Integrated Energy System and Operation Method of Photovoltaic Green Hydrogen Production and Storage Collaborating with Thermal Power Plant Peak Shaving

Abstract

This invention discloses an integrated energy system and operation method for photovoltaic green hydrogen production and storage in conjunction with peak shaving in thermal power plants. This integrated energy system combines thermal power generation, photovoltaic power generation, fuel cell power generation, water electrolysis for hydrogen production, energy storage, hydrogen storage, and thermal storage. When the grid load fluctuates, fuel cells and energy storage batteries, individually or in combination, assist the thermal power units in compensating for grid load fluctuations. The energy storage batteries and electrolyzers absorb excess electrical energy from the thermal power units. Because photovoltaic power generation is unstable and intermittent, and the photovoltaic array in the system is not connected to the grid, this system can "store and use" energy simultaneously or "store first and then use" without increasing grid volatility, thereby achieving "peak shaving and valley filling," ensuring stable and reliable power supply, improving the flexibility of thermal power units, and enhancing the system's renewable energy absorption capacity. This system can achieve complementarity and supply-demand coordination of multiple energy sources, effectively improving the overall energy efficiency of the system, and simultaneously meeting the needs for electricity, hydrogen, and heat.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive energy utilization technology, and in particular relates to a comprehensive energy system and operation method that combines photovoltaic green hydrogen production and storage with peak shaving of thermal power plants. Background Art

[0002] To support its "dual carbon" goals, my country is accelerating the transformation and development of its energy sector. Electricity is a central link in this transformation and a key area for carbon emission reduction. Traditional thermal power technology is mature and highly reliable, and it still dominates my country's energy structure, serving as the main force in power development. However, the application of thermal power is subject to several limitations: First, a prominent problem with thermal power is its poor peak-shaving capacity due to factors such as the large proportion of combined heat and power (CHP) units, making it difficult to fully meet the peak-shaving needs of the power system in actual operation. Second, thermal power has low energy conversion efficiency, generating a large amount of waste heat during combustion, which cannot be effectively utilized, resulting in energy waste. Third, thermal power mainly relies on coal, which is a non-renewable resource. Excessive use not only leads to resource depletion but also its combustion products cause pollution and harm to the environment.

[0003] The government is strongly supporting the development of thermal power combined with new energy sources to achieve large-scale grid connection and absorb renewable resources. How to improve the flexibility and energy efficiency of thermal power units, and enhance the system's peak-shaving and renewable energy absorption capabilities, is a pressing technical challenge that needs to be addressed. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated energy system and operation method that combines photovoltaic green hydrogen production and storage with peak shaving in thermal power plants. This system can improve the flexibility and energy utilization of thermal power units, and enhance the system's peak shaving and renewable energy absorption capabilities.

[0005] This invention is implemented as follows: a comprehensive energy system for photovoltaic green hydrogen production and storage in conjunction with peak shaving in thermal power plants, comprising a thermal power generation system, a photovoltaic array, an electrolyzer, a fuel cell, a compressor, an energy storage system, a power grid, a hydrogen refueling machine, and a heat utilization system; wherein, the thermal power generation system includes a coal-fired boiler, a steam turbine, and a generator; the energy storage system includes energy storage batteries, hydrogen storage cylinders, and thermal storage tanks; the heat utilization system includes a primary grid, a heat exchange station, a secondary grid, and heat users;

[0006] The power output terminal of the photovoltaic array is divided into two paths, which are respectively connected to the power input terminals of the energy storage battery and the electrolytic cell;

[0007] The energy input terminal of the energy storage battery is divided into two paths, which are respectively connected to the energy output terminal of the photovoltaic array and the energy output terminal of the generator; the energy output terminal of the energy storage battery is divided into two paths, which are respectively connected to the energy input terminal of the power grid and the energy input terminal of the electrolytic cell.

