A solid oxide stack anode leak on-line detection system

Abstract

The application provides a solid oxide pile anode leakage online detection system, which comprises a solid oxide pile, a hot box shell, a temperature sensor, an electric heating wire, an inert gas cylinder, an electromagnetic valve, a flow meter, a cooler, a hydrogen sensor and a pressure sensor; the application has the beneficial effect that when the solid oxide pile has hydrogen leakage, the leaked hydrogen cannot burn due to the lack of oxygen because the inner cavity of the hot box shell is filled with inert purge gas, thereby avoiding the continuous burning of the leakage point, melting and causing the pile to be scrapped, and further causing a serious accident of hydrogen leakage, equipment burning and even explosion; the leaked hydrogen flows through the cooler along with the nitrogen, and the gas flow is cooled and then flows through the hydrogen sensor, and when the hydrogen concentration exceeds the set value, an alarm can be given and the machine can be stopped; in addition, the electric heating wire cannot be oxidized because the nitrogen continuously flows into the inner cavity of the hot box shell without oxygen, thereby greatly prolonging the service life of the electric heating wire.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen fuel cell technology, specifically relating to online detection technology for hydrogen leakage in solid oxide fuel cells. Background Technology

[0002] Currently, solid oxide fuel cell power generation systems (SOFC), solid oxide fuel cell electrolysis water production systems (SOEC), and solid oxide fuel cell testing platforms all require the solid oxide fuel cell (hereinafter referred to as solid oxide stack) to be encapsulated in a hot box. When hydrogen leaks from the anode of the solid oxide stack, the operating temperature of the solid oxide stack and the inner cavity of the hot box is as high as about 700°C, and the hot box contains air. The leaked hydrogen will burn inside the hot box, making it impossible to detect whether there is a hydrogen leak. As the hydrogen continues to leak and burn, it will melt the area near the leak point, causing the amount of hydrogen leak to increase continuously, eventually leading to the scrapping of the stack. A large leak of hydrogen can burn out the equipment or even cause an explosion. Summary of the Invention

[0003] Purpose of the invention: The technical problem to be solved by the present invention is to provide an online detection system for anode leakage of solid oxide fuel cell stacks, which can effectively prevent hydrogen leaking from the anode of solid oxide fuel cell stacks from burning in the hot box, and can accurately detect the hydrogen leakage status.

[0004] An online detection system for anode leakage of a solid oxide fuel cell (SOCF) includes a SOCF, a heat chamber housing, a temperature sensor, and a heating wire. The SOCF is encapsulated within the inner cavity of the heat chamber housing. The heat chamber housing is sealed and has a heat insulation layer. The inlet and outlet ports of the SOCF anode flow channel pass through the heat chamber housing and are connected to an anode pipeline outside the heat chamber housing. The inlet and outlet ports of the SOCF cathode flow channel also pass through the heat chamber housing and are connected to a cathode pipeline outside the heat chamber housing. The positive and negative electrodes of the SOCF pass through the heat chamber housing and are connected to a heating wire outside the heat chamber housing. The source components are connected; the temperature sensor probe extends into the inner cavity of the hot box shell; the heating wire is placed on the inner wall of the hot box shell; characterized in that: a purge gas inlet and a purge gas outlet are also provided on the hot box shell; an inert gas cylinder, a solenoid valve, a flow meter, a cooler, a hydrogen sensor, and a pressure sensor are also provided outside the hot box shell; the outlet of the inert gas cylinder is connected to the solenoid valve and the pressure sensor, the solenoid valve and the flow meter are connected in series, the outlet of the flow meter is connected to the purge gas inlet, the purge gas outlet is connected to the hot side flow channel of the cooler, and the hydrogen sensor is placed at the outlet of the hot side flow channel of the cooler.

