Fuel cell stack air tightness testing device and method

Abstract

The present invention relates to a fuel cell stack air tightness test device and method, the device comprising: a helium supply assembly: used for injecting helium into an oxidizing gas cavity, a fuel gas cavity, and a cooling cavity of a fuel cell stack; a test tank: used for sealing and containing a fuel cell stack to be tested; a gas supply valve group: connected to the test tank, used for injecting helium into each cavity of the fuel cell stack; an exhaust valve group: connected to the test tank, used for exhausting the gas in each cavity of the fuel cell stack and the test tank; a helium detection assembly: used for detecting the gas exhausted by the exhaust assembly and determining the air tightness of the fuel cell stack; an emptying assembly: used for emptying the test tank and each cavity of the fuel cell stack before and after the air tightness test; an atmosphere connection assembly: used for balancing the air pressure in the test tank and each cavity of the fuel cell stack after the air tightness test. Compared with the prior art, the present invention has the advantages of convenient operation and high response frequency.

Description

Technical Field

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

[0002] Fuel cells are the main technical means to solve environmental pollution and reduce carbon dioxide emissions. The airtightness of a fuel cell stack is related to the working performance and reliability of the fuel cell stack, and has become a key indicator for measuring the long-term and stable operation of a fuel cell. The airtightness of a fuel cell stack mainly refers to whether the stack leaks. There are two forms of leakage: external leakage and cross leakage. External leakage refers to the leakage of the oxidizing gas cavity, fuel gas cavity, and cooling cavity in the stack to the atmosphere. Cross leakage refers to the mutual leakage of the oxidizing gas cavity, fuel gas cavity, and cooling cavity in the stack.

[0003] There are two main problems with existing fuel cell airtightness measurement devices and methods: inconvenient operation and low response frequency. The inconvenience in operation mainly refers to the fact that during the fuel cell airtightness detection process, a large number of mobile devices are required to confirm the problem of fuel cell airtightness, that is, the location of the leak. It is mainly aimed at the complex operation and low efficiency in the process of using helium mass spectrometry to detect leaks in the absence of auxiliary devices. The low response frequency is mainly aimed at the method of testing leaks based on pressure sensors. The resolution of pressure sensors is limited, resulting in smaller leakage rates being hidden by sensor errors. Summary of the invention

[0004] The purpose of the present invention is to provide a fuel cell stack air tightness testing device and method in order to overcome the defects of the above-mentioned prior art.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A fuel cell stack air tightness testing device, the device comprising:

[0007] Helium gas supply assembly: used to inject helium into the oxidizing gas chamber, fuel gas chamber, and cooling chamber of the fuel cell stack during air tightness testing;

[0008] Test tank: used to seal and hold the fuel cell stack to be tested;

[0009] Gas supply valve group: connected to the test tank, used to inject helium into each cavity of the fuel cell stack;

[0010] Exhaust valve group: connected to the test tank, used to discharge the gas in each cavity of the fuel cell stack and the test tank;

[0011] Helium detection component: used to detect the gas discharged from the exhaust component and determine the air tightness of the fuel cell stack;

[0012] Emptying assembly: used to empty the test tank and each cavity of the fuel cell stack before and after the air tightness test;

[0013] Atmospheric connection assembly: used to balance the air pressure in the test tank and each cavity of the fuel cell stack after the air tightness test.

[0014] Preferably, the test tank comprises a tank body, a battery stack inlet interface, a battery stack outlet interface and an external leakage interface. The battery stack inlet interface and the battery stack outlet interface are respectively provided with three, which are used to correspond to the inlets and outlets of the electric propulsion oxidation gas cavity, the fuel gas cavity and the cooling cavity. The external leakage interface is connected to the internal space of the tank body, the battery stack inlet interface is connected to the helium supply assembly through the gas supply valve group, and the battery stack outlet interface and the external leakage interface are connected to the helium detection assembly through the exhaust valve group.

[0015] Preferably, the gas supply valve group includes a first gas supply valve, a second gas supply valve and a third gas supply valve for respectively controlling the injection of helium into the oxidation gas chamber, the fuel gas chamber and the cooling chamber of the fuel cell stack, the input ends of the first gas supply valve, the second gas supply valve and the third gas supply valve are all connected to the helium supply assembly, and the output ends of the first gas supply valve, the second gas supply valve and the third gas supply valve are correspondingly connected to the corresponding stack inlet interfaces.

