Comprehensive energy system coupling renewable energy, conventional energy and stored energy

Abstract

The invention relates to a comprehensive energy system coupling renewable energy, conventional energy and stored energy. The comprehensive energy system comprises an electric heating heat storage subsystem, a compressed gas (or liquefied gas) energy storage subsystem and a gas-steam combined cycle or IGCC power generation subsystem. The electric heating heat storage subsystem can store heat through liquid such as fused salt and heat conduction oil and can also store heat through solid, and compression heat of the compressed gas (or liquefied gas) energy storage subsystem is stored in a medium with the low heat storage temperature. And a gas power generation part of the gas-steam combined cycle subsystem is used for making up the defects of renewable energy sources and a heat storage system. The system is used for a large renewable energy base, the flexibility of the power supply side and the power supply reliability can be improved, and carbon emission is remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a comprehensive energy system coupling renewable energy, conventional energy and energy storage. Background Art

[0002] In order to achieve the dual carbon goals, the scale of development of new energy power generation such as wind power and solar energy is expanding day by day, and the randomness and volatility of new energy power generation have put forward more stringent requirements on the regulation capacity of the power grid. Therefore, the development of energy storage technology and the transformation of existing power generation systems have become the current research focus. Chinese patent CN221299319U (compressed air energy storage peak-shaving power station for gas-air combined cycle), Chinese patent application CN118208304A (a gas-coal combined power generation method and system with integrated compressed air energy storage), Chinese patent application CN114856735A (an air turbine coupled gas turbine power generation system based on compressed air energy storage), and Chinese patent application CN112855302A (an IGCC power station coupled air liquefaction equipment system and its working method) all propose to couple compressed air energy storage with gas turbine units or IGCC units to improve system flexibility, but compressed air storage cannot respond quickly to power fluctuations and cannot completely solve the problem of renewable energy consumption. Compressed gas energy storage has the advantages of long life, large scale and low cost. It has developed rapidly in recent years, but the low temperature of gas turbine during energy release limits the efficiency of the system. Electric heating energy storage is low-cost, safe and reliable, with flexible and controllable heating power, which can quickly respond to wind and solar power fluctuations. Coupling with gas-steam combined cycle power generation system can effectively solve the problem that the power generation system is limited by the "heat-to-electricity" working mode. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides an integrated energy system that couples renewable energy, conventional energy and energy storage. When storing energy, excess electricity is used to compress gas and store compression heat, and an electric heater is used to heat molten salt for heat storage. When releasing energy, the gas in the gas storage is supplied to a gas turbine for power generation, and the stored compression heat and hot molten salt generate steam to generate electricity through a steam turbine.

[0004] The present invention can be used to support the large-scale grid-connected consumption of renewable energy, and the gas-fired power generation part of the gas-steam combined cycle subsystem is used to make up for the deficiencies of renewable energy and heat storage systems. If the compressed gas is air, it can also be used in the gas cycle of the gas-steam combined cycle, which is equivalent to supplementary compressed air energy storage; the compressed gas (or liquefied gas) can also be natural gas, which can be used for power generation in the gas-steam combined cycle subsystem, or it can first exchange heat with the aforementioned heat storage medium and be used to drive the expander to do work, and then enter the gas-steam combined cycle unit. When the compressed gas (or liquefied gas) is liquefied air, the liquefied air can be separated into liquid nitrogen and liquid oxygen, and can also be used in IGCC (integrated coal gasification combined cycle power generation subsystem) power generation system. The present invention is used in large-scale renewable energy bases, which can improve the flexibility and power supply reliability of the power supply side and significantly reduce carbon emissions.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme:

