A closed proton exchange membrane fuel cell system housing ventilation and drainage device

Abstract

The present invention discloses a closed proton exchange membrane fuel cell system housing ventilation and drainage device, which relates to the field of fuel cell technology. The device includes a fuel cell stack, a stack housing, an air compressor, and a hydrogen intake circulation device. The fuel cell stack is arranged in the stack housing, and an internal ventilation flow channel is formed between the fuel cell stack and the inner wall of the stack housing. The air compressor and the hydrogen intake circulation device are arranged outside the stack housing, and the air compressor outlet is connected to the fuel cell stack through the stack air intake pipe. The present invention has the characteristics of being able to cool the working environment of the fuel cell stack, remove condensed water or leaked water inside the stack housing, and provide sealing protection for the stack housing.

Description

Technical Field

[0001] The invention relates to the technical field of fuel cells, in particular to a closed proton exchange membrane fuel cell system housing ventilation and drainage device. Background Art

[0002] A hydrogen fuel cell stack is a place where hydrogen and oxygen undergo electrochemical reactions. Its main function is to generate electricity through electrochemical reactions, and the product is water. A fuel cell stack consists of a certain number of single cells stacked and sealed. The internal structure of a single cell is: bipolar plate-gas diffusion layer-electrode-catalytic layer-proton exchange membrane-catalytic layer-electrode-gas diffusion layer-bipolar plate, and a sealing ring is used to seal the two bipolar plates.

[0003] At present, most automotive fuel cell systems use a modular approach with closed shell packaging to ensure sealing, protect against dust and water, and protect the fuel cell stack. However, during the operation of the system, a small amount of hydrogen may leak and accumulate in the closed stack shell. If it cannot be diluted and discharged in time, there will be great safety hazards. In addition, the stack drain pipe interface may also leak liquid, and the temperature difference in the shell may produce condensed water.

[0004] For example, the Chinese patent: "A Ventilation Device for a Closed Fuel Cell System", with publication number (CN202585635U), has a branch line from the air compressor (11) to the front of the humidifier (7) connected to the shell gas distribution pipe (1,5-16), which is purged by the distribution block and the explosion-proof fan (14) at the same time to fully ventilate and dilute the inside of the stack shell. After the purge, the gas flows into the fuel cell air tail pipe (18) from the air outlet (17) and is discharged with the tail gas. Although the device has a relatively comprehensive ventilation and purge inside the shell without dead ends, this shell ventilation method is complex to design and install, and requires a large space for arrangement inside the stack shell. The temperature of the air directly drawn from the rear of the air compressor is high, which may cause high-temperature aging of the internal parts of the shell. In addition, the exhaust gas is connected to the tail pipe, which poses a risk of backflow of ambient air and moisture.

[0005] In addition, the Chinese patent: "Improved Ventilation Fuel Cell System", publication number (CN109638323A), uses the suction force generated by the negative pressure in front of the air compressor (16) to draw air from the outside of the stack shell through the flow limiter (32) to ventilate and purge the shell, so as to achieve the purpose of diluting the possible hydrogen leakage, and the purged gas is merged into the air compressor intake. Although this design is simple in principle, easy to design and install, and does not consume extra energy; but its disadvantages are also obvious: when there is hydrogen leakage or a small amount of overflow in the stack in the shell, there is a risk that the air compressor directly pumps hydrogen-containing compressed air into the cathode circuit of the fuel cell stack, which may cause damage to the stack; in addition, if the air inlet flow limiter has no air filtering function, it may also cause S-containing and N-containing compound impurities in the air to contaminate the proton exchange membrane.

