CN111579173A - Automatic detection equipment and detection method for three-cavity pressure maintaining air tightness of fuel cell system - Google Patents

Abstract

The invention discloses a three-chamber pressure-maintaining air-tightness automatic detection device of a fuel cell system and a detection method thereof. The device comprises: a gas storage device communicated with a nitrogen cylinder through a gas storage pipeline; There are a pressure reducing valve and an intake valve. The gas storage device is provided with three parallel outlet pipes corresponding to the three cavities of the fuel cell system, and each outlet pipe is provided with a three-way valve, a flow meter and an external interface along the gas outlet direction. , the gas storage device is also provided with a pressure sensor and an exhaust pipe, the exhaust pipe is provided with a first exhaust valve, and the three-way valve of each gas outlet pipe is also connected with each other for detecting fuel cells. Leak detection piping between system chambers. A gas storage device is added to the equipment of the invention, which can ensure the uniformity of the air pressure in the three chambers of the fuel cell system, avoid damage to the membrane electrode of the fuel cell, and improve the life of the fuel cell.

Description

A three-chamber pressure-maintaining air-tightness automatic detection device for fuel cell system and its detection method

technical field

The invention relates to the technical field of hydrogen fuel cell system testing, in particular to an automatic detection device and a detection method for the three-chamber pressure-maintaining air tightness of a hydrogen fuel cell system.

Background technique

In order to cope with international environmental problems and energy crisis, hydrogen fuel cell vehicles have become the development strategies of countries around the world. With the popularization of hydrogen fuel cell vehicles, more and more problems have emerged. Among them, there are many problems in the detection of air tightness and pressure maintenance of the fuel cell system. The gas is kept under pressure for a period of time, and the leakage of the three chambers to the atmosphere and the inter-connection of each chamber are detected. The traditional air-tightness and pressure-maintaining testing is aimed at different fuel cell systems, and the three-way pressure-maintaining pipelines and pressure-retaining devices of the hydrogen supply circuit, air circuit and water circuit need to be rebuilt. During serial testing, it is necessary to continuously manually modify the testing equipment to perform the corresponding sealing test, which cannot realize automatic air tightness testing, and has no versatility and practicability. During the test, there is a large pressure difference between the various chambers of the fuel cell, which makes the membrane electrode of the fuel cell permanently damaged and affects the life of the fuel cell.

The Chinese utility model patent with publication number CN205879471U discloses a fuel cell air tightness detection system. The structure includes various two-way ball valves and three-way ball valves, resulting in extremely complicated pipeline layout and operation of the entire detection system. The Chinese invention patent with publication number CN 108120568 A discloses a real-time detection device for the air tightness of a fuel cell stack. For the detection of oxidants and oxidants, valves, flow meters, pressure gauges, etc. are required to be installed on the inlet and outlet pipes. During the external leakage test, it is even necessary to compare and process multiple parameters on the inlet and outlet pipes to obtain the results. , the detection efficiency is low. Moreover, there is no component in the above two patents that can make the air pressure uniform when each chamber of the fuel cell is ventilated, and the membrane electrode of the fuel cell is easily damaged.

Therefore, it is necessary to develop a three-chamber pressure-holding and air-tightness automatic detection equipment for fuel cell systems, which can realize automatic air-tightness detection and air-pressure control, reduce the construction time of the pressure-holding test system and the time of manual operation of the air-tightness detection system, and improve the detection efficiency. The versatility and practicability of the system, the operation is simpler and faster, the damage to the membrane electrode of the fuel cell is avoided, and the life of the fuel cell is improved.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the above-mentioned deficiencies of the background technology, and to provide a three-chamber pressure-keeping and air-tightness automatic detection device and a detection method for a fuel cell system with simple structure, high versatility, fast operation, and consistent air pressure in each chamber.

