tank 12 and the cold tank 11, and the second pipeline 16 is connected in series to transport the heat storage medium from the hot tank 12 to various devices in the cold tank 11.

[0030] Specifically, the first pipeline 15 sequentially connects the outlet of the cold tank 11 and the medium inlet of the energy storage and heat storage module 201, the outlet of the heat storage medium of the energy storage and heat storage module 201 and the inlet of the heater 13, and the outlet of the heater 13 and the inlet of the hot tank 12. The first pipeline 15 is used to transport the heat storage medium, output the heat storage medium in the cold tank 11 to the energy storage and heat storage module 201 for heat absorption, and then heat it up by electric power of the heater 13, and finally input it into the hot tank 12 for storage. In this process, the heat storage medium can absorb part of the heat released by the energy storage medium, save energy consumption, and improve energy utilization. The second pipeline 16 sequentially connects the outlet of the hot tank 12 and the heat storage medium inlet of the energy release and heat absorption module 202, the heat storage medium inlet of the energy release and heat absorption module 202 and the inlet of the cold tank 11. The second pipeline 16 is used to transport the heat storage medium, output the heat storage medium in the hot tank 12 to the energy release and heat absorption module 202 for heat release, and then input it into the cold tank 11 for storage. In this process, the energy storage medium can be heated by the temperature released by the heat storage medium. Since the heat storage medium can reach a higher temperature through the heater 13 at this time, the released heat can greatly improve the power generation capacity and thermal efficiency of the energy storage power generation device 2. Under the condition of mutual sharing and full utilization, the system energy storage efficiency can be improved, and the normal supply of industrial steam can still be maintained. Therefore, the utility model indirectly reduces the cost of molten salt heat storage and improves the energy storage efficiency of compressed liquefied carbon dioxide, which can effectively help high-energy-load industrial enterprises reduce energy costs.

[0031] It can be understood that the heat storage medium inlet of the energy releasing heat absorption module 202, the heat storage medium outlet of the energy releasing heat absorption module 202, the heat storage medium inlet of the energy storage heat storage module 201 and the heat storage medium outlet of the energy storage heat storage module 201 are all used to exchange the heat storage medium, and the inlet of the energy releasing heat absorption module 202, the outlet of the energy releasing heat absorption module 202, the inlet of the energy storage heat storage module 201 and the outlet of the energy storage heat storage module 201 are used to exchange the energy storage medium.

[0032] The thermal storage steam supply is coupled with the energy storage power generation. The thermal storage steam supply device utilizes the heat released by the energy storage power generation device to produce steam, thereby achieving the purpose of reducing the investment cost of the thermal storage steam supply device. The energy storage power generation device utilizes the high temperature provided by the thermal storage steam supply device to greatly improve the power generation capacity and thermal efficiency, reducing the high-grade energy loss while increasing the power generation capacity and thermal efficiency, giving full play to the performance of the thermal storage steam supply device and the energy storage power generation device, and realizing energy-temperature matching and cascade utilization.

[0033] In one embodiment, if Figure 2 As shown, the energy storage heat storage module 201 includes: a gas compression module 203, the inlet of the gas compression module 203 is connected to the outlet of the first storage tank 21, and the gas compression module 203 is configured to compress the energy storage medium in the first state into compressed gas; a heat storage heat exchanger 25, the inlet of the heat storage heat exchanger 25 is connected to the outlet of the gas compression module 203, the heat storage medium inlet of the heat storage heat exchanger 25 is connected to the outlet of the cold tank 11, and the heat storage medium outlet of the heat storage heat exchanger 25 is connected to the inlet of the heater 13, wherein the storage medium The heat storage medium inlet of the heat exchanger 25 is the heat storage medium inlet of the energy storage heat storage module 201, and the heat storage medium outlet of the heat storage heat exchanger 25 is the heat storage medium outlet of the energy storage heat storage module 201; the first regenerator 23, the first regenerator 23 is connected in series with the gas compression module 203, and the first inlet of the first regenerator 23 is connected to the outlet of the heat storage heat exchanger 25; and the condenser 26, the outlet of the condenser 26 is connected to the inlet of the second storage tank 27, and the inlet of the condenser 26 is connected to the first outlet of the first regenerator 23.