[0016] Preferably, the exhaust valve group includes a first exhaust valve, a second exhaust valve, a third exhaust valve and a fourth exhaust valve for respectively controlling the exhaust gas in the oxidizing gas chamber, the fuel gas chamber, the cooling chamber and the test tank of the fuel cell stack, the input ends of the first exhaust valve, the second exhaust valve and the third exhaust valve are correspondingly connected to the corresponding stack outlet interfaces, the input end of the fourth exhaust valve is connected to the external leakage interface, and the output ends of the first exhaust valve, the second exhaust valve, the third exhaust valve and the fourth exhaust valve are connected to the helium detection component.

[0017] Preferably, the helium detection assembly comprises a test control valve and a helium mass spectrometer leak detector, and the helium mass spectrometer leak detector is connected to the output end of the exhaust valve group through the test control valve.

[0018] Preferably, the exhaust assembly comprises a vacuum pumping structure and an exhaust valve, and the vacuum pumping structure is connected to the output end of the exhaust valve group through the exhaust valve.

[0019] Preferably, the atmosphere communication component comprises an atmosphere communication control valve, and the atmosphere communication control valve is arranged at the output end of the exhaust valve group.

[0020] Preferably, the atmosphere communication component further comprises an air filter, and the air filter is connected to the atmosphere communication control valve.

[0021] Preferably, the device further comprises a helium recovery component, and the helium recovery component is arranged at the output end of the exhaust valve group.

[0022] A fuel cell stack air tightness test method, based on the fuel cell stack air tightness test device, the method comprises:

[0023] Close the air supply valve group and the atmosphere connection components;

[0024] Open the vent assembly to vent the gas;

[0025] Any one cavity of the fuel cell stack is used as the test cavity, and the other two cavities are used as the first leakage cavity and the second leakage cavity respectively. The gas supply valve group is controlled to introduce helium into the test cavity of the fuel cell stack, the helium detection component is opened, the working state of the exhaust valve group is controlled so that the helium detection component is connected to the test tank, and the helium detection component measures the external leakage data of the test cavity, the working state of the exhaust valve group is controlled so that the helium detection component is connected to the first leakage cavity of the fuel cell stack, and the helium detection component measures the leakage data from the test cavity to the first leakage cavity, the working state of the exhaust valve group is controlled so that the helium detection component is connected to the second leakage cavity of the fuel cell stack, and the helium detection component measures the leakage data from the test cavity to the second leakage cavity.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] (1) The present invention injects helium into each cavity of the fuel cell stack by setting a gas supply valve group, and exhausts the helium in the tank and each cavity of the fuel cell stack through the exhaust valve group, thereby detecting external leakage and cross-leakage in turn, which is easy to operate and has a high response frequency.

[0028] (2) The present invention uses a helium mass spectrometer leak detector to detect the exhausted helium, which has the advantages of being fast and accurate;

[0029] (3) The present invention provides an atmospheric communication component to achieve pressure balance between the tank body and the fuel cell stack and the atmosphere, that is, the tank body can be opened and the fuel cell stack can be removed only after the external atmosphere enters the tank body and the fuel cell, thereby ensuring safety;

[0030] (4) The present invention provides a helium recovery component to achieve effective recovery of helium and avoid waste of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of a fuel cell stack air tightness testing device in Example 1 of the present invention;

[0032] Figure 2This is a schematic structural diagram of a fuel cell stack air tightness testing device in Example 2 of the present invention;

[0033] Figure 3 This is a schematic structural diagram of a fuel cell stack air tightness testing device in Example 3 of the present invention;

[0034] Figure 4 This is a schematic structural diagram of a fuel cell stack air tightness testing device in Example 4 of the present invention.

