Electric pile air tightness testing device and testing method thereof

Abstract

The invention relates to the field of galvanic pile testing, in particular to a galvanic pile airtightness testing device and a testing method thereof. The two ends of the air supply path are communicated with the galvanic pile and the air inlet respectively, the galvanic pile is communicated with the exhaust hole, the two ends of the purification water path are communicated with the transparent water tank and the water inlet respectively, the transparent water tank is communicated with the water outlet, and the galvanic pile can be placed in the transparent water tank. Before testing, the air supply path supplies air and ensures that the air pressure is the testing pressure, the water purification path purifies water in the whole system, the galvanic pile is placed in the transparent water tank, and the sealing effect of the galvanic pile is judged according to whether the pure water has bubbles or not in the air supply process, namely the air leakage phenomenon. Compared with the prior art that the water purification path purifies the test water in the transparent water tank into pure water, the pure water test environment can be formed only by using common water without adding pure water, the use cost is greatly reduced, the transparent water tank is convenient for observing bubbles, the detection effect is very obvious, and fault points are relatively directly found.

Description

Technical Field

[0001] This invention relates to the field of fuel cell stack testing, and more particularly to a fuel cell stack airtightness testing device and testing method. Background Technology

[0002] In the current field of fuel cell stack airtightness testing, traditional test benches, while providing accurate test results, are prohibitively expensive for many companies. Furthermore, although test benches can detect leaks, the process of observing these leaks is not intuitive, causing confusion for operators. On the other hand, while tooling testing is a viable alternative, its connection process is cumbersome, its integration is low, and it requires adding pure water to a transparent tank for each test, increasing operational complexity and leading to frequent water changes. The utilization rate of pure water is also very low under these circumstances, resulting in resource waste.

[0003] The existing technical solutions mainly include the following two types:

[0004] 1. Test bench testing: While this method can provide accurate test results, its high cost makes it unaffordable for many companies. Furthermore, although test benches can detect leaks, the process of observing these leaks is not intuitive, which can be confusing for operators.

[0005] 2. Tooling Testing: Tooling testing mainly consists of two forms: soap bubble testing and pure water testing. While soap bubble testing can detect leaks, the process of observing the leak is not intuitive and carries the risk of contamination. Pure water testing, on the other hand, requires frequent water changes, resulting in very low utilization of pure water and wasting resources. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a fuel cell stack airtightness testing device and testing method, thereby solving the problem of difficult fuel cell stack testing.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A fuel cell stack airtightness testing device includes a shell, a transparent water tank, a fuel cell stack, a gas supply line, and a purification water line. The shell is provided with an air inlet, an exhaust port, a water inlet, and a drain port. The two ends of the gas supply line are respectively connected to the fuel cell stack and the air inlet. The fuel cell stack is connected to the exhaust port. The two ends of the purification water line are respectively connected to the transparent water tank and the water inlet. The transparent water tank is connected to the drain port. The fuel cell stack can be placed inside the transparent water tank.

[0008] Furthermore, the gas supply path includes an intake solenoid valve, a thermometer, and a first digital pressure gauge connected in sequence via pipelines. The intake solenoid valve is connected to the air inlet, and the first digital pressure gauge is connected to the fuel cell stack. A venting path is provided on the pipeline connecting the intake solenoid valve and the air inlet, and a venting solenoid valve is provided on the venting path.

[0009] Furthermore, a pressure reducing valve and a second digital pressure gauge are provided between the intake solenoid valve and the intake port, and both the pressure reducing valve and the second digital pressure gauge are connected to the pipeline connecting the intake solenoid valve and the intake port.

[0010] Furthermore, a timer and an exhaust solenoid valve are installed on the pipeline connecting the fuel cell stack to the exhaust port.

[0011] Furthermore, the purification water circuit includes a water pump, a deionizer, and an inlet solenoid valve connected in sequence by pipelines. The water pump is connected to the water inlet, and the inlet solenoid valve is connected to the transparent water tank.