[0034] The heat storage medium inlet of the energy storage heat storage module 201 is the heat storage medium inlet of the heat storage heat exchanger 25. The carbon dioxide stored in the first reservoir 21 is in the first state, which is the thermodynamic state of the gas-liquid-solid coexistence point. The liquid carbon dioxide in the first reservoir 21 changes into solid and gaseous carbon dioxide. The solid carbon dioxide is retained in the first reservoir 21, and the gaseous carbon dioxide is output. The gaseous carbon dioxide is compressed by the gas compression module 203, and the heat is released and cooled by the heat storage heat exchanger 25, and then the heat is released and cooled by the first regenerator 23, and then cooled to room temperature and liquefied by the condenser 26 to become the second state. The second state is the thermodynamic state of the liquid phase at room temperature. The carbon dioxide in the second state is input into the second reservoir 27 for storage. At the same time, in the heat storage steam supply device 1, the cold tank 11 outputs molten salt, absorbs heat through the heat storage heat exchanger 25, and then heats up through the electric heater 13, and is input into the hot tank 12 for storage. The heat absorbed by the molten salt here is the high-temperature heat released by the gaseous carbon dioxide.

[0035] The energy-releasing heat-absorbing module 202 receives the carbon dioxide in the second state output from the second reservoir 27, and receives the hot heat storage medium output from the hot tank 12, and utilizes the environmental or industrial waste heat to gasify the carbon dioxide in the second state, and utilizes the hot heat storage medium to heat the carbon dioxide. The carbon dioxide is then expanded to generate electricity and becomes a low-temperature, low-pressure gas, which is then input into the first reservoir 21 and changes phase with the solid carbon dioxide in the first reservoir 21 to become liquid carbon dioxide and then changes into the first state, and is stored in the first reservoir 21.

[0036] It can be understood that the heat storage medium inlet and the heat storage medium outlet of the heat storage heat exchanger 25 are used to exchange the heat storage medium (such as molten salt), and the inlet and the outlet of the heat storage heat exchanger 25 are used to exchange the energy storage medium (such as carbon dioxide).

[0037] In another embodiment, if Figure 2 As shown, the gas compression module 203 includes: a first compressor 22, the inlet of the first compressor 22 is connected to the outlet of the first reservoir 21, and the outlet of the first compressor 22 is connected to the second inlet of the first regenerator 23; a second compressor 24, the inlet of the second compressor 24 is connected to the second outlet of the first regenerator 23, and the outlet of the second compressor 24 is connected to the inlet of the heat storage heat exchanger 25.

[0038] The liquid carbon dioxide stored in the first reservoir 21 changes into solid and gaseous carbon dioxide. The solid carbon dioxide is retained in the first reservoir 21, and the gaseous carbon dioxide is output to the first compressor 22. The gaseous carbon dioxide is compressed by the electrically driven first compressor 22 to a temperature of about 40°C, and then enters the first regenerator 23 through the second inlet of the first regenerator 23 to be preheated to about 180°C. The inlet of the second compressor 24 is connected to the second outlet of the first regenerator 23, and the carbon dioxide preheated to 180°C passes through the second outlet of the first regenerator 23. The carbon dioxide is output to the inlet of the second compressor 24, and then compressed to about 350°C by the electrically driven second compressor 24. The outlet of the second compressor 24 is connected with the inlet of the heat storage heat exchanger 25, and then released and cooled to about 200°C by the heat storage heat exchanger 25. The heat storage heat exchanger 25 is connected with the first inlet of the first regenerator 23. The carbon dioxide released and cooled to about 200°C is input back to the first regenerator 23 to release and cool to about 50°C, and then cooled to room temperature and liquefied by the condenser 26. The room temperature high-pressure liquid carbon dioxide is input to the second storage tank 27 for storage.

[0039] Specifically, the third pipeline 33 is connected in series with various devices that transport the energy storage medium from the first reservoir 21 to the second reservoir 27, including the first compressor 22, the first reheater 23, the second compressor 24, the heat storage heat exchanger 25 and the condenser 26 in sequence. The inlet of the first compressor 22 is connected to the outlet of the first reservoir 21, the outlet of the first compressor 22 is connected to the second inlet of the first reheater 23, the second outlet of the first reheater 23 is connected to the inlet of the second compressor 24, the outlet of the second compressor 24 is connected to the inlet of the heat storage heat exchanger 25, the outlet of the heat storage heat exchanger 25 is connected to the first inlet of the first reheater 23, the first outlet of the first reheater 23 is connected to the inlet of the condenser 26, and the outlet of the condenser 26 is connected to the inlet of the second reservoir 27, so as to realize the energy storage process. During the energy storage process, the gaseous energy storage medium is output from the first storage tank 21, compressed by the first compressor 22, preheated by the low-pressure channel of the first regenerator 23, compressed by the second compressor 24, released heat to the heat storage medium through the energy storage medium channel of the heat storage heat exchanger 25, released heat through the high-pressure channel of the first regenerator 23, liquefied by the condenser 26, and finally input into the second storage tank 27. At the same time, the heat storage medium inlet of the heat storage heat exchanger 25 is connected with the outlet of the cold tank 11, and the heat storage medium outlet of the heat storage heat exchanger 25 is connected with the inlet of the heater 13, and the heat storage medium enters the heat storage heat exchanger 25 to absorb the heat released by the energy storage medium channel.

