A photo-thermal coupling hydrogen energy energy storage peak shaving power generation system and its operation method

Abstract

The present invention discloses a photo-thermal coupled hydrogen energy storage peak shaving power generation system and its operation method. The system includes a photo-thermal collector system, a renewable energy power generation system, an electrolytic hydrogen production system, a thermochemical energy storage system, a fuel cell system, a heat storage tank, a turbine unit, a condenser and a heat exchange system; the power output end of the renewable energy power generation system is connected to the electrolytic hydrogen production system, the electrolytic hydrogen production system is connected to the chemical energy storage system, the chemical energy storage system is connected to the heat storage tank, the heat storage tank is connected to the working medium outlet and the working medium inlet of the photo-thermal collector system, the heat storage tank is connected to the hot side inlet and outlet of the heat exchange system, the outlet of the heat exchange system is connected to the turbine unit, and the exhaust port of the turbine unit is sequentially connected to the condenser and the heat exchange system. By using the abandoned photovoltaic power to produce hydrogen, store hydrogen, and store heat in the heat storage tank of the photo-thermal system, and by staggering the power generation of photovoltaic, photo-thermal and fuel cells, the utilization of abandoned power, system peak shaving and stable power output are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage, and particularly relates to a solar-thermal coupled hydrogen energy storage peak shaving power generation system and an operation method thereof. Background Art

[0002] As an important link closely related to users in the process of hydrogen energy utilization, hydrogen storage research will be of great significance. Although traditional high-pressure compression hydrogen storage and cryogenic liquefaction hydrogen storage technologies are convenient and mature, they also bring various problems such as large volume and potential safety hazards. Therefore, research institutions around the world are committed to developing new hydrogen storage technologies and corresponding hydrogen storage systems.

[0003] Hydrogen storage technology based on the reversible hydrogen absorption and desorption process of metal hydrides at different temperatures has attracted more and more attention in recent years. This technology is safer than high-pressure hydrogen storage technology, and its volumetric energy density of hydrogen storage is comparable to that of liquid hydrogen. Although the hydrogen storage mass fraction of most metal hydrides is currently still less than 5.0%, with the development of a large number of hydrogen storage materials, the hydrogen storage density of this technology has been continuously improved.

[0004] When a thermochemical energy storage system is combined with a fuel cell, metal hydrides generate hydrogen during heat storage, and there is still a problem of hydrogen storage. And when releasing heat, hydrogen is consumed, reducing the overall work capacity of the system. Therefore, a single system and application scenario cannot completely solve the energy storage problem. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a solar-thermal coupled hydrogen energy storage peak shaving power generation system, which uses photovoltaic abandoned electricity to produce hydrogen, store hydrogen, and store heat in the heat storage tank of the solar-thermal collection system. Photovoltaic, solar-thermal and fuel cells generate electricity during off-peak periods, realizing the utilization of abandoned electricity, system peak shaving and stable power output.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: a solar-thermal coupled hydrogen energy storage peak shaving power generation system, including a solar-thermal collection system, a renewable energy power generation system, an electrolytic hydrogen production system, a thermochemical energy storage system, a fuel cell system, a heat storage tank, a turbine unit, a condenser and a heat exchange system; the power output end of the renewable energy power generation system is connected to the electrolytic hydrogen production system, the electrolytic hydrogen production system is connected to the thermochemical energy storage system, the thermochemical energy storage system is connected to the heat storage tank, the heat storage tank is connected to the working medium outlet and the working medium inlet of the solar-thermal collection system, the heat storage tank is connected to the hot side inlet and the hot side outlet of the heat exchange system, the cold side outlet of the heat exchange system is connected to the turbine unit, the turbine unit is connected to the generator, and the exhaust port of the turbine unit is sequentially connected to the condenser and the cold side of the heat exchange system.

[0007] The solar-thermal collection system can be a tower-type, trough-type, linear Fresnel or dish-type solar-thermal collection system.

[0008] The renewable energy power generation system is a photovoltaic power generation system, a wind power generation system or a hydraulic power generation system.

[0009] The electrolytic hydrogen production system is a proton exchange membrane water electrolysis, alkaline water electrolysis or solid oxide water electrolysis hydrogen production system.