[0006] The Chinese utility model patent, with publication number (CN203039265U), mentions that the hydrogen concentration sensor sets the fan to start according to the hydrogen concentration. The specific description is: "When the hydrogen concentration in the indoor air of the battery room or high-voltage room reaches 1 / 4 of its lower explosion concentration, the hydrogen concentration sensor triggers the start end of the hydrogen concentration relay QQ, the coil of the hydrogen concentration relay QQ is energized, and the normally open contact of the hydrogen concentration relay QQ is closed, so that the coil of the second AC contactor JJ2 is energized, and the normally open contact of the second AC contactor JJ2 is closed, and the electric fan runs to discharge the indoor air to the outside." Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a closed proton exchange membrane fuel cell system shell ventilation and drainage device, the purpose of which is to solve the problems of high temperature in the stack shell, aging of internal parts, and backflow of air and moisture.

[0008] To achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0009] A closed proton exchange membrane fuel cell system housing ventilation and drainage device, comprising a fuel cell stack, a stack housing, an air compressor, and a hydrogen intake circulation device, wherein the fuel cell stack is arranged in the stack housing, an inner ventilation channel is formed between the fuel cell stack and the inner wall of the stack housing, the air compressor and the hydrogen intake circulation device are arranged outside the stack housing, the air compressor outlet is connected to the fuel cell stack through the stack air intake pipe, the air compressor inlet is provided with an air compressor intake pipe, the hydrogen intake circulation device outlet is connected to the fuel cell stack through the stack hydrogen intake pipe, and the hydrogen intake circulation device is provided with two inlets, one of which is on the A hydrogen inlet pipe is provided, and another inlet is connected with the fuel cell stack through the stack hydrogen outlet pipe; a hydrogen concentration sensor for detecting the hydrogen concentration is provided on the inner wall of the stack shell; an air tail exhaust pipe is provided at the lower part of the fuel cell stack, and the air tail exhaust pipe passes through the stack shell and extends outward; an electronic fan for adjusting according to the hydrogen concentration is provided on the side wall of the stack shell near the top; the electronic fan is connected with the air tail exhaust pipe through the stack shell outlet pipe; a one-way check valve is provided on the stack shell outlet pipe; a stack shell inlet pipe is also provided at the bottom of the stack shell, and a selective filter valve is provided on the stack shell inlet pipe.

[0010] Preferably, an adjustable stop valve is provided on the stack hydrogen outlet pipe, so as to control the flow rate and speed of the stack hydrogen reflux.

[0011] Preferably, the compressor air intake pipe inlet is provided with an air filter and is connected to the air filter outlet, and the air filter inlet is provided with an air filter inlet pipe, so that dust, particulate matter, moisture, etc. in the gas can be filtered out to clean the air.

[0012] Beneficial effects of the present invention:

[0013] 1. The solution provided by the present invention does not take air from the air compressor for housing ventilation, which reduces the burden on the air compressor and improves the stability of air supply in the air path. In addition, the air intake temperature is relatively low, which can cool the working environment of the fuel cell stack.

[0014] 2. In the solution provided by the present invention, a filter valve is arranged on the air intake pipe of the stack housing to have a filtering function, thereby ensuring the cleanliness and dryness of the intake air and protecting the internal components of the stack and the housing;

[0015] 3. The solution provided by the present invention, in addition, a filter valve is arranged on the air inlet pipe of the stack shell, which also has the function of eliminating condensation or leakage of water inside the stack shell.

[0016] 4. In the solution provided by the present invention, the one-way check valve and the filter valve can provide sealing protection for the battery stack casing when the system is shut down. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a closed proton exchange membrane fuel cell system housing ventilation and drainage device provided in an embodiment of the present invention;

[0018] In the figure, 1-fuel cell stack; 2-selective filter valve; 3-electronic fan; 4-one-way check valve; 5-stack housing; 6-air compressor; 7-air filter; 8-hydrogen intake circulation device; 9-hydrogen concentration sensor; 10-adjustable stop valve; 11-air filter inlet pipe; 12-air compressor inlet pipe; 13-stack air inlet pipe; 14-air tail exhaust pipe; 15-stack housing inlet pipe; 16-internal ventilation flow channel; 17-stack housing outlet pipe; 18-hydrogen inlet pipe; 19-stack hydrogen inlet pipe; 20-stack hydrogen outlet pipe. DETAILED DESCRIPTION

[0019] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is a description of the embodiments in conjunction with the accompanying drawings.