[0040] In another embodiment, if Figure 2 As shown, the energy-releasing heat absorption module 202 includes: a vaporizer 28, which is connected to the outlet of the second storage tank 27; a second reheater 29, whose first inlet is connected to the outlet of the vaporizer 28; a heat-releasing heat exchanger 30, whose inlet is connected to the first outlet of the second reheater 29, whose heat storage medium outlet is connected to the inlet of the cold tank 11, whose heat storage medium inlet is connected to the outlet of the hot tank 12; a first expander 31, whose inlet is connected to the outlet of the heat-releasing heat exchanger 30, whose outlet is connected to the second inlet of the second reheater 29; and a second expander 32, whose inlet is connected to the second outlet of the second reheater 29, whose outlet is connected to the inlet of the first storage tank 21.

[0041] During the energy release process, the second reservoir 27 outputs liquid carbon dioxide, which is converted into gaseous state by using environmental or industrial waste heat through the gasifier 28, then preheated by the second regenerator 29, then heated by the heat release heat exchanger 30, then expanded by the first expander 31 to generate electricity and reduce temperature and pressure, then released heat by the second regenerator 29, then expanded by the second expander 32 to generate electricity and reduce temperature and pressure, and the pressure drops slightly higher than the pressure of the first reservoir 21, and is input into the first reservoir 21 for storage, and the gaseous and solid carbon dioxide in the first reservoir 21 are phase-changed into liquid carbon dioxide and converted into the first state. The original single energy storage and power generation device has a heat storage temperature not exceeding the outlet temperature of the second compressor 24, that is, about 350°C, which means that the inlet temperature of the first expander 31 does not exceed 350°C, and the heat released by the heat storage medium in the hot tank 12 can provide a high temperature of about 600°C, which can make the inlet temperature of the first expander 31 reach above 550°C, thereby greatly improving the power generation capacity and thermal efficiency of the first expander 31.

[0042] Specifically, the fourth pipeline 34 is connected in series to transport the energy storage medium from the second reservoir 27 to various devices of the first reservoir 21, including the gasifier 28, the second reheater 29, the heat releasing heat exchanger 30, the first expander 31 and the second expander 32. The outlet of the second reservoir 27 is connected to the gasifier 28, the outlet of the gasifier 28 is connected to the first inlet of the second reheater 29, the first outlet of the second reheater 29 is connected to the inlet of the heat releasing heat exchanger 30, the outlet of the heat releasing heat exchanger 30 is connected to the inlet of the first expander 31, the outlet of the first expander 31 is connected to the second inlet of the second reheater 29, the second outlet of the second reheater 29 is connected to the inlet of the second expander 32, and the outlet of the second expander 32 is connected to the inlet of the first reservoir 21.

[0043] During the energy release process, the liquid energy storage medium is output from the second reservoir 27, converted into gaseous state through the vaporizer 28, and then preheated through the high-pressure channel of the second regenerator 29, and then absorbs heat from the heat storage medium through the energy storage medium channel of the heat release heat exchanger 30, and then expands and generates electricity through the first expander 31. The first expander 31 and the second regenerator 29 can be connected to a device requiring heat to obtain heat supply. After being heated by the device requiring heat, it absorbs heat through the low-pressure channel of the second regenerator 29, and then expands and generates electricity through the second expander 32, and finally inputs into the first reservoir 21. At this time, the heat storage medium outlet of the heat release heat exchanger 30 is connected to the inlet of the cold tank 11, and the heat storage medium inlet of the heat release heat exchanger 30 is connected to the outlet of the hot tank 12. The hot tank 12 outputs the heat storage medium to the heat release heat exchanger 30, releases heat and cools down through the heat release heat exchanger 30, and is input into the cold tank 11 for storage. The heat storage medium releases heat for heating the energy storage medium. The energy storage power generation device 2 utilizes the high temperature provided by the heat storage steam supply device 1 to greatly improve the power generation capacity and thermal efficiency.