[0035] In the figure, 1 is a helium supply assembly, 2 is a test tank, 21 is a first battery stack inlet interface, 22 is a second battery stack inlet interface, 23 is a third battery stack inlet interface, 24 is a first battery stack outlet interface, 25 is a second battery stack outlet interface, 26 is a third battery stack outlet interface, 27 is an external leakage interface, 28 is a first inlet hose, 29 is a second inlet hose, 210 is a third inlet hose, 211 is a first outlet hose, 212 is a second outlet hose, 213 is a third outlet hose, 214 is a tank body, 3 is a gas supply valve group, 31 is a first gas supply Valve, 32 is the second air supply valve, 33 is the third air supply valve, 4 is the exhaust valve group, 41 is the first exhaust valve, 42 is the second exhaust valve, 43 is the third exhaust valve, 44 is the fourth exhaust valve, 5 is the helium detection component, 51 is the test control valve, 52 is the helium mass spectrometer leak detector, 6 is the emptying component, 61 is the vacuum pumping structure, 62 is the emptying valve, 7 is the atmosphere connecting component, 71 is the atmosphere connecting control valve, 72 is the air filter, 8 is the helium recovery component, 81 is the helium recovery control valve, 82 is the helium recovery structure, and 9 is the fuel cell stack. DETAILED DESCRIPTION

[0036] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Note that the following embodiments are merely illustrative in nature, and the present invention is not intended to limit its applicable objects or uses, and the present invention is not limited to the following embodiments.

[0037] Example 1

[0038] like Figure 1 As shown, this embodiment provides a fuel cell stack air tightness test device, the device comprising:

[0039] Helium gas supply assembly 1: used to inject helium into the oxidizing gas cavity, the fuel gas cavity, and the cooling cavity of the fuel cell stack 9 during the air tightness test;

[0040] Test tank 2: used for sealing and containing the fuel cell stack 9 to be tested;

[0041] Gas supply valve group 3: connected to the test tank 2, used to inject helium into each cavity of the fuel cell stack 9;

[0042] Exhaust valve group 4: connected to the test tank 2, used to discharge the gas in each cavity of the fuel cell stack 9 and the test tank 2;

[0043] Helium detection component 5: used to detect the gas discharged from the exhaust component and determine the air tightness of the fuel cell stack 9;

[0044] Emptying assembly 6: used to empty the test tank 2 and each cavity of the fuel cell stack 9 before and after the air tightness test;

[0045] Atmosphere connecting assembly 7: used to balance the air pressure in the test tank 2 and each cavity of the fuel cell stack 9 after the air tightness test.

[0046] Among them, the test tank 2 includes a tank body 214, a battery stack inlet interface, a battery stack outlet interface and an external leakage interface 27. The battery stack inlet interface and the battery stack outlet interface are respectively provided with three, namely the first battery stack inlet interface 21, the second battery stack inlet interface 22, the third battery stack inlet interface 23, the first battery stack outlet interface 24, the second battery stack outlet interface 25, and the third battery stack outlet interface 26. The three pairs of battery stack inlet interface and battery stack outlet interface are used to correspond to the inlets and outlets of the electric push oxidizing gas cavity, the fuel gas cavity, and the cooling cavity connected to the electric push through the first inlet hose 28, the second inlet hose 29, the third inlet hose 210, the first outlet hose 211, the second outlet hose 212, and the third outlet hose 213. The external leakage interface 27 is connected to the internal space of the tank body 214, the battery stack inlet interface is connected to the helium supply component 1 through the gas supply valve group 3, and the battery stack outlet interface and the external leakage interface 27 are connected to the helium detection component 5 through the exhaust valve group 4. The first inlet hose 28 , the second inlet hose 29 , the third inlet hose 210 , the first outlet hose 211 , the second outlet hose 212 and the third outlet hose 213 are made of polytetrafluoroethylene or stainless steel.

[0047] The gas supply valve group 3 includes a first gas supply valve 31, a second gas supply valve 32 and a third gas supply valve 33 for respectively controlling the injection of helium into the oxidation gas chamber, the fuel gas chamber and the cooling chamber of the fuel cell stack 9. The input ends of the first gas supply valve 31, the second gas supply valve 32 and the third gas supply valve 33 are all connected to the helium supply assembly 1, and the output ends of the first gas supply valve 31, the second gas supply valve 32 and the third gas supply valve 33 are correspondingly connected to the corresponding stack inlet interfaces.