[0005] The beneficial effect of this invention is that when there is hydrogen leakage in the anode flow channel of the solid oxide fuel cell, the leaked hydrogen will not burn due to the lack of oxygen because the inner cavity of the hot box shell is filled with inert purging gas. This avoids the continuous burning and melting of the leak point, which would lead to the scrapping of the fuel cell and cause serious accidents such as equipment burnout or even explosion due to a large amount of hydrogen leakage.

[0006] Another beneficial effect of this invention is that it can effectively prevent the oxidation of the heating wire and extend the life of the heating wire.

[0007] Hydrogen leaking into the inner cavity of the hot box shell will flow out from the purge gas outlet along with the inert purge gas. After being cooled by the cooler, it will be detected and alarmed in time by the hydrogen sensor, which greatly improves the safety performance of the system. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the preferred embodiment of the present invention;

[0009] Figure label:

[0010] 100-Hot chamber shell, 101-Purge gas inlet, 102-Purge gas outlet, 103-Temperature sensor, 104-Heating wire, 200-Solid oxide fuel cell stack, 201-Anode flow channel, 202-Cathode flow channel, 203-Positive and negative electrodes, 301-Inert gas cylinder, 302-Solenoid valve, 303-Flow meter, 304-Check valve, 305-Cooler, 306-Hydrogen sensor, 307-Pressure sensor. Detailed Implementation

[0011] It should be noted that certain terms are used in the specification and claims to refer to specific components; those skilled in the art should understand that they may use different terms to refer to the same component; this specification and claims do not use the difference in terminology as a way to distinguish components, but rather the difference in function of components as the distinguishing criterion; the terms "comprising" or "including" mentioned throughout the specification and claims are open-ended terms and should therefore be interpreted as "including but not limited to".

[0012] To facilitate understanding of the embodiments of the present invention, further explanation will be provided below in conjunction with the accompanying drawings:

[0013] Figure 1This is a preferred embodiment of the present invention, an online detection system for anode leakage of a solid oxide fuel cell, comprising a solid oxide fuel cell 200, a heat box housing 100, a temperature sensor 103, and a heating wire 104; the solid oxide fuel cell 200 is encapsulated in the inner cavity of the heat box housing 100; the heat box housing 100 is in a closed state and has a heat insulation layer; the input and output ports of the anode flow channel 201 of the solid oxide fuel cell 200 pass through the heat box housing 100 and are connected to the anode pipeline outside the heat box housing 100; the input and output ports of the cathode flow channel 202 of the solid oxide fuel cell 200 pass through the heat box housing 100 and are connected to the cathode pipeline outside the heat box housing 100; the positive and negative electrodes 203 of the solid oxide fuel cell 200 pass through the heat box housing 100 and are connected to the power supply assembly outside the heat box housing 100. The temperature sensor 103's temperature probe extends into the inner cavity of the hot box shell 100; the heating wire 104 is disposed on the inner wall of the hot box shell 100; the hot box shell 100 is also provided with a purge gas inlet 101 and a purge gas outlet 102; an inert gas cylinder 301, a solenoid valve 302, a flow meter 303, a one-way valve 304, a cooler 305, a hydrogen sensor 306, and a pressure sensor 307 are also disposed outside the hot box shell 100; the solenoid valve 302 and the pressure sensor 307 are connected to the outlet of the inert gas cylinder 301; the solenoid valve 302, the flow meter 303, and the one-way valve 304 are connected in series; the outlet of the one-way valve 304 is connected to the purge gas inlet 101; the purge gas outlet 102 is connected to the hot side flow channel of the cooler 305; and the hydrogen sensor 306 is disposed at the outlet of the hot side flow channel of the cooler 305.

[0014] The inert gas cylinder 301 can be a nitrogen cylinder, an argon cylinder, etc.

[0015] The flow meter 303 may be a rotor flow meter, a gas mass flow meter, a gas mass flow controller, etc.

[0016] The cooler 305 can be a gas-liquid heat exchanger, an air-cooled radiator, etc.