[0044] It can be understood that the heat storage medium inlet of the heat-releasing heat exchanger 30 and the heat storage medium outlet of the heat-releasing heat exchanger 30 are used to exchange the heat storage medium, and the inlet of the heat-releasing heat exchanger 30 and the outlet of the heat-releasing heat exchanger 30 are used to exchange the energy storage medium. The outlet of the first expander 31 can be directly connected to the inlet of the second regenerator 29, or a steam generator can be connected between the first expander 31 and the second regenerator 29. In addition, the first expander 31 and the second regenerator 29 can also be connected to other heat-using equipment.

[0045] In another embodiment, if Figure 2 As shown, the air inlet of the steam generator 14 is connected to the outlet of the first expansion machine 31, the outlet of the steam generator 14 is connected to the second inlet of the second reheater 29, and the outlet of the first expansion machine 31 is connected to the second inlet of the second reheater 29 through the steam generator 14, wherein the outlet of the first expansion machine is the intermediate energy storage medium outlet of the energy releasing and heat absorbing module, the second inlet of the second reheater is the intermediate energy storage medium inlet of the energy releasing and heat absorbing module, the energy storage medium inlet of the steam generator is the air inlet of the steam generator, and the energy storage medium outlet of the steam generator is the air outlet of the steam generator.

[0046] The device requiring heat connected between the first expander 31 and the second regenerator 29 may be a steam generator 14. In the energy release process, the liquid energy storage medium is output from the second reservoir 27, converted into gaseous state through the vaporizer 28, and then preheated through the high-pressure channel of the second regenerator 29, and then absorbs heat from the heat storage medium through the energy storage medium channel of the heat release heat exchanger 30, and then expands and generates electricity through the first expander 31, and then releases heat to the water supply pipeline 42 through the steam generator 14, and then absorbs heat through the low-pressure channel of the second regenerator 29, and then expands and generates electricity through the second expander 32, and finally inputs into the first reservoir 21. Not only does the energy storage power generation device 2 utilize the high temperature provided by the heat storage steam supply device 1 to greatly improve the power generation capacity and thermal efficiency, but it can also maintain the normal supply of industrial steam, and reduce the cost of molten salt heat storage while improving the energy storage efficiency of compressed liquefied carbon dioxide. The steam generator 14 is a device used to heat liquid (usually water) and convert it into steam. The steam generator 14 also includes a water supply pipeline 42 and a steam supply pipeline 41. The water supply pipeline 42 is used to transport water into the steam generator 14. After being heated and converted into steam, it is applied to other equipment through the steam supply pipeline 41.

[0047] In another embodiment, the carbon dioxide stored in the second reservoir is in a thermodynamic state of a liquid phase at room temperature, preferably at a pressure of 5 to 10 MPa.

[0048] The energy storage and release process of the thermal storage coupled energy storage system can be:

[0049] Energy storage processes, such as Figure 2As shown, in the energy storage power generation device 2, the liquid carbon dioxide in the first reservoir 21 is phase-changed into solid and gaseous carbon dioxide, the solid carbon dioxide is retained in the first reservoir 21, and the gaseous carbon dioxide is output. The gaseous carbon dioxide is compressed by the electrically driven first compressor 22 to a temperature of about 40°C, and then preheated to about 180°C by the first regenerator 23, and then compressed to about 350°C by the electrically driven second compressor 24, and then released heat and cooled to about 200°C by the heat storage heat exchanger 25, and then released heat and cooled to about 50°C by the first regenerator 23, and then cooled to room temperature by the condenser 26 and liquefied into a second state, and the liquid carbon dioxide in the second state is input into the second reservoir 27 for storage;

[0050] At the same time, in the thermal storage steam supply device 1, the cold tank 11 outputs molten salt, which absorbs heat through the thermal storage heat exchanger 25, is heated to about 600°C by the electrically heated heater 13, and is input into the hot tank 12 for storage.