[0012] Furthermore, it also includes a conductivity meter, a drain solenoid valve, and a circulating water circuit. The conductivity meter and the drain solenoid valve are installed on the pipeline connecting the transparent water tank and the drain outlet. One end of the circulating water circuit is connected to the pipeline connecting the water pump and the water inlet, and the other end of the circulating water circuit is connected to the pipeline connecting the conductivity meter and the drain solenoid valve. A circulating solenoid valve is installed on the circulating water circuit.

[0013] A method for testing the airtightness of a fuel cell stack includes the following steps:

[0014] S1: Adjust intake pressure;

[0015] S2: Open the inlet solenoid valve, close the drain solenoid valve, and stop filling the water when the liquid level display reaches 75%.

[0016] S3: Open the circulation solenoid valve. When the digital conductivity meter reading is ≤10μS / cm, turn off the water pump, close the inlet solenoid valve, and close the circulation solenoid valve.

[0017] S4: The fuel cell stack is placed in pure water in a transparent water tank for a leak test;

[0018] S5: Drain, close the circulation solenoid valve, open the drain solenoid valve, and close the drain solenoid valve when the liquid level gauge shows 0.

[0019] Furthermore, the adjustment method in step S1 is as follows:

[0020] According to the fuel cell stack to be tested, adjust the nitrogen pressure entering the stack, close the inlet solenoid valve and the vent solenoid valve, open the gas source, and adjust the pressure reducing valve and the vent solenoid valve to make the value of the second digital pressure gauge change to the pressure that the fuel cell stack to be tested can withstand.

[0021] Furthermore, the testing method for step S4 is as follows:

[0022] Close the venting solenoid valve and the exhaust solenoid valve. Open the intake solenoid valve and observe the pressure on the first digital pressure gauge and whether there are bubbles in the transparent water tank. The location where the bubbles are generated is the external leakage point of the fuel cell stack. If there are no bubbles and the value of the first digital pressure gauge does not decrease rapidly, close the intake solenoid valve and record the pressure on the digital fuel cell stack pressure gauge at this time. Enter the pressure holding state, time for 5 minutes, record the pressure on the digital fuel cell stack pressure gauge after 5 minutes, and automatically calculate the leakage amount.

[0023] This invention provides a fuel cell stack airtightness testing device, comprising a housing, a transparent water tank, a fuel cell stack, a gas supply path, and a purified water path. The housing is provided with an air inlet, an exhaust port, a water inlet, and a drain port. The gas supply path is connected at both ends to the fuel cell stack and the air inlet, respectively. The fuel cell stack is connected to the exhaust port. The purified water path is connected at both ends to the transparent water tank and the water inlet, respectively. The transparent water tank is connected to the drain port. The fuel cell stack can be placed inside the transparent water tank. In this way, all components are integrated inside the housing. Before testing, the gas supply path supplies gas, ensuring the gas pressure is at the test pressure. The purified water path purifies the water in the entire system. The fuel cell stack is placed in the transparent water tank. The airtightness of the fuel cell stack is judged by whether there are air bubbles (i.e., air leakage) in the pure water during the gas supply process. Compared to existing technologies where the purified water path purifies the test water in the transparent water tank to pure water, this device eliminates the need to add pure water and uses only ordinary water to create a pure water testing environment, significantly reducing operating costs. Furthermore, the transparent water tank facilitates observation of air bubbles, resulting in a very clear detection effect and relatively direct identification of fault points.

[0024] This invention provides a method for testing the airtightness of a fuel cell stack, comprising the following steps:

[0025] S1: Adjust intake pressure;

[0026] S2: Open the inlet solenoid valve, close the drain solenoid valve, and stop filling the water when the liquid level display reaches 75%.

[0027] S3: Open the circulation solenoid valve. When the digital conductivity meter reading is ≤10μS / cm, turn off the water pump, close the inlet solenoid valve, and close the circulation solenoid valve.

[0028] S4: The fuel cell stack is placed in pure water in a transparent water tank for a leak test;

[0029] S5: Drain, close the circulation solenoid valve, open the drain solenoid valve, and close the drain solenoid valve when the liquid level gauge shows 0. Attached Figure Description

[0030] Figure 1This is a schematic diagram of the structure of the fuel cell stack airtightness testing device of the present invention;

[0031] Figure 2 This is a schematic diagram of the process for testing the airtightness of a fuel cell stack according to the present invention.

