Fuel cell stack air tightness testing device and testing method

Abstract

The present invention provides a fuel cell stack air tightness test device and test method, wherein the test device includes: a pressure fluid source; an air intake pipe assembly, one end of which is connected to the pressure gas source through a pressure control component, the air intake pipe assembly including a flow test pipe assembly, the flow test pipe assembly being provided with a first flow meter and including a plurality of first branch pipes connected in parallel, the fluid outlet ends of the plurality of first branch pipes being controllably connected to a plurality of chambers of the fuel cell stack in a one-to-one correspondence; and a plurality of exhaust pipe assemblies, each exhaust pipe assembly being connected in series with a second flow meter. The present invention can accurately obtain the amount of cross-talk from a corresponding chamber to each other chamber, and can obtain the amount of external leakage of the aforementioned chamber under the same pressure by taking the difference between the changes in the first flow meter and the second flow meter. The test results are accurate, and the test time and cost can be effectively reduced, thereby improving the test efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cell stack air tightness detection, and in particular relates to a fuel cell stack air tightness testing device and a testing method. Background Art

[0002] Fuel cells, particularly proton exchange membrane fuel cells, have become a hot topic and a key focus of development in the energy and power industries due to their high energy density, high efficiency, quiet operation, and zero emissions. They boast a wide range of applications and are considered one of the best solutions for addressing energy crises and environmental pollution in the new century. A fuel cell stack consists of multiple single cells stacked in series. The stack contains three chambers for oxidant, fuel, and coolant, each sealed and isolated from the others. Poor sealing between these chambers can reduce fuel cell efficiency at best, or even cause an explosion. Therefore, after assembly, a fuel cell stack must undergo an airtightness test to check for external and cross-leakage within the three chambers. If the leakage rate exceeds a specified value, the product is deemed defective. Therefore, airtightness testing is a key step in ensuring fuel cell stack safety and improving cell efficiency.

[0003] The prior art provides a test method for automatically detecting internal and external leakage of a fuel cell stack. When testing internal leakage of the stack, "the gas flows to the relatively high-pressure cavity through the straight main pipe, and the leaked gas enters the corresponding branch pipe and flow meter bypass from the other cavity to obtain the internal leakage from the relatively high-pressure cavity to the other cavity; the actual internal leakage is calculated based on the external leakage of the relatively high-pressure cavity under the same pressure." This test method has certain defects: first, the internal pressure holding pressure of the stack will be different when measuring internal leakage and external leakage. When the pressure holding pressure is different, before testing the internal leakage, it is also necessary to test the external leakage under the same pressure; second, during the test, only the external leakage of one cavity can be tested at a time, which will lead to a significant increase in test time and test cost. Summary of the Invention

[0004] Therefore, the present invention provides a fuel cell stack airtightness testing device and testing method, which can overcome the shortcomings of the airtightness testing device in the related art, such as the greatly increased internal leakage testing time and testing cost.

[0005] In order to solve the above problems, the present invention provides a fuel cell stack airtightness testing device, comprising:

[0006] a source of pressurized fluid;

[0007] an air intake pipe assembly, one end of which is connected to the pressure gas source via a pressure control component, the air intake pipe assembly including a flow test pipe assembly, the flow test pipe assembly being provided with a first flow meter and comprising a plurality of first branch pipes connected in parallel, wherein the fluid outlet ends of the plurality of first branch pipes are controllably connected to the plurality of chambers of the fuel cell stack in a one-to-one correspondence;

[0008] A plurality of emptying pipeline components are controllably connected to the plurality of chambers in a one-to-one correspondence, and each of the emptying pipeline components is serially connected to a second flow meter.

[0009] In some embodiments,

[0010] The flow test pipeline assembly has a first main pipe, the first flow meter is connected in series to the first main pipe, and a plurality of first branch pipes connected in parallel are located at the fluid outlet end of the first flow meter.

[0011] In some embodiments,

[0012] The air intake pipe assembly also includes a straight-through pipe assembly connected in parallel with the flow test pipe assembly, and the straight-through pipe assembly has a second main pipe and multiple second branch pipes. The second main pipe is connected in parallel with the first main pipe and is both connected to the fluid outlet end of the pressure control component. The fluid outlet ends of the multiple second branch pipes are respectively and one-to-one correspondingly connected to the multiple chambers in a controllable manner, and the first branch pipe and the second branch pipe connected to each chamber are connected in parallel to each other.

[0013] In some embodiments,

[0014] Each of the exhaust pipe assemblies is provided with a first exhaust valve and a second exhaust valve, wherein the first exhaust valve is located at the fluid outlet end of the second flow meter, and the second exhaust valve is located at the fluid inlet end of the second flow meter.