[0008] The electrolyzer has three power input terminals, which are respectively connected to the power output terminals of the photovoltaic array, the energy storage battery, and the generator; the hydrogen output terminal of the electrolyzer is connected to the hydrogen input terminal of the compressor, and the hydrogen output terminal of the compressor is connected to the hydrogen input terminal of the hydrogen storage cylinder to store the produced hydrogen in the hydrogen storage cylinder; the oxygen output terminal of the electrolyzer is connected to the oxygen input terminal of the coal-fired boiler.

[0009] The power grid's power input terminal is divided into three paths, which are respectively connected to the power output terminals of the energy storage battery, the fuel cell, and the generator;

[0010] The thermal energy output terminal of the coal-fired boiler is connected to the thermal energy input terminal of the steam turbine, and the mechanical energy output by the steam turbine provides power for the generator to generate electricity; the output terminal of the generator is divided into three electrical energy output terminals and one thermal energy output terminal. The three electrical energy output terminals of the generator are respectively connected to the electrical energy input terminals of the power grid, the electrolytic cell and the energy storage battery, and the one thermal energy output terminal of the generator is connected to the thermal energy input terminal of the thermal storage tank.

[0011] The hydrogen output terminal of the hydrogen storage cylinder is divided into three paths, which are respectively connected to the hydrogen input terminals of the fuel cell, the generator, and the hydrogen refueling machine;

[0012] The thermal energy input terminal of the thermal storage tank is divided into five channels, which are respectively connected to the thermal energy output terminals of the coal-fired boiler, the steam turbine, the electrolytic cell, the fuel cell, and the generator. The thermal energy output terminal of the thermal storage tank is connected to the thermal energy input terminal of the primary network, the thermal energy output terminal of the primary network is connected to the thermal energy input terminal of the heat exchange station, the thermal energy output terminal of the heat exchange station is connected to the thermal energy input terminal of the secondary network, and the thermal energy output terminal of the secondary network is connected to the thermal energy input terminal of the heat user.

[0013] To achieve the above-mentioned objectives, the present invention also provides an operation method for the aforementioned integrated energy system, which includes a peak-shaving process for a thermal power plant:

[0014] The photovoltaic array generates electricity during sunshine hours, sending one path to charge the energy storage battery and another path to the electrolyzer to electrolyze water to produce hydrogen and oxygen. The produced hydrogen is stored in a hydrogen storage tank, and the produced oxygen is sent to the coal-fired boiler to create an oxygen-rich combustion atmosphere and play a role in combustion.

[0015] When the grid load increases, the power generation of thermal power plants cannot meet the load demand. Hydrogen storage tanks provide hydrogen to fuel cells for power generation. If the power generation of thermal power plants and fuel cells still cannot meet the grid load demand, energy storage batteries serve as auxiliary power sources and work together with fuel cells to generate electricity to compensate the grid.

[0016] When the grid load decreases, the power generation of thermal power plants exceeds the load demand. The surplus electricity is preferentially delivered to charge the energy storage battery. If the energy storage battery is already fully charged, it is delivered to the electrolyzer to produce hydrogen, so as to convert electrical energy into hydrogen energy for storage to meet the hydrogen demand.

[0017] Furthermore, the operating method also includes a hydrogen processing procedure:

[0018] The hydrogen in the storage tank is used for three purposes: first, for fuel cell power generation; second, for hydrogen refueling stations to provide fuel for fuel cell vehicles and for transporting coal to power plants; and third, as a cooling medium for generators. Hydrogen is injected into the generator from the storage tank through connecting pipes, and flows in the generator chamber using fans at both ends of the rotor to cool the stator windings, rotor windings, and iron core. After being cooled by hydrogen coolers located at the four corners of the stator frame, it is circulated again. If there is a hydrogen leak in the generator, or if other factors cause low hydrogen pressure, hydrogen can be replenished through the connecting pipes. If the hydrogen purity is not up to standard, the hydrogen is discharged from the generator to the atmosphere, and then high-purity hydrogen is re-injected. The hydrogen content in the storage tank must be higher than the fixed amount of hydrogen required for generator replenishment.