[0006] A comprehensive energy system that couples renewable energy, conventional energy, and energy storage, including a compressed gas energy storage subsystem or a liquefied gas energy storage subsystem, an electric heating heat storage subsystem, a gas-steam combined cycle power generation subsystem, or an IGCC power generation system; during periods of abundant renewable energy, i.e., during daytime or when the wind is strong, the electric heating heat storage subsystem, the compressed gas energy storage subsystem, or the liquefied gas energy storage subsystem is used to store energy, wherein the heating power of the electric heating heat storage subsystem is flexible and controllable, and is used to respond to fluctuations in wind and solar power, and the energy storage power of compressed gas or liquefied gas is relatively stable; the electric heating heat storage subsystem uses molten salt Heat storage, heat transfer oil storage, or solid heat storage, the compression heat of the compressed gas energy storage subsystem or the liquefied gas energy storage subsystem is stored in a medium with a lower heat storage temperature; during periods of lack of renewable energy, that is, at night or when the wind is weak, the heat storage medium in the compressed gas energy storage subsystem or the liquefied gas energy storage subsystem and the high-temperature heat storage medium in the electric heating heat storage subsystem are used to exchange heat with the working fluid, and are used for direct heating or steam cycle power generation, or for expansion work of compressed gas or liquefied gas; the gas power generation part of the gas-steam combined cycle subsystem is used to make up for the lack of energy from renewable energy and the heat storage system.

[0007] Furthermore, the compressed gas of the compressed gas energy storage subsystem is air, natural gas or carbon dioxide; when the compressed gas is air, it is used for the gas cycle of the gas-steam combined cycle, that is, supplementary compressed air energy storage; when the compressed gas is natural gas, it is used for power generation in the gas-steam combined cycle subsystem, or first exchanges heat with a heat storage medium with a lower heat storage temperature and is used to drive the expander to do work, and then enters the gas-steam combined cycle unit; when the compressed gas is liquefied air, the liquefied air is separated into liquid nitrogen and liquid oxygen, and used in the IGCC power generation system.

[0008] Furthermore, when the compressed gas is air, the compressed gas energy storage subsystem includes compressor 1, compressor 2, heat exchanger 1, heat exchanger 2, a low-temperature heat storage tank, liquid pump 1, a high-temperature heat storage tank, liquid pump 2, and a gas storage reservoir; during energy storage, after the air is compressed by compressor 1, the heat generated by the compression is transferred to the heat storage medium through heat exchanger 1, and after being compressed by compressor 2 and heat exchanged by heat exchanger 2, the compressed air enters the gas storage reservoir for storage.

[0009] Furthermore, the electric heating heat storage subsystem includes an electric heater, a molten salt pump 1, a low-temperature molten salt storage tank, a heat exchanger 3, a heat exchanger 4, a molten salt pump 2, and a high-temperature molten salt storage tank; the low-temperature molten salt flows out from the low-temperature molten salt storage tank, is heated by the electric heater, and then enters the high-temperature molten salt storage tank for storage.

[0010] Furthermore, the gas-steam combined cycle power generation subsystem includes a gas turbine compressor, a combustion chamber, a gas turbine turbine, a waste heat boiler, and a steam turbine; when releasing energy, the air in the gas storage reservoir is released and mixed with the air at the gas turbine compressor outlet, and then mixed with the fuel and burned in the combustion chamber, and the high-temperature gas is discharged through the gas turbine turbine to generate power; the condensed water at the steam turbine outlet passes through the waste heat boiler and heat exchanger three and heat exchanger four respectively, absorbs the waste heat of the flue gas at the gas turbine turbine outlet, the compression heat stored in the high-temperature heat storage tank, and the heat of the molten salt in the high-temperature molten salt storage tank to generate steam, and the steam can be used for steam turbine power generation or direct heating.

[0011] Furthermore, the gas-steam combined cycle power generation combined cycle subsystem is coupled to a chemical energy storage system for synthesizing methanol, and the chemical energy storage system includes an electrolyzer, a hydrogen storage tank, a mixer, a methanol synthesis reactor, a methanol storage tank, and a CO2 capture device; the electrolyzer is used to electrolyze water to produce hydrogen and oxygen, the hydrogen enters the hydrogen storage tank for storage, and the oxygen is passed into the combustion chamber for oxygen-enriched combustion, and the CO2 capture device is used to collect CO2 in the flue gas exhausted by the gas turbine, and then after mixing with hydrogen in the mixer, enters the methanol synthesis reactor to react and generate methanol, and the methanol is stored in the methanol storage tank.

