A wind-solar-hydrogen storage integrated comprehensive energy utilization system and method thereof

Abstract

This invention relates to the field of energy supply technology, and particularly to an integrated wind-solar-hydrogen-storage comprehensive energy utilization system and method. The system includes photovoltaic power generation equipment, wind power generation equipment, energy conversion and storage equipment, power conversion equipment, a balance of power (BOP) system, and material storage equipment. The energy conversion and storage equipment includes an SOEC electrolyzer, a PEMFC fuel cell, and a battery. The power conversion equipment includes an AC-DC converter and a DC-AC converter. During the day, when solar resources are abundant and wind resources are relatively scarce, excess photovoltaic power, besides supplying users, is used for hydrogen electrolysis and storage or for battery storage. Wind power is used to supply the user side and the BOP system. At night, when solar resources are scarce and wind resources are abundant, the SOEC is only in a heat preservation state. Wind power is supplied to the user side and for SOEC heat preservation, and excess wind power is stored in the battery. This invention achieves multi-level energy utilization from high to low energy levels, while ensuring rapid response on the user side, and possesses strong flexibility and adjustability.

Description

Technical Field

[0001] This invention relates to the field of energy supply technology, and in particular to an integrated energy utilization system and method that combines wind, solar, hydrogen, and storage. Background Technology

[0002] In the next decade, my country's total installed capacity of wind and solar power will reach over 1200 GW, and non-fossil energy will account for about 25% of primary energy consumption. At that time, the grid connection and consumption of these renewable energy sources will become urgent issues. Therefore, the comprehensive utilization of wind and solar power has become a research direction in academia.

[0003] Patent CN102851682B discloses a wind power high-temperature electrolysis hydrogen production system and method. When the AC voltage output by the AC power source drops significantly, an auxiliary thermal storage unit supplies the stored energy to a high-temperature superheated steam preparation unit, enabling the unit to stably output superheated steam. However, this thermal storage solution for addressing wind power voltage fluctuations suffers from low electrical-to-thermal energy conversion efficiency and limited compensation for voltage drops, making it unsuitable for adapting to large-scale fluctuations in wind power.

[0004] Patent CN109882737A proposes a system and process for integrated gas-electricity-hydrogen supply using new energy sources such as LNG, wind, and solar power. It employs liquefied natural gas as the start-up fuel for SOFCs, providing a stable power and heat source, and forms a coupled power system with on-site distributed wind and solar power generation equipment. The system ultimately utilizes SOEC electrolysis of water to produce hydrogen, representing a highly safe fuel cell electrolyzer system and its operating method. However, from the perspective of wind, solar, and hydrogen storage, the proposed integrated gas-electricity-hydrogen supply system requires LNG as fuel, and the description of the heat exchange unit in the system is rather vague.

[0005] Patent CN112993347A proposes an energy device and power generation system based on solid-state oxide batteries (SOC batteries), employing a combined SOFC-SOEC hydrogen energy storage and power generation system. It outlines a simple operation method: when wind and solar power generation meets user needs, SOFC is used in real-time to stabilize power quality and supply the user; when there is surplus wind and solar power, surplus electricity is used in real-time to produce hydrogen (or co-decomposition gas), which is then stored or its generated electricity is connected to the grid in real-time without impacting the power grid; when wind and solar power generation is insufficient, the stored hydrogen (or co-decomposition gas) is used as fuel to power the SOFC, meeting user needs. However, the proposed SOC battery energy device only involves material transfer, relying on simple chemical-to-electrical energy conversion for user-side energy replenishment. It does not include a complete thermal design for the SOC system, nor does it consider the impact of primary energy fluctuations on the system.

[0006] Patent CN113278992B discloses a steam turbocharged fuel cell electrolyzer system. This system replaces the high-temperature circulating pump and ejector with a steam turbocharger, solving the problem of cathode outlet gas recirculation. High-temperature steam mixes with room-temperature hydrogen in the steam turbocharger before entering the SOEC stack, simultaneously improving steam utilization. The proposed steam turbocharged recirculation system, without additional heating after the hydrogen and steam mixture, may struggle to reach the desired inlet temperature of the stack, leading to decreased stack performance and durability. The high-temperature circulating pump recirculation and reheating scheme, however, ensures the gas inlet temperature of the stack. Summary of the Invention

[0007] This invention provides an integrated energy utilization system and method combining wind, solar, hydrogen, and storage, aiming to solve the problems existing in current research on integrated energy systems.

[0008] This invention provides an integrated wind, solar, hydrogen, and storage energy utilization system, comprising a photovoltaic power generation device, a wind power generation device, an energy conversion and storage device, a power conversion device, a balance of power generation (BOP) device, and a material storage device. The energy conversion and storage device includes a solid oxide fuel cell, a proton exchange membrane fuel cell, and a battery. The power conversion device includes an AC-DC converter and a DC-AC converter. The photovoltaic power generation device is directly connected to and supplies power to the solid oxide fuel cell. The photovoltaic power generation device is connected to the battery and supplies power to the user side via the DC-AC converter. The wind power generation device is directly connected to and supplies power to both the user side and the BOP device. The wind power generation device supplies power to the battery via the AC-DC converter, and the battery supplies power to the user side via the DC-AC converter. The solid oxide fuel cell is connected to the material storage device via the BOP device to obtain materials for water electrolysis to produce hydrogen. The proton exchange membrane fuel cell is connected to the material storage device via the BOP device to obtain hydrogen and generate electricity from it. The proton exchange membrane fuel cell is connected to the user side via the DC-AC converter.