[0015] The present invention also provides a testing method based on the above-mentioned fuel cell stack air tightness testing device, comprising:

[0016] Controlling the air intake pipe assembly to inflate the plurality of chambers to a first preset pressure value, and when the pressure in each chamber is at the first preset pressure value, the corresponding fuel cell stack air tightness test device is in a state of the test initial state;

[0017] Testing the leakage out of each chamber of the fuel cell stack;

[0018] After the leakage out of the single chamber corresponding to each chamber is tested respectively, controlling each chamber to return to the initial state of the test;

[0019] The total external leakage of the plurality of chambers is tested.

[0020] In some embodiments, when a straight-through pipe assembly is included, before testing the external leakage or cross-leakage of at least one of the multiple chambers, the straight-through pipe assembly is connected to the corresponding chamber, and when testing the external leakage or cross-leakage of at least one of the multiple chambers, the flow test pipe assembly is connected to the corresponding chamber.

[0021] In some embodiments, the leakage outside the single chamber is obtained by the following steps:

[0022] Controlling the second branch pipe corresponding to the tested chamber to be cut off and the first branch pipe to be connected, and controlling the other chambers and the pressure control component to be maintained at the first preset pressure value;

[0023] After maintaining the first preset time, a first change value of the first flow meter is obtained.

[0024] In some embodiments, after the single-chamber external leakage test of each chamber is completed, the second branch pipe corresponding to the tested chamber is controlled to be connected and the first branch pipe is cut off, so that the chamber is restored to the initial state of the test.

[0025] In some embodiments, the total leakage is obtained by the following steps:

[0026] Controlling the disconnection of the second branch pipe and the connection of the first branch pipe corresponding to each test chamber;

[0027] After maintaining the second preset time, a second change value of the first flow meter is obtained.

[0028] In some embodiments, after the total leakage value test is completed, the method further comprises:

[0029] Adjusting the outlet pressure of the pressure control component to zero, controlling one of the plurality of chambers to be evacuated until the pressure therein reaches a second preset pressure value higher than zero, and controlling the remaining chambers of the plurality of chambers to be evacuated until the pressure therein reaches zero, wherein the chamber having the pressure therein reaching the second preset pressure value is defined as the first chamber;

[0030] The cross-leakage amount of the first chamber is tested.

[0031] In some embodiments, after testing the cross-talk leakage of the first chamber, the method further includes testing the cross-talk leakage of any one of the plurality of chambers remaining except the first chamber, wherein the any one chamber is defined as a second chamber.

[0032] In some embodiments, the cross-talk amount of the first chamber or the second chamber is obtained by the following steps:

[0033] adjusting the outlet pressure of the pressure control component to the second preset pressure value, controlling the drain pipeline assembly connected to the first chamber or the second chamber to be in a blocked state, and controlling the first drain valves in the drain pipeline assemblies connected to the other chambers to be in a draining state and the second drain valves to be in a blocked state;

[0034] After maintaining the third preset time, the change values ​​of the second flow meters connected to the other chambers are obtained and summed to obtain a third change value.

[0035] In some embodiments, the testing method further includes the step of obtaining the leakage amount of the first chamber or the second chamber, specifically including:

[0036] A fourth change value of the first flow meter is obtained while the third change value is obtained, and a fifth change value is obtained by subtracting the fourth change value from the third change value.

[0037] The present invention provides a fuel cell stack air tightness testing device and testing method, which detects the change of fluid flow in the intake pipe assembly through a first flow meter, and detects the change of fluid flow in the exhaust pipe assembly through a second flow meter, so as to accurately obtain the corresponding leakage amount from a certain chamber to other chambers (that is, the internal leakage amount of a certain chamber), and can obtain the external leakage amount of the aforementioned certain chamber at the same pressure by the difference between the change amounts of the first flow meter and the second flow meter. The test results are accurate, and can effectively reduce the test time and test cost, and improve the test efficiency; the arrangement of each second flow meter can accurately measure the cross-flow amount of the tested chamber to other adjacent chambers when performing the internal leakage (cross-flow) test of each chamber, without the need to separately obtain the external leakage amount at the same pressure as the cross-flow test when testing the cross-flow, and then perform the difference calculation, as in the prior art, and time and cost will be significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the principle of the fuel cell stack air tightness test device (including the fuel cell stack) according to an embodiment of the present invention;

[0039] Figure 2 This is a schematic structural diagram of a fuel cell stack air tightness testing device (including a fuel cell stack) according to an embodiment of the present invention.