[0019] Furthermore, the operating method also includes a thermal energy treatment process:

[0020] The heat medium is used to recover the high-temperature flue gas waste heat from the coal-fired boiler, the high-temperature exhaust steam waste heat from the steam turbine, and the heat generated during the operation of the generator, electrolyzer, and fuel cell, and store them in the heat storage tank. The heat energy stored in the heat medium in the heat storage tank can be successively transported to the heat user end through the primary network, heat exchange station, and secondary network to achieve dual supply of heating and cooling, and meet the living and production needs of the residents in the plant area.

[0021] Cooling process: The heat medium is taken out from the heat storage tank and sent to the primary network. Then, it is converted into cold water by the chiller in the heat exchange station and transferred to the secondary network. Finally, it is delivered to the heat users through the secondary network. The heat users then absorb the indoor heat through the cooling equipment.

[0022] Heating process: The heat medium is taken out from the heat storage tank and sent to the primary network. Then, the heat is transferred to the secondary network through the heat exchanger of the heat exchange station. Finally, the heat is delivered to the heat users through the secondary network, and the heat users then dissipate the heat into the room through the heating equipment.

[0023] Furthermore, the electrolytic cell is an alkaline electrolytic cell, and the chemical reaction in the electrolytic cell is: 2H2O→2H2+O2.

[0024] Furthermore, the fuel cell is a low-temperature proton exchange membrane fuel cell, and the chemical reaction in the fuel cell is: O2 + 2H2 → 2H2O.

[0025] Compared with the prior art, the integrated energy system and operation method of photovoltaic green hydrogen production and storage combined with peak shaving of thermal power plants provided by the present invention have the following beneficial effects:

[0026] This integrated energy system combines thermal power generation, photovoltaic power generation, fuel cell power generation, water electrolysis for hydrogen production, energy storage, hydrogen storage, and thermal storage. When grid load fluctuates, fuel cells and energy storage batteries, individually or in combination, assist the thermal power units in compensating for grid imbalances. The energy storage batteries and electrolyzers absorb excess electrical energy from the thermal power units. Fuel cells, with their slow dynamic response, cannot output instantaneous high power and primarily serve a peak-shaving function. In contrast, energy storage batteries, with their high energy density and fast response speed, can achieve transient high-power output and primarily serve a frequency regulation function. First, due to the instability and intermittency of photovoltaic power generation, and since the photovoltaic array in the system is not connected to the grid, this system can "store and use" energy simultaneously or "store first and then use" without increasing grid fluctuations, thereby achieving "peak shaving and valley filling," ensuring stable and reliable power supply, effectively solving the problem of poor peak-shaving capacity of thermal power units, improving the flexibility of thermal power units, and enhancing the system's renewable energy absorption capacity. Second, the system involves solar energy, hydrogen energy, electricity, and heat energy, realizing the complementarity and supply-demand coordination of multiple energy sources, effectively improving the overall energy efficiency of the system, and simultaneously meeting the needs for electricity, hydrogen, and heat. Then, the electricity generated by photovoltaic power is used to electrolyze water in an electrolyzer to produce hydrogen, which is then stored. This process of using renewable energy (solar energy) to produce green hydrogen has zero carbon emissions, realizing the utilization of clean energy. Attached Figure Description

[0027] Figure 1 This is a structural block diagram of an integrated energy system for photovoltaic green hydrogen production and storage combined with peak shaving of thermal power plants, provided in an embodiment of the present invention. Detailed Implementation

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to 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.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention; the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "joined" should be interpreted broadly, for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Combination Figure 1 As shown, this embodiment provides an integrated energy system for photovoltaic green hydrogen production and storage in conjunction with peak shaving in thermal power plants, including a thermal power generation system, a photovoltaic array, an electrolyzer, a fuel cell, a compressor, an energy storage system, a power grid, a hydrogen refueling machine, and a heat system; wherein, the thermal power generation system includes a coal-fired boiler, a steam turbine, and a generator; the energy storage system includes energy storage batteries, hydrogen storage cylinders, and thermal storage tanks; the heat system includes a primary grid, a heat exchange station, a secondary grid, and heat users.

