Solid oxide fuel cell and electrolytic tank reversible operation system

Abstract

The invention discloses a solid oxide fuel cell and an electrolytic tank reversible operation system. The device is characterized by comprising a solid oxide electric pile, an electric pile heater, an oxygen electrode fan, an oxygen electrode heat exchanger, an oxygen electrode electric heater, a hydrogen electrode water pump, a hydrogen electrode heat exchanger, a hydrogen electrode electric heater, a gas-liquid separator, a condensate water electric control valve, a hydrogen compressor, a hydrogen circulating pump, an anode waste gas electric control valve, a hydrogen cylinder, a hydrogen electric control valve and a flow controller, the water electrolysis hydrogen production device has the beneficial effects that the device can work in a water electrolysis hydrogen production mode, the solid oxide galvanic pile is used as an electrolytic tank, and waste photoelectric wind power is utilized for water electrolysis hydrogen production and storage; the solid oxide stack can also work in a power generation mode, the solid oxide stack is used as a fuel cell, and the stored hydrogen produced by electrolyzing water is used for fuel cell power generation and then is input into a power grid.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid oxide fuel cells, and specifically relates to a solid oxide fuel cell power generation and a solid oxide electrolysis cell for electrolyzing water to produce hydrogen, and a reversible operation system. Background Art

[0002] At present, the installed capacity of photovoltaic power generation and wind power generation is already very large. However, due to the large fluctuations in the power generation of photovoltaic power generation and wind power generation, it is very unfavorable to the stability of grid-connected operation, resulting in a large amount of abandoned power from photovoltaic power generation and wind power generation, which is a serious waste. To avoid the abandonment of power, during the peak period of photovoltaic power generation and wind power generation, the excess electricity that cannot be absorbed by the power grid can be electrolyzed to produce hydrogen and stored. During the trough period of photovoltaic power generation and wind power generation, the stored hydrogen can be generated through fuel cells and then connected to the power grid, which can make the grid-connected operation relatively stable. Currently, alkaline electrolysis cells are mainly used to electrolyze water to produce hydrogen, and then PEM fuel cells are used to generate electricity. The overall efficiency is very low and the system is complex. Summary of the invention

[0003] Purpose of the invention: The technical problem to be solved by the present invention is to provide a reversible operation system of a solid oxide fuel cell and an electrolytic cell, which uses the same solid oxide fuel cell stack, which can be used as a fuel cell to generate electricity and can also be used as an electrolytic cell to electrolyze water to produce hydrogen, thereby improving the overall efficiency and simplifying the system.

[0004] A solid oxide fuel cell and electrolytic cell reversible operation system, characterized by: comprising a solid oxide stack, a stack heater, an oxygen electrode fan, an oxygen electrode heat exchanger, an oxygen electrode electric heater, a hydrogen electrode water pump, a hydrogen electrode heat exchanger, a hydrogen electrode electric heater, a gas-liquid separator, a condensate electric control valve, a hydrogen compressor, a hydrogen circulation pump, an anode exhaust gas electric control valve, a hydrogen bottle, a hydrogen electric control valve, and a flow controller; The outlet of the oxygen electrode fan is connected to the cold side flow channel inlet of the oxygen electrode heat exchanger, the cold side flow channel outlet of the oxygen electrode heat exchanger is connected to the inlet of the oxygen electrode electric heater, the outlet of the oxygen electrode electric heater is connected to the oxygen electrode flow channel inlet of the solid oxide stack, and the oxygen electrode flow channel outlet of the solid oxide stack is connected to the hot side flow channel inlet of the oxygen electrode heat exchanger; Connect the outlet of the hydrogen pole water pump to the cold side flow channel inlet of the hydrogen pole heat exchanger, the cold side flow channel outlet of the hydrogen pole heat exchanger is connected to the inlet of the hydrogen pole electric heater, the outlet of the hydrogen pole electric heater is connected to the hydrogen pole flow channel inlet of the solid oxide fuel cell stack, the hydrogen pole flow channel outlet of the solid oxide fuel cell stack is connected to the hot side flow channel inlet of the hydrogen pole heat exchanger, the hot side flow channel outlet of the hydrogen pole heat exchanger is connected to the inlet of the gas-liquid separator, the outlet of the gas-liquid separator is connected to the inlet of the hydrogen compressor, and the outlet of the hydrogen compressor is connected to the hydrogen cylinder; Connect the inlet of the hydrogen circulation pump to the outlet of the gas-liquid separator, connect the outlet of the hydrogen circulation pump to the inlet of the cold-side flow channel of the hydrogen electrode heat exchanger, connect one end of the anode exhaust gas electric control valve to the outlet of the hydrogen circulation pump, and connect one end of the condensate water electric control valve to the drain port of the gas-liquid separator; Connect one end of the hydrogen electric control valve to the hydrogen cylinder and the other end to the input port of the flow controller. Connect the output port of the flow controller to the inlet of the cold-side flow channel of the hydrogen electrode heat exchanger.