[0012] Furthermore, when the gas-steam combined cycle power generation subsystem is an integrated coal gasification combined cycle power generation system, it includes a gas turbine compressor, a combustion chamber, a gas turbine turbine, a waste heat boiler, a steam turbine, an air separation unit, a gasifier, and a purification unit; the air separation unit provides the oxygen required for gasification for coal gasification, and the waste heat of the flue gas at the gas turbine turbine outlet is used to generate water vapor for coal gasification through the waste heat boiler, and the coal powder reacts in the gasifier to generate a crude synthesis gas, which is purified by the purification unit and then introduced into the combustion chamber; when releasing energy, the air in the gas storage reservoir is released and mixed with the air at the gas turbine compressor outlet, and then mixed with the coal gas through the combustion chamber and burned, and the high-temperature gas is discharged and passes through the gas turbine turbine to generate power; the condensed water at the steam turbine outlet passes through heat exchanger three and heat exchanger four, absorbs the compression heat stored in the high-temperature heat storage tank and the heat of the molten salt in the high-temperature molten salt storage tank to generate steam, and the steam can be used for steam turbine power generation or direct heating.

[0013] Furthermore, the integrated coal gasification combined cycle power generation system is coupled with a chemical energy storage system for synthesizing ammonia, and the chemical energy storage system includes an electrolyzer, a hydrogen storage tank, a mixer, an ammonia synthesis reactor, and an ammonia storage tank; the electrolyzer is used to electrolyze water to produce hydrogen and oxygen, the hydrogen enters the hydrogen storage tank for storage, and the oxygen is passed into the combustion chamber for oxygen-enriched combustion; the nitrogen separated by the air separation unit is mixed with the hydrogen in the mixer, and then enters the ammonia synthesis reactor to react and generate ammonia, and the ammonia is stored in the ammonia storage tank.

[0014] Furthermore, when the compressed gas is natural gas, the compressed gas energy storage subsystem includes compressor 1, compressor 2, heat exchanger 1, heat exchanger 2, low-temperature heat storage tank, liquid pump 1, high-temperature heat storage tank, liquid pump 2, gas storage reservoir, heat exchanger 5, and natural gas expander; when storing energy, the natural gas is compressed by compressor 1, and the heat generated by the compression is transferred to the heat storage medium through heat exchanger 1. After being compressed by compressor 2 and heat exchanged by heat exchanger 2, the compressed natural gas enters the gas storage reservoir for storage; when releasing energy, the compressed natural gas exchanges heat with the heat storage medium through heat exchanger 5 and enters the natural gas expander to generate power.

[0015] Furthermore, the heat storage medium of the compressed gas energy storage subsystem is water or heat transfer oil.

[0016] Furthermore, the gas storage reservoir is a salt cavern, an abandoned mine, an artificial chamber or a pipeline steel.

[0017] Furthermore, the gas storage method of the gas storage reservoir is variable pressure gas storage or constant pressure gas storage.

[0018] Furthermore, the electric heating heat storage subsystem includes an electric heater, a molten salt pump 1, a low-temperature molten salt storage tank, a heat exchanger 4, a molten salt pump 2, and a high-temperature molten salt storage tank; the low-temperature molten salt flows out from the low-temperature molten salt storage tank, is heated by the electric heater, and then enters the high-temperature molten salt storage tank for storage.

[0019] Furthermore, the gas-steam combined cycle power generation subsystem includes a gas turbine compressor, a combustion chamber, a gas turbine turbine, a waste heat boiler, and a steam turbine. When releasing energy, the air at the outlet of the gas turbine compressor and the low-pressure natural gas at the outlet of the natural gas expander are mixed in the combustion chamber and then burned, and the high-temperature gas is discharged and passes through the gas turbine turbine to generate power; the condensed water at the outlet of the steam turbine passes through the waste heat boiler and the heat exchanger 4 respectively, and absorbs the heat of the flue gas at the outlet of the gas turbine turbine and the molten salt in the high-temperature molten salt storage tank to generate steam, which can be used for steam turbine power generation or direct heating.

