Air tightness detection device for liquid cooling galvanic pile

Abstract

The utility model discloses an air tightness detection device for a liquid cooling galvanic pile. The air tightness detection device comprises an air storage tank, a pressure reducing valve, a first air inlet valve, a second air inlet valve, a third air inlet valve, a fourth air inlet valve, a fifth air inlet valve, a first exhaust valve, a second exhaust valve, a third exhaust valve, a fourth exhaust valve and a first flow meter, the gas storage tank is communicated with a first gas inlet valve through a pressure reducing valve, the first gas inlet valve is communicated with a first flowmeter and a second gas inlet valve, and the first flowmeter is communicated with the second gas inlet valve, a third gas inlet valve, a fourth gas inlet valve and a fifth gas inlet valve; the third gas inlet valve, the fourth gas inlet valve and the fifth gas inlet valve are respectively communicated with the fuel gas cavity, the coolant cavity and the oxidant cavity; a first exhaust valve is arranged on a pipeline between the first air inlet valve and the first flow meter; and a second exhaust valve, a third exhaust valve and a fourth exhaust valve are respectively arranged on the fuel gas cavity, the coolant cavity and the oxidant cavity. According to the utility model, the detection efficiency and the detection accuracy are improved.

Description

Technical Field

[0001] This utility model belongs to the field of fuel cell air tightness testing technology, and in particular relates to an air tightness testing device for liquid-cooled fuel cell stacks. Background Technology

[0002] Fuel cells convert the chemical energy stored in fuel (such as hydrogen) and oxidant (such as air) into electrical energy. Compared with existing conventional energy conversion technologies, fuel cells have many advantages, including higher energy conversion efficiency, zero emissions, and quiet operation with no moving parts. In membrane fuel cells, bipolar plates are the core component, accounting for a significant proportion of the overall weight and cost of the fuel cell stack. Their main functions are as follows:

[0003] ① It provides structural support for the fuel cell stack; ② It provides a flow channel (or "flow field") for the three media involved in the reaction, namely hydrogen, air and coolant, while isolating the three media; ③ It conducts electricity, connecting the individual cells in series to form a whole stack.

[0004] Bipolar plates are typically constructed by stacking and welding or bonding fuel plates and oxidizer plates. Two or more bipolar plates are then bonded and sealed together to form fuel gas chambers, oxidizer chambers, and coolant chambers. Leakage in any of these chambers directly affects the power generation efficiency, performance, and safety of the liquid-cooled fuel cell stack. Therefore, airtightness testing is a critical technology for fuel cells.

[0005] Currently, the airtightness test of liquid-cooled fuel cells typically involves directly immersing the cell in water to observe for bubble formation. If bubbles are generated, the entire liquid-cooled fuel cell is disassembled, the faulty plate is replaced, and the airtightness test is repeated until no bubbles are generated. This testing method is not only time-consuming and inefficient, resulting in inaccurate results, but also carries a certain risk of damage during the testing process. Utility Model Content

[0006] The purpose of this invention is to provide a liquid-cooled fuel cell stack airtightness testing device to solve the problems of low testing efficiency, low accuracy of testing results, and potential damage risk of traditional testing technologies.

[0007] The present invention solves the above-mentioned technical problems through the following technical solution: a liquid-cooled electric stack air tightness detection device, comprising an air storage tank, a pressure reducing valve, a first air inlet valve, a second air inlet valve, a third air inlet valve, a fourth air inlet valve, a fifth air inlet valve, a first exhaust valve, a second exhaust valve, a third exhaust valve, a fourth exhaust valve, and a first flow meter;

[0008] The gas storage tank is connected to the inlet of the first inlet valve via a pressure reducing valve. The outlet of the first inlet valve is connected to the inlet of the first flow meter and the second inlet valve. The first flow meter is connected to the outlet of the second inlet valve, the third inlet valve, the fourth inlet valve, and the fifth inlet valve. The third inlet valve is also connected to the fuel gas chamber, the fourth inlet valve is also connected to the coolant chamber, and the fifth inlet valve is also connected to the oxidant chamber. A first exhaust valve is provided on the pipeline between the first inlet valve and the first flow meter. A second exhaust valve, a third exhaust valve, and a fourth exhaust valve are respectively provided on the fuel gas chamber, the coolant chamber, and the oxidant chamber.