[0005] The beneficial effects of the present invention are as follows: During the peak stage of photovoltaic power generation and wind power generation, when the power grid cannot fully absorb the generated electric energy, it can operate in the electrolytic water hydrogen production mode. The solid oxide stack is used as an electrolytic cell to utilize the wasted photovoltaic and wind power for electrolytic water hydrogen production and storage. During the low valley stage of photovoltaic power generation and wind power generation, when the power grid power is insufficient, it can operate in the power generation mode. The solid oxide stack is used as a fuel cell to utilize the hydrogen produced by electrolytic water and stored before for fuel cell power generation and then input into the power grid. Brief Description of the Drawings

[0006] Figure 1 It is a schematic diagram of an embodiment of the present invention; Reference Signs: 10 - Solid oxide stack, 10a - Stack hydrogen electrode flow channel, 10b - Stack oxygen electrode flow channel, 11 - Stack heater, 20 - Oxygen electrode fan, 21 - Oxygen electrode heat exchanger, 21a - Cold-side flow channel of the oxygen electrode heat exchanger, 21b - Hot-side flow channel of the oxygen electrode heat exchanger, 22 - Oxygen electrode electric heater, 30 - Hydrogen electrode water pump, 31 - Check valve, 32 - Hydrogen electrode heat exchanger, 32a - Cold-side flow channel of the hydrogen electrode heat exchanger, 32b - Hot-side flow channel of the hydrogen electrode heat exchanger, 33 - Hydrogen electrode electric heater, 40 - Gas-liquid separator, 40a - Gas-liquid separator inlet, 40b - Gas-liquid separator outlet, 40c - Gas-liquid separator drain port, 41 - Condensate water electric control valve, 50 - Hydrogen compressor, 51 - Check valve, 60 - Hydrogen circulation pump, 61 - Check valve, 62 - Anode exhaust gas electric control valve, 70 - Hydrogen cylinder, 71 - Hydrogen electric control valve, 72 - Flow controller, 73 - Check valve. Embodiment

[0007] It should be noted that in the specification and claims, certain terms are used to refer to specific components. Those skilled in the art should understand that different terms may be used to refer to the same component. The specification and claims do not distinguish components based on the difference in terms, but rather on the functional differences of the components. For example, the terms "comprising" or "including" mentioned throughout the specification and claims are open-ended terms and should be interpreted as "including but not limited to". The "stack" in the specification and claims is an abbreviation of "fuel cell".