[0048] The exhaust valve group 4 includes a first exhaust valve 41, a second exhaust valve 42, a third exhaust valve 43 and a fourth exhaust valve 44 for respectively controlling the exhaust gas in the oxidizing gas chamber, the fuel gas chamber, the cooling chamber and the test tank 2 of the fuel cell stack 9. The input ends of the first exhaust valve 41, the second exhaust valve 42 and the third exhaust valve 43 are correspondingly connected to the corresponding stack outlet interface, the input end of the fourth exhaust valve 44 is connected to the external leakage interface 27, and the output ends of the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43 and the fourth exhaust valve 44 are connected to the helium detection component 5.

[0049] The intake valve and exhaust valve in the above-mentioned air supply valve group 3 and exhaust valve group 4 are selected to have a leakage rate of 10 -7 ~10 -1 pa·m 3 / s valve.

[0050] The helium detection assembly 5 comprises a test control valve 51 and a helium mass spectrometer leak detector 52 . The helium mass spectrometer leak detector 52 is connected to the output end of the exhaust valve group 4 through the test control valve 51 .

[0051] The exhaust assembly 6 includes a vacuum pumping structure 61 and an exhaust valve 62 . The vacuum pumping structure 61 is connected to the output end of the exhaust valve group 4 via the exhaust valve 62 .

[0052] The atmosphere communication component 7 includes an atmosphere communication control valve 71, and the atmosphere communication control valve 71 is arranged at the output end of the exhaust valve group 4. The atmosphere communication component 7 also includes an air filter 72, and the air filter 72 is connected to the atmosphere communication control valve 71. The air filter 72 is a filter that can filter solid particles and grease larger than 50 microns. During the detection process, the tank body 214 is evacuated; after the detection is completed, helium is recovered, and the fuel cell stack 9 also needs to be evacuated to a negative pressure state; the atmosphere communication component 7 is used to achieve pressure balance with the atmosphere; that is, the external atmosphere enters the tank body 214 and the fuel cell; then the tank body 214 can be opened and the fuel cell stack 9 can be removed;

[0053] The main form of the atmospheric communication component 7: the atmospheric communication component 7 is mainly constructed based on a valve. The valve is opened, and then the air enters the tank body 214 and the inside of the battery stack through the valve and the gas pipeline. The atmospheric communication component 7 can also be a structure similar to a bottle cork, that is, the bottle cork is unscrewed, and the air enters the tank body 214 and the inside of the battery stack through the gas pipeline. Another technical variation of the atmospheric communication component 7 is: using the above structure, it is connected to a nitrogen cylinder or a compressed air cylinder. In this embodiment, an air filter 72 is provided, and the air filter 72 can filter foreign particles, oil and water in the air, so that the air entering the battery stack will not damage the battery stack.

[0054] The device also includes a helium recovery component 8, which is arranged at the output end of the exhaust valve group 4. The helium recovery component 8 includes a helium recovery control valve 81 and a helium recovery structure 82. Since helium is a non-renewable resource and is relatively expensive, a large amount of helium is consumed in the process of leak detection for a large number of fuel cell stacks 9. The use of the helium recovery component 8 can achieve resource recycling. The helium recovery component 8 includes two basic methods: ① using an oil-free pumping device to extract the helium filled in the stack, and then using a gas compression device to compress the helium and fill it into the cylinder to achieve helium recovery; ② using an oil-free pumping device to extract the helium filled in the stack, and then using a low-temperature refrigerator (deep-cold refrigerator) to cool the helium into liquid, and flow into the liquid helium dewar to achieve helium recovery; currently there is a special helium recovery component 8 on the market, which is developed based on the above two basic principles. This embodiment uses the existing helium recovery component 8 on the market to achieve helium recovery.

[0055] Based on the above-mentioned fuel cell stack air tightness testing device, this embodiment also provides a fuel cell stack air tightness testing method, which includes:

[0056] Close the air supply valve group 3 and the atmosphere connection component 7;

[0057] Open the exhaust assembly 6 to exhaust the gas;

[0058] Any one cavity of the fuel cell stack 9 is used as the test cavity, and the other two cavities are used as the first leakage cavity and the second leakage cavity respectively. The gas supply valve group 3 is controlled to introduce helium into the test cavity of the fuel cell stack 9, and the helium detection component 5 is opened. The working state of the exhaust valve group 4 is controlled so that the helium detection component 5 is connected to the test tank 2, and the helium detection component 5 measures the external leakage data of the test cavity. The working state of the exhaust valve group 4 is controlled so that the helium detection component 5 is connected to the first leakage cavity of the fuel cell stack 9, and the helium detection component 5 measures the leakage data from the test cavity to the first leakage cavity. The working state of the exhaust valve group 4 is controlled so that the helium detection component 5 is connected to the second leakage cavity of the fuel cell stack 9, and the helium detection component 5 measures the leakage data from the test cavity to the second leakage cavity.