[0009] Furthermore, a pressure transmitter is provided at the outlet of the first flow meter.

[0010] Furthermore, the airtightness detection device also includes a second flow meter, a first pneumatic valve, a second pneumatic valve, and a third pneumatic valve. The fuel gas chamber is connected to the second flow meter through the first pneumatic valve, the coolant chamber is connected to the second flow meter through the second pneumatic valve, and the oxidant chamber is connected to the second flow meter through the third pneumatic valve.

[0011] The fuel gas chamber and the coolant chamber share a common wall surface, and the coolant chamber and the oxidant chamber share a common wall surface.

[0012] Furthermore, the airtightness detection device also includes a control module, and the first intake valve, the second intake valve, the third intake valve, the fourth intake valve, the fifth intake valve, the first exhaust valve, the second exhaust valve, the third exhaust valve, and the fourth exhaust valve are respectively connected to the control module.

[0013] Furthermore, a safety valve is provided on the gas storage tank.

[0014] Furthermore, a filter is installed on the pipeline between the gas storage tank and the pressure reducing valve.

[0015] Furthermore, the gas storage tank is also connected to an external gas source via a triplet.

[0016] Compared with the prior art, the advantages of this utility model are:

[0017] The liquid-cooled fuel cell stack airtightness testing device provided by this utility model uses an air storage tank to ventilate each cavity and judges the external leakage of each cavity based on the flow meter reading, which improves the testing efficiency and accuracy and avoids the risk of damage that may be caused by directly immersing the liquid-cooled fuel cell stack in water.

[0018] Compared with traditional airtightness testing devices, this utility model has a simple structure, low environmental requirements, strong anti-interference ability, and small space occupation, solving the problems of traditional testing equipment being heavy, occupying a large area, and being inconvenient for maintenance, troubleshooting, and relocation. Attached Figure Description

[0019] To more clearly illustrate the technical solution of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only one embodiment of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the liquid-cooled fuel cell stack airtightness detection device in an embodiment of this utility model. Detailed Implementation

[0021] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0022] Figure 1 A schematic diagram of the liquid-cooled fuel cell stack airtightness testing device is shown. Figure 1 As shown, the liquid-cooled fuel cell stack airtightness testing device provided by this utility model includes a gas storage tank, a pressure reducing valve, a first inlet valve, a second inlet valve, a third inlet valve, a fourth inlet valve, a fifth inlet valve, a first exhaust valve, a second exhaust valve, a third exhaust valve, a fourth exhaust valve, and a first flow meter. The gas storage tank is connected to the inlet of the first inlet valve through the pressure reducing valve. The outlet of the first inlet valve is connected to the inlet of the first flow meter and the second inlet valve. The first flow meter is connected to the outlet of the second inlet valve, the third inlet valve, the fourth inlet valve, and the fifth inlet valve. The third inlet valve is also connected to the fuel gas chamber, the fourth inlet valve is also connected to the coolant chamber, and the fifth inlet valve is also connected to the oxidizer chamber. A first exhaust valve is provided on the pipeline between the first inlet valve and the first flow meter. A second exhaust valve, a third exhaust valve, and a fourth exhaust valve are respectively provided on the fuel gas chamber, the coolant chamber, and the oxidizer chamber.

[0023] The airtightness testing of liquid-cooled fuel cell stacks includes external leakage testing of the fuel gas chamber, coolant chamber, and oxidizer chamber. There are two methods for external leakage testing: the first method involves simultaneous testing of the fuel gas chamber, coolant chamber, and oxidizer chamber; the second method involves separate testing of the fuel gas chamber, coolant chamber, and oxidizer chamber.