[0032] The attached diagram lists the components represented by each number as follows:

[0033] 1. Shell, 2. Transparent water tank, 3. Fuel cell stack, 4. Air inlet, 5. Exhaust port, 6. Water inlet, 7. Drain outlet, 8. Air inlet solenoid valve, 9. Thermometer, 10. First digital pressure gauge, 11. Venting solenoid valve, 12. Pressure reducing valve, 13. Second digital pressure gauge, 14. Timer, 15. Exhaust solenoid valve, 16. Water pump, 17. Deionizer, 18. Water inlet solenoid valve, 19. Conductivity meter, 20. Drain solenoid valve, 21. Circulation solenoid valve. Detailed Implementation

[0034] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0035] In the description of this invention, it should be understood that the terms "upper", "lower", "center", "inner", "outer", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] like Figure 1As shown, the present invention provides an airtightness testing device for an electric fuel cell stack, comprising a housing 1, a transparent water tank 2, an electric fuel cell stack 3, an air supply path, and a purification water path. The housing 1 is provided with an air inlet 4, an exhaust port 5, a water inlet 6, and a drain port 7. The two ends of the air supply path are respectively connected to the electric fuel cell stack 3 and the air inlet 4, and the electric fuel cell stack 3 is connected to the exhaust port 5. The two ends of the purification water path are respectively connected to the transparent water tank 2 and the water inlet 6, and the transparent water tank 2 is connected to the drain port 7. The electric fuel cell stack 3 can be placed inside the transparent water tank 2. In this way, all components are integrated inside the housing 1. Before testing, the gas supply circuit supplies gas and ensures that the gas pressure is the test pressure. The purification water circuit purifies the water in the entire system. The fuel cell stack 3 is placed in the transparent water tank 2. The sealing effect of the fuel cell stack 3 is judged by whether there are air bubbles or leakage in the pure water during the gas supply process. Compared with the existing technology where the purification water circuit purifies the test water in the transparent water tank 2 to pure water, there is no need to add pure water. Ordinary water can be used to form a pure water test environment, which greatly reduces the cost of use. Moreover, the transparent water tank 2 makes it easy to observe air bubbles, and the detection effect is very obvious and the fault point can be found relatively directly.

[0038] The fuel cell stack airtightness testing device of the present invention, such as Figure 1 As shown, based on the previously described technical solution, the gas supply path can also be as follows: the gas supply path includes an inlet solenoid valve 8, a thermometer 9, and a first digital pressure gauge 10 connected in sequence via pipelines. The inlet solenoid valve 8 is connected to the inlet port 4, and the first digital pressure gauge 10 is connected to the fuel cell stack 3. A venting path is provided on the pipeline connecting the inlet solenoid valve 8 and the inlet port 4, and a venting solenoid valve 11 is provided on the venting path. Thus, during gas supply, after the inlet solenoid valve 8, the gas enters the fuel cell stack 3 through the thermometer 9 and the first digital pressure gauge 10. The thermometer 9 can monitor whether the temperature of the gas entering the fuel cell stack 3 meets the requirements, and the first digital pressure gauge 10 displays the real-time pressure value of the fuel cell stack 3. If the gas pressure value exceeds the pressure value that the fuel cell stack 3 can withstand during the gas supply process, the pressure is regulated by the venting valve.