[0059] The following is a detailed description of the specific process of air tightness testing:

[0060] First, the external leakage and cross-leakage test of the fuel gas chamber (referred to as the hydrogen chamber in this embodiment) is performed:

[0061] 1) Pipeline connection

[0062] The fuel cell stack 9 is placed in the tank 214, the first inlet hose 28 and the first outlet hose 211 are connected to the hydrogen inlet and the hydrogen outlet of the stack respectively; the second inlet hose 29 and the second outlet hose 212 are connected to the air inlet and the air outlet of the stack respectively; the third inlet hose 210 and the third outlet hose 213 are connected to the coolant inlet and the coolant outlet of the stack respectively;

[0063] 2) The valve opens and gas passes through;

[0064] Open the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43, the fourth exhaust valve 44 and the drain valve 62;

[0065] 3) The valve is closed and gas does not pass through;

[0066] Close the first gas supply valve 31, the second gas supply valve 32, the third gas supply valve 33, the test control valve 51, the atmosphere connection control valve 71 and the helium recovery control valve 81;

[0067] 4) Open the vacuum pumping structure 61 to pump air from the tank 214 and the stack; -1 After pa, the vacuum pumping structure 61 is closed, and the exhaust valve 62 is closed;

[0068] 5) Open the first air supply valve 31; close the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43, and the fourth exhaust valve 44;

[0069] 6) Maintain the second gas supply valve 32, the third gas supply valve 33, the exhaust valve 62, the test control valve 51, the atmosphere connection control valve 71 and the helium recovery control valve 81 closed;

[0070] 7) The helium supply assembly 1 supplies helium to the hydrogen chamber inside the fuel cell stack through the first gas supply valve 31;

[0071] 8) Turn on the helium mass spectrometer and open the test control valve 51;

[0072] 9) Open the fourth exhaust valve 44, and keep the other valves in step 5) unchanged, so as to obtain the leakage data from the hydrogen chamber of the stack to the tank 214, which can be considered as the external leakage data of the hydrogen chamber; close the fourth exhaust valve 44;

[0073] 10) Open the third exhaust valve 43, and keep the other valves in step 5) unchanged, so as to obtain the leakage data from the hydrogen chamber of the fuel cell stack to the coolant chamber; close the third exhaust valve 43;

[0074] 11) Open the second exhaust valve 42, and keep the other valves in step 5) unchanged, so as to obtain the leakage data from the hydrogen chamber to the air chamber of the stack; close the second exhaust valve 42;

[0075] 12) The above test of hydrogen chamber leakage and hydrogen chamber leakage is completed; close the first gas supply valve 31, open the first exhaust valve 41, and the helium recovery control valve 81; the other valve states are processed according to step 5), and the helium recovery structure 82 is used to recover the helium in the hydrogen chamber; close the helium recovery control valve 81;

[0076] 13) Open the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43, the fourth exhaust valve 44 and the test control valve 51, and the other valves are in the same state as in step 5); use a vacuum pump to reduce the pressure of the battery stack and the tank 214 to less than 10 -1 Pa.

[0077] Then, the external leakage and cross-leakage test of the oxidizing gas chamber (referred to as the air chamber in this embodiment) is completed according to the following steps:

[0078] 1) Pipeline connection

[0079] The fuel cell stack 9 is placed in the tank 214, the first inlet hose 28 and the first outlet hose 211 are connected to the hydrogen inlet and the hydrogen outlet of the stack respectively; the second inlet hose 29 and the second outlet hose 212 are connected to the air inlet and the air outlet of the stack respectively; the third inlet hose 210 and the third outlet hose 213 are connected to the coolant inlet and the coolant outlet of the stack respectively;

[0080] 2) The valve opens and gas passes through;

[0081] Open the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43, the fourth exhaust valve 44 and the drain valve 62;