[0020] Furthermore, the electricity used for energy storage in the integrated energy system comes from new energy generation such as photovoltaic power generation or wind power generation. When the output of new energy power generation is stable, it can be directly connected to the grid, and energy can be stored when electricity consumption is low or when new energy power generation fluctuates.

[0021] Beneficial effects:

[0022] 1. The present invention uses compressed gas and electric heating as an energy storage system, which can flexibly adjust the energy storage power. The electric heating energy storage can quickly respond to electric power fluctuations. The compressed gas energy storage can be used as a large-capacity energy storage system, so that the power grid can better adapt to the access of renewable energy and make the best possible use of renewable energy.

[0023] 2. The present invention couples the compressed gas and electric heating energy storage system with the gas-steam combined cycle power generation system, which greatly improves the thermal-electric decoupling capability of the gas-steam combined cycle power generation system and can respond to higher grid load power generation demands. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a gas-steam combined cycle power generation system coupled with electric heating and compressed air energy storage provided in Example 1 of the present invention;

[0025] Figure 2 A schematic diagram of a gas-steam combined cycle power generation system (synthetic methanol) coupled with electric heating and compressed air energy storage provided in Example 2 of the present invention;

[0026] Figure 3 A schematic diagram of a coal gasification combined cycle power generation system coupled with electric heating and compressed air energy storage provided in Example 3 of the present invention;

[0027] Figure 4 A schematic diagram of a coal gasification combined cycle power generation system (synthetic ammonia) coupled with electric heating and compressed air energy storage provided in Example 4 of the present invention;

[0028] Figure 5 A schematic diagram of a gas-steam combined cycle power generation system coupled with electric heating and compressed natural gas energy storage provided in Example 5 of the present invention;

[0029] Among them, the figure numbers are: 101-compressor one; 102-compressor two; 103-heat exchanger one; 104-heat exchanger two; 105-low-temperature heat storage tank; 106-liquid pump one; 107-high-temperature heat storage tank; 108-liquid pump two; 109-gas storage reservoir; 110-heat exchanger five; 111-natural gas expander; 201-electric heater; 202-molten salt pump one; 203-low-temperature molten salt storage tank; 204-heat exchanger three; 205-heat exchanger four; 206-molten salt Pump 2; 207-high temperature molten salt storage tank; 301-gas turbine compressor; 302-combustion chamber; 303-gas turbine turbine; 304-waste heat boiler; 305-steam turbine; 306-air separation unit; 307-gasifier; 308-purification system; 401-electrolyzer; 402-hydrogen storage tank; 403-mixer; 404-methanol synthesis reactor; 405-methanol storage tank; 406-CO2 capture device; 407-ammonia synthesis reactor; 408-ammonia storage tank. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] like Figure 1 As shown, it is a schematic diagram of a gas-steam combined cycle power generation system coupled with electric heating heat storage and compressed air energy storage provided in Example 1 of the present invention, including a compressed air subsystem, an electric heating heat storage subsystem, and a gas-steam combined cycle power generation subsystem.

[0032] When the compressed gas is air, the compressed gas subsystem includes compressor 1 101, compressor 2 102, heat exchanger 1 103, heat exchanger 2 104, low temperature heat storage tank 105, liquid pump 1 106, high temperature heat storage tank 107, liquid pump 2 108, and gas storage reservoir 109. During energy storage, after the air is compressed by compressor 1 101, the heat generated by the compression is transferred to the heat storage medium through heat exchanger 1 103, and after being compressed by compressor 2 102 and heat exchanged by heat exchanger 2 104, the compressed air enters the gas storage reservoir 109 for storage.

[0033] The electric heating heat storage subsystem includes an electric heater 201, a molten salt pump 1 202, a low-temperature molten salt storage tank 203, a heat exchanger 3 204, a heat exchanger 4 205, a molten salt pump 2 206, and a high-temperature molten salt storage tank 207. The low-temperature molten salt flows out of the low-temperature molten salt storage tank 203, is heated by the electric heater 201, and then enters the high-temperature molten salt storage tank 207 for storage.