[0031] Specifically, the power output of the photovoltaic array is divided into two paths, which are connected to the power input of the energy storage battery and the electrolytic cell, respectively.

[0032] The energy storage battery has two power input terminals, which are connected to the power output terminals of the photovoltaic array and the generator, respectively; the energy output terminals of the energy storage battery have two power output terminals, which are connected to the power input terminals of the power grid and the electrolytic cell, respectively.

[0033] The electrolyzer has three power input terminals, which are connected to the power output terminals of the photovoltaic array, energy storage battery, and generator, respectively. The hydrogen output terminal of the electrolyzer is connected to the hydrogen input terminal of the compressor, and the hydrogen output terminal of the compressor is connected to the hydrogen input terminal of the hydrogen storage tank to store the produced hydrogen in the hydrogen storage tank. The oxygen output terminal of the electrolyzer is connected to the oxygen input terminal of the coal-fired boiler.

[0034] The power grid's input terminals are divided into three paths, which are respectively connected to the output terminals of energy storage batteries, fuel cells, and generators.

[0035] The thermal energy output end of the coal-fired boiler is connected to the thermal energy input end of the steam turbine. The mechanical energy output by the steam turbine provides power for the generator to generate electricity. The generator output end is divided into three electrical energy output ends and one thermal energy output end. The three electrical energy output ends of the generator are respectively connected to the power grid, the electrolytic cell and the energy storage battery's electrical energy input ends. The one thermal energy output end of the generator is connected to the thermal energy input end of the thermal storage tank.

[0036] The hydrogen storage tank has three hydrogen output channels, which are connected to the hydrogen input channels of the fuel cell, generator, and hydrogen refueling machine, respectively.

[0037] The thermal energy input end of the thermal storage tank is divided into five channels, which are respectively connected to the thermal energy output ends of the coal-fired boiler, steam turbine, electrolytic cell, fuel cell and generator; the thermal energy output end of the thermal storage tank is connected to the thermal energy input end of the primary network, the thermal energy output end of the primary network is connected to the thermal energy input end of the heat exchange station, the thermal energy output end of the heat exchange station is connected to the thermal energy input end of the secondary network, and the thermal energy output end of the secondary network is connected to the thermal energy input end of the heat user.

[0038] Preferably, the electrolyzer in this embodiment is an alkaline electrolyzer, and the chemical reaction in the electrolyzer is: 2H₂O → 2H₂ + O₂. The fuel cell is a low-temperature proton exchange membrane fuel cell, and the chemical reaction in the fuel cell is: O₂ + 2H₂ → 2H₂O.

[0039] This embodiment also provides an operation method for the above-mentioned integrated energy system, including a peak shaving process for thermal power plants, a hydrogen processing process, and a thermal energy processing process.

[0040] Peak shaving process in thermal power plants:

[0041] The photovoltaic array generates electricity during sunshine hours, sending one path to charge the energy storage battery and another path to the electrolyzer to electrolyze water to produce hydrogen and oxygen. The produced hydrogen is stored in a hydrogen storage tank, and the produced oxygen is sent to the coal-fired boiler to create an oxygen-rich combustion atmosphere and play a role in combustion.

[0042] When the grid load increases, the power generation of thermal power plants cannot meet the load demand. Hydrogen storage tanks provide hydrogen to fuel cells for power generation. If the power generation of thermal power plants and fuel cells still cannot meet the grid load demand, energy storage batteries serve as auxiliary power sources and work together with fuel cells to generate electricity to compensate the grid.