[0009] As a further improvement of the present invention, the BOP equipment includes a first air compressor, a first compressor, a second compressor, a third compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a condensing heat exchanger, a first electric heater, a second electric heater, a mixing chamber, an evaporator, and a water pump; the material storage equipment includes a water tank and a hydrogen storage tank.

[0010] The anode air inlet structure of the solid oxide fuel electrolyzer is as follows: the anode air inlet of the first air compressor, the anode air inlet of the first heat exchanger, the first electric heater, and the anode air inlet of the solid oxide fuel electrolyzer are connected in sequence through the anode air inlet pipe.

[0011] The cathode air inlet structure of the solid oxide fuel electrolyzer is as follows: a water tank, a water pump, the cathode air inlet end of the fourth heat exchanger, the cathode air inlet end of the condenser heat exchanger, the cathode air inlet end of the fifth heat exchanger, the cathode air inlet end of the second heat exchanger, an evaporator, a mixing chamber, the cathode air inlet end of the third heat exchanger, a second electric heater, and the cathode air inlet of the solid oxide fuel electrolyzer are connected in sequence through the cathode air inlet pipe.

[0012] The anode tail gas outlet structure of the solid oxide fuel electrolyzer is as follows: the anode exhaust port of the solid oxide fuel electrolyzer, the anode exhaust end of the first heat exchanger, the anode exhaust end of the second heat exchanger, and the external environment of the system are connected in sequence through the anode exhaust pipe.

[0013] The cathode exhaust gas structure of the solid oxide fuel electrolyzer is as follows: A cathode exhaust pipe is sequentially connected to the cathode exhaust port of the solid oxide fuel electrolyzer, the cathode exhaust end of the third heat exchanger, the cathode exhaust end of the fourth heat exchanger, the second compressor, the cathode exhaust end of the condensing heat exchanger, the third compressor, the cathode exhaust end of the fifth heat exchanger, and a hydrogen storage tank; the cathode exhaust pipe is also sequentially connected to the cathode exhaust port of the solid oxide fuel electrolyzer, the first compressor, the mixing chamber, and the cathode inlet of the third heat exchanger.

[0014] As a further improvement of the present invention, the BOP device also includes an ejector and a second air compressor. The hydrogen storage tank is introduced into the anode inlet of the proton exchange membrane fuel cell through a pressure reducing valve. The second air compressor is connected to the cathode inlet of the proton exchange membrane fuel cell. One end of the anode outlet of the proton exchange membrane fuel cell is returned through the ejector, and the other end is directly connected to the external environment of the system. The cathode outlet of the proton exchange membrane fuel cell is connected to the external environment of the system.

[0015] As a further improvement of the present invention, the wind power generation equipment is respectively connected to and supplies power to a first air compressor, a first electric heater, a heating module in a solid oxide fuel electrolysis cell, a second electric heater, an evaporator, a water pump, a second compressor, and a third compressor.

[0016] As a further improvement of the present invention, the solid oxide fuel electrolyzer includes an electrolysis unit, a ceramic plate heater, a pressurizing device, and a heat insulation layer. Multiple electrolysis units are stacked and connected to form a fuel cell stack. Ceramic plate heaters are inserted at the top, bottom, and between every two electrolysis units. The heat insulation layer is wrapped around the outside of the fuel cell stack. The pressurizing device is connected to the fuel cell stack. The photovoltaic power generation equipment is connected to and supplies power to the electrolysis unit. The wind power generation equipment is connected to and supplies power to the ceramic plate heater.

[0017] This invention also provides a method for integrated wind, solar, hydrogen, and energy storage utilization, comprising the following steps:

[0018] S1. When solar and wind resources are abundant during the day, the power supply method is as follows:

[0019] The photovoltaic power generation equipment generates electricity for normal use by the user side, and transmits excess photovoltaic electricity to the battery for energy storage, and to the solid oxide fuel electrolyzer for hydrogen production and energy storage; the wind power generation equipment generates electricity for normal use by the user side, and transmits excess wind power to the battery for energy storage through the AC-DC converter, and supplies the BOP equipment; when the photovoltaic power output fluctuates, the battery is adjusted to supplement the power supplied by the photovoltaic power generation equipment.

[0020] S2. When wind resources are abundant at night and solar resources are almost zero, the power supply method is as follows:

[0021] When the solid oxide fuel cell stops electrolysis, the proton exchange membrane fuel cell generates electricity using the stored hydrogen energy. This electricity, combined with the output from the battery, compensates for the energy of the photovoltaic power generation equipment and supplies power to the user side via a DC-AC converter. The wind power generation equipment generates electricity to supply the user side for normal use and supplies excess wind power to the solid oxide fuel cell for insulation.