The technical scheme of the present invention is as follows: an automatic detection device for the pressure-maintaining air-tightness of a fuel cell system with three cavities, which is characterized in that it includes a gas storage device, and a gas storage pipe is arranged on the gas storage device to communicate with a nitrogen cylinder, and the gas storage pipe A pressure reducing valve and an intake valve are arranged on the channel along the intake direction. The gas storage device is provided with three parallel outlet pipes corresponding to the three cavities of the fuel cell system, and each outlet pipe is provided with a three-way valve along the outlet direction. , flowmeter and external interface, the gas storage device is also provided with a pressure sensor and an exhaust pipe, the exhaust pipe is provided with a first exhaust valve, and the three-way valve of each gas outlet pipe is also provided with mutual communication . The detection pipeline used to detect the leakage between the chambers of the fuel cell system.

Preferably, the three-way parallel air outlet pipes are respectively a first air outlet pipe, a second air outlet pipe and a third air outlet pipe, and the first air outlet pipe is provided with a first three-way valve, a first flow meter and a The first external interface, the second air outlet pipeline is provided with a second three-way valve, a second flow meter and a second external interface in sequence along the air outlet direction, and the third air outlet pipeline is sequentially provided with a third three-way valve along the air outlet direction. through valve, third flow meter and third external interface;

The first three-way valve, the second three-way valve, and the third three-way valve are two of which are connected with the first air outlet pipe, the second air outlet pipe, and the third air outlet pipe, and the detection pipe connects the first and third air outlets. After the through valve, the second three-way valve, and the other channel of the third three-way valve are connected and merged, a second exhaust valve is arranged to lead to the rear of the first exhaust valve on the exhaust pipeline.

Further, an air inlet port is provided on the gas storage pipeline to be connected to the nitrogen cylinder correspondingly, and an exhaust port is provided at the end of the exhaust pipe to communicate with the atmosphere.

Further, it also includes a pressure display and control device, the pressure display and control device includes a display and a system controller, the system controller and the first exhaust valve, the second exhaust valve, the pressure reducing valve, the intake valve , The first three-way valve, the second three-way valve, the third three-way valve, the pressure sensor, the first flowmeter, the second flowmeter, and the third flowmeter are signally connected, and the display is connected to the system controller for signal connection. Displays the detection data of the pressure sensor, the first flowmeter, the second flowmeter, and the third flowmeter.

The present invention also provides a detection method for the above-mentioned three-chamber pressure-maintaining and air-tightness automatic detection device for a fuel cell system, which is characterized in that it includes a working mode for external leakage and pressure-maintaining detection, a working mode for detecting the inter-connection of hydrogen cavity and air cavity, and an air cavity. And the water cavity inter-series detection working mode;

Before starting the above working mode, make sure that the gas storage pipeline and the nitrogen cylinder, as well as the first gas outlet pipeline, the second gas outlet pipeline, and the third gas outlet pipeline, form a sealed connection with the hydrogen chamber, air chamber and water chamber pipelines of the fuel cell respectively. The exhaust valve, the second exhaust valve, the pressure reducing valve and the intake valve are closed;

The working mode of the external leakage and pressure-retaining detection is:

Inflation and pressure regulation: open the intake valve, slowly adjust the pressure reducing valve, and let the nitrogen in the nitrogen bottle decompress and enter the gas storage device; open the first three-way valve, the second three-way valve, and the third three-way valve to store the gas The device and the fuel cell system are connected to inflate each chamber; the pressure sensor detects the pressure in the gas storage device, and adjusts the pressure in the gas storage device to a threshold value P _t through the pressure reducing valve and the first exhaust valve;

Test data: close the intake valve and the first exhaust valve. After the duration of T1, the pressure value in the gas storage device is detected and recorded by the pressure sensor, and the pressure reducing valve is adjusted to zero. No more intake air in the gas storage device, again Open the first exhaust valve, discharge the gas inside the system, reduce the internal pressure of the stack to the same atmospheric pressure, repeat the above steps n times, and obtain the recorded P1, P2...Pn, a total of n pressure values;

Test result: Calculate the differential pressure △P=P _t -(P1+P2+…Pn)/n,

If △P < set value △P _max , it means that the external leakage detection of the three cavities is qualified.