[0082] 3) The valve is closed and gas does not pass through;

[0083] Close the first gas supply valve 31, the second gas supply valve 32, the third gas supply valve 33, the test control valve 51, the atmosphere connection control valve 71 and the helium recovery control valve 81;

[0084] 4) Open the vacuum pumping structure 61 to pump air from the tank 214 and the stack; -1 After pa, the vacuum pumping structure 61 is closed, and the exhaust valve 62 is closed;

[0085] 5) Open the second air supply valve 32; close the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43, and the fourth exhaust valve 44;

[0086] 6) Maintain the first gas supply valve 31, the third gas supply valve 33, the exhaust valve 62, the test control valve 51, the atmosphere connection control valve 71 and the helium recovery control valve 81 closed;

[0087] 7) The helium supply assembly 1 supplies helium to the air cavity inside the fuel cell stack through the second gas supply valve 32;

[0088] 8) Turn on the helium mass spectrometer and open the test control valve 51;

[0089] 9) Open the fourth exhaust valve 44, and keep the other valves in step 5) unchanged, so as to obtain the leakage data from the stack air cavity to the tank 214, which can be considered as the external leakage data of the air cavity; close the fourth exhaust valve 44;

[0090] 10) Open the third exhaust valve 43, and keep the other valves in step 5) unchanged, so as to obtain the leakage data from the stack air cavity to the coolant cavity; close the third exhaust valve 43;

[0091] 11) Open the first exhaust valve 41 and keep the other valves in step 5) unchanged, so as to obtain the leakage data from the air chamber to the hydrogen chamber of the stack; close the first exhaust valve 41;

[0092] 12) The above test of air cavity leakage and air cavity leakage is completed; close the second air supply valve 32, open the second exhaust valve 42, and the helium recovery control valve 81; the other valve states are processed according to step 5), and the helium recovery structure 82 is used to recover the helium in the air cavity; close the helium recovery control valve 81;

[0093] 13) Open the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43, the fourth exhaust valve 44 and the test control valve 51, and the other valves are in the same state as in step 5); use a vacuum pump to reduce the pressure of the battery stack and the tank 214 to less than 10 -1 Pa.

[0094] Next, complete the external leakage and cross leakage test of the cooling cavity (referred to as the cooling liquid cavity in this embodiment) according to the following steps:

[0095] 1) Pipeline connection

[0096] The fuel cell stack 9 is placed in the tank 214, the first inlet hose 28 and the first outlet hose 211 are connected to the hydrogen inlet and the hydrogen outlet of the stack respectively; the second inlet hose 29 and the second outlet hose 212 are connected to the air inlet and the air outlet of the stack respectively; the third inlet hose 210 and the third outlet hose 213 are connected to the coolant inlet and the coolant outlet of the stack respectively;

[0097] 2) The valve opens and gas passes through;

[0098] Open the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43, the fourth exhaust valve 44 and the drain valve 62;

[0099] 3) The valve is closed and gas does not pass through;

[0100] Close the first gas supply valve 31, the second gas supply valve 32, the third gas supply valve 33, the test control valve 51, the atmosphere connection control valve 71 and the helium recovery control valve 81;

[0101] 4) Open the vacuum pumping structure 61 to pump air from the tank 214 and the stack; -1 After pa, the vacuum pumping structure 61 is closed, and the exhaust valve 62 is closed;

[0102] 5) Open the third air supply valve 33; close the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43, and the fourth exhaust valve 44;

[0103] 6) Maintain the first gas supply valve 31, the second gas supply valve 32, the exhaust valve 62, the test control valve 51, the atmosphere connection control valve 71 and the helium recovery control valve 81 closed;

[0104] 7) The helium supply assembly 1 supplies helium to the cooling liquid cavity inside the fuel cell stack through the third gas supply valve 33;

[0105] 8) Turn on the helium mass spectrometer and open the test control valve 51;

[0106] 9) Open the fourth exhaust valve 44, and keep the other valves in step 5) unchanged, so as to obtain the leakage data from the stack coolant chamber to the tank 214, which can be considered as the leakage data of the coolant chamber; close the fourth exhaust valve 44;

[0107] 10) Open the second exhaust valve 42, and keep the other valves in step 5) unchanged, so as to obtain the leakage data from the stack coolant chamber to the air chamber; close the second exhaust valve 42;