[0040] The reference numerals indicate:

[0041] 1. Gas source; 2. Pressure reducing valve; 3. Pressure control component; 4. First electrically controlled shut-off valve; 5. Second electrically controlled shut-off valve; 6. Third electrically controlled shut-off valve; 7. Fourth electrically controlled shut-off valve; 8. Fifth electrically controlled shut-off valve; 9. Sixth electrically controlled shut-off valve; 10. Seventh electrically controlled shut-off valve; 11. First drain valve; 12. Second drain valve; 17. First flow meter; 18. Second flow meter; 21. Fuel cell stack; 22. Device housing; 23. Display unit. DETAILED DESCRIPTION

[0042] See also Figures 1 to 2 As shown, according to an embodiment of the present invention, a fuel cell stack air tightness testing device is provided, including: a pressure fluid source, wherein the fluid can be gas or liquid, and when it is gas, it can specifically be one of nitrogen or helium; an intake pipe assembly, one end of which is connected to the pressure gas source through a pressure control component 3 (specifically a pressure control component), the intake pipe assembly includes a flow test pipe assembly, the flow test pipe assembly is provided with a first flow meter 17 and includes a plurality of parallel first branches, the fluid outlet ends of the plurality of first branches can be respectively and one-to-one correspondingly connected to a plurality of chambers of the fuel cell stack 21 in a controllable manner; a plurality of exhaust pipe assemblies, the plurality of exhaust pipe assemblies are respectively and one-to-one correspondingly connected to a plurality of chambers in a controllable manner, and each exhaust pipe assembly is connected in series with a second flow meter 18.

[0043] In this technical solution, the first flowmeter 17 is used to detect the change in fluid flow in the intake pipe assembly, and the second flowmeter 18 is used to detect the change in fluid flow in the exhaust pipe assembly, so that the corresponding cross-flow amount from a certain chamber to each other chamber (that is, the internal leakage of a certain chamber) can be accurately obtained, and the external leakage of the aforementioned certain chamber at the same pressure can be obtained by taking the difference between the change amounts of the first flowmeter 17 and the second flowmeter 18. The test results are accurate, and the test time and test costs can be effectively reduced, thereby improving the test efficiency. It should be noted that the arrangement of each second flowmeter 18 in this technical solution can accurately measure the cross-flow amount from the tested chamber to other adjacent chambers when performing the internal leakage (cross-flow) test of each chamber, without the need to separately obtain the external leakage amount at the same pressure as the cross-flow test and then perform the difference calculation, as in the prior art. Time and cost can be significantly reduced.

[0044] In some embodiments, the flow test pipeline assembly has a first main pipe, a first flow meter 17 is connected in series to the first main pipe, and multiple first branch pipes connected in parallel are located at the fluid outlet end of the first flow meter 17. In this way, only one first flow meter 17 is provided in the flow test pipeline assembly to achieve accurate measurement of the fluid entering different chambers by switching on and off each first branch pipe, further reducing the manufacturing cost of the device. Figure 1As shown, corresponding to a fuel cell stack 21, there are three chambers therein that should be sealed independently from each other, namely, an oxidant chamber, a coolant chamber and a fuel chamber. A second electrically controlled shut-off valve 5 is connected in series on the first branch pipe connected to the oxidant chamber, a third electrically controlled shut-off valve 6 is connected in series on the first branch pipe connected to the coolant chamber, and a fourth electrically controlled shut-off valve 7 is connected in series on the first branch pipe connected to the fuel chamber. The aforementioned second electrically controlled shut-off valve 5, third electrically controlled shut-off valve 6 and fourth electrically controlled shut-off valve 7 are respectively controlled to be turned on when it is necessary to perform a leakage test on the chambers connected thereto, thereby realizing selective on-off control of each first branch pipe.

[0045] In some embodiments, the air intake pipe assembly also includes a straight-through pipe assembly connected in parallel with the flow test pipe assembly. The straight-through pipe assembly has a second main pipe and multiple second branch pipes. The second main pipe is connected in parallel with the first main pipe and both are connected to the fluid outlet end of the pressure control component 3. The fluid outlet ends of the multiple second branch pipes are controllably connected to multiple chambers one by one, and the first branch pipe and the second branch pipe connected to each chamber are connected in parallel. It can be understood that the arrangement of the straight-through pipe assembly is similar to that of the flow test pipe assembly. The main difference between the straight-through pipe assembly and the flow test pipe assembly is that the first flow meter 17 is not separately provided in the straight-through pipe assembly. In this way, the pipe assembly can be controlled to open when the corresponding chamber needs to be quickly inflated, thereby improving the efficiency of the test operation. See Figure 1 As shown, a fifth electrically controlled shutoff valve 8 is connected in series to the second branch pipe communicating with the oxidant chamber, a sixth electrically controlled shutoff valve 9 is connected in series to the second branch pipe communicating with the coolant chamber, and a seventh electrically controlled shutoff valve 10 is connected in series to the second branch pipe communicating with the fuel chamber. The aforementioned fifth electrically controlled shutoff valve 8, sixth electrically controlled shutoff valve 9, and seventh electrically controlled shutoff valve 10 are controlled to be shut off when a leakage test is required for the chambers connected thereto, thereby realizing selective on-off control of each first branch pipe.

[0046] Furthermore, a first electrically controlled shut-off valve 4 is provided on the second main pipe. Especially when the pipeline length in the corresponding straight-through pipeline assembly is large, there will be a cavity effect. The setting of the first electrically controlled shut-off valve 4 can effectively suppress pressure fluctuations and realize rapid and stable flow of gas.