[0024] The specific process of the first detection method is as follows: The first, second, third, and fourth exhaust valves are closed. The gas in the storage tank is reduced to 200 kPa through a pressure reducing valve to provide the detection pressure. The reduced-pressure gas flows through the first inlet valve into the first flow meter and the second inlet valve. The third, fourth, and fifth inlet valves are all open, rapidly filling the fuel gas chamber, coolant chamber, and oxidizer chamber with gas. After the gas pressure in the pipeline stabilizes, the second inlet valve is closed, and the reading of the first flow meter is obtained. After testing for several minutes (e.g., 5 minutes), it is determined whether the reading of the first flow meter exceeds the standard threshold. If not, it indicates that there is no external leakage in the fuel gas chamber, coolant chamber, and oxidizer chamber, and the test passes. If yes, it indicates that at least one of the fuel gas chamber, coolant chamber, and oxidizer chamber has an external leakage. External leakage detection is performed on the fuel gas chamber, coolant chamber, and oxidizer chamber separately to determine which chamber has an external leakage. After the test is completed, close the first intake valve and open the first exhaust valve, second exhaust valve, third exhaust valve and fourth exhaust valve to expel excess gas from the pipeline and cavity.

[0025] In the second detection method, the specific process for detecting external leakage in the fuel gas chamber is as follows: The first, second, third, and fourth exhaust valves, the fourth intake valve, and the fifth intake valve are closed. Gas in the storage tank is depressurized by the pressure reducing valve and then flows through the first intake valve into the first flow meter and the second intake valve. The third intake valve is open, and the fuel gas chamber is rapidly filled with gas through the second and third intake valves. After the gas pressure in the pipeline stabilizes, the second intake valve is closed, and the reading of the first flow meter is obtained. After testing for several minutes (e.g., 5 minutes), it is determined whether the reading of the first flow meter exceeds the standard threshold. If not, it indicates that there is no external leakage in the fuel gas chamber, and the test passes; if so, it indicates that there is external leakage in the fuel gas chamber, and the test fails. After the fuel gas chamber test is completed, the first intake valve is closed, and the first and second exhaust valves are opened to expel excess gas from the pipeline and the fuel gas chamber.

[0026] In the second detection method, the specific process for detecting external leakage in the coolant chamber is as follows: The first, second, third, and fourth exhaust valves, the third intake valve, and the fifth intake valve are closed. Gas in the storage tank is depressurized by the pressure reducing valve and then flows through the first intake valve into the first flow meter and the second intake valve. The fourth intake valve is open, and the coolant chamber is rapidly inflated through the second and fourth intake valves. After the gas pressure in the pipeline stabilizes, the second intake valve is closed, and the reading of the first flow meter is obtained. After testing for several minutes (e.g., 5 minutes), it is determined whether the reading of the first flow meter exceeds the standard threshold. If not, it indicates that there is no external leakage in the coolant chamber, and the test passes; if so, it indicates that there is external leakage in the coolant chamber, and the test fails. After the coolant chamber test is completed, the first intake valve is closed, and the first and third exhaust valves are opened to expel excess gas from the pipeline and the coolant chamber.

[0027] In the second detection method, the specific process for detecting external leakage in the oxidizer chamber is as follows: The first, second, third, and fourth exhaust valves, as well as the third and fourth intake valves, are closed. Gas in the storage tank is depressurized by the pressure reducing valve and then flows through the first intake valve into the first flow meter and the second intake valve. The fifth intake valve is open, and the oxidizer chamber is rapidly filled with gas through the second and fifth intake valves. After the gas pressure in the pipeline stabilizes, the second intake valve is closed, and the reading of the first flow meter is obtained. After testing for several minutes (e.g., 5 minutes), it is determined whether the reading of the first flow meter exceeds the standard threshold. If not, it indicates that there is no external leakage in the oxidizer chamber, and the test passes; if so, it indicates that there is external leakage in the oxidizer chamber, and the test fails. After the oxidizer chamber test is completed, the first intake valve is closed, and the first and fourth exhaust valves are opened to expel excess gas from the pipeline and the oxidizer chamber.

[0028] The standard threshold is set based on the number of stacked liquid-cooled fuel cell stacks and the airtightness requirements. In this embodiment, the standard threshold is set to 0.03 sccm * number of stacked liquid-cooled fuel cell stacks.