[0020] Example

[0021] like Figure 1 As shown, the present invention provides a closed proton exchange membrane fuel cell system shell ventilation and drainage device, including a fuel cell stack 1, a stack shell 5, an air compressor 6, and a hydrogen intake circulation device 8. The fuel cell stack 1 is arranged in the stack shell 5, and an internal ventilation flow channel 16 is formed between the fuel cell stack 1 and the inner wall of the stack shell 5. The air compressor 6 and the hydrogen intake circulation device 8 are arranged outside the stack shell 5. The outlet of the air compressor 6 is connected to the fuel cell stack 1 through the stack air intake pipe 13, and the inlet of the air compressor 6 is provided with an air compressor intake pipe 12. The outlet of the hydrogen intake circulation device 8 is connected to the fuel cell stack 1 through the stack hydrogen intake pipe 19. The hydrogen intake circulation device 8 is provided with two inlets, one of which is an inlet. A hydrogen inlet pipe 18 is arranged on the inlet, and the other inlet is connected with the fuel cell stack 1 through the stack hydrogen outlet pipe 20. A hydrogen concentration sensor 9 for detecting the hydrogen concentration is arranged on the inner wall of the stack shell 5. An air tail exhaust pipe 14 is arranged at the lower part of the fuel cell stack 1. The air tail exhaust pipe 14 passes through the stack shell 5 and extends outward. An electronic fan 3 for adjusting according to the hydrogen concentration is arranged on the side wall of the stack shell 5 near the top. The electronic fan 3 is connected with the air tail exhaust pipe 14 through the stack shell outlet pipe 17. A one-way check valve 4 is arranged on the stack shell outlet pipe 17. A stack shell inlet pipe 15 is also arranged at the bottom of the stack shell 5, and a selective filter valve 2 is arranged on the stack shell inlet pipe 15.

[0022] like Figure 1As shown, when the fuel cell stack 1 is working, air is obtained at the inlet of the air compressor 6 through the air compressor intake pipe 12, and then the air compressor 6 continuously provides air to the fuel cell stack 1 through the stack air intake pipe 13; at the same time, the hydrogen intake circulation device 8 receives the hydrogen coming in from the hydrogen intake pipe 18, and provides hydrogen to the fuel cell stack 1 through the stack hydrogen intake pipe 19. After the fuel cell stack 1 has been working for a period of time, if the concentration of hydrogen in the fuel cell stack 1 is too high, it can flow back to the hydrogen intake circulation device 8 through the stack hydrogen outlet pipe 20 and then be provided to the fuel cell stack 1; the excess air in the fuel cell stack 1 can be discharged through the air tail pipe 14. In the closed battery stack shell 5, during the operation of the system, a small amount of hydrogen may leak and accumulate in the battery stack shell 5. When the hydrogen concentration sensor 9 on the inner wall of the battery stack shell 5 detects that the hydrogen concentration reaches the warning value, the electronic fan 3 starts to operate at a high speed to increase the ventilation volume (please refer to the prior art CN203039265U), quickly dilute and remove the hydrogen leaked in the shell, and the gas flow route is as follows: the gas enters the battery stack shell 5 through the battery stack shell inlet pipe 15, and because the electronic fan 3 continuously extracts gas and discharges it through the battery stack shell outlet pipe 17, the gas entering the battery stack shell 5 will pass through the internal ventilation flow channel 16 together with the hydrogen and moisture generated by the fuel cell stack 1, and flow through the electronic fan 3, the one-way check valve 4, the battery stack shell outlet pipe 17, and the air tail exhaust pipe 14 and be discharged outside the battery stack shell 5, thereby preventing hydrogen and moisture from accumulating in the battery stack shell 5;