[0010] The thermochemical energy storage system is a metal hydride thermochemical energy storage, ammonia energy storage or organic matter energy storage system.

[0011] The high-temperature storage tank adopts solid heat storage, phase change heat storage, molten salt heat storage or heat transfer oil heat storage.

[0012] The molten salt and heat transfer oil heat storage system adopts double-tank or multi-tank storage. When using double-tank storage, the heat storage tank includes a high-temperature storage tank and a low-temperature storage tank. The thermochemical energy storage system is respectively connected to the high-temperature storage tank and the low-temperature storage tank. The high-temperature storage tank and the low-temperature storage tank are respectively connected to the working medium outlet and the working medium inlet of the solar thermal collector system, and the high-temperature storage tank and the low-temperature storage tank are connected to the hot side inlet and the hot side outlet of the heat exchange system.

[0013] The working medium of the turbine unit can be water and steam, or supercritical carbon dioxide.

[0014] The output end of the turbine unit is connected to the generator or connected to the feed water pump through a speed change device.

[0015] Based on the operation method of the solar thermal coupling hydrogen energy storage peak shaving power generation system described in the present invention, during the large power generation period of the renewable energy power generation system, the abandoned electricity is sent into the electrolytic hydrogen production system to generate hydrogen, and then the hydrogen is sent into the thermochemical energy storage system. The heat released after the reaction is stored in the heat storage tank. The hydrogen after the reaction is stored in the thermochemical energy storage system in the form of solid compounds or liquid compounds. At the same time, the heat storage tank also receives heat from the solar thermal collector system. This part of the heat generates steam through the heat exchange system and then is sent into the turbine unit to do work and drive the generator to generate electricity. During the low power generation period of the photovoltaic power generation system, the heat in the heat storage tank is sent into the thermochemical energy storage system for heat exchange and then recovered. The hydrogen generated after the reaction in the thermochemical energy storage system is sent into the fuel cell system to generate electricity to supplement the insufficient power generation of the renewable energy power generation system.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: The system described in the present invention uses the abandoned electricity of renewable energy to produce hydrogen based on the electrolytic hydrogen production system, and at the same time uses the thermochemical energy storage system to store the prepared hydrogen. It can also use hydrogen and the fuel cell system to generate electricity, eliminating the need for a large-capacity hydrogen storage tank. The heat of the whole process is stored in the heat storage tank of the solar thermal collector system, and a large amount of heat is released through the heat exchange system. The working medium is used to drive the turbine unit to do work and generate electricity or output mechanical energy. It is a technical route for renewable energy utilization, peak shaving power generation of solar thermal and fuel cells, and at the same time realizes the utilization of abandoned electricity, system peak shaving and stable power output. It is a feasible all-renewable energy energy storage power generation system.

[0017] The present invention proposes an operation method for the above system, constructs an operation method of the system under different scenarios, and through the operation mode described in the present invention, the system can meet the dispatching requirements of the power grid system for the system under various working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of an implementable system of the present invention.

[0019] In the figure, 1 - solar thermal collector system, 2 - renewable energy power generation system, 3 - electrolytic hydrogen production system, 4 - thermochemical energy storage system, 5 - fuel cell system, 6 - high-temperature storage tank, 7 - low-temperature storage tank, 8 - steam turbine unit, 9 - condenser, 10 - generator, 11 - heat exchange system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The present invention will be described in detail below with reference to the accompanying drawings.

[0021] Reference Figure 1 , the present invention provides a solar thermal-coupled hydrogen energy storage peak shaving power generation system, including a solar thermal collector system 1, a renewable energy power generation system 2, an electrolytic hydrogen production system 3, a thermochemical energy storage system 4, a fuel cell system 5, a heat storage tank, a steam turbine unit 8, a condenser 9 and a heat exchange system 11; the power output end of the renewable energy power generation system 2 is connected to the electrolytic hydrogen production system 3, the electrolytic hydrogen production system 3 is connected to the thermochemical energy storage system 4, the thermochemical energy storage system 4 is connected to the heat storage tank, the heat storage tank is connected to the working medium outlet and the working medium inlet of the solar thermal collector system 1, the heat storage tank is connected to the hot side inlet and the hot side outlet of the heat exchange system 11, the cold side outlet of the heat exchange system 11 is connected to the steam turbine unit 8, and the exhaust port of the steam turbine unit 8 is sequentially connected to the condenser 9 and the cold side of the heat exchange system 11.