[0008] For the convenience of understanding the embodiments of the present invention, the following will be further explained by taking specific embodiments as examples in conjunction with the drawings: Figure 1 As a preferred embodiment of the present invention, a solid oxide fuel cell and electrolyzer reversible operation system includes a solid oxide stack 10, a stack heater 11, an oxygen electrode blower 20, an oxygen electrode heat exchanger 21, an oxygen electrode electric heater 22, a hydrogen electrode water pump 30, a hydrogen electrode heat exchanger 32, a hydrogen electrode electric heater 33, a gas-liquid separator 40, a condensate water control valve 41, a hydrogen compressor 50, a hydrogen circulation pump 60, an anode exhaust gas control valve 62, a hydrogen cylinder 70, a hydrogen control valve 71, and a flow controller 72. Among them, the outlet of the oxygen electrode blower 20 is connected to the inlet of the cold-side flow channel 21a of the oxygen electrode heat exchanger, the outlet of the cold-side flow channel 21a of the oxygen electrode heat exchanger is connected to the inlet of the oxygen electrode electric heater 22, the outlet of the oxygen electrode electric heater 22 is connected to the inlet of the stack oxygen electrode flow channel 10b, and the outlet of the stack oxygen electrode flow channel 10b is connected to the inlet of the hot-side flow channel 21b of the oxygen electrode heat exchanger. The outlet of the hydrogen electrode water pump 30 is connected to the inlet of the cold-side flow channel 32a of the hydrogen electrode heat exchanger through a check valve 31. The outlet of the cold-side flow channel 32a of the hydrogen electrode heat exchanger is connected to the inlet of the hydrogen electrode electric heater 33. The outlet of the hydrogen electrode electric heater 33 is connected to the inlet of the stack hydrogen electrode flow channel 10a. The outlet of the stack hydrogen electrode flow channel 10a is connected to the inlet of the hot-side flow channel 32b of the hydrogen electrode heat exchanger. The outlet of the hot-side flow channel 32b of the hydrogen electrode heat exchanger is connected to the inlet 40a of the gas-liquid separator. The outlet 40b of the gas-liquid separator is connected to the inlet of the hydrogen compressor 50. The outlet of the hydrogen compressor 50 is connected to the hydrogen cylinder 70 through a check valve 51. The inlet of the hydrogen circulation pump 60 is connected to the outlet 40b of the gas-liquid separator. The outlet of the hydrogen circulation pump 60 is connected to the inlet of the cold-side flow channel 32a of the hydrogen electrode heat exchanger through a check valve 61. One end of the anode exhaust gas control valve 62 is connected to the outlet of the hydrogen circulation pump 60. One end of the condensate water control valve 41 is connected to the drain port 40c of the gas-liquid separator. Connect one end of the hydrogen electronic control valve 71 to the hydrogen cylinder 70, and the other end to the input port of the flow controller 72. The output port of the flow controller 72 is connected to the inlet of the cold-side flow channel 32a of the hydrogen electrode heat exchanger through the one-way valve 73.