If △P ≥ the set value △P _max , it means that the external leakage detection of the three cavities is unqualified.

Preferably, the steps of detecting the working mode of the hydrogen cavity and the air cavity in series are:

The working mode steps of the hydrogen cavity and the air cavity inter-series detection are as follows:

Inflation and pressure regulation: open the intake valve, slowly adjust the pressure reducing valve, and then enter the gas storage device after decompression of nitrogen; control the first three-way valve to connect the gas storage device and the fuel cell system to inflate the hydrogen chamber, and control the second The three-way valve and the third three-way valve connect the fuel cell system and the detection pipeline; the pressure sensor detects the pressure in the gas storage device, and adjusts the pressure in the gas storage device to a threshold value P _H2 through the pressure reducing valve and the first exhaust valve. ;

Test data: close the first exhaust valve and open the second exhaust valve at the same time, detect and record the air flow value through the second flow meter; adjust the pressure reducing valve to the zero point, no more intake air in the air storage device, and open it again The first exhaust valve discharges the gas inside the system, reduces the internal pressure of the stack to the same atmospheric pressure, repeats the above steps n times, and obtains the recorded Fair1, Fair2...Fairn, a total of n flow values;

Test result: Calculate the flow average value Fair=(Fair1+Fair2+…Fairn)/n,

If Fair < the set value Fair _max , it means that the hydrogen chamber and the air chamber pass the mutual test. If Fair ≥ the set value Fair _max , the hydrogen chamber and the air chamber fail to pass the test.

Preferably, the working mode of the air cavity and the water cavity mutual series detection is:

Inflation and pressure regulation: open the intake valve, slowly adjust the pressure reducing valve, and then enter the gas storage device after the nitrogen is decompressed; control the first three-way valve and the second three-way valve to conduct the gas storage device and the fuel cell system to hydrogen The cavity and the air cavity are inflated, and the third three-way valve is controlled to make the fuel cell system and the detection pipeline conduct; the pressure sensor detects the pressure in the gas storage device, and adjusts the pressure in the gas storage device through the pressure reducing valve and the first exhaust valve. threshold P _t ;

Test data: close the first exhaust valve and open the second exhaust valve at the same time, detect and record the water flow value through the third flow meter; adjust the pressure reducing valve to zero point, no more intake air in the gas storage device, open the third flow meter again. An exhaust valve, which discharges the gas inside the system, reduces the internal pressure of the stack to the same atmospheric pressure, repeats the above steps n times, and obtains a total of n flow values of Fwt1, Fwt2...Fwtn;

Test result: Calculate the flow average value Fwt=(Fwt1+Fwt2+...Fwtn)/n,

If Fwt < the set value Fwt _max , it means that the air cavity and the water cavity are tested in series.

If Fwt ≥ the set value Fwt _max , it means that the air cavity and the water cavity fail to pass the test.

Further, the specific operation of adjusting the pressure in the gas storage device to be the threshold value P _t is: compare the pressure value measured by the pressure sensor with the threshold value P _t , and when the pressure value is lower than the threshold value P _t , adjust the pressure reducing valve to pressurize; When the value is higher than the threshold value _Pt , the first exhaust valve is opened to reduce pressure.

The beneficial effects of the present invention are:

1. The equipment can be adapted to different fuel cell system pipeline interfaces, pipelines and devices, without distinguishing air, hydrogen and water, it can be connected to the three cavities of hydrogen, air and water in the fuel cell system, and it does not need to be in the fuel cell system. The test site builds and modifies the air tightness detection pipeline and device, which improves the versatility and practicability of the system. In addition to testing the air tightness of the three cavities of the fuel stack, it also detects the air tightness of the inlet and outlet pipes of the three cavities of the fuel power system.

2. Realize the automatic air tightness detection and air pressure control of the fuel cell system, reduce the construction time of the pressure holding test system and the time to manually operate the air tightness detection equipment, making the operation simpler and faster, and the fuel cell membrane can also be avoided through pressure control. Electrodes are damaged, increasing fuel cell life.