[0043] When the grid load decreases, the power generation of thermal power plants exceeds the load demand. The surplus electricity is preferentially delivered to charge the energy storage battery. If the energy storage battery is already fully charged, it is delivered to the electrolyzer to produce hydrogen, so as to convert electrical energy into hydrogen energy for storage to meet the hydrogen demand.

[0044] Hydrogen processing flow:

[0045] The hydrogen in the storage tank is used for three purposes: first, for fuel cell power generation; second, for hydrogen refueling stations to provide fuel for fuel cell vehicles and for transporting coal to power plants; and third, as a cooling medium for generators. Hydrogen is injected into the generator from the storage tank through connecting pipes, and flows in the generator chamber using fans at both ends of the rotor to cool the stator windings, rotor windings, and iron core. After being cooled by hydrogen coolers located at the four corners of the stator frame, it is circulated again. If there is a hydrogen leak in the generator, or if other factors cause low hydrogen pressure, hydrogen can be replenished through the connecting pipes. If the hydrogen purity is not up to standard, the hydrogen is discharged from the generator to the atmosphere, and then high-purity hydrogen is re-injected. The hydrogen content in the storage tank must be higher than the fixed amount of hydrogen required for generator replenishment.

[0046] Thermal energy treatment process:

[0047] The heat medium is used to recover the high-temperature flue gas waste heat from the coal-fired boiler, the high-temperature exhaust steam waste heat from the steam turbine, and the heat generated during the operation of the generator, electrolyzer, and fuel cell, and store them in the heat storage tank. The heat energy stored in the heat medium in the heat storage tank can be successively transported to the heat user end through the primary network, heat exchange station, and secondary network to achieve dual supply of heating and cooling, and meet the living and production needs of the residents in the plant area.

[0048] Cooling process: The heat medium is taken out from the heat storage tank and sent to the primary network. Then, it is converted into cold water by the chiller in the heat exchange station and transferred to the secondary network. Finally, it is delivered to the heat users through the secondary network. The heat users then absorb the indoor heat through the cooling equipment.

[0049] Heating process: The heat medium is taken out from the heat storage tank and sent to the primary network. Then, the heat is transferred to the secondary network through the heat exchanger of the heat exchange station. Finally, the heat is delivered to the heat users through the secondary network, and the heat users then dissipate the heat into the room through the heating equipment.

[0050] In summary, the integrated energy system of this embodiment has the following advantages:

[0051] (1) It integrates thermal power generation, photovoltaic power generation, fuel cell power generation, water electrolysis for hydrogen production, energy storage, hydrogen storage, and thermal storage. When the grid load fluctuates, the fuel cell and energy storage battery, individually or in combination, assist the thermal power unit to compensate the grid, while the energy storage battery and electrolyzer absorb the excess electrical energy of the thermal power unit. Among them, the fuel cell has a slow dynamic response and cannot output instantaneous high power, so it mainly plays the role of peak shaving, while the energy storage battery has high energy density and fast response speed, and can achieve transient high power output, so it mainly plays the role of frequency regulation. First, due to the instability and intermittency of photovoltaic power generation, and since the photovoltaic array in the system is not connected to the grid, this system can "store and use" energy simultaneously or "store first and then use" without increasing grid fluctuations, thereby achieving "peak shaving and valley filling," ensuring stable and reliable power supply, effectively solving the problem of poor peak-shaving capacity of thermal power units, improving the flexibility of thermal power units, and enhancing the system's renewable energy absorption capacity. Second, the system involves solar energy, hydrogen energy, electricity, and heat energy, realizing the complementarity and supply-demand coordination of multiple energy sources, effectively improving the overall energy efficiency of the system, and simultaneously meeting the needs for electricity, hydrogen, and heat. Then, the electricity generated by photovoltaic power is used to electrolyze water in an electrolyzer to produce hydrogen, which is then stored. This process of using renewable energy (solar energy) to produce green hydrogen has zero carbon emissions, realizing the utilization of clean energy.