[0047] In some embodiments, each drain pipe assembly is provided with a first drain valve 11 and a second drain valve 12, wherein the first drain valve 11 is located at the fluid outlet of the second flow meter 18, and the second drain valve 12 is located at the fluid inlet of the second flow meter 18. During a specific test, when it is necessary to drain the corresponding chamber, the second drain valve 12 is preferably controlled to be open, that is, the drain fluid in the corresponding chamber does not flow through the second flow meter 18, thereby enabling faster draining and higher testing efficiency. When it is necessary to test the leakage (cross-flow) of the corresponding chamber, the corresponding first drain valve 11 is controlled to be open.

[0048] The pressure fluid source includes an air source 1 and a pressure reducing valve 2. The pressure reducing valve 2 is located between the pressure control component 3 and the air source 1. The pressure reducing valve 2 can reduce the air flow of the high-pressure air source 1 to the required pressure value to prevent excessive fluid pressure from damaging the structure of the fuel cell stack 21.

[0049] See also Figure 2 As shown, the fuel cell stack air tightness test device also includes a device box 22, and the air intake pipe assembly and the exhaust pipe assembly are integrated and assembled in the device box 22, so that the structure of the device is integrated into one, and the structure is more compact, and the pressure fluid source is detachably connected to the outside of the device box 22, so that the application conditions of the device are more diverse. For example, a movable compressor can be used as the gas source 1, and a compressed air pipe in a factory workshop can also be used as the gas source 1. A display unit 23 is provided on the device box 22. The display unit 23 can obtain and display the flow parameters of the first flow meter 17 and the second flow meter 18, and the pressure parameters of the pressure control component 3, so that the corresponding test results can be displayed intuitively.

[0050] According to an embodiment of the present invention, a test method based on the above-mentioned fuel cell stack air tightness test device is also provided, including: controlling the air intake pipeline assembly to inflate multiple chambers to a first preset pressure value, when the pressure in each chamber is at the first preset pressure value (in a specific embodiment, 150kPa, and the various pressures in the present invention refer to gauge pressure, not absolute pressure), the corresponding fuel cell stack air tightness test device is in the initial state of the test, specifically at this time, the first electrically controlled shut-off valve 4, the fifth electrically controlled shut-off valve 8, and the sixth electrically controlled shut-off valve 9 are in the initial state of the test. Valve 9 and the seventh electrically controlled shut-off valve 10 are turned on, the second electrically controlled shut-off valve 5, the third electrically controlled shut-off valve 6, the fourth electrically controlled shut-off valve 7, the first drain valves 11 and the second drain valve 12 are all in a blocked state (i.e., a closed state), and the outlet pressure of the pressure control component 3 is adjusted to the aforementioned first preset pressure value; the external leakage of a single chamber corresponding to each chamber of the fuel cell stack 21 is tested separately; after the external leakage of a single chamber corresponding to each chamber is tested separately, each chamber is controlled to return to the initial state of the test; and then the total external leakage of multiple chambers is further tested.

[0051] In this technical solution, each chamber is maintained at a first preset pressure value after one inflation. After the single-chamber external leakage test is completed, each chamber of the device is restored to the initial test state, and the total external leakage test of each chamber is further performed. There is no need to further inflate each chamber, which simplifies the control process and connects different leakage test processes with each other, thereby achieving higher test efficiency and reducing test time and cost.

[0052] In some embodiments, when a straight-through pipe assembly is included, before testing the external leakage or cross-leakage of at least one of the multiple chambers, the straight-through pipe assembly is connected to the corresponding chamber, and when testing the external leakage or cross-leakage of at least one of the multiple chambers, the flow test pipe assembly is connected to the corresponding chamber, that is, before conducting the leakage test, each chamber is inflated through the straight-through pipe assembly, and the inflation is not limited to the nominal flow upper limit of the first flowmeter 17, so that the gauge pressure of each chamber can reach the aforementioned first preset pressure value more quickly, and when conducting the leakage test, the flow test pipe assembly is used to accurately detect the change in the fluid amount in the corresponding chamber through the first flowmeter 17.

[0053] As a specific implementation method, the leakage amount outside a single chamber is obtained through the following steps: controlling the second branch corresponding to the tested chamber to be cut off and the first branch to be connected, controlling the other chambers and the pressure control component 3 to be maintained at a first preset pressure value; and obtaining the first change value of the first flowmeter 17 after maintaining the first preset time. For example, taking the tested chamber as the oxidant chamber, the second electrically controlled shut-off valve 5 on the corresponding first branch pipe is connected, and the fifth electrically controlled shut-off valve 8 on the second branch pipe is cut off, while the other electrically controlled shut-off valves and drain valves in the device are all in the initial state of the test (that is, all are in the cut-off or closed state), and the pressure is maintained at the first preset pressure value for 15 minutes. During this period, the reading of the first flowmeter 17 is the single-chamber out-leakage volume of the oxidant chamber; similarly, corresponding operations are performed on the coolant chamber and the fuel chamber respectively, and the single-chamber out-leakage volume of the two chambers is obtained respectively. In this process, it can be seen that it is only necessary to connect the corresponding electrically controlled shut-off valve of the first branch pipe for each cavity, and cut off the electrically controlled shut-off valve of the second branch pipe. The operation and control logic are very simple and the test is restored to the initial state, thereby improving the test efficiency.