[0023] When the fuel cell stack is not working, the electronic fan 3 stops working, and the selective filter valve 2 and the one-way check valve 4 cooperate with the stack housing 5 to seal and protect the working environment of the fuel cell stack 1 to prevent harmful gases, impurities and moisture in the ambient atmosphere from entering the stack housing 5; when the fuel cell stack 1 system is shut down, the fuel cell stack 1 and the hydrogen intake circulation device 8 and the air compressor 6 stop working, and the electronic fan 3 continues to work and purge for a certain period of time to remove hydrogen and moisture that may remain in the stack housing 5. After the electronic fan 3 completes the purge, the selective filter valve 2 and the one-way check valve 4 can prevent impurities, moisture, etc. from entering the stack housing 5, thereby playing a role in sealing and protection.

[0024] Therefore, through this device, the working environment of the fuel cell stack 1 can be ventilated, protected from hydrogen leakage and cooled; during the system shutdown process and shutdown state, the sealing protection function inside the shell can also be realized, and the air inlet selective filter valve 2 can have a filtering function to ensure the cleanliness and dryness of the intake air, protect the internal components of the stack shell 5, and at the same time, condense water or leaked moisture inside the stack shell 5.

[0025] Furthermore, an adjustable stop valve 10 is provided on the hydrogen outlet pipe 19 of the fuel cell stack, so as to control the flow rate and speed of the hydrogen in the fuel cell stack 1 flowing back to the hydrogen intake circulation device 8.

[0026] Meanwhile, in another embodiment, the inlet of the air compressor intake pipe 12 is provided with an air filter 7, which is communicated with the outlet of the air filter 7, and the inlet of the air filter 7 is provided with an air filter intake pipe 11. In this way, dust, particulate matter, moisture, etc. in the air entering the air compressor 6 can be filtered out, thereby playing the role of cleaning the air.

[0027] Although the present invention has been described in detail above with specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A closed proton exchange membrane fuel cell system housing ventilation and drainage device, characterized in that: The invention comprises a fuel cell stack (1), a stack shell (5), an air compressor (6), and a hydrogen intake circulation device (8), wherein the fuel cell stack (1) is arranged in the stack shell (5), an inner ventilation channel (16) is formed between the fuel cell stack (1) and the inner wall of the stack shell (5), the air compressor (6) and the hydrogen intake circulation device (8) are arranged outside the stack shell (5), the outlet of the air compressor (6) is connected to the fuel cell stack (1) through the stack air intake pipe (13), the inlet of the air compressor (6) is provided with an air compressor intake pipe (12), the outlet of the hydrogen intake circulation device (8) is connected to the fuel cell stack (1) through the stack hydrogen intake pipe (19), the hydrogen intake circulation device (8) is provided with two inlets, one of which is provided with a hydrogen intake pipe (18), and the other inlet is connected to the fuel cell stack (1) through the stack hydrogen outlet pipe (20), and a gas detection device (21) is provided on the inner wall of the stack shell (5). A hydrogen concentration sensor (9) for measuring hydrogen concentration, wherein an air tail exhaust pipe (14) is arranged at the lower part of the fuel cell stack (1), the air tail exhaust pipe (14) passes through the stack shell (5) and extends outward, an electronic fan (3) for adjusting according to the hydrogen concentration is arranged on the side wall of the stack shell (5) near the top, the electronic fan (3) is connected to the air tail exhaust pipe (14) through the stack shell outlet pipe (17), and the stack shell outlet pipe (17) is provided with A one-way check valve (4) is provided, and a stack housing air inlet pipe (15) is also provided at the bottom of the stack housing (5), and a selective filter valve (2) is provided on the stack housing air inlet pipe (15); an adjustable stop valve (10) is provided on the stack hydrogen outlet pipe (20); an air filter (7) is provided at the inlet of the air compressor air inlet pipe (12), and is connected to the outlet of the air filter (7), and an air filter air inlet pipe (11) is provided at the inlet of the air filter (7).

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