[0029] In a specific embodiment of this utility model, a pressure transmitter is provided at the outlet of the first flow meter. The pressure transmitter detects the air pressure in the pipeline, and the air pressure curve is used to determine whether the air pressure in the pipeline is stable during the air tightness test. At the same time, the air pressure curve can also help determine whether there is a leak. If the air pressure curve remains within a certain range, it indicates that there is no leak.

[0030] In a specific embodiment of this utility model, the airtightness detection device further includes a second flow meter, a first pneumatic valve, a second pneumatic valve, and a third pneumatic valve. The fuel gas chamber is connected to the second flow meter through the first pneumatic valve, the coolant chamber is connected to the second flow meter through the second pneumatic valve, and the oxidant chamber is connected to the second flow meter through the third pneumatic valve. The other end of the second flow meter is open to the atmosphere.

[0031] When the fuel gas chamber and coolant chamber share the same wall surface, and the coolant chamber and oxidizer chamber share the same wall surface, only external leakage can be detected in the fuel gas chamber, coolant chamber and oxidizer chamber, but cross-leakage between the chambers cannot be detected. Therefore, a second flow meter, a first pneumatic valve, a second pneumatic valve and a third pneumatic valve are added to detect cross-leakage.

[0032] During the cross-leakage detection between the fuel gas chamber and the coolant chamber (when the fuel gas is hydrogen and the coolant is water, i.e., hydrogen-water cross-leakage detection), the first exhaust valve, second exhaust valve, third exhaust valve, fourth exhaust valve, fourth intake valve, fifth intake valve, first pneumatic valve, and third pneumatic valve are closed. The gas in the storage tank is depressurized by the pressure reducing valve and flows into the first flow meter and second intake valve through the first intake valve. The third intake valve is in the open state. The gas enters the fuel gas chamber through the second and third intake valves. The second pneumatic valve is in the open state. The reading of the second flow meter is obtained. After testing for a few minutes (e.g., 5 minutes), it is determined whether the reading of the second flow meter exceeds the standard threshold. If not, it indicates that there is no cross-leakage between the fuel gas chamber and the coolant chamber, and the test passes; if yes, it indicates that there is cross-leakage between the fuel gas chamber and the coolant chamber, and the test fails.

[0033] During the leakage detection between the fuel gas chamber and the oxidizer chamber (when the fuel gas is hydrogen and the oxidizer is oxygen, i.e., hydrogen-oxygen leakage detection), the first exhaust valve, second exhaust valve, third exhaust valve, fourth exhaust valve, fourth intake valve, fifth intake valve, first pneumatic valve, and second pneumatic valve are closed. The gas in the storage tank is depressurized by the pressure reducing valve and flows into the first flow meter and second intake valve through the first intake valve. The third intake valve is in the open state. The gas enters the fuel gas chamber through the second and third intake valves. The third pneumatic valve is in the open state. The reading of the second flow meter is obtained. After testing for a few minutes (e.g., 5 minutes), it is determined whether the reading of the second flow meter exceeds the standard threshold. If not, it indicates that there is no leakage between the fuel gas chamber and the oxidizer chamber, and the test passes; if yes, it indicates that there is leakage between the fuel gas chamber and the oxidizer chamber, and the test fails.

[0034] During the leakage detection of the fuel gas chamber, oxidizer chamber, and coolant chamber (when the fuel gas is hydrogen, the coolant is water, and the oxidant is oxygen, i.e., hydrogen-oxygen-water leakage detection), the first exhaust valve, second exhaust valve, third exhaust valve, fourth exhaust valve, fourth intake valve, first pneumatic valve, and third pneumatic valve are closed. The gas in the storage tank is depressurized by the pressure reducing valve and flows into the first flow meter and second intake valve through the first intake valve. The third and fifth intake valves are in the open state. The gas enters the fuel gas chamber and oxidizer chamber through the second, third, and fifth intake valves. The second pneumatic valve is in the open state. The reading of the second flow meter is obtained. After testing for a few minutes (e.g., 5 minutes), it is determined whether the reading of the second flow meter exceeds the standard threshold. If not, it indicates that there is no leakage between the fuel gas chamber and the coolant chamber, or between the oxidizer chamber and the coolant chamber, and the test passes. If yes, it indicates that there is leakage between the fuel gas chamber and the coolant chamber, or between the oxidizer chamber and the coolant chamber, and the test fails.