[0054] After the single-chamber external leakage test of each chamber is completed, the second branch corresponding to the tested chamber is controlled to be connected and the first branch is cut off to restore the chamber to the initial state of the test. As mentioned above, the restoration of the initial state of the test only requires opening and closing the two electrically controlled shut-off valves on the second branch and the first branch in actual operation. The total external leakage is obtained by the following steps: controlling the second branch corresponding to each test chamber to be cut off and the first branch to be connected; after maintaining the second preset time (for example, it can also be 60 minutes), the second change value of the first flowmeter 17 is obtained. Specifically, at this time, the first electrically controlled shut-off valve 4, the fifth electrically controlled shut-off valve 8, the sixth electrically controlled shut-off valve 9, the seventh electrically controlled shut-off valve 10, the first drain valve 11, and the second drain valve 12 are all cut off, and the second electrically controlled shut-off valve 5, the third electrically controlled shut-off valve 6, and the fourth electrically controlled shut-off valve 7 are all in the conducting state. The reading on the first flowmeter 17 is the total value of the external leakage of all chambers, that is, the aforementioned total external leakage. It should be noted that in this test process, the total external leakage test can be achieved by simply cutting off the electric shut-off valves on the three second branches in the initial state of the test and turning on the electric shut-off valves on the three first branches. The control is simple and convenient.

[0055] As a better implementation method, after the total leakage value test is completed, it also includes: adjusting the outlet pressure of the pressure control component 3 to zero (gauge pressure) to ensure that the subsequent related chambers can be emptied to a state where the pressure in the chamber is zero, controlling one of the multiple chambers to be emptied to a second preset pressure value higher than zero. It can be understood that the second preset pressure value at this time is lower than the first preset pressure value, controlling the remaining chambers in the multiple chambers to be emptied to a second preset pressure value higher than zero. For the sake of clarity, the chamber with an intracavity pressure of the second preset pressure value is defined as the first chamber; testing the cross-leakage of the first chamber. In this technical solution, based on the requirements of the internal leakage test of each chamber, after the process of testing the total leakage value is completed, the chamber with the first preset pressure value is directly emptied to form the aforementioned second preset pressure value and zero, thereby forming a perfect connection in the process. This connection enables the process to achieve pressure regulation of the relevant chambers through one-way emptying without the need to individually control and change the on-off of each pipeline, further optimizing and simplifying the test process and improving test efficiency. The aforementioned second preset pressure may be, for example, 50 kPa or 100 kPa. The second preset pressures corresponding to different chambers may be the same or different, depending on actual needs.

[0056] Furthermore, after testing the cross-leakage amount of the first chamber, the method also includes a step of testing the cross-leakage amount of any one of the multiple chambers remaining except the first chamber. In order to simplify the description, any one chamber is defined as the second chamber, thereby realizing the cross-leakage amount test of each chamber.

[0057] Specifically, the amount of leakage from the first chamber or the second chamber is obtained by the following steps: adjusting the outlet pressure of the pressure control component 3 to a second preset pressure value, controlling the drain pipe assembly connected to the first chamber or the second chamber to be in a blocked state (that is, the first drain valve 11 and the second drain valve 12 thereon are both in a blocked state), and the first drain valve 11 in the drain pipe assembly connected to each other chamber is in an emptying state and the second drain valve 12 is in a blocked state; after maintaining the third preset time, obtaining the change value of each second flow meter 18 connected to each other chamber and summing them to obtain a third change value. Furthermore, the test method also includes the step of obtaining the amount of leakage from the first chamber or the second chamber, specifically including: obtaining a fourth change value of the first flow meter 17 while obtaining the third change value, and subtracting the fourth change value from the third change value to obtain a fifth change value. Taking the oxidizer chamber leakage test as an example, the first drain valve 11 in the drain line assembly connected to the coolant chamber and the fuel chamber is connected, while the second drain valve 12 is closed. Both the first drain valve 11 and the second drain valve 12 in the drain line assembly connected to the oxidizer chamber are closed, and the pressure is maintained at a second preset pressure, assumed to be 50 kPa, for 15 minutes. During this process, the sum of the readings of the second flowmeter 18 in the drain line assembly connected to the coolant chamber and the fuel chamber is the oxidizer chamber leakage. Meanwhile, the reading of the first flowmeter 17 is the sum of the oxidizer chamber external leakage and the leakage, and the difference between the reading of the first flowmeter 17 and the sum of the readings of the two second flowmeters 18 is the oxidizer chamber leakage at the second preset pressure. In other words, the same process can simultaneously obtain the leakage of the chamber under test at the same preset pressure and the external leakage of the single chamber, resulting in higher testing efficiency, more accurate test results, and more comprehensive test results.