[0052] (2) The heat medium (hot water or steam) is used to recover the high-temperature flue gas waste heat of the coal-fired boiler, the high-temperature exhaust steam waste heat of the steam turbine, and the heat generated during the operation of the generator, electrolytic cell and fuel cell through the heat exchanger, and stored in the heat storage tank. The heat energy stored in the heat medium in the heat storage tank is transported to the heat user end through the primary network, heat exchange station (heat exchanger and chiller) and secondary network. This process not only recovers and utilizes the waste heat from thermal power, electrolytic cell and fuel cell, improves the overall energy efficiency of the system and reduces energy waste, but also realizes the dual supply of heating and cooling over a large area, has flexible adjustment capability, and can well meet the living and production needs of the residents in the plant area.

[0053] (3) Hydrogen produced by water electrolysis can be used in three ways: first, for fuel cell power generation; second, for hydrogen refueling stations to provide fuel for fuel cell vehicles; third, for transporting coal to thermal power plants; and finally, for providing cooling medium for generators. The oxygen produced during the water electrolysis process is introduced into the coal-fired boiler to create an oxygen-rich combustion atmosphere and play a role in combustion.

[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 and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A comprehensive energy system integrating photovoltaic green hydrogen production and storage with peak shaving by thermal power plants, characterized in that, It includes thermal power generation systems, photovoltaic arrays, electrolyzers, fuel cells, compressors, energy storage systems, power grids, hydrogen refueling machines, and heat systems; among which, thermal power generation systems include coal-fired boilers, steam turbines, and generators; energy storage systems include energy storage batteries, hydrogen storage cylinders, and thermal storage tanks; and heat systems include primary grids, heat exchange stations, secondary grids, and heat users. The power output terminal of the photovoltaic array is divided into two paths, which are respectively connected to the power input terminals of the energy storage battery and the electrolytic cell; The energy input terminal of the energy storage battery is divided into two paths, which are respectively connected to the energy output terminal of the photovoltaic array and the energy output terminal of the generator; the energy output terminal of the energy storage battery is divided into two paths, which are respectively connected to the energy input terminal of the power grid and the energy input terminal of the electrolytic cell. The electrolyzer has three power input terminals, which are respectively connected to the power output terminals of the photovoltaic array, the energy storage battery, and the generator; the hydrogen output terminal of the electrolyzer is connected to the hydrogen input terminal of the compressor, and the hydrogen output terminal of the compressor is connected to the hydrogen input terminal of the hydrogen storage cylinder to store the produced hydrogen in the hydrogen storage cylinder; the oxygen output terminal of the electrolyzer is connected to the oxygen input terminal of the coal-fired boiler. The power grid's power input terminal is divided into three paths, which are respectively connected to the power output terminals of the energy storage battery, the fuel cell, and the generator; The thermal energy output terminal of the coal-fired boiler is connected to the thermal energy input terminal of the steam turbine, and the mechanical energy output by the steam turbine provides power for the generator to generate electricity; the output terminal of the generator is divided into three electrical energy output terminals and one thermal energy output terminal. The three electrical energy output terminals of the generator are respectively connected to the electrical energy input terminals of the power grid, the electrolytic cell and the energy storage battery, and the one thermal energy output terminal of the generator is connected to the thermal energy input terminal of the thermal storage tank. The hydrogen outlet of the hydrogen storage cylinder is divided into three paths, which are respectively connected to the hydrogen input of the fuel cell, the generator, and the hydrogen refueling machine. The thermal energy input terminal of the thermal storage tank is divided into five channels, which are respectively connected to the thermal energy output terminals of the coal-fired boiler, the steam turbine, the electrolytic cell, the fuel cell, and the generator. The thermal energy output terminal of the thermal storage tank is connected to the thermal energy input terminal of the primary network, the thermal energy output terminal of the primary network is connected to the thermal energy input terminal of the heat exchange station, the thermal energy output terminal of the heat exchange station is connected to the thermal energy input terminal of the secondary network, and the thermal energy output terminal of the secondary network is connected to the thermal energy input terminal of the heat user.