[0034] The gas-steam combined cycle power generation subsystem includes a gas turbine compressor 301, a combustion chamber 302, a gas turbine 303, a waste heat boiler 304, and a steam turbine 305. When releasing energy, the air in the gas storage reservoir 109 is released and mixed with the air at the outlet of the gas turbine compressor 301, and then mixed with the fuel through the combustion chamber 302 to burn, and the high-temperature gas is discharged to generate power through the gas turbine 303. The condensed water at the outlet of the steam turbine 305 passes through the waste heat boiler 304 and the heat exchanger three 204 and the heat exchanger four 205 respectively, and absorbs the waste heat of the flue gas at the outlet of the gas turbine 303, the compression heat stored in the high-temperature heat storage tank 107, and the heat of the molten salt in the high-temperature molten salt storage tank 207 to generate steam, which can be used for power generation or direct heating by the steam turbine 305.

[0035] like Figure 2 As shown, it is a schematic diagram of a gas-steam combined cycle power generation system (synthetic methanol) coupled with electric heating heat storage and compressed air energy storage provided in Example 2 of the present invention. The gas-steam combined cycle power generation subsystem can be coupled with a chemical energy storage system for synthesizing methanol, including an electrolyzer 401, a hydrogen storage tank 402, a mixer 403, a methanol synthesis reactor 404, a methanol storage tank 405, and a CO2 capture device 406. The electrolyzer 401 is used to electrolyze water to produce hydrogen and oxygen. The hydrogen enters the hydrogen storage tank 402 for storage, and the oxygen is passed into the combustion chamber 302 for oxygen-enriched combustion. The CO2 in the exhaust gas of the gas turbine is collected by the CO2 capture device 406, and then mixed with hydrogen in the mixer 403, and then enters the methanol synthesis reactor 404 to react to generate methanol, and the methanol is stored in the methanol storage tank 405.

[0036] like Figure 3 As shown, it is a schematic diagram of a coal gasification combined cycle power generation system coupled with electric heating heat storage and compressed air energy storage provided in Example 3 of the present invention. When the gas-steam combined cycle power generation subsystem is a coal gasification combined cycle power generation system, it includes a gas turbine compressor 301, a combustion chamber 302, a gas turbine turbine 303, a waste heat boiler 304, a steam turbine 305, an air separation unit 306, a gasifier 307, and a purification unit 308. The air separation unit 306 provides oxygen required for gasification for coal gasification, and the waste heat of the flue gas at the outlet of the gas turbine turbine 303 is used to generate water vapor for coal gasification through the waste heat boiler 304. The coal powder reacts in the gasifier 307 to generate a crude synthesis gas, which is purified by the purification unit 308 and then passed into the combustion chamber. When releasing energy, the air in the gas storage reservoir 109 is released and mixed with the air at the outlet of the gas turbine compressor 301, and then mixed with the coal gas through the combustion chamber 302 and burned, and the high-temperature gas is discharged through the gas turbine turbine 303 to generate power. The condensed water at the outlet of the steam turbine 305 passes through the heat exchanger three 204 and the heat exchanger four 205, absorbs the compression heat stored in the high-temperature heat storage tank 107 and the heat of the molten salt in the high-temperature molten salt storage tank 207 to generate steam, and the steam can be used for the steam turbine 305 to generate electricity or directly provide heat.

[0037] like Figure 4 As shown, it is a schematic diagram of a coal gasification combined cycle power generation system (synthetic ammonia) coupled with electric heating heat storage and compressed air energy storage provided in Example 4 of the present invention. The coal gasification combined cycle power generation system can be coupled with a chemical energy storage system for synthetic ammonia, including an electrolyzer 401, a hydrogen storage tank 402, a mixer 403, an ammonia synthesis reactor 407, and an ammonia storage tank 408. The electrolyzer 401 is used to electrolyze water to produce hydrogen and oxygen. The hydrogen enters the hydrogen storage tank 402 for storage, and the oxygen is passed into the combustion chamber 302 for oxygen-enriched combustion. The nitrogen separated by the air separation unit 306 is mixed with the hydrogen in the mixer 403, and then enters the ammonia synthesis reactor 407 to react and generate ammonia, and the ammonia is stored in the ammonia storage tank 408.