[0058] It should be noted that, when each chamber is maintained at the first preset pressure value or the second preset pressure value, if the pressure is too high, the second exhaust valve 12 of the corresponding chamber is controlled to release pressure so that the pressure of the corresponding chamber is maintained at the corresponding preset pressure value.

[0059] The following combination Figure 1 and Figure 2 A preferred embodiment of the present invention is described.

[0060] The present invention also provides a fuel cell stack air tightness test method. Based on the fuel cell stack test device described above, after the gas supply device, air tightness test device, and fuel cell stack are connected via pipelines, the gas source 1 switch is first manually turned on, and the pressure reducing valve 2 is adjusted to less than 1 MPa. The entire test process can then be completed with one click. The specific test method and control logic include the following steps:

[0061] 1. Single cavity air tightness test method (i.e., method for obtaining single cavity external leakage)

[0062] (1) Oxidant chamber test

[0063] a. The system automatically opens the first electrically controlled shutoff valve 4, the fifth electrically controlled shutoff valve 8, the sixth electrically controlled shutoff valve 9, and the seventh electrically controlled shutoff valve 10, adjusts the outlet pressure of the pressure control component 3 (for example, 0.3 MPa), and quickly inflates the three cavities;

[0064] b. When the gauge pressure inside the three cavities reaches the required value, such as 150 kPa (the average gauge pressure of the three second flow meters 18), the system automatically adjusts the outlet gauge pressure of the pressure control component 3 to 150 kPa to maintain the pressure of the three cavities; if the pressure is too high, the system automatically opens the second drain valve 12 to release the pressure, thereby maintaining the pressure stable at 150 kPa;

[0065] c. Close the fifth electrically controlled shutoff valve 8; open the second electrically controlled shutoff valve 5 and test for 15 minutes. The reading of the first flowmeter 17 is the leakage of the oxidant chamber.

[0066] d. Close the second electrically controlled shutoff valve 5 and open the fifth electrically controlled shutoff valve 8;

[0067] (2) Coolant chamber test

[0068] a. Close the sixth electrically controlled shutoff valve 9; open the third electrically controlled shutoff valve 6 and test for 15 minutes. The reading of the first flowmeter 17 is the amount of coolant chamber leakage.

[0069] b. Close the third electrically controlled shutoff valve 6 and open the sixth electrically controlled shutoff valve 9;

[0070] (3) Fuel chamber test

[0071] a. Close the seventh electrically controlled shutoff valve 10; open the fourth electrically controlled shutoff valve 7 and test for 15 minutes. The reading of the first flowmeter 17 is the leakage of the fuel chamber.

[0072] c. Close the fourth electrically controlled shutoff valve 7 and open the seventh electrically controlled shutoff valve 10;

[0073] The test order of the three chambers mentioned above can be adjusted as needed.

[0074] 2. Three cavity air tightness test methods (also known as the method for obtaining the total external leakage)

[0075] a. Close the first electrically controlled shut-off valve 4, the fifth electrically controlled shut-off valve 8, the sixth electrically controlled shut-off valve 9, and the seventh electrically controlled shut-off valve 10;

[0076] b. Open the second electrically controlled shutoff valve 5, the third electrically controlled shutoff valve 6, and the fourth electrically controlled shutoff valve 7; test for 60 minutes, at which point the first flowmeter 17 reading is the total external leakage of the three cavities;

[0077] c. Close the second electrically controlled shutoff valve 5, the third electrically controlled shutoff valve 6, and the fourth electrically controlled shutoff valve 7; (all electrically controlled shutoff valves are closed at this time)

[0078] d. The outlet pressure of the pressure control component 3 is adjusted to 0.

[0079] At this point, the total external leakage test of the three cavities is completed.

[0080] 3. Three-cavity cross-leakage test method

[0081] (1) Oxidant chamber leakage test method

[0082] a. Open the three second drain valves 12; when the gauge pressure in the oxidizer chamber is 50 kPa, close the second drain valve 12 communicating therewith; when the gauge pressure in the coolant chamber and the fuel chamber is 0, close the two second drain valves 12 communicating with the two chambers, respectively;

[0083] b. Automatically adjust the outlet pressure of the pressure control component 3 to a gauge pressure of 50kPa;

[0084] c. Open the second electrically controlled shut-off valve 5 to maintain pressure;

[0085] d. Open the first drain valve 11 corresponding to the coolant chamber and the fuel chamber, respectively, and test for 15 minutes. At this time, the readings of the two second flow meters 18 corresponding to the coolant chamber and the fuel chamber are the cross-leakage value from the oxidizer chamber to the fuel chamber and the cross-leakage value from the oxidizer chamber to the coolant chamber, respectively;

[0086] e. The reading of the first flow meter 17 minus the reading of the two second flow meters 18 is the leakage value of the oxidant chamber at this pressure.