[0022] As a further improvement of the present invention, the electrolytic hydrogen production and energy storage process in a solid oxide fuel electrolyzer is as follows:

[0023] Anode gas supply: The process gas on the anode side is compressed to 1.01 bar by an air compressor, and then heats up to about 450°C by exchanging heat with the anode tail gas through the first heat exchanger. It is then heated to 650°C by the first electric heater and enters the anode inlet of the solid oxide fuel electrolysis cell.

[0024] Anode exhaust discharge: The high-temperature anode tail gas from the air outlet passes through the first heat exchanger and the second heat exchanger, and after exchanging heat with the anode inlet gas and the cathode inlet gas respectively, it is discharged from the external environment of the system at a temperature not exceeding 120°C.

[0025] Cathode gas supply: The process gas on the cathode side is taken out of the water tank by a water pump, and after passing through the fourth heat exchanger, condenser heat exchanger, and fifth heat exchanger to exchange heat with the cathode outlet tail gas, and after exchanging heat with the second heat exchanger to exchange heat with the anode outlet tail gas for preheating, it enters the evaporator to evaporate into water vapor, mixes with part of the cathode outlet tail gas through the mixing chamber, and then passes through the third heat exchanger to exchange heat with the cathode outlet tail gas and be heated to 400°C. It is then heated to 550°C by the second electric heater and enters the cathode inlet of the solid oxide fuel electrolysis cell.

[0026] Cathode exhaust: The high-temperature exhaust gas at the cathode outlet is partially returned to the mixing chamber by the first compressor to mix with the cathode inlet gas, and the other part is directly cooled to 370°C and 160°C by the third and fourth heat exchangers respectively, then compressed to 15 bar and 340°C by the second compressor, cooled to 160°C by the condenser heat exchanger, then compressed to 35 bar and 360°C by the third compressor, cooled to below 120°C by the fifth heat exchanger, and then entered the hydrogen tank for storage at a pressure of 35 bar.

[0027] As a further improvement of the present invention, the power generation process of the proton exchange membrane fuel cell is as follows:

[0028] The anode inlet of the proton exchange membrane fuel cell is supplied with hydrogen gas through a hydrogen storage tank via a pressure reducing valve at a pressure of 1.4 bar. Air is pressurized to 1.42 bar by a second air compressor and then introduced into the cathode inlet. The energy generated by the reaction of the proton exchange membrane fuel cell is supplied to the user side through a DC-AC converter. The exhaust gas at the anode outlet of the proton exchange membrane fuel cell is returned through an ejector to recover some hydrogen gas, and the exhaust gas at the cathode outlet is directly discharged into the external environment of the system.

[0029] As a further improvement of the present invention, in step S1, the BOP equipment supplied by the wind power generation equipment includes a first air compressor, a first electric heater, a heating module in the solid oxide fuel electrolysis cell, a second electric heater, an evaporator, a water pump, a second compressor, and a third compressor; in step S2, the BOP equipment supplied by the wind power generation equipment is a heating module in the solid oxide fuel electrolysis cell.

[0030] As a further improvement of the present invention, the integrated wind-solar-hydrogen-storage comprehensive energy utilization method further includes the following steps:

[0031] S3. When encountering continuous adverse weather and insufficient wind and solar resources for an extended period, the power supply method is as follows:

[0032] Power is supplied to the user side by the storage battery through a DC-AC converter. When the battery's power is insufficient, the proton exchange membrane fuel cell generates electricity and temporarily supplies power to the user side through the DC-AC converter.

[0033] The beneficial effects of this invention are:

[0034] (1) Compared with the existing wind-solar-hydrogen storage integrated system, this system adopts a combination of SOEC high-temperature electrolysis unit and PEMFC low-temperature fuel cell to realize multi-level utilization of energy from high to low, while ensuring rapid response on the user side.

[0035] (2) The wind-solar-hydrogen storage integrated system takes into account the impact of wind and solar input fluctuations on the electrolysis unit, and uses battery regulation to ensure the stable operation of high-temperature electrolysis, avoid frequent start-up and shutdown of the high-temperature electrolysis unit, and ensure its durability.

[0036] (3) In response to fluctuations in weather and user demand, the design and operation method of this integrated wind-solar-hydrogen storage system has strong flexibility and adjustment capabilities;

[0037] (4) The system has multi-stage heat exchange units at the cathode and anode outlets of the high-temperature electrolysis unit, and integrates a hydrogen compression system and uses its energy for fuel preheating, making full use of energy and improving the energy efficiency of the system. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the integrated wind, solar, hydrogen, and energy storage system of the present invention.