[0035] In a specific embodiment of this utility model, the airtightness detection device further includes a control module. The first air inlet valve, the second air inlet valve, the third air inlet valve, the fourth air inlet valve, the fifth air inlet valve, the first exhaust valve, the second exhaust valve, the third exhaust valve, and the fourth exhaust valve are respectively connected to the control module. The control module controls the opening and closing of each valve, which can realize automatic detection, improve detection efficiency, and save time and manpower.

[0036] In a specific embodiment of this utility model, a safety valve is provided on the gas storage tank. The safety valve improves the safety of gas use and prevents excessive gas in the gas storage tank.

[0037] In a specific embodiment of this utility model, a filter is provided on the pipeline between the gas storage tank and the pressure reducing valve. The filter removes impurities from the gas, thus preventing contamination of the pipeline by impurities.

[0038] In a specific embodiment of this utility model, the gas storage tank is also connected to an external gas source through a triplet. By filling the gas storage tank with gas through the triplet, the gas fluctuations at the front end can be stabilized.

[0039] The above description only discloses specific embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or modifications that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A liquid-cooled fuel cell stack airtightness testing device, characterized in that: The airtightness testing device includes an air tank, a pressure reducing valve, a first air inlet valve, a second air inlet valve, a third air inlet valve, a fourth air inlet valve, a fifth air inlet valve, a first exhaust valve, a second exhaust valve, a third exhaust valve, a fourth exhaust valve, and a first flow meter; The gas storage tank is connected to the inlet of the first inlet valve via a pressure reducing valve. The outlet of the first inlet valve is connected to the inlet of the first flow meter and the second inlet valve. The first flow meter is connected to the outlet of the second inlet valve, the third inlet valve, the fourth inlet valve, and the fifth inlet valve. The third inlet valve is also connected to the fuel gas chamber, the fourth inlet valve is also connected to the coolant chamber, and the fifth inlet valve is also connected to the oxidant chamber. A first exhaust valve is provided on the pipeline between the first inlet valve and the first flow meter. A second exhaust valve, a third exhaust valve, and a fourth exhaust valve are respectively provided on the fuel gas chamber, the coolant chamber, and the oxidant chamber.

2. The liquid-cooled fuel cell stack airtightness testing device according to claim 1, characterized in that: A pressure transmitter is installed at the outlet of the first flow meter.

3. The liquid-cooled fuel cell stack airtightness testing device according to claim 1, characterized in that: The airtightness detection device further includes a second flow meter, a first pneumatic valve, a second pneumatic valve, and a third pneumatic valve. The fuel gas chamber is connected to the second flow meter through the first pneumatic valve, the coolant chamber is connected to the second flow meter through the second pneumatic valve, and the oxidant chamber is connected to the second flow meter through the third pneumatic valve. The fuel gas chamber and the coolant chamber share a common wall surface, and the coolant chamber and the oxidant chamber share a common wall surface.

4. The liquid-cooled fuel cell stack airtightness testing device according to claim 1, characterized in that: The airtightness detection device also includes a control module, and the first air intake valve, the second air intake valve, the third air intake valve, the fourth air intake valve, the fifth air intake valve, the first exhaust valve, the second exhaust valve, the third exhaust valve, and the fourth exhaust valve are respectively connected to the control module.

5. The liquid-cooled fuel cell stack airtightness testing device according to claim 1, characterized in that: A safety valve is installed on the gas storage tank.

6. The liquid-cooled fuel cell stack airtightness testing device according to claim 1, characterized in that: A filter is installed on the pipeline between the gas storage tank and the pressure reducing valve.

7. The liquid-cooled fuel cell stack airtightness testing device according to any one of claims 1 to 6, characterized in that: The gas storage tank is also connected to an external gas source via a triplet.

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