[0087] (2) Coolant cavity leakage test method

[0088] a. Close the second electrically controlled shutoff valve 5; open the second drain valve 12 corresponding to the oxidant chamber;

[0089] b. Until the gauge pressure in the three chambers is 0, close the second drain valve 12 corresponding to the oxidizer chamber and the first drain valve 11 corresponding to the coolant chamber and the fuel chamber;

[0090] c. Open the third electronically controlled shut-off valve 6;

[0091] d. The system adjusts the outlet pressure of the pressure control component 3 to 0.1 MPa (50 kPa in some cases) to achieve rapid inflation of the coolant cavity;

[0092] e. When the gauge pressure in the coolant chamber is 50kPa, set the outlet pressure value of the pressure control component 3 to 50kPa; start maintaining pressure;

[0093] f. Open the two first drain valves 11 corresponding to the oxidizer chamber and the fuel chamber, respectively; test for 15 minutes, at which point the readings of the two second flowmeters 18 corresponding to the oxidizer chamber and the fuel chamber, respectively, are the cross-leakage values ​​from the coolant chamber to the oxidizer chamber and the cross-leakage values ​​from the coolant chamber to the fuel chamber, respectively;

[0094] g. The reading of the first flow meter 17 minus the reading of the two second flow meters 18 is the leakage value of the coolant chamber at this pressure.

[0095] (3) Fuel chamber leakage test method

[0096] a. Close the third electrically controlled shutoff valve 6; open the second drain valve 12 corresponding to the oxidant chamber;

[0097] b. Until the gauge pressure in the three chambers reaches 0, close the second drain valve 12 corresponding to the coolant chamber and the first drain valve 11 corresponding to the oxidizer chamber and the fuel chamber;

[0098] c. Open the fourth electronically controlled shutoff valve 7;

[0099] d. The system adjusts the outlet pressure of the pressure control component 3 to 0.1 MPa (or 50 kPa in some cases) to achieve rapid inflation of the fuel cavity;

[0100] e. When the gauge pressure in the fuel chamber is 50kPa, the outlet pressure value of the pressure control component 3 is set to 50kPa and the pressure is maintained;

[0101] f. Open the two first drain valves 11 corresponding to the oxidant chamber and the coolant chamber respectively; test for 15 minutes, at which time the readings of the two second flow meters 18 corresponding to the oxidant chamber and the coolant chamber respectively are the cross leakage value from the fuel chamber to the coolant chamber and the cross leakage value from the fuel chamber to the oxidant chamber;

[0102] g. The reading of the first flow meter 17 minus the reading of the two second flow meters 19 is the leakage value of the fuel chamber at this pressure.

[0103] h. Close the fourth electrically controlled shutoff valve 7; open the second drain valve 12 communicating with the fuel chamber;

[0104] i. Until the three second flow meters 18 show that the gauge pressure in the three chambers is 0, close the second drain valve 12 communicating with the fuel chamber and the two first drain valves 11 communicating with the oxidizer chamber and the coolant chamber respectively;

[0105] j. The system adjusts the pressure control component 3 outlet pressure value to 0.

[0106] At this point, the entire fuel cell stack air tightness test process is completed.

[0107] In addition, when testing a cavity leakage value or cross-link leakage value, when the leakage value measured by the flow meter is greater than a certain set value (the leakage is very large), after this step of the test is completed, the program will be directly jumped out, and the test of the next step will no longer be performed, and the test work will be ended.

[0108] During the entire air tightness test process, the display unit will show the leakage volume collected by the flow meter in real time; at the same time, after the test is completed, the system will automatically compare the test value with the pre-set standard value, and display the final test results, the external leakage value / cross-leakage value of the three cavities and whether it is qualified on the screen.

[0109] The technical solution of the present invention has the following advantages:

[0110] 1. One-click fully automatic fuel cell stack air tightness test is achieved, greatly improving work efficiency;

[0111] 2. The use of high-precision flow sensors (i.e., the aforementioned first flow meter 17 and second flow meter 18) improves the accuracy of the test results;

[0112] 3. Achieve comprehensiveness, efficiency, and reliability of the testing process through optimal testing logic;

[0113] 4. Using a pressure controller to regulate pressure and a solenoid valve to exhaust (i.e., the aforementioned second exhaust valve 12) can achieve rapid charging and discharging of the fuel cell stack;

[0114] 5. It has functions such as data acquisition, display, storage and analysis, which greatly improves the intelligence level of the test device.

[0115] 6. The entire testing process is simple and efficient, the test content is comprehensive, and the results are accurate and reliable.