[0039] Figure 2 This is a diagram of the internal structure of the solid oxide fuel electrolyzer in this invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0041] Example 1:

[0042] like Figure 1As shown, the present invention discloses a wind-solar-hydrogen storage integrated energy system utilizing a solid oxide electrolyzer and a proton exchange membrane fuel cell 18, comprising a photovoltaic power generation device 24, a wind power generation device 21, an energy conversion and storage device, a power conversion device, and a balance of power (BOP) device. The plant (power plant auxiliary equipment), material storage equipment, and energy conversion and storage equipment include a solid oxide fuel cell 27, a proton exchange membrane fuel cell 18, and a battery 23. Power conversion equipment includes an AC-DC converter 22 and a DC-AC converter 25. A photovoltaic power generation device 24 is directly connected to and supplies power to the solid oxide fuel cell 27. The photovoltaic power generation device 24 is connected to the battery 23 and supplies power to the user side 26 via the DC-AC converter 25. A wind power generation device 21 is directly connected to and supplies power to the user side 26 and the BOP (Battery on Plant) equipment. The wind power generation device 21 supplies power to the battery 23 via the AC-DC converter 22, and the battery 23 supplies power to the user side 26 via the DC-AC converter 25. The solid oxide fuel cell 27 is connected to the material storage equipment via the BOP equipment to obtain materials for water electrolysis to produce hydrogen. The proton exchange membrane fuel cell 18 is connected to the material storage equipment via the BOP equipment to obtain hydrogen and generate electricity from it. The proton exchange membrane fuel cell 18 is connected to the material storage equipment via the BOP equipment to obtain hydrogen and generate electricity from it. The proton exchange membrane fuel cell 18 is connected to the user side 26 via the DC-AC converter 25.

[0043] Solid oxide fuel cell (SOEC) is a high-temperature electrolyzer that operates at around 600-800°C. Due to its high ionic conductivity, its theoretical efficiency in producing hydrogen from water vapor through electrolysis can exceed 100%. Compared to other water electrolysis hydrogen production technologies, SOEC has a significant advantage in efficiency, and its combination with primary energy sources makes it a very promising hydrogen production and energy storage technology. Using SOEC, excess daytime wind or solar power can be converted into hydrogen energy through water vapor electrolysis.

[0044] Battery 23 is an electrochemical energy storage method with the advantages of fast response and stability and reliability. Its functions are: 1) to absorb the abandoned electricity when there is too much abandoned electricity that cannot be fully utilized by SOEC electrolysis through energy storage; 2) to quickly respond and supplement the power gap when the user side 26 suddenly increases the electricity consumption.

[0045] The proton exchange membrane fuel cell 18 (PEMFC) is a fuel that uses hydrogen as fuel, air or pure oxygen as oxidant, and ion-conducting polymer as electrolyte. It can convert the generated hydrogen into electrical energy for storage. It has the advantages of low-temperature operation, fast start-up, and compact structure. Its function is to quickly supplement the power shortage in special situations where wind and solar resources are insufficient and the battery 23 is not enough to power the user side 26.

[0046] This system uses a 50KW wind power generation device 21 and a photovoltaic power generation device 24 as primary energy inputs. It utilizes a 20KW solid oxide fuel cell 27 composed of four 5KW SOEC stacks, and together with a 70KW battery 23, it performs water electrolysis for hydrogen storage and electrochemical energy storage. A 10KW proton exchange membrane fuel cell 18 is used to convert hydrogen into electricity when necessary to compensate for sudden situations where renewable energy power generation is insufficient.

[0047] like Figure 1 As shown, the BOP equipment includes a first air compressor 1, a first compressor 5, a second compressor 13, a third compressor 15, a first heat exchanger 2, a second heat exchanger 4, a third heat exchanger 7, a fourth heat exchanger 11, a fifth heat exchanger 16, a condenser heat exchanger 14, a first electric heater 3, a second electric heater 8, a mixing chamber 6, an evaporator 12, and a water pump 10. The material storage equipment includes a water tank 9 and a hydrogen storage tank 17.

[0048] The anode air inlet structure of the solid oxide fuel electrolyzer 27 is as follows: the anode air inlet of the first air compressor 1, the anode air inlet of the first heat exchanger 2, the first electric heater 3, and the anode air inlet of the solid oxide fuel electrolyzer 27 are connected in sequence through the anode air inlet pipe.

[0049] The cathode air inlet structure of the solid oxide fuel electrolysis cell 27 is as follows: the cathode air inlet pipe connects in sequence to the water tank 9, water pump 10, the cathode air inlet end of the fourth heat exchanger 11, the cathode air inlet end of the condenser heat exchanger 14, the cathode air inlet end of the fifth heat exchanger 16, the cathode air inlet end of the second heat exchanger 4, the evaporator 12, the mixing chamber 6, the cathode air inlet end of the third heat exchanger 7, the second electric heater 8, and the cathode air inlet of the solid oxide fuel electrolysis cell 27.

[0050] The anode tail gas outlet structure of the solid oxide fuel electrolysis cell 27 is as follows: the anode exhaust port of the solid oxide fuel electrolysis cell 27, the anode exhaust end of the first heat exchanger 2, the anode exhaust end of the second heat exchanger 4, and the external environment of the system are connected in sequence through the anode exhaust pipe.

[0051] The cathode exhaust gas structure of the solid oxide fuel electrolyzer 27 is as follows: the cathode exhaust port of the solid oxide fuel electrolyzer 27, the cathode exhaust end of the third heat exchanger 7, the cathode exhaust end of the fourth heat exchanger 11, the second compressor 13, the cathode exhaust end of the condensing heat exchanger 14, the third compressor 15, the cathode exhaust end of the fifth heat exchanger 16, and the hydrogen storage tank 17 are connected in sequence through the cathode exhaust pipe; the cathode exhaust pipe is also connected in sequence to the cathode exhaust port of the solid oxide fuel electrolyzer 27, the first compressor 5, the mixing chamber 6, and the cathode inlet of the third heat exchanger 7.