[0022] As a preferred embodiment, the steam turbine unit 8 is coaxially connected to a generator 10 to provide power when the power demand increases.

[0023] Preferably, the heat storage tank adopts a molten salt double storage tank, that is, the heat storage tank includes a high-temperature storage tank 6 and a low-temperature storage tank 7, the thermochemical energy storage system 4 is respectively connected to the high-temperature storage tank 6 and the low-temperature storage tank 7, the high-temperature storage tank 6 and the low-temperature storage tank 7 are respectively connected to the working medium outlet and the working medium inlet of the solar thermal collector system 1, and the high-temperature storage tank 6 and the low-temperature storage tank 7 are connected to the hot side inlet and the hot side outlet of the heat exchange system 11; of course, the heat storage working medium can also be heat-conducting oil.

[0024] The solar thermal collector system 1 can adopt a tower-type, trough-type, linear Fresnel or dish-type solar thermal collector system.

[0025] The renewable energy power generation system 2 is a photovoltaic power generation system, a wind power generation system or a hydraulic power generation system.

[0026] The electrolytic hydrogen production system 3 can adopt a proton exchange membrane water electrolysis, alkaline water electrolysis or solid oxide water electrolysis hydrogen production system.

[0027] The thermochemical energy storage system 4 can adopt a metal hydride thermochemical energy storage, ammonia energy storage or organic matter energy storage system.

[0028] The high-temperature storage tank 6 can adopt solid heat storage, phase change heat storage, molten salt heat storage or heat transfer oil heat storage.

[0029] The working medium of the turbine unit 8 can be water and steam, or supercritical carbon dioxide.

[0030] The output end of the turbine unit 8 is connected to the generator 10 or is connected to the feed water pump through a speed change device.

[0031] Based on the operation method of the solar thermal coupling hydrogen energy storage peak shaving power generation system described in the present invention, during the large power generation period of the renewable energy power generation system 2, the abandoned electricity is sent into the electrolytic hydrogen production system 3 to generate hydrogen, and then the hydrogen is sent into the thermochemical energy storage system 4. The heat released after the reaction is stored in the heat storage tank, and the hydrogen after the reaction is stored in the thermochemical energy storage system 4 in the form of solid compounds or liquid compounds. At the same time, the heat storage tank also receives the heat from the solar thermal collection system 1. This part of the heat generates steam through the heat exchange system 11 and then is sent into the turbine unit 8 to do work and drive the generator 10 to generate electricity. During the low power generation period of the photovoltaic power generation system 2, the heat in the heat storage tank is sent into the thermochemical energy storage system 4 for heat exchange and then recovered. The hydrogen generated after the reaction in the thermochemical energy storage system is sent into the fuel cell system 5 to generate electricity to supplement the insufficient power generation of the renewable energy power generation system 2.

[0032] Preferably, the renewable energy adopts a photovoltaic power generation system, the solar thermal collection system adopts a solar thermal molten salt heat storage system, and the thermochemical energy storage system adopts a thermochemical hydrogen storage system.

[0033] Adopt the photovoltaic power generation system and the solar thermal collection system to operate independently: When the output of the photovoltaic power generation system and the output of the solar thermal collection system sum is less than the grid load limit , and the energy storage capacity of the thermochemical hydrogen storage system = 0, the photovoltaic power generation system and the solar thermal collection system operate independently to generate electricity, and the total grid-connected electricity .

[0034] The photovoltaic power generation system, the solar thermal collection system and the thermochemical hydrogen storage system operate together: When the output of the photovoltaic power generation system is greater than the grid load limit , the solar thermal collection system does not generate electricity but only stores energy. The thermochemical hydrogen storage system uses the abandoned electricity of the photovoltaic power generation system to store hydrogen, and the amount of abandoned electricity is , and the grid-connected electricity .