[0039] The fuel cell stack airtightness testing device of the present invention, such as Figure 1As shown, based on the previously described technical solution, it can also be: a pressure reducing valve 12 and a second digital pressure gauge 13 are provided between the intake solenoid valve 8 and the intake port 4. Both the pressure reducing valve 12 and the second digital pressure gauge 13 are connected to the pipeline connecting the intake solenoid valve 8 and the intake port 4. In this way, by setting the pressure reducing valve 12 and the second digital pressure gauge 13 in the pipeline between the intake solenoid valve 8 and the intake port 4, the pressure reducing valve 12 reduces the pressure of the high-pressure gas at the intake port 4 according to a set pressure value through an internal adjustment mechanism, ensuring that the gas pressure entering the intake solenoid valve 8 is stable and lower than the original pressure at the intake port 4. When the intake pressure fluctuates, the pressure reducing valve 12 can automatically adjust its opening to keep the outlet pressure (i.e., the pressure before entering the intake solenoid valve 8) constant at a preset value, thereby achieving precise control of the gas pressure. The second digital pressure gauge 13 senses and measures the gas pressure at the outlet of the pressure reducing valve 12, i.e., the pressure before the intake solenoid valve 8, in real time through an internal pressure sensor. The pressure signal collected by the pressure sensor is converted into an electrical signal, processed by a digital processor, and clearly displayed digitally on the screen for easy real-time monitoring and recording by the operator. The pressure reducing valve 12 effectively ensures the stability of the gas pressure entering the intake solenoid valve 8, avoiding adverse effects on the solenoid valve performance caused by intake pressure fluctuations, thus improving the stability and reliability of the system. The regulating action of the pressure reducing valve 12 prevents damage to the intake solenoid valve 8 or other related equipment due to excessive intake pressure, thereby providing safety protection. The second digital pressure gauge 13 allows operators to understand the gas pressure before the intake solenoid valve 8 in real time and accurately, providing strong support for precise system control and adjustment. When a system malfunctions or abnormal pressure occurs, operators can quickly locate the problem by observing the display value of the second digital pressure gauge 13, thereby improving the efficiency of troubleshooting and handling.

[0040] The fuel cell stack airtightness testing device of the present invention, such as Figure 1 As shown, based on the technical solution described above, another option is to install a timer 14 and an exhaust solenoid valve 15 on the pipeline connecting the fuel cell stack 3 and the exhaust port 5. In this way, during the fuel cell stack 3 leakage test, to better ensure the accuracy of the test, the stack is left to stand in a pressurized environment for a period of time, and the difference in values ​​before and after the second digital pressure gauge 13 is used to further determine whether there is a leak. This ensures that even if the fuel cell stack 3 only experiences a slight leak that is not easily observed directly, the leak can be easily detected, guaranteeing the accuracy of the test.

[0041] The fuel cell stack airtightness testing device of the present invention, such as Figure 1As shown, based on the previously described technical solution, the purification water circuit can also be configured as follows: the purification water circuit includes a water pump 16, a deionizer 17, and an inlet solenoid valve 18 connected in sequence via pipelines. The water pump 16 is connected to the water inlet 6, and the inlet solenoid valve 18 is connected to the transparent water tank 2. In this way, the application of the deionizer 17 effectively removes ionic impurities from the water, such as calcium, magnesium, and other mineral ions, as well as any potentially present heavy metal ions, thereby significantly improving the water quality entering the transparent water tank 2 and ensuring the purity and accuracy for subsequent use or experiments. The combined use of the water pump 16 and the inlet solenoid valve 18 achieves automated water flow control. The water pump 16 is responsible for drawing water from the water inlet 6, while the inlet solenoid valve 18 precisely controls the water inflow according to system instructions. This not only improves work efficiency but also reduces the tediousness and error rate of manual operation. Because the components of the purification water circuit are relatively independent and easy to disassemble, maintenance or replacement of components can be performed conveniently and quickly, reducing maintenance costs and difficulty.