[0052] like Figure 1As shown, the BOP device also includes an ejector 19, a second air compressor 20, a hydrogen storage tank 17 which is connected to the anode inlet of the proton exchange membrane fuel cell 18 through a pressure reducing valve, the second air compressor 20 which is connected to the cathode inlet of the proton exchange membrane fuel cell 18, one end of the anode outlet of the proton exchange membrane fuel cell 18 is returned through the ejector 19 and the other end is directly connected to the external environment of the system, and the cathode outlet of the proton exchange membrane fuel cell 18 is connected to the external environment of the system.

[0053] The wind power generation equipment 21 is connected to and supplies power to the first air compressor 1, the first electric heater 3, the ceramic plate heater 29 in the solid oxide fuel electrolysis cell 27, the second electric heater 8, the evaporator 12, the water pump 10, the second compressor 13, and the third compressor 15.

[0054] Distributed photovoltaic power generation equipment 24, distributed wind power generation equipment 21, storage battery 23, and proton exchange membrane fuel cell 18 are all connected to the user side 26. Except for the wind power generation equipment 21, a DC-AC converter 25 is required for conversion. The wind power generation equipment 21 is connected to the storage battery 23 via an AC-DC converter 22. In addition to normal use on the user side 26, the distributed photovoltaic power generation equipment 24 also provides DC power for the electrolysis of hydrogen in the solid oxide fuel cell 27 and for electrochemical storage in the storage battery 23. In addition to normal use on the user side 26, the distributed wind power generation equipment 21 also provides AC power for the ceramic plate heater 29 in the solid oxide fuel cell 27. Figure 1 The solid oxide fuel cell 27 (heating module and electrolysis module are not separately distinguished), gas electric heater, compressor, water pump 10, and other BOP equipment operate, and electrochemical storage is performed through AC-DC converter 22. Battery 23 supplements the power shortage on the user side 26 when wind and solar resources are insufficient. Proton exchange membrane fuel cell 18, through hydrogen-to-electricity conversion, can provide additional power support when the power of battery 23 is insufficient. Both battery 23 and proton exchange membrane fuel cell 18 have rapid response characteristics, capable of meeting the power fluctuation needs of user side 26.

[0055] like Figure 2 As shown, the solid oxide fuel electrolyzer 27 includes an electrolysis unit 28, a ceramic plate heater 29, a pressurizing device 30, and an insulation layer 31. Multiple electrolysis units 28 are stacked and connected to form a fuel cell stack. Ceramic plate heaters 29 are inserted at the top, bottom, and between every two electrolysis units 28. The insulation layer 31 is wrapped around the outside of the fuel cell stack. The pressurizing device 30 is connected to the fuel cell stack. A photovoltaic power generation device 24 is connected to and supplies power to the electrolysis unit 28. A wind power generation device 21 is connected to and supplies power to the ceramic plate heater 29.

[0056] In the 20kW solid oxide high-temperature electrolyzer, its electrolysis unit 28 operates at 750℃ and a thermal neutral voltage of 1.29V. During operation, a constant fuel utilization rate (70%) control strategy is adopted to cope with fluctuations. The stack heating method adopts a stacked design, with ceramic plate heaters 29 inserted at the top, bottom, and between the stacks of each solid oxide high-temperature electrolyzer, to reduce heat loss with a compact structure and ensure uniform temperature of each stack.

[0057] Example 2:

[0058] Based on the above system, the present invention also provides a method for integrated wind, solar, hydrogen, and energy storage utilization, characterized by comprising the following steps:

[0059] S1. When solar and wind resources are abundant during the day, the power supply method is as follows:

[0060] The photovoltaic power generation equipment 24 generates electricity to supply the user side 26 for normal use, and transmits excess photovoltaic electricity to the storage battery 23 for energy storage, and to the solid oxide fuel electrolyzer 27 for electrolysis to produce hydrogen for energy storage; the wind power generation equipment 21 generates electricity to supply the user side 26 for normal use, and transmits excess wind power to the storage battery 23 for energy storage through the AC-DC converter 22, and supplies it to the BOP equipment; the BOP equipment supplied by the wind power generation equipment 21 includes a first air compressor 1, a first electric heater 3, a heating module in the solid oxide fuel electrolyzer 27, a second electric heater 8, an evaporator 12, a water pump 10, a second compressor 13, and a third compressor 15.

[0061] When the photovoltaic power output fluctuates, the battery 23 is adjusted to supplement the power supplied by the photovoltaic power generation equipment 24. When the photovoltaic power generation equipment 24 fluctuates, the battery 23 is adjusted to keep the power input to the solid oxide fuel electrolyzer 27 basically stable.