[0108] 11) Open the first exhaust valve 41 and keep the other valves in step 5) unchanged, so as to obtain the leakage data from the stack coolant chamber to the hydrogen chamber; close the first exhaust valve 41;

[0109] 12) The above test of cooling liquid chamber leakage and air chamber leakage is completed; close the third air supply valve 33, open the third exhaust valve 43, and the helium recovery control valve 81; the other valve states are processed according to step 5), and the helium recovery structure 82 is used to recover the helium in the cooling liquid chamber; close the helium recovery control valve 81;

[0110] 13) Open the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43, the fourth exhaust valve 44 and the test control valve 51, and the other valves are in the same state as in step 5); use a vacuum pump to reduce the pressure of the battery stack and the tank 214 to less than 10 -1 Pa.

[0111] After the above steps, the test of the external leakage and cross leakage of the battery stack can be completed. The order of measuring the external leakage and cross leakage of the above chamber can be changed.

[0112] After completing all cavity tests, open the first exhaust valve 41, the second exhaust valve 42, the third exhaust valve 43, the fourth exhaust valve 44 and the atmosphere connection control valve 71, and the remaining valves are processed according to step 5); the atmosphere enters the fuel cell stack and the tank body 214 through the atmosphere connection component 7; after the pressure is balanced, the tank body 214 can be opened to transfer the fuel cell stack 9.

[0113] Example 2

[0114] like Figure 2 As shown, this embodiment provides a fuel cell stack air tightness test device, the structure of which is basically the same as that in Example 1, except that the helium recovery assembly 8 (including the helium recovery control valve 81 and the helium recovery structure 82 in Example 1) is not provided in this embodiment. The method of using the test device in this embodiment to perform an air tightness test on the fuel cell stack 9 is also basically the same as that in Example 1, the only thing that fails is that this embodiment no longer performs helium recovery. The specific structure of the fuel cell stack air tightness test device in this embodiment and the specific method of using the device to perform an air tightness test are not described in detail.

[0115] Example 3

[0116] like Figure 3 As shown, this embodiment provides a fuel cell stack air tightness test device, the structure of the device is basically the same as that in Example 1, the difference is that the atmosphere connection component 7 in this embodiment no longer has an air filter 72, and the rest is the same as Example 1. The method of using the test device in this embodiment to perform an air tightness test on the fuel cell stack 9 is also the same as that in Example 1, and will not be repeated in this embodiment.

[0117] Example 4

[0118] like Figure 4 As shown, this embodiment provides a fuel cell stack air tightness test device, the structure of the device is basically the same as that in Example 1, the difference is that in this embodiment, the air filter 72 is no longer provided in the atmosphere connection component 7, and the helium recovery component 8 is no longer provided in this embodiment. The rest is the same as in Example 1. The method of using the test device in this embodiment to perform the fuel cell stack 9 air tightness test is also the same as in Example 1, and will not be repeated in this embodiment.

[0119] The above embodiments are merely examples and do not limit the scope of the present invention. These embodiments can also be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the technical concept of the present invention.