[0042] The fuel cell stack airtightness testing device of the present invention, such as Figure 1 As shown, based on the previously described technical solution, it can also include a conductivity meter 19, a drain solenoid valve 20, and a circulating water circuit. The conductivity meter 19 and the drain solenoid valve 20 are installed on the pipeline connecting the transparent water tank 2 and the drain outlet 7. One end of the circulating water circuit is connected to the pipeline connecting the water pump 16 and the water inlet 6, and the other end is connected to the pipeline connecting the conductivity meter 19 and the drain solenoid valve 20. A circulating solenoid valve 21 is installed on the circulating water circuit. In this way, the water pump 16 draws water from the water inlet 6 and sends the water into the transparent water tank 2 through the pipeline. This step provides a continuous water supply for the equipment. After the water enters the transparent water tank 2, the conductivity meter 19 starts working and monitors the conductivity of the water in the tank. Conductivity is a physical quantity that measures the amount of ions in an aqueous solution and can reflect the purity of the water or the concentration of specific ions. The conductivity meter 19 compares the monitored conductivity data with a preset standard value or threshold. If the water's conductivity exceeds or falls below the set range, it indicates that the water quality does not meet the requirements and needs treatment. Simultaneously, the circulating water circuit begins operation. The circulating solenoid valve 21 opens, allowing the water to re-enter the water tank through the circulating water circuit. In this way, the water is continuously monitored by the conductivity meter 19 during circulation until the water quality meets the requirements. This improves the accuracy and timeliness of water quality monitoring: Real-time monitoring of water quality by the conductivity meter 19 allows for timely detection of water quality problems and the implementation of corresponding measures, preventing the impact of water quality deterioration on subsequent processes or equipment. It also reduces operating costs: The ability to promptly detect and address water quality problems avoids additional expenses such as equipment damage or downtime for maintenance due to substandard water quality, thus reducing operating costs.

[0043] like Figure 2As shown, this invention provides a method for testing the airtightness of a fuel cell stack. Based on the fuel cell stack 3 to be tested, the nitrogen pressure entering the stack is adjusted, the inlet solenoid valve 8 and the vent solenoid valve 11 are closed, the gas source is opened (nitrogen is preferred as it is an inert gas and will not damage the fuel cell stack 3), the pressure reducing valve 12 and the vent solenoid valve 11 are adjusted so that the value on the second digital pressure gauge 13 becomes the pressure that the fuel cell stack 3 can withstand, the water pump 16 is turned on, water (tap water is acceptable) enters through the water inlet, the water inlet solenoid valve 18 is opened, the drain solenoid valve 20 is closed, the circulation solenoid valve 21 is opened, and the liquid level is increased to 75%, then the process is stopped. When the water flow stops and the digital conductivity meter reading 19 ≤ 10 μS / cm, turn off the water pump 16, the inlet solenoid valve 18, and the circulation solenoid valve 21. At this time, the water in the transparent water tank 2 becomes pure water. Connect the quick-connect port of the fuel cell stack 3 after the second digital pressure gauge 13 to the air inlet port 4 of the fuel cell stack 3. Connect the quick-connect port of the fuel cell stack 3 before the timer 14 to the air outlet port of the fuel cell stack 3. Place the fuel cell stack 3 in the pure water in the water tank, close the vent solenoid valve 11, close the exhaust solenoid valve 15, open the inlet solenoid valve 8, and observe the pressure of the first digital pressure gauge 10 and whether there are bubbles generated in the transparent water tank 2. The location where the bubble is generated is the external leakage point of fuel cell stack 3. If there is no bubble, the value of the first digital display pressure gauge does not decrease rapidly. Then close the air inlet solenoid valve 8, record the pressure of the first digital display pressure gauge 10 at this time, and enter the pressure holding state. Timer 14 counts for 5 minutes, and records the pressure of the first digital display pressure gauge 10 after 5 minutes. The leakage amount is automatically calculated. Replace the test chamber. If the normal airtightness test chamber is connected, other operations are as above. Drainage: close the circulation solenoid valve 21, open the drain solenoid valve 20, and close the drain solenoid valve 20 when the liquid level gauge is 0.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for testing the airtightness of a fuel cell stack, characterized in that: The device includes a housing (1), a transparent water tank (2), an electric stack (3), an air supply path, and a purification water path. The housing (1) is provided with an air inlet (4), an exhaust port (5), a water inlet (6), and a drain outlet (7). The two ends of the air supply path are connected to the electric stack (3) and the air inlet (4), respectively. The electric stack (3) is connected to the exhaust port (5). The two ends of the purification water path are connected to the transparent water tank (2) and the water inlet (6), respectively. The transparent water tank (2) is connected to the drain outlet (7). The electric stack (3) can be placed inside the transparent water tank (2).