[0062] S2. When wind resources are abundant at night and solar resources are almost zero, the power supply method is as follows:

[0063] The solid oxide fuel cell 27 does not perform electrolysis. The proton exchange membrane fuel cell 18 generates electricity from the stored hydrogen energy, which, together with the output of the battery 23, compensates for the energy of the photovoltaic power generation equipment 24. The electricity is then supplied to the user side 26 through the DC-AC converter 25. The wind power generation equipment 21 generates electricity to supply the user side 26 for normal use, and supplies the excess wind power to the solid oxide fuel cell 27 for insulation. Specifically, the BOP equipment supplied by the wind power generation equipment 21 is the heating module in the solid oxide fuel cell 27, namely the ceramic plate heater 29.

[0064] S3. When encountering continuous adverse weather and insufficient wind and solar resources for an extended period, the power supply method is as follows:

[0065] The battery 23 supplies power to the user side 26 through the DC-AC converter 25. When the power of the battery 23 is insufficient due to self-discharge and consumption on the user side 26, the proton exchange membrane fuel cell 18 can still generate power to temporarily supply power to the user side 26 through the DC-AC converter 25.

[0066] The electrolytic hydrogen production and storage process in solid oxide fuel electrolyzer 27 is as follows:

[0067] Anode gas supply: The main process gas (air) on the anode side is compressed to 1.01 bar by an air compressor, and then heats up to about 450°C by exchanging heat with the anode tail gas through the first heat exchanger 2. It is then heated to 650°C by the first electric heater 3 and enters the anode inlet of the solid oxide fuel electrolysis cell 27.

[0068] Anode exhaust discharge: The high-temperature anode tail gas (oxygen-enriched air, 700℃) at the air outlet passes through the first heat exchanger 2 and the second heat exchanger 4, and exchanges heat with the anode inlet gas and the cathode inlet gas respectively. After being cooled to 400℃ and 120℃ respectively, it is discharged from the external environment of the system at a temperature not exceeding 120℃.

[0069] Cathode gas supply: The main process gas (water vapor) on the cathode side is taken out from the water tank 9 by the water pump 10, and after passing through the fourth heat exchanger 11, the condenser heat exchanger 14, the fifth heat exchanger 16 (first-stage heat exchanger) to exchange heat with the cathode outlet tail gas, and after exchanging heat with the second heat exchanger 4 (second-stage heat exchanger) to exchange heat with the anode outlet tail gas for preheating, it enters the evaporator 12 to evaporate into water vapor (temperature 150℃), and then passes through the mixing chamber 6 to mix with part of the cathode outlet tail gas, so that the molar fraction of hydrogen in the cathode inlet mixed gas is about 10%. Then it passes through the third heat exchanger 7 to exchange heat with the cathode outlet tail gas and is heated to 400℃. It is then heated to 550℃ by the second electric heater 8 and enters the cathode inlet of the solid oxide fuel electrolysis cell 27.

[0070] Cathode exhaust: The high-temperature exhaust gas (hydrogen, water vapor, 600℃) at the cathode outlet is partially returned to the mixing chamber 6 by the first compressor 5 to mix with the cathode inlet gas. The other part is directly cooled to 370℃ and 160℃ by the third heat exchanger 7 and the fourth heat exchanger 11, respectively. It is then compressed to 15 bar and 340℃ by the second compressor 13, cooled to 160℃ by the condenser heat exchanger 14, compressed to 35 bar and 360℃ by the third compressor 15, cooled to below 120℃ by the fifth heat exchanger 16, and then entered the hydrogen tank for storage at a pressure of 35 bar.

[0071] The power generation process of the proton exchange membrane fuel cell 18 is as follows:

[0072] The 10kW proton exchange membrane fuel cell 18 operates at 70°C and is cooled by a water-cooling system (not shown in the attached diagram). Hydrogen gas (1.4 bar) is introduced into the anode inlet of the proton exchange membrane fuel cell 18 through the hydrogen storage tank 17 and a pressure reducing valve. Air is pressurized to 1.42 bar by the second air compressor 20 and introduced into the cathode inlet. The energy generated by the reaction in the proton exchange membrane fuel cell 18 is supplied to the user side 26 via the DC-AC converter 25. The exhaust gas from the anode outlet of the proton exchange membrane fuel cell 18 is recycled through the ejector 19 to recover some hydrogen, improving the fuel cell efficiency. The exhaust gas from the cathode outlet is directly discharged into the external environment.

[0073] The auxiliary energy supply system for the user side 26 is constructed using a proton exchange membrane fuel cell 18 and a battery 23. This system can adapt to complex and changeable weather conditions. During the day, when there is abundant sunlight and relatively little wind, excess photovoltaic power, besides supplying the user, is used for hydrogen electrolysis and storage or stored in the battery 23. Wind power is used to supply the user side 26 and the BOP (Battery on Plant) equipment. At night, when there is little sunlight and abundant wind, the solid oxide fuel cell 27 is only kept warm. Wind power is supplied to the user side 26 and for the insulation of the solid oxide fuel cell 27, and excess wind power is stored in the battery 23. When the user side 26 experiences a surge in electricity consumption leading to insufficient power supply, electricity is provided through hydrogen-to-electricity conversion via the battery 23 and the proton exchange membrane fuel cell 18. In the event of continuous unforeseen weather conditions, where both sunlight and wind resources are insufficient throughout the day, temporary power supply to the user side 26 can still be guaranteed by converting hydrogen into electricity through the proton exchange membrane fuel cell 18.