Claims

1. A fuel cell stack air tightness test device, characterized in that: The device includes: Helium gas supply assembly (1): used for injecting helium into the oxidation gas cavity, the fuel gas cavity and the cooling cavity of the fuel cell stack (9) during air tightness testing; Test tank (2): used for sealing and containing the fuel cell stack (9) to be tested; Gas supply valve assembly (3): connected to the test tank (2) and used to inject helium into each cavity of the fuel cell stack (9); An exhaust valve assembly (4) connected to the test tank (2) and used to exhaust the gas in each cavity of the fuel cell stack (9) and the test tank (2); Helium detection component (5): used to detect the gas discharged from the exhaust component and determine the air tightness of the fuel cell stack (9); An exhaust assembly (6) is used to exhaust the test tank (2) and each cavity of the fuel cell stack (9) before and after the air tightness test; Atmosphere communication component (7): used to balance the air pressure in the test tank (2) and each cavity of the fuel cell stack (9) after the air tightness test; The test tank (2) comprises a tank body (214), a stack inlet interface, a stack outlet interface and an external leakage interface (27), wherein the stack inlet interface and the stack outlet interface are respectively provided with three, and are used to correspond to the inlet and outlet of the oxidation gas cavity, the fuel gas cavity and the cooling cavity of the electric propulsion, and the external leakage interface (27) is connected to the internal space of the tank body (214), the stack inlet interface is connected to the helium gas supply component (1) through the gas supply valve group (3), and the stack outlet interface and the external leakage interface (27) are connected to the helium gas supply component (1) through the gas supply valve group (3). The exhaust valve assembly (4) is connected to the helium detection assembly (5); the gas supply valve assembly (3) comprises a first gas supply valve (31), a second gas supply valve (32) and a third gas supply valve (33) for respectively controlling the injection of helium into the oxidation gas chamber, the fuel gas chamber and the cooling chamber of the fuel cell stack (9); the input ends of the first gas supply valve (31), the second gas supply valve (32) and the third gas supply valve (33) are all connected to the helium supply assembly (1); the first gas supply valve (31), the second gas supply valve (32) and the third gas supply valve (33) are connected to the helium supply assembly (1); The output ends of the first exhaust valve (41), the second exhaust valve (42), the third exhaust valve (43) and the fourth exhaust valve (44) are connected to the corresponding fuel cell stack inlet interfaces; the exhaust valve group (4) comprises a first exhaust valve (41), a second exhaust valve (42), a third exhaust valve (43) and a fourth exhaust valve (44) for respectively controlling the exhaust gas from the oxidizing gas chamber, the fuel gas chamber, the cooling chamber and the test tank (2) of the fuel cell stack; the input ends of the first exhaust valve (41), the second exhaust valve (42) and the third exhaust valve (43) are connected to the corresponding fuel cell stack inlet interfaces; The fourth exhaust valve (44) has an input end connected to the external leakage interface (27), and the output ends of the first exhaust valve (41), the second exhaust valve (42), the third exhaust valve (43) and the fourth exhaust valve (44) are connected to the helium detection component (5); the helium detection component (5) comprises a test control valve (51) and a helium mass spectrometer leak detector (52), and the helium mass spectrometer leak detector (52) is connected to the output end of the exhaust valve group (4) through the test control valve (51).

2. A fuel cell stack air tightness testing device according to claim 1, characterized in that: The exhaust assembly (6) comprises a vacuum pumping structure (61) and an exhaust valve (62), and the vacuum pumping structure (61) is connected to the output end of the exhaust valve group (4) via the exhaust valve (62).

3. A fuel cell stack air tightness testing device according to claim 1, characterized in that: The atmosphere communication component (7) comprises an atmosphere communication control valve (71), and the atmosphere communication control valve (71) is arranged at the output end of the exhaust valve group (4).

4. A fuel cell stack air tightness testing device according to claim 3, characterized in that: The atmosphere communication component (7) further comprises an air filter (72), and the air filter (72) is connected to the atmosphere communication control valve (71).

5. A fuel cell stack air tightness testing device according to claim 1, characterized in that: The device also comprises a helium recovery component (8), wherein the helium recovery component (8) is arranged at the output end of the exhaust valve group (4).

6. A fuel cell stack air tightness testing method, characterized in that: The method is based on the fuel cell stack air tightness testing device according to any one of claims 1 to 5, and the method comprises: Close the air supply valve assembly (3) and the atmosphere connection assembly (7); Open the exhaust assembly (6) to exhaust the gas; Any one cavity of the fuel cell stack (9) is used as a test cavity, and the other two cavities are used as a first leakage cavity and a second leakage cavity respectively; the gas supply valve group (3) is controlled to introduce helium into the test cavity of the fuel cell stack (9); the helium detection component (5) is turned on; the working state of the exhaust valve group (4) is controlled so that the helium detection component (5) is connected to the test tank (2); the helium detection component (5) measures and obtains leakage data of the test cavity; the working state of the exhaust valve group (4) is controlled so that the helium detection component (5) is connected to the first leakage cavity of the fuel cell stack (9); the helium detection component (5) measures and obtains leakage data from the test cavity to the first leakage cavity; the working state of the exhaust valve group (4) is controlled so that the helium detection component (5) is connected to the second leakage cavity of the fuel cell stack (9); the helium detection component (5) measures and obtains leakage data from the test cavity to the second leakage cavity.

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