2. The fuel cell stack airtightness testing device according to claim 1, characterized in that: The gas supply circuit includes an intake solenoid valve (8), a thermometer (9) and a first digital pressure gauge (10) connected in sequence by pipelines. The intake solenoid valve (8) is connected to the intake port (4), and the first digital pressure gauge (10) is connected to the fuel cell stack (3). A venting circuit is provided on the pipeline connecting the intake solenoid valve (8) and the intake port (4), and a venting solenoid valve (11) is provided on the venting circuit.

3. The fuel cell stack airtightness testing device according to claim 2, characterized in that: A pressure reducing valve (12) and a second digital pressure gauge (13) are provided between the intake solenoid valve (8) and the intake port (4). The pressure reducing valve (12) and the second digital pressure gauge (13) are both connected to the pipeline connecting the intake solenoid valve (8) and the intake port (4).

4. The fuel cell stack airtightness testing device according to claim 3, characterized in that: A timer (14) and an exhaust solenoid valve (15) are installed on the pipeline connecting the fuel cell stack (3) and the exhaust port (5).

5. The fuel cell stack airtightness testing device according to claim 1, characterized in that: The purification water circuit includes a water pump (16), a deionizer (17), and an inlet solenoid valve (18) connected in sequence by pipelines. The water pump (16) is connected to the water inlet (6), and the inlet solenoid valve (18) is connected to the transparent water tank (2).

6. The fuel cell stack airtightness testing device according to claim 1, characterized in that: It also includes a conductivity meter (19), a drain solenoid valve (20) and a circulating water circuit. The conductivity meter (19) and the drain solenoid valve (20) are installed on the pipeline connecting the transparent water tank (2) and the drain outlet (7). One end of the circulating water circuit is connected to the pipeline connecting the water pump (16) and the water inlet (6). The other end of the circulating water circuit is connected to the pipeline connecting the conductivity meter (19) and the drain solenoid valve (20). A circulating solenoid valve (21) is installed on the circulating water circuit.

7. A method for testing the airtightness of a fuel cell stack, characterized in that, Includes the following steps: S1: Adjust intake pressure; S2: Open the inlet solenoid valve (18), close the drain solenoid valve (20), the liquid level display shows 75%, and stop water injection; S3: Open the circulation solenoid valve (21). When the digital conductivity meter (19) is ≤10μS / cm, turn off the water pump (16), close the inlet solenoid valve (18), and close the circulation solenoid valve (21). S4: The fuel cell stack (3) is placed in pure water in a transparent water tank (2) for a leak test; S5: Drain, close the circulation solenoid valve (21), open the drain solenoid valve (20), when the liquid level gauge is 0, close the drain solenoid valve (20).

8. The fuel cell stack airtightness testing method according to claim 7, characterized in that, The adjustment method for step S1 is as follows: According to the fuel cell stack (3) to be tested, adjust the nitrogen pressure entering the stack, close the inlet solenoid valve (8) and the vent solenoid valve (11), open the gas source, adjust the pressure reducing valve (12) and the vent solenoid valve (11) to make the value of the second digital display pressure gauge (13) change to the pressure that the fuel cell stack (3) to be tested can withstand.

9. The fuel cell stack airtightness testing method according to claim 7, characterized in that, The test method for step S4 is as follows: Close the venting solenoid valve (11), close the exhaust solenoid valve (15), open the intake solenoid valve (8), observe the pressure of the first digital display pressure gauge (10), and whether there are bubbles generated in the transparent water tank (2). The location where the bubbles are generated is the external leakage point of the fuel cell stack (3). If there are no bubbles, the value of the first digital display pressure gauge (10) does not decrease rapidly. Then close the intake solenoid valve (8), record the pressure of the digital display fuel cell stack pressure gauge at this time, enter the pressure holding state, timer (14) counts for 5 minutes, record the pressure of the digital display fuel cell stack pressure gauge after 5 minutes, and automatically calculate the leakage amount.

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