[0116] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0117] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A fuel cell stack air tightness test device, characterized in that: include: a source of pressurized fluid; An air intake pipe assembly, one end of which is connected to the pressure fluid source via a pressure control component (3), the air intake pipe assembly including a flow test pipe assembly, the flow test pipe assembly being provided with a first flow meter (17) and comprising a plurality of first branch pipes connected in parallel, the fluid outlet ends of the plurality of first branch pipes being controllably connected to a plurality of chambers of the fuel cell stack (21) in a one-to-one correspondence. A plurality of drain pipe assemblies, each of the drain pipe assemblies being controllably connected to the plurality of chambers in a one-to-one correspondence, and each drain pipe assembly being serially connected to a second flow meter (18); The flow test pipeline assembly comprises a first main pipe, the first flow meter (17) is connected in series to the first main pipe, and a plurality of first branch pipes connected in parallel are located at the fluid outlet end of the first flow meter (17); The air intake pipe assembly further includes a straight-through pipe assembly connected in parallel with the flow test pipe assembly, the straight-through pipe assembly having a second main pipe and a plurality of second branch pipes, the second main pipe being connected in parallel with the first main pipe and both being connected to the fluid outlet end of the pressure control component (3), the fluid outlet ends of the plurality of second branch pipes being controllably connected to the plurality of chambers in a one-to-one correspondence, and the first branch pipe and the second branch pipe connected to each chamber being connected in parallel, and a first electrically controlled shutoff valve (4) being provided on the second main pipe; Each of the drain pipe assemblies is provided with a first drain valve (11) and a second drain valve (12), wherein the first drain valve (11) is located at the fluid outlet end of the second flow meter (18), and the second drain valve (12) is located at the fluid inlet end of the second flow meter (18).

2. A test method based on the fuel cell stack airtightness test device according to claim 1, characterized in that: include: Controlling the air intake pipe assembly to inflate the plurality of chambers to a first preset pressure value, and when the pressure in each chamber is at the first preset pressure value, the corresponding fuel cell stack air tightness test device is in a state of the test initial state; Testing the leakage out of each chamber of the fuel cell stack (21) respectively; After the leakage out of the single chamber corresponding to each chamber is tested respectively, controlling each chamber to return to the initial state of the test; The total external leakage of the plurality of chambers is tested.

3. The testing method according to claim 2, wherein: When a straight-through pipe assembly is included, before testing the external leakage or cross-leakage of at least one of the multiple chambers, the straight-through pipe assembly is connected to the corresponding chamber, and when testing the external leakage or cross-leakage of at least one of the multiple chambers, the flow test pipe assembly is connected to the corresponding chamber.

4. The testing method according to claim 3, wherein: The external leakage of the single chamber is obtained by the following steps: Controlling the second branch pipe corresponding to the tested chamber to be cut off and the first branch pipe to be connected, and controlling the other chambers and the pressure control component (3) to be maintained at the first preset pressure value; After maintaining the first preset time, a first change value of the first flow meter (17) is obtained.

5. The testing method according to claim 4, characterized in that: After the single-chamber external leakage test of each chamber is completed, the second branch pipe corresponding to the tested chamber is controlled to be connected and the first branch pipe is cut off, so that the chamber is restored to the initial state of the test.

6. The testing method according to claim 3, characterized in that: The total external leakage is obtained by the following steps: Controlling the disconnection of the second branch pipe and the connection of the first branch pipe corresponding to each test chamber; After maintaining the second preset time, a second change value of the first flow meter (17) is obtained.

7. The testing method according to claim 2 or 3, characterized in that: After the total external leakage test is completed, it also includes: Adjusting the outlet pressure of the pressure control component (3) to zero, controlling one of the plurality of chambers to be emptied until the pressure inside the chamber is a second preset pressure value higher than zero, controlling the remaining chambers of the plurality of chambers to be emptied until the pressure inside the chamber is zero, and the chamber whose pressure inside the chamber is the second preset pressure value is defined as the first chamber; The cross-leakage amount of the first chamber is tested.

8. The testing method according to claim 7, characterized in that: After testing the cross-leakage amount of the first chamber, the method further includes testing the cross-leakage amount of any one of the plurality of chambers remaining except the first chamber, wherein the any one chamber is defined as a second chamber.

9. The testing method according to claim 8, characterized in that: The cross-leakage amount of the first chamber or the second chamber is obtained by the following steps: Adjusting the outlet pressure of the pressure control component (3) to the second preset pressure value, controlling the emptying pipeline assembly connected to the first chamber or the second chamber to be in a blocked state, and controlling the first emptying valve (11) in the emptying pipeline assembly connected to the other chambers to be in an emptying state and the second emptying valve (12) to be in a blocked state; After maintaining the third preset time, the change values ​​of each second flow meter (18) connected to each other chamber are obtained and summed to obtain a third change value.

10. The testing method according to claim 9, characterized in that: The method further includes the step of obtaining the leakage amount of the first chamber or the second chamber, specifically comprising: While obtaining the third change value, a fourth change value of the first flow meter (17) is obtained, and a fifth change value is obtained by subtracting the fourth change value from the third change value.

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