[0074] Meanwhile, when the system is operating normally, the photovoltaic system only provides electrolytic electricity to the solid oxide fuel electrolyzer 27, while the wind power AC power supplies the BOP, minimizing the AC / DC conversion efficiency loss. The system also has multiple heat exchangers to achieve extremely high energy utilization.

[0075] This integrated wind-solar-hydrogen-storage energy utilization system offers greater flexibility compared to traditional primary energy electrolysis hydrogen production and storage systems or electrochemical energy storage systems. It can withstand fluctuations in wind and solar power demand and user-side demand to a certain extent. This integrated wind-solar-hydrogen-storage system is of great significance for energy utilization in coastal and sandy areas with abundant wind and solar resources.

[0076] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. An integrated wind-solar-hydrogen-storage comprehensive energy utilization system, characterized in that, The system includes photovoltaic (PV) power generation equipment, wind power generation equipment, energy conversion and storage equipment, power conversion equipment, a Balance of Plant (BOP) system, and material storage equipment. The energy conversion and storage equipment includes a solid oxide fuel cell, a proton exchange membrane fuel cell, and a battery. The power conversion equipment includes an AC-DC converter and a DC-AC converter. The PV power generation equipment is directly connected to and supplies power to the solid oxide fuel cell. The PV power generation equipment is also connected to the battery and supplies power to the user side via the DC-AC converter. The wind power generation equipment is directly connected to and supplies power to both the user side and the BOP system. The wind power generation equipment supplies power to the battery via the AC-DC converter, and the battery supplies power to the user side via the DC-AC converter. The solid oxide fuel cell is connected to the material storage equipment via the BOP system to obtain materials for water electrolysis to produce hydrogen. The proton exchange membrane fuel cell is connected to the material storage equipment via the BOP system to obtain hydrogen and generate electricity from it. The proton exchange membrane fuel cell is connected to the user side via the DC-AC converter. The BOP equipment includes a first air compressor, a first compressor, a second compressor, a third compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a condenser heat exchanger, a first electric heater, a second electric heater, a mixing chamber, an evaporator, and a water pump. The material storage equipment includes a water tank and a hydrogen storage tank. The anode air inlet structure of the solid oxide fuel electrolyzer is as follows: the anode air inlet of the first air compressor, the anode air inlet of the first heat exchanger, the first electric heater, and the anode air inlet of the solid oxide fuel electrolyzer are connected in sequence through the anode air inlet pipe. The cathode air inlet structure of the solid oxide fuel electrolyzer is as follows: a water tank, a water pump, the cathode air inlet end of the fourth heat exchanger, the cathode air inlet end of the condenser heat exchanger, the cathode air inlet end of the fifth heat exchanger, the cathode air inlet end of the second heat exchanger, an evaporator, a mixing chamber, the cathode air inlet end of the third heat exchanger, a second electric heater, and the cathode air inlet of the solid oxide fuel electrolyzer are connected in sequence through the cathode air inlet pipe. The anode tail gas outlet structure of the solid oxide fuel electrolyzer is as follows: the anode exhaust port of the solid oxide fuel electrolyzer, the anode exhaust end of the first heat exchanger, the anode exhaust end of the second heat exchanger, and the external environment of the system are connected in sequence through the anode exhaust pipe. The cathode exhaust gas structure of the solid oxide fuel electrolyzer is as follows: the cathode exhaust port of the solid oxide fuel electrolyzer, the cathode exhaust end of the third heat exchanger, the cathode exhaust end of the fourth heat exchanger, the second compressor, the cathode exhaust end of the condensing heat exchanger, the third compressor, the cathode exhaust end of the fifth heat exchanger, and the hydrogen storage tank are connected in sequence through the cathode exhaust pipe; the cathode exhaust pipe is also connected in sequence to the cathode exhaust port of the solid oxide fuel electrolyzer, the first compressor, the mixing chamber, and the cathode inlet of the third heat exchanger.

2. The integrated wind-solar-hydrogen-storage comprehensive energy utilization system according to claim 1, characterized in that, The BOP device also includes an ejector and a second air compressor. The hydrogen storage tank is connected to the anode inlet of the proton exchange membrane fuel cell through a pressure reducing valve. The second air compressor is connected to the cathode inlet of the proton exchange membrane fuel cell. One end of the anode outlet of the proton exchange membrane fuel cell is returned through the ejector, and the other end is directly connected to the external environment of the system. The cathode outlet of the proton exchange membrane fuel cell is connected to the external environment of the system.

3. The integrated wind-solar-hydrogen-storage comprehensive energy utilization system according to claim 2, characterized in that, The wind power generation equipment is connected to and supplies power to the first air compressor, the first electric heater, the heating module in the solid oxide fuel electrolysis cell, the second electric heater, the evaporator, the water pump, the second compressor, and the third compressor.