2. A method for operating an integrated energy system as described in claim 1, characterized in that, Including peak shaving processes in thermal power plants: The photovoltaic array generates electricity during sunshine hours, sending one path to charge the energy storage battery and another path to the electrolyzer to electrolyze water to produce hydrogen and oxygen. The produced hydrogen is stored in a hydrogen storage tank, and the produced oxygen is sent to the coal-fired boiler to create an oxygen-rich combustion atmosphere and play a role in combustion. When the grid load increases, the power generation of thermal power plants cannot meet the load demand. Hydrogen storage tanks provide hydrogen to fuel cells for power generation. If the power generation of thermal power plants and fuel cells still cannot meet the grid load demand, energy storage batteries serve as auxiliary power sources and work together with fuel cells to generate electricity to compensate the grid. When the grid load decreases, the power generation of thermal power plants exceeds the load demand. The surplus electricity is preferentially delivered to charge the energy storage batteries. If the energy storage batteries are already fully charged, they are delivered to the electrolyzer to produce hydrogen, so as to convert electrical energy into hydrogen energy for storage to meet the demand for hydrogen.

3. The method for operating the integrated energy system according to claim 2, characterized in that, It also includes heat energy processing: The heat medium is used to recover the high-temperature flue gas waste heat from the coal-fired boiler, the high-temperature exhaust steam waste heat from the steam turbine, and the heat generated during the operation of the generator, electrolyzer, and fuel cell, and store them in the heat storage tank. The heat energy stored in the heat medium in the heat storage tank can be successively transported to the heat user end through the primary network, heat exchange station, and secondary network to achieve dual supply of heating and cooling, and meet the living and production needs of the residents in the plant area. Cooling process: The heat medium is taken out from the heat storage tank and sent to the primary network. Then, it is converted into cold water by the chiller in the heat exchange station and transferred to the secondary network. Finally, it is delivered to the heat users through the secondary network. The heat users then absorb the indoor heat through the cooling equipment. Heating process: The heat medium is taken out from the heat storage tank and sent to the primary network. Then, the heat is transferred to the secondary network through the heat exchanger of the heat exchange station. Finally, the heat is delivered to the heat users through the secondary network, and the heat users then dissipate the heat into the room through the heating equipment.

4. The method for operating the integrated energy system according to claim 2, characterized in that, It also includes hydrogen processing procedures: The hydrogen in the storage tank is used for three purposes: first, for fuel cell power generation; second, for hydrogen refueling stations to provide fuel for fuel cell vehicles and for transporting coal to thermal power plants; and finally, for providing a cooling medium for generators. Hydrogen is injected into the generator from the storage tank through connecting pipes, and flows in the generator chamber by the fans at both ends of the rotor to cool the stator windings, rotor windings and iron core. After being cooled by hydrogen coolers set at the four corners of the stator frame, it is circulated again. If the generator leaks hydrogen or other factors cause low hydrogen pressure, hydrogen can be replenished through the connecting pipeline. If the hydrogen purity is not up to standard, the hydrogen should be discharged from the generator to the atmosphere and then high-purity hydrogen should be re-injected. The hydrogen content in the hydrogen storage cylinder must be higher than the fixed amount of hydrogen required to replenish the generator.

5. The operation method of the integrated energy system according to claim 2, characterized in that, The electrolytic cell is an alkaline electrolytic cell, and the chemical reaction in the electrolytic cell is: 2H2O→2H2+O2.

6. The method for operating the integrated energy system according to claim 2, characterized in that, The fuel cell is a low-temperature proton exchange membrane fuel cell, and the chemical reaction in the fuel cell is: O2 + 2H2 → 2H2O.

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