[0009] When operating in the electrolytic cell mode: The hydrogen electrode water pump 30 inputs deionized water into the cold-side flow channel 32a of the hydrogen electrode heat exchanger through the one-way valve 31. After exchanging heat with the high-temperature fluid in the hot-side flow channel 32b of the hydrogen electrode heat exchanger, it is heated to become water vapor. This water vapor enters the hydrogen electrode electric heater 33 and is further heated to become superheated steam. This superheated steam enters the hydrogen electrode flow channel 10a of the stack; at this time, a DC voltage is applied to the two electrodes of the solid oxide stack 10, and the water vapor is electrolyzed into hydrogen protons and oxygen ions; Among them, the oxygen ions pass through the electrolyte layer of the stack, enter the oxygen electrode flow channel 10b of the stack, and become oxygen after losing electrons. Then, it is diluted by the purge air in the oxygen electrode flow channel 10b of the stack and discharged into the air; The hydrogen protons remain in the hydrogen electrode flow channel 10a of the stack. After obtaining electrons, they become hydrogen. This hydrogen and part of the remaining un-electrolyzed water vapor enter the hot-side flow channel 32b of the hydrogen electrode heat exchanger together. After exchanging heat and cooling with the deionized water in the cold-side flow channel 32a of the hydrogen electrode heat exchanger, they enter the gas-liquid separator 40. The condensed water is separated to the lower part of the gas-liquid separator 40, and the water can be discharged through the condensate electronic control valve 41; the hydrogen is output from the outlet 40b of the gas-liquid separator. The hydrogen compressor 50 compresses the hydrogen and stores it in the hydrogen cylinder 70 through the one-way valve 51; The oxygen electrode fan 20 inputs air into the cold-side flow channel 21a of the oxygen electrode heat exchanger. After exchanging heat and warming up with the high-temperature fluid in the hot-side flow channel 21b of the oxygen electrode heat exchanger, it enters the oxygen electrode electric heater 22 and is heated and warmed up again, and then is input into the oxygen electrode flow channel 10b of the stack to dilute and purge the oxygen generated during the electrolysis process. This purge air is discharged into the air after being cooled by the oxygen electrode heat exchanger 21; The hydrogen circulation pump 60 sends a part of the hydrogen generated by electrolyzing water back to the cold-side flow channel 32a of the hydrogen electrode heat exchanger through the one-way valve 61. After mixing with the deionized water and warming up, they enter the hydrogen electrode flow channel 10a of the stack together, so that the entire hydrogen electrode flow channel 10a of the stack is in a reducing atmosphere, which can prevent the hydrogen electrode of the stack from being oxidized; During the process of electrolyzing water to produce hydrogen, the stack heater 11, the oxygen electrode electric heater 22, and the hydrogen electrode electric heater 33 are all in the power-on heating state to ensure that the electrolytic cell is at the optimal working temperature.

[0010] When operating in the fuel cell mode: The oxygen-pole blower 20 inputs air into the cold-side flow channel 21a of the oxygen-pole heat exchanger. After heat exchange with the high-temperature fluid in the hot-side flow channel 21b of the oxygen-pole heat exchanger and temperature rise, it is input into the fuel cell oxygen-pole flow channel 10b through the oxygen-pole electric heater 22. Under the action of the electrolyte, the oxygen in the air obtains electrons and becomes oxygen ions. The oxygen ions pass through the electrolyte layer of the fuel cell stack and enter the fuel cell hydrogen-pole flow channel 10a, where they react with hydrogen to generate water, and a DC voltage is output on the two electrodes of the solid oxide fuel cell stack 10. At this time, the fuel cell hydrogen-pole flow channel 10a serves as the anode of the fuel cell, and the fuel cell oxygen-pole flow channel 10b serves as the cathode of the fuel cell. The cathode exhaust gas passes through the hot-side flow channel 21b of the oxygen-pole heat exchanger, is cooled by heat exchange, and then discharged into the air. The hydrogen in the hydrogen cylinder 70 is input into the cold-side flow channel 32a of the hydrogen-pole heat exchanger after passing through the hydrogen electronic control valve 71, the flow controller 72, and the one-way valve 73. After being heated and temperature-rise by the hydrogen-pole heat exchanger 32, it enters the fuel cell hydrogen-pole flow channel 10a through the hydrogen-pole electric heater 33. The hydrogen combines with the oxygen ions from the cathode to generate water and generate electricity. At this time, the water vapor and the remaining unreacted hydrogen in the fuel cell hydrogen-pole flow channel 10a are input into the hot-side flow channel 32b of the hydrogen-pole heat exchanger under the action of the hydrogen circulation pump 60. After being cooled by heat exchange with the hydrogen-pole heat exchanger 32, they enter the gas-liquid separator 40. The condensed water is separated to the lower part of the gas-liquid separator 40, and the water can be discharged through the condensed water electronic control valve 41. The hydrogen is output from the outlet 40b of the gas-liquid separator and enters the hydrogen circulation pump 60 to form a cycle, thereby improving the hydrogen utilization rate. The anode exhaust gas electronic control valve 62 intermittently discharges the anode exhaust gas to prevent impurity gases from accumulating in the anode channel and affecting the power generation efficiency of the fuel cell stack. When operating in the fuel cell mode, the stack heater 11, the oxygen-pole electric heater 22, and the hydrogen-pole electric heater 33 can all be in the power-off state to save electrical energy.