[0035] The photovoltaic power generation system, the solar thermal collector system and the thermochemical hydrogen storage system operate together: When the output of the photovoltaic power generation system is less than the grid load limit and the minimum output of the solar thermal collector system sum is greater than the grid load limit the photovoltaic power generation system generates electricity, the solar thermal collector system operates at the minimum output, the system's curtailed electricity is used for energy storage in the thermochemical hydrogen storage system, and the grid-connected electricity .

[0036] The photovoltaic power generation system, the solar thermal collector system and the fuel cell system 5 operate together: When the photovoltaic power generation system and the output of the solar thermal collector system sum is less than the grid load limit , and the stored energy of the thermochemical hydrogen storage system > 0, the photovoltaic power generation system, the solar thermal collector system and the fuel cell system 5 operate independently to generate electricity, and the total grid-connected electricity , is the electricity generated by the independent operation of the fuel cell system 5.

[0037] When the light resource conditions are insufficient, the photovoltaic power generation system does not generate electricity, and the solar thermal collector system and the fuel cell system 5 operate together to generate electricity: The solar thermal molten salt energy storage system has energy storage, the thermochemical hydrogen storage system has energy storage, the sum of the output of the solar thermal collector system and the output of the fuel cell system 5 is less than the grid load limit, the photovoltaic power generation system does not generate electricity, the solar thermal collector system generates electricity, and the fuel cell system 5 generates electricity, and the total grid-connected electricity .

[0038] When the light resource conditions are insufficient, the photovoltaic power generation system and the solar thermal collector system do not generate electricity, and the fuel cell system 5 operates to generate electricity. The solar thermal molten salt energy storage system has energy storage but is not sufficient to support the simultaneous power generation of the solar thermal and fuel cell systems 5, and the thermochemical hydrogen storage system has energy storage. When the output of the fuel cell system 5 is less than the grid load limit, the photovoltaic power generation system does not generate electricity, the solar thermal collector system does not generate electricity, and the fuel cell system 5 generates electricity, and the total grid-connected electricity .

[0039] Example 1: The solar thermal collector system 1 adopts a tower-type collector system, the renewable energy power generation system 2 adopts a photovoltaic power generation system, the electrolytic hydrogen production system 3 adopts a proton exchange membrane electrolytic water hydrogen production system, the thermochemical energy storage system 4 adopts a MgH2 thermochemical energy storage system, the fuel cell system 5, the high-temperature storage tank 6 uses molten salt for heat storage, and the steam turbine unit 8 uses steam as the working medium.

[0040] Example 2: The solar thermal collector system 1 adopts a trough collector system, the renewable energy power generation system 2 adopts a wind power generation system, the electrolytic hydrogen production system 3 adopts an alkaline water electrolysis hydrogen production system, the thermochemical energy storage system 4 adopts an ammonia-based thermochemical energy storage system, the fuel cell system 5, the high-temperature storage tank 6 uses heat transfer oil for heat storage, and the steam turbine unit 8 uses steam as the working medium.

[0041] Example 3: The solar thermal collector system 1 adopts a trough collector system, the renewable energy power generation system 2 adopts a wind power generation system, the electrolytic hydrogen production system 3 adopts a solid oxide water electrolysis hydrogen production system, the thermochemical energy storage system 4 adopts an organic working fluid thermochemical energy storage system, the fuel cell system 5, the high-temperature storage tank 6 uses solids, and the steam turbine unit 8 uses supercritical carbon dioxide as the working medium.