[0051] Energy release process, such as Figure 2 As shown, in the energy storage power generation device 2, the second reservoir 27 outputs liquid carbon dioxide, which is converted into gaseous state by using environmental or industrial waste heat through the gasifier 28, and then preheated to about 200°C through the second regenerator 29, and then heated to about 550°C through the heat release heat exchanger 30, and then expanded by the first expander 31 to generate electricity and reduce temperature and pressure, and the temperature drops to about 400°C, and then released heat and produced industrial steam through the steam generator 14, and the temperature drops to about 230°C, and then released heat to near room temperature through the second regenerator 29, and then expanded by the second expander 32 to generate electricity and reduce temperature and pressure, and the pressure drops to slightly higher than the pressure of the first reservoir 21, and then input into the first reservoir 21, and the gaseous and solid carbon dioxide in the first reservoir 21 are phase-changed into liquid carbon dioxide and converted into the first state, and stored in the first reservoir 21;

[0052] At the same time, in the heat storage steam supply device 1, the hot tank 12 outputs molten salt, which is cooled to about 220° C. by the heat release heat exchanger 30 and then input into the cold tank 11 for storage.

[0053] The process of using a thermal storage coupled energy storage system to perform thermal storage coupled energy storage and energy release integrates the thermal storage steam supply device and the energy storage power generation device, realizes the sharing and full use of thermal storage facilities, namely the cold tank, the hot tank and the thermal storage medium, and greatly reduces the investment cost of the cold tank, the hot tank and the thermal storage medium; the hot tank can provide a high temperature of about 600°C, so that the inlet temperature of the first expander reaches above 550°C, thereby greatly improving the power generation capacity and thermal efficiency of the first expander, and the system energy storage efficiency can be increased from 70% to more than 85%, and still maintain the normal supply of industrial steam. Therefore, the utility model indirectly reduces the cost of molten salt thermal storage and improves the energy storage efficiency of compressed liquefied carbon dioxide, which can effectively help high-energy-load industrial enterprises reduce energy costs.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A thermal storage coupled energy storage system, characterized in that: include: A heat storage steam supply device (1), the heat storage steam supply device (1) comprising: a cold tank (11) for storing a cold heat storage medium, a hot tank (12) for storing a hot heat storage medium, a heater (13) for secondary heating the heat storage medium to further raise the heat storage medium to its upper limit of use temperature, and a steam generator (14) for producing industrial steam; An energy storage power generation device (2), the energy storage power generation device (2) comprising: a first reservoir (21) for storing an energy storage medium in a first state, a second reservoir (27) for storing an energy storage medium in a second state, an energy storage heat storage module (201) and an energy release heat absorption module (202); The inlet of the energy storage and heat storage module (201) is connected to the outlet of the first reservoir (21), the outlet of the energy storage and heat storage module (201) is connected to the inlet of the second reservoir (27), the outlet of the cold tank (11) is connected to the inlet of the heat storage medium of the energy storage and heat storage module (201), the outlet of the heat storage medium of the energy storage and heat storage module (201) is connected to the inlet of the heater (13), the outlet of the heater (13) is connected to the inlet of the hot tank (12), the outlet of the hot tank (12) is connected to the outlet of the heat storage medium of the energy release and heat absorption module (202), and the outlet of the cold tank (11) is connected to the outlet of the heat storage medium of the energy release and heat absorption module (202). The heat medium inlet is connected, the inlet of the energy releasing heat absorbing module (202) is connected to the outlet of the second reservoir (27), the outlet of the energy releasing heat absorbing module (202) is connected to the inlet of the first reservoir (21), the heat storage medium outlet of the energy releasing heat absorbing module (202) is connected to the cold tank (11), the intermediate energy storage medium outlet of the energy releasing heat absorbing module (202) is connected to the energy storage medium inlet of the steam generator (14), and the energy storage medium outlet of the steam generator (14) is connected to the intermediate energy storage medium inlet of the energy releasing heat absorbing module (202); The energy storage and heat storage module (201) is configured to: compress the energy storage medium in the first state and liquefy it, convert it into the second state, and generate a first heat, the first heat is used to heat the cold heat storage medium output by the cold tank (11), the heated heat storage medium passes through the heat storage medium outlet of the energy storage and heat storage module (201) to the inlet of the heater (13), enters the heater (13) for secondary heating, and the heat storage medium after secondary heating is stored in the hot tank (12); The energy-releasing heat-absorbing module (202) is configured to receive the hot heat storage medium output by the hot tank (12), and utilize the heat of the hot heat storage medium to heat the second-state energy storage medium output by the second reservoir (27) so that the energy storage medium expands to generate electricity, and then transforms to the first state, so as to store the energy storage medium in the first state in the first reservoir (21), and utilize the residual heat of the energy storage medium after partial expansion to generate electricity to heat the steam generator (14) to produce industrial steam.