[0038] like Figure 5 As shown, it is a schematic diagram of a gas-steam combined cycle power generation system coupled with electric heating heat storage and compressed natural gas energy storage provided by Example 5 of the present invention. When the compressed gas is natural gas, the compressed gas subsystem includes compressor 1 101, compressor 2 102, heat exchanger 1 103, heat exchanger 2 104, low-temperature heat storage tank 105, liquid pump 1 106, high-temperature heat storage tank 107, liquid pump 2 108, gas storage reservoir 109, heat exchanger 5 110, and natural gas expander 111. When storing energy, after the natural gas is compressed by compressor 1 101, the heat generated by the compression is transferred to the heat storage medium through heat exchanger 1 103. After being compressed by compressor 2 102 and heat exchanged by heat exchanger 2 104, the compressed natural gas enters the gas storage reservoir 109 for storage. When releasing energy, the compressed natural gas enters the natural gas expander 111 to generate power after heat exchange with the heat storage medium through heat exchanger 5 110.

[0039] Preferably, the heat storage medium of the compressed gas subsystem may be water or thermal oil. The gas storage reservoir 109 may be a salt cave, an abandoned mine, an artificial chamber, or pipeline steel. The gas storage method of the gas storage reservoir 109 may be variable pressure gas storage or constant pressure gas storage.

[0040] The electric heating heat storage subsystem includes an electric heater 201, a molten salt pump 1 202, a low-temperature molten salt storage tank 203, a heat exchanger 4 205, a molten salt pump 2 206, and a high-temperature molten salt storage tank 207. The low-temperature molten salt flows out of the low-temperature molten salt storage tank 203, is heated by the electric heater 201, and then enters the high-temperature molten salt storage tank 207 for storage.

[0041] The gas-steam combined cycle power generation subsystem includes a gas turbine compressor 301, a combustion chamber 302, a gas turbine 303, a waste heat boiler 304, and a steam turbine 305. When releasing energy, the air at the outlet of the gas turbine compressor 301 and the low-pressure natural gas at the outlet of the natural gas expander 111 are mixed in the combustion chamber 302 and then burned, and the high-temperature gas is discharged to generate power through the gas turbine 303. The condensed water at the outlet of the steam turbine 305 passes through the waste heat boiler 304 and the heat exchanger 205 respectively, and absorbs the heat of the flue gas at the outlet of the gas turbine 303 and the molten salt in the high-temperature molten salt storage tank 207 to generate steam, which can be used for power generation or direct heating by the steam turbine 305.

[0042] The electricity used for energy storage in the integrated energy system coupling renewable energy, conventional energy and energy storage comes from new energy power generation such as photovoltaic power generation or wind power generation. When the output of new energy power generation is stable, it can be directly connected to the grid, and energy storage is performed when electricity consumption is low or new energy power generation fluctuates.

[0043] So far, the technical route of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. An integrated energy system coupling renewable energy, conventional energy and energy storage, characterized in that: It includes a compressed gas energy storage subsystem or a liquefied gas energy storage subsystem, an electric heating heat storage subsystem, a gas-steam combined cycle power generation subsystem or an IGCC power generation system; during the period when renewable energy is abundant, that is, during the day or when the wind is strong, the electric heating heat storage subsystem, the compressed gas energy storage subsystem or the liquefied gas energy storage subsystem is used to store energy, wherein the heating power of the electric heating heat storage subsystem is flexible and controllable, and is used to respond to the fluctuation of wind and solar power, and the energy storage power of compressed gas or liquefied gas is relatively stable; the electric heating heat storage subsystem uses molten salt heat storage, thermal oil heat storage, or solid Heat storage in the form of a compressed gas energy storage subsystem or a liquefied gas energy storage subsystem, where the compression heat of the compressed gas energy storage subsystem or the liquefied gas energy storage subsystem is stored in a medium with a lower heat storage temperature; during periods of lack of renewable energy, i.e. at night or when the wind is weak, the heat storage medium in the compressed gas energy storage subsystem or the liquefied gas energy storage subsystem and the high-temperature heat storage medium in the electric heating heat storage subsystem are used to exchange heat with the working fluid, and are used for direct heating or steam cycle power generation, or for expansion work of compressed gas or liquefied gas; the gas-fired power generation part of the gas-steam combined cycle subsystem is used to make up for the lack of energy from renewable energy and the heat storage system.

2. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 1, characterized in that: The compressed gas of the compressed gas energy storage subsystem is air, natural gas or carbon dioxide; when the compressed gas is air, it is used for the gas cycle of the gas-steam combined cycle, that is, supplementary combustion type compressed air energy storage; when the compressed gas is natural gas, it is used for power generation in the gas-steam combined cycle subsystem, or first exchanges heat with a heat storage medium with a lower heat storage temperature and is used to drive the expander to do work, and then enters the gas-steam combined cycle unit; when the compressed gas is liquefied air, the liquefied air is separated into liquid nitrogen and liquid oxygen, and used in the IGCC power generation system.

3. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 2, characterized in that: When the compressed gas is air, the compressed gas energy storage subsystem includes compressor 1, compressor 2, heat exchanger 1, heat exchanger 2, low-temperature heat storage tank, liquid pump 1, high-temperature heat storage tank, liquid pump 2, and gas storage reservoir; during energy storage, after the air is compressed by compressor 1, the heat generated by the compression is transferred to the heat storage medium through heat exchanger 1, and after being compressed by compressor 2 and heat exchanged by heat exchanger 2, the compressed air enters the gas storage reservoir for storage.

4. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 1, characterized in that: The electric heating heat storage subsystem includes an electric heater, a molten salt pump 1, a low-temperature molten salt storage tank, a heat exchanger 3, a heat exchanger 4, a molten salt pump 2, and a high-temperature molten salt storage tank; the low-temperature molten salt flows out of the low-temperature molten salt storage tank, is heated by the electric heater, and then enters the high-temperature molten salt storage tank for storage.

5. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 1, characterized in that: The gas-steam combined cycle power generation subsystem includes a gas turbine compressor, a combustion chamber, a gas turbine turbine, a waste heat boiler, and a steam turbine; when releasing energy, the air in the gas storage reservoir is released and mixed with the air at the gas turbine compressor outlet, and then mixed with the fuel and burned in the combustion chamber, and the high-temperature gas is discharged through the gas turbine turbine to generate power; the condensed water at the steam turbine outlet passes through the waste heat boiler and heat exchanger three and heat exchanger four respectively, absorbs the waste heat of the flue gas at the gas turbine turbine outlet, the compression heat stored in the high-temperature heat storage tank, and the heat of the molten salt in the high-temperature molten salt storage tank to generate steam, and the steam can be used for steam turbine power generation or direct heating.

6. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 5, characterized in that: The gas-steam combined cycle power generation combined cycle subsystem is coupled with a chemical energy storage system for synthesizing methanol, and the chemical energy storage system includes an electrolyzer, a hydrogen storage tank, a mixer, a methanol synthesis reactor, a methanol storage tank, and a CO2 capture device; the electrolyzer is used to electrolyze water to produce hydrogen and oxygen, the hydrogen enters the hydrogen storage tank for storage, the oxygen enters the combustion chamber for oxygen-enriched combustion, the CO2 capture device is used to collect CO2 in the flue gas exhausted by the gas turbine, and then after mixing with hydrogen in the mixer, enters the methanol synthesis reactor to react and generate methanol, and the methanol is stored in the methanol storage tank.

7. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 1, characterized in that: When the gas-steam combined cycle power generation subsystem is an integrated coal gasification combined cycle power generation system, it includes a gas turbine compressor, a combustion chamber, a gas turbine turbine, a waste heat boiler, a steam turbine, an air separation unit, a gasifier, and a purification unit; the air separation unit provides oxygen required for gasification for coal gasification, and the waste heat of the flue gas at the gas turbine turbine outlet is used to generate water vapor for coal gasification through the waste heat boiler, and the coal powder is reacted in the gasifier to generate a crude synthesis gas, which is purified by the purification unit and then introduced into the combustion chamber; when releasing energy, the air in the gas storage reservoir is released and mixed with the air at the gas turbine compressor outlet, and then mixed with the coal gas through the combustion chamber and burned, and the high-temperature gas is discharged and passes through the gas turbine turbine to generate power; the condensed water at the steam turbine outlet passes through heat exchanger three and heat exchanger four, absorbs the compression heat stored in the high-temperature heat storage tank and the heat of the molten salt in the high-temperature molten salt storage tank to generate steam, and the steam can be used for steam turbine power generation or direct heating.

8. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 7, characterized in that: The integrated coal gasification combined cycle power generation system is coupled with a chemical energy storage system for synthesizing ammonia, and the chemical energy storage system includes an electrolyzer, a hydrogen storage tank, a mixer, an ammonia synthesis reactor, and an ammonia storage tank; the electrolyzer is used to electrolyze water to produce hydrogen and oxygen, the hydrogen enters the hydrogen storage tank for storage, and the oxygen is introduced into the combustion chamber for oxygen-enriched combustion; the nitrogen separated by the air separation unit is mixed with the hydrogen in the mixer, and then enters the ammonia synthesis reactor to react and generate ammonia, and the ammonia is stored in the ammonia storage tank.

9. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 2, characterized in that: When the compressed gas is natural gas, the compressed gas energy storage subsystem includes compressor 1, compressor 2, heat exchanger 1, heat exchanger 2, low-temperature heat storage tank, liquid pump 1, high-temperature heat storage tank, liquid pump 2, gas storage, heat exchanger 5, and natural gas expander; when storing energy, the natural gas is compressed by compressor 1, and the heat generated by the compression is transferred to the heat storage medium through heat exchanger 1. After being compressed by compressor 2 and heat exchanged by heat exchanger 2, the compressed natural gas enters the gas storage for storage; when releasing energy, the compressed natural gas exchanges heat with the heat storage medium through heat exchanger 5 and enters the natural gas expander to generate power.

10. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 3, characterized in that: The heat storage medium of the compressed gas energy storage subsystem is water or heat transfer oil.

11. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 3, characterized in that: The gas storage is a salt cavern, abandoned mine, artificial chamber or pipeline steel.

12. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 3, characterized in that: The gas storage method of the gas storage facility is variable pressure storage or constant pressure storage.

13. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 1, characterized in that: The electric heating heat storage subsystem includes an electric heater, a molten salt pump 1, a low-temperature molten salt storage tank, a heat exchanger 4, a molten salt pump 2, and a high-temperature molten salt storage tank; the low-temperature molten salt flows out from the low-temperature molten salt storage tank, is heated by the electric heater, and then enters the high-temperature molten salt storage tank for storage.

14. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 1, characterized in that: The gas-steam combined cycle power generation subsystem includes a gas turbine compressor, a combustion chamber, a gas turbine turbine, a waste heat boiler, and a steam turbine. When releasing energy, the air at the outlet of the gas turbine compressor and the low-pressure natural gas at the outlet of the natural gas expander are mixed in the combustion chamber and then burned, and the high-temperature gas is discharged to pass through the gas turbine turbine to generate power; the condensed water at the outlet of the steam turbine passes through the waste heat boiler and the heat exchanger 4 respectively, and absorbs the heat of the flue gas at the outlet of the gas turbine turbine and the molten salt in the high-temperature molten salt storage tank to generate steam, which can be used for steam turbine power generation or direct heating.

15. The integrated energy system coupling renewable energy, conventional energy and energy storage according to claim 1, characterized in that: The electricity used for energy storage in the integrated energy system comes from new energy generation such as photovoltaic power generation or wind power generation. When the output of new energy power generation is stable, it can be directly connected to the grid, and energy can be stored when electricity consumption is low or when new energy power generation fluctuates.

Images