[0017] The work process is as follows:

[0018] After powering on, the pressure value of the pressure sensor 307 is used to determine whether there is enough nitrogen in the inert gas cylinder 301. If there is enough nitrogen, the solenoid valve 302 is opened. The flow rate of nitrogen can be controlled by the flow meter 303. The flow rate of nitrogen should not be too high to avoid excessive heat loss. The flow rate of nitrogen can be limited to 1-3 L / min. Nitrogen is introduced into the inner cavity of the hot box shell 100 through the purge gas inlet 101 via the one-way valve 304. Since the hot box shell 100 is sealed, the nitrogen introduced from the purge gas inlet 101 can only flow out from the purge gas outlet 102, thereby purging the air in the inner cavity of the hot box shell 100.

[0019] Then the heating wire 104 can be turned on to heat the solid oxide fuel cell 200. Since nitrogen gas continuously flows into the inner cavity of the heat box shell 100, the heating wire 104 will not be oxidized because there is no oxygen, thus greatly extending the service life of the heating wire 104.

[0020] Temperature sensor 103 can detect the temperature of solid oxide fuel cell 200. When the temperature of solid oxide fuel cell 200 reaches the operating temperature of 620-750°C, air can be introduced into cathode channel 202 and hydrogen can be introduced into anode channel 201 to generate electricity; or air can be introduced into cathode channel 202 and high-temperature water vapor can be introduced into anode channel 201 to produce hydrogen by electrolysis of water.

[0021] At this time, the hydrogen in the anode flow channel 201 has a certain pressure. If the hydrogen in the anode flow channel 201 leaks into the inner cavity of the hot box shell 100, since there is only nitrogen and no oxygen in the inner cavity of the hot box shell 100, the leaked hydrogen will not burn. The hydrogen will flow out from the purge gas outlet 102 with the nitrogen flow and enter the hot side flow channel of the cooler 305. After the flow is cooled, it passes through the hydrogen sensor 306 and is then discharged into the air. The hydrogen sensor 306 can detect the hydrogen concentration in the nitrogen flow. When the hydrogen concentration exceeds the set value, an alarm will be triggered and the machine will be shut down.

[0022] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments and application fields described above. The specific embodiments described above are merely illustrative and guiding, and not restrictive. Those skilled in the art can make many other forms under the guidance of this specification and without departing from the scope of protection of the claims of the present invention, and these are all within the scope of protection of the present invention.

Claims

1. An online detection system for anode leakage of a solid oxide fuel cell, comprising a solid oxide fuel cell (200), a heat box shell (100), a temperature sensor (103), and a heating wire (104); the solid oxide fuel cell (200) is encapsulated in the inner cavity of the heat box shell (100); the heat box shell (100) is in a closed state and has a heat insulation layer; the input and output ports of the anode flow channel (201) of the solid oxide fuel cell (200) pass through the heat box shell (100) respectively and are connected to the anode pipeline outside the heat box shell (100). Connections; the input and output ports of the cathode flow channel (202) of the solid oxide fuel cell (200) pass through the heat box housing (100) respectively and are connected to the cathode pipeline outside the heat box housing (100); the positive and negative electrodes (203) of the solid oxide fuel cell (200) pass through the heat box housing (100) respectively and are connected to the power supply assembly outside the heat box housing (100); the temperature probe of the temperature sensor (103) extends into the inner cavity of the heat box housing (100); the heating wire (104) is set on the inner wall of the heat box housing (100); its characteristics are: The hot box housing (100) is also provided with a purge gas inlet (101) and a purge gas outlet (102); an inert gas cylinder (301), a solenoid valve (302), a flow meter (303), a cooler (305), and a hydrogen sensor (306) are also provided outside the hot box housing (100); the solenoid valve (302) is connected to the outlet of the inert gas cylinder (301), the solenoid valve (302) and the flow meter (303) are connected in series, the outlet of the flow meter (303) is connected to the purge gas inlet (101), the purge gas outlet (102) is connected to the hot side flow channel of the cooler (305), and the hydrogen sensor (306) is set at the outlet of the hot side flow channel of the cooler (305).

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