2. The thermal storage coupled energy storage system according to claim 1, characterized in that: The energy storage and heat storage module (201) comprises: a gas compression module (203), the inlet of the gas compression module (203) being in communication with the outlet of the first reservoir (21), the gas compression module (203) being configured to compress the energy storage medium in the first state into compressed gas; A heat storage heat exchanger (25), wherein the inlet of the heat storage heat exchanger (25) is connected to the outlet of the gas compression module, the heat storage medium inlet of the heat storage heat exchanger (25) is connected to the outlet of the cold tank (11), and the heat storage medium outlet of the heat storage heat exchanger (25) is connected to the inlet of the heater (13), wherein the heat storage medium inlet of the heat storage heat exchanger (25) is the heat storage medium inlet of the energy storage heat storage module (201), and the heat storage medium outlet of the heat storage heat exchanger (25) is the heat storage medium outlet of the energy storage heat storage module (201); a first regenerator (23), the first regenerator (23) being connected in series with the gas compression module (203), and a first inlet of the first regenerator (23) being connected to an outlet of the heat storage heat exchanger (25); and A condenser (26), wherein the outlet of the condenser (26) is communicated with the inlet of the second reservoir (27), and the inlet of the condenser (26) is communicated with the first outlet of the first regenerator (23).

3. The thermal storage coupled energy storage system according to claim 2, characterized in that: The gas compression module (203) comprises: a first compressor (22), wherein an inlet of the first compressor (22) is connected to an outlet of the first reservoir (21), and an outlet of the first compressor (22) is connected to a second inlet of the first regenerator (23); A second compressor (24), wherein the inlet of the second compressor (24) is communicated with the second outlet of the first regenerator (23), and the outlet of the second compressor (24) is communicated with the inlet of the heat storage heat exchanger (25).

4. The thermal storage coupled energy storage system according to claim 2, characterized in that: The energy-releasing heat-absorbing module (202) comprises: a vaporizer (28), the vaporizer (28) being in communication with an outlet of the second reservoir (27); a second regenerator (29), wherein a first inlet of the second regenerator (29) is in communication with an outlet of the gasifier (28); a heat-releasing heat exchanger (30), wherein the inlet of the heat-releasing heat exchanger (30) is connected to the first outlet of the second heat regenerator (29), the heat storage medium outlet of the heat-releasing heat exchanger (30) is connected to the inlet of the cold tank (11), and the heat storage medium inlet of the heat-releasing heat exchanger (30) is connected to the outlet of the hot tank (12); a first expander (31), wherein an inlet of the first expander (31) is in communication with an outlet of the heat-releasing heat exchanger (30); The outlet of the first expander (31) is in communication with the second inlet of the second regenerator (29); and A second expander (32), wherein the inlet of the second expander (32) is connected to the second outlet of the second regenerator (29), and the outlet of the second expander (32) is connected to the inlet of the first storage tank (21).

5. The thermal storage coupled energy storage system according to claim 4, characterized in that: The air inlet of the steam generator (14) is connected to the outlet of the first expansion machine (31), the air outlet of the steam generator (14) is connected to the second inlet of the second reheater (29), and the outlet of the first expansion machine (31) is connected to the second inlet of the second reheater (29) through the steam generator (14); wherein, the outlet of the first expansion machine (31) is the intermediate energy storage medium outlet of the energy release and heat absorption module (202), the second inlet of the second reheater (29) is the intermediate energy storage medium inlet of the energy release and heat absorption module (202), the energy storage medium inlet of the steam generator (14) is the air inlet of the steam generator (14), and the energy storage medium outlet of the steam generator (14) is the air outlet of the steam generator (14).

6. The thermal storage coupled energy storage system according to claim 1, characterized in that: The energy storage medium includes carbon dioxide.

7. The thermal storage coupled energy storage system according to claim 6, characterized in that: The first state of the carbon dioxide is a thermodynamic state of a gas-liquid-solid coexistence point.

8. The thermal storage coupled energy storage system according to claim 6, characterized in that: The second state of the carbon dioxide is a thermodynamic state of a liquid phase at room temperature.

9. The thermal storage coupled energy storage system according to claim 8, characterized in that: The pressure in the second state is 5-10 MPa.

10. The thermal storage coupled energy storage system according to claim 1, characterized in that: The thermal storage medium includes molten salt.

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