Claims

1. A method for operating a photo-thermal coupled hydrogen energy storage peak shaving power generation system, characterized in that The above-mentioned photo-thermal coupled hydrogen energy storage peak shaving power generation system includes a photo-thermal collection system (1), a renewable energy power generation system (2), an electrolytic hydrogen production system (3), a thermochemical energy storage system (4), a fuel cell system (5), a heat storage tank, a turbine unit (8), a condenser (9) and a heat exchange system (11); the power output end of the renewable energy power generation system (2) is connected to the electrolytic hydrogen production system (3), the electrolytic hydrogen production system (3) is connected to the thermochemical energy storage system (4), the thermochemical energy storage system (4) is connected to the heat storage tank, the heat storage tank is connected to the working fluid outlet and the working fluid inlet of the photo-thermal collection system (1), the heat storage tank is connected to the hot side inlet and the hot side outlet of the heat exchange system (11), the cold side outlet of the heat exchange system (11) is connected to the turbine unit (8), the turbine unit (8) is connected to the generator (10), and the exhaust port of the turbine unit (8) is sequentially connected to the condenser (9) and the cold side of the heat exchange system (11); during the large power generation period of the renewable energy power generation system (2), the abandoned electricity is sent into the electrolytic hydrogen production system (3) to generate hydrogen, and then the heat released after the reaction in the thermochemical energy storage system (4) is stored in the heat storage tank. The hydrogen after the reaction is stored in the thermochemical energy storage system (4) in the form of a solid compound or a liquid compound. At the same time, the heat storage tank also receives the heat from the photo-thermal collection system (1). This part of the heat generates steam through the heat exchange system (11) and is sent into the turbine unit (8) to do work, and drives the generator (10) to generate electricity. When the renewable energy power generation system (2) is a photovoltaic power generation system, during the low power generation period of the photovoltaic power generation system (2), the heat in the heat storage tank is sent into the thermochemical energy storage system (4) for heat exchange and recovery. The hydrogen generated after the reaction in the thermochemical energy storage system (4) is sent into the fuel cell system (5) to generate electricity to supplement the insufficient power generation of the renewable energy power generation system (2). It operates based on the following modes: independent power generation by the photovoltaic power generation system and the photo-thermal collection system; power generation by the photovoltaic power generation system, operation of the photo-thermal collection system and the thermochemical hydrogen storage system; joint operation of the photovoltaic power generation system, power generation by the photo-thermal collection system and the thermochemical energy storage system; power generation by the photovoltaic power generation system, power generation by the photo-thermal collection system, and power generation by the fuel cell system; no power generation by the photovoltaic power generation system, power generation by the photo-thermal collection system, and power generation by the fuel cell system; no power generation by the photovoltaic power generation system and the photo-thermal collection system, and power generation by the fuel cell system.

2. The operating method of the photo-thermal coupled hydrogen energy storage peak shaving power generation system according to claim 1, characterized in that, The photo-thermal collection system (1) is a tower-type, trough-type, linear Fresnel or dish-type photo-thermal collection system.

3. The operating method of the photo-thermal coupling hydrogen energy storage peak shaving power generation system according to claim 1, characterized in that, The renewable energy power generation system (2) is a photovoltaic power generation system, a wind power generation system or a hydraulic power generation system.

4. The operating method of the photo-thermal coupling hydrogen energy storage peak shaving power generation system according to claim 1, characterized in that, The electrolytic hydrogen production system (3) is a proton exchange membrane water electrolysis, alkaline water electrolysis or solid oxide water electrolysis hydrogen production system.

5. The operating method of the photo-thermal coupled hydrogen energy storage peak shaving power generation system according to claim 1, wherein, The thermochemical energy storage system (4) is a metal hydride thermochemical energy storage, ammonia energy storage or organic matter energy storage system.

6. The operation method of the photo-thermal coupled hydrogen energy storage peak shaving power generation system according to claim 1, characterized in that, The high-temperature storage tank (6) adopts solid heat storage, phase change heat storage, molten salt heat storage or heat transfer oil heat storage.

7. The operating method of the photo-thermal coupled hydrogen energy storage peak shaving power generation system according to claim 6, characterized in that, The molten salt and heat transfer oil thermal energy storage system adopts double-tank or multi-tank storage. When double-tank storage is adopted, the heat storage tank includes a high-temperature storage tank (6) and a low-temperature storage tank (7). The thermochemical energy storage system (4) is respectively connected to the high-temperature storage tank (6) and the low-temperature storage tank (7). The high-temperature storage tank (6) and the low-temperature storage tank (7) are respectively connected to the working medium outlet and the working medium inlet of the solar thermal collector system (1). The high-temperature storage tank (6) and the low-temperature storage tank (7) are connected to the hot-side inlet and the hot-side outlet of the heat exchange system (11).

8. The operating method of the photo-thermal coupled hydrogen energy storage peak shaving power generation system according to claim 1, characterized in that The working medium of the turbine unit (8) is water, steam or supercritical carbon dioxide.

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