4. The integrated wind-solar-hydrogen-storage comprehensive energy utilization system according to claim 1, characterized in that, The solid oxide fuel electrolyzer includes an electrolysis unit, a ceramic plate heater, a pressurizing device, and an insulation layer. Multiple electrolysis units are stacked to form a fuel cell stack. Ceramic plate heaters are inserted at the top, bottom, and between every two electrolysis units. The insulation layer wraps around the fuel cell stack. The pressurizing device is connected to the fuel cell stack. The photovoltaic power generation equipment is connected to and supplies power to the electrolysis unit. The wind power generation equipment is connected to and supplies power to the ceramic plate heater.

5. A method for integrated energy utilization of wind, solar, hydrogen, and storage systems according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1. When solar and wind resources are abundant during the day, the power supply method is as follows: The photovoltaic power generation equipment generates electricity for normal use by the user side, and transmits excess photovoltaic electricity to the battery for energy storage, and to the solid oxide fuel electrolyzer for hydrogen production and energy storage; the wind power generation equipment generates electricity for normal use by the user side, and transmits excess wind power to the battery for energy storage through the AC-DC converter, and supplies the BOP equipment; when the photovoltaic power output fluctuates, the battery is adjusted to supplement the power supplied by the photovoltaic power generation equipment. S2. When wind resources are abundant at night and solar resources are almost zero, the power supply method is as follows: When the solid oxide fuel cell stops electrolysis, the proton exchange membrane fuel cell generates electricity using the stored hydrogen energy. This electricity, combined with the output from the battery, compensates for the energy of the photovoltaic power generation equipment and supplies power to the user side via a DC-AC converter. The wind power generation equipment generates electricity to supply the user side for normal use and supplies excess wind power to the solid oxide fuel cell for insulation.

6. The integrated wind-solar-hydrogen-storage comprehensive energy utilization method according to claim 5, characterized in that, The process of producing hydrogen through electrolysis and storing energy in a solid oxide fuel electrolyzer is as follows: Anode gas supply: The process gas on the anode side is compressed to 1.01 bar by an air compressor, and then heats up to about 450°C by exchanging heat with the anode tail gas through the first heat exchanger. It is then heated to 650°C by the first electric heater and enters the anode inlet of the solid oxide fuel electrolysis cell. Anode exhaust discharge: The high-temperature anode tail gas from the air outlet passes through the first heat exchanger and the second heat exchanger, and after exchanging heat with the anode inlet gas and the cathode inlet gas respectively, it is discharged from the external environment of the system at a temperature not exceeding 120°C. Cathode gas supply: The process gas on the cathode side is taken out of the water tank by a water pump, and after passing through the fourth heat exchanger, condenser heat exchanger, and fifth heat exchanger to exchange heat with the cathode outlet tail gas, and after exchanging heat with the second heat exchanger to exchange heat with the anode outlet tail gas for preheating, it enters the evaporator to evaporate into water vapor, mixes with part of the cathode outlet tail gas through the mixing chamber, and then passes through the third heat exchanger to exchange heat with the cathode outlet tail gas and be heated to 400°C. It is then heated to 550°C by the second electric heater and enters the cathode inlet of the solid oxide fuel electrolysis cell. Cathode exhaust: The high-temperature exhaust gas at the cathode outlet is partially returned to the mixing chamber by the first compressor to mix with the cathode inlet gas, and the other part is directly cooled to 370°C and 160°C by the third and fourth heat exchangers respectively, then compressed to 15 bar and 340°C by the second compressor, cooled to 160°C by the condenser heat exchanger, then compressed to 35 bar and 360°C by the third compressor, cooled to below 120°C by the fifth heat exchanger, and then entered the hydrogen tank for storage at a pressure of 35 bar.

7. The integrated wind-solar-hydrogen-storage comprehensive energy utilization method according to claim 6, characterized in that, The power generation process of a proton exchange membrane fuel cell is as follows: The anode inlet of the proton exchange membrane fuel cell is supplied with hydrogen gas through a hydrogen storage tank via a pressure reducing valve at a pressure of 1.4 bar. Air is pressurized to 1.42 bar by a second air compressor and then introduced into the cathode inlet. The energy generated by the reaction of the proton exchange membrane fuel cell is supplied to the user side through a DC-AC converter. The exhaust gas at the anode outlet of the proton exchange membrane fuel cell is returned through an ejector to recover some hydrogen gas, and the exhaust gas at the cathode outlet is directly discharged into the external environment of the system.

8. The integrated wind-solar-hydrogen-storage comprehensive energy utilization method according to claim 5, characterized in that, In step S1, the BOP equipment supplied by the wind power generation equipment includes a first air compressor, a first electric heater, a heating module in the solid oxide fuel electrolyzer, a second electric heater, an evaporator, a water pump, a second compressor, and a third compressor; in step S2, the BOP equipment supplied by the wind power generation equipment is the heating module in the solid oxide fuel electrolyzer.

9. The integrated wind-solar-hydrogen-storage comprehensive energy utilization method according to claim 5, characterized in that, It also includes the following steps: S3. When encountering continuous adverse weather and insufficient wind and solar resources for an extended period, the power supply method is as follows: Power is supplied to the user side by the storage battery through a DC-AC converter. When the battery's power is insufficient, the proton exchange membrane fuel cell generates electricity and temporarily supplies power to the user side through the DC-AC converter.

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