[0011] The beneficial effect of the present invention is that during the peak stage of photovoltaic power generation and wind power generation, when the electric energy generated by the power grid cannot be fully absorbed, it can operate in the electrolytic water hydrogen production mode. The solid oxide fuel cell stack is used as an electrolytic cell, and the waste photovoltaic and wind power are utilized to electrolyze water to produce hydrogen and store it. During the low valley stage of photovoltaic power generation and wind power generation, when the power grid power is insufficient, it can operate in the power generation mode. The solid oxide fuel cell stack is used as a fuel cell, and the hydrogen produced by electrolyzing water and stored before is utilized to generate fuel cell power and then input into the power grid.

[0012] The above describes the implementation embodiments of the present invention, but the present invention is not limited to the above specific implementation embodiments and application fields. The above specific implementation embodiments are merely illustrative and guiding, rather than restrictive. Those of ordinary skill in the art, under the inspiration of this specification and without departing from the scope protected by the claims of the present invention, can also make many forms, and all of these fall within the scope of protection of the present invention.

Claims

1. A solid oxide fuel cell and electrolytic cell reversible operation system, characterized in that: It includes a solid oxide stack (10), a stack heater (11), an oxygen electrode blower (20), an oxygen electrode heat exchanger (21), an oxygen electrode electric heater (22), a hydrogen electrode water pump (30), a hydrogen electrode heat exchanger (32), a hydrogen electrode electric heater (33), a gas-liquid separator (40), a condensate water control valve (41), a hydrogen compressor (50), a hydrogen circulation pump (60), an anode exhaust gas control valve (62), a hydrogen cylinder (70), a hydrogen control valve (71), and a flow controller (72); connect the outlet of the oxygen electrode blower (20) to the inlet of the cold-side flow channel (21a) of the oxygen electrode heat exchanger, connect the outlet of the cold-side flow channel (21a) of the oxygen electrode heat exchanger to the inlet of the oxygen electrode electric heater (22), connect the outlet of the oxygen electrode electric heater (22) to the inlet of the stack oxygen electrode flow channel (10b), and connect the outlet of the stack oxygen electrode flow channel (10b) to the inlet of the hot-side flow channel (21b) of the oxygen electrode heat exchanger; connect the outlet of the hydrogen electrode water pump (30) to the inlet of the cold-side flow channel (32a) of the hydrogen electrode heat exchanger, connect the outlet of the cold-side flow channel (32a) of the hydrogen electrode heat exchanger to the inlet of the hydrogen electrode electric heater (33), connect the outlet of the hydrogen electrode electric heater (33) to the inlet of the stack hydrogen electrode flow channel (10a), connect the outlet of the stack hydrogen electrode flow channel (10a) to the inlet of the hot-side flow channel (32b) of the hydrogen electrode heat exchanger, connect the outlet of the hot-side flow channel (32b) of the hydrogen electrode heat exchanger to the inlet (40a) of the gas-liquid separator, connect the outlet (40b) of the gas-liquid separator to the inlet of the hydrogen compressor (50), and connect the outlet of the hydrogen compressor (50) to the hydrogen cylinder (70); connect the inlet of the hydrogen circulation pump (60) to the outlet (40b) of the gas-liquid separator, connect the outlet of the hydrogen circulation pump (60) to the inlet of the cold-side flow channel (32a) of the hydrogen electrode heat exchanger, connect one end of the anode exhaust gas control valve (62) to the outlet of the hydrogen circulation pump (60), and connect one end of the condensate water control valve (41) to the drain port (40c) of the gas-liquid separator; connect one end of the hydrogen control valve (71) to the hydrogen cylinder (70), connect the other end to the input port of the flow controller (72), and connect the output port of the flow controller (72) to the inlet of the cold-side flow channel (32a) of the hydrogen electrode heat exchanger.

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