3. An air storage device is added to the system to ensure the consistency of air pressure in the three chambers of the fuel cell system.

Description of drawings

Fig. 1 is the schematic diagram of the three-chamber pressure-maintaining air-tightness testing equipment of the hydrogen fuel cell according to the present invention

Fig. 2 is the electrical connection diagram of the three-chamber pressure-maintaining air-tightness testing equipment of the hydrogen fuel cell of the present invention

Figure 3 is a schematic diagram of the gas flow in the working mode of external leakage and pressure-maintaining detection

Figure 4 is a schematic diagram of the gas flow when the hydrogen cavity and the air cavity are connected in series detection mode

Figure 5 is a schematic diagram of the gas flow when the air cavity and the water cavity are in the working mode of mutual series detection

Among them: 1-nitrogen cylinder 2-pressure reducing valve 3-inlet valve 4-pressure sensor 5-gas storage device 6-air outlet pipeline (61-first air outlet 62-second air outlet 63-third air outlet) 7 -Three-way valve (71-first three-way valve 72-second three-way valve 73-third three-way valve) 8-flowmeter (81-first flowmeter 82-second flowmeter 83-third flowmeter ) 9-external interface (91-first external interface 92-second external interface 93-third external interface) 10-detection pipeline 11-display 12-system controller 13-fuel cell system 14-gas storage pipeline 15-row Air duct 16 - exhaust port 17 - intake port 601 - first exhaust valve 602 - second exhaust valve.

Detailed ways

The following specific examples will further illustrate the present invention in detail.

As shown in Figures 1-2, the present invention provides an automatic detection device for the pressure-keeping and air-tightness of the three-chamber hydrogen fuel cell system, including a gas storage device 5, and a gas storage pipeline 14 is arranged on the gas storage device 5 to communicate with the nitrogen cylinder 1, and the storage The gas pipeline 14 is provided with a decompression valve 2 and an intake valve 3 along the intake direction, and the gas storage device 5 is provided with three parallel-connected gas outlet pipelines 6 corresponding to the three cavities of the fuel cell system 13 respectively. A three-way valve 7, a flow meter 8 and an external interface 9 are arranged along the gas outlet direction of the gas storage device 5. The gas storage device 5 is also provided with a pressure sensor 4 and an exhaust pipe 15, and the exhaust pipe 15 is provided with a first exhaust valve. 601 , the three-way valve 7 of each gas outlet pipe 6 is further provided with a detection pipe 10 that communicates with each other and is used for detecting leakage between the chambers of the fuel cell system 13 .

The three-way parallel air outlet pipes 6 are respectively a first air outlet pipe 61, a second air outlet pipe 62 and a third air outlet pipe 63. The first air outlet pipe 61 is provided with a first three-way valve 71, The first flow meter 81 and the first external port 91, the second air outlet pipe 62 are sequentially provided with a second three-way valve 72, a second flow meter 82 and a second external port 92 along the air outlet direction, and the third air outlet pipe 63 The air outlet direction is provided with a third three-way valve 73, a third flow meter 83 and a third external interface 93 in sequence; the first three-way valve 71, the second three-way valve 72, and the third three-way valve 73 are two of the channels. Connected with the first air outlet pipe 61 , the second air outlet pipe 62 and the third air outlet pipe 63 , the other channels of the first three-way valve 71 , the second three-way valve 72 and the third three-way valve 73 are connected and merged by the detection pipe 10 A second exhaust valve 602 is provided behind the first exhaust valve 601 on the exhaust duct 15 . In this embodiment, the first three-way valve 71, the second three-way valve 72, and the third three-way valve 73 are all two-position three-way solenoid valves, and two of the three channels must be open, one is closed, and the first three-way valve is closed. The three channels of the three-way valve 71 , the second three-way valve 72 , and the third three-way valve 73 are channel 1 , channel 2 , and channel 3 . The first three-way valve 71, the second three-way valve 72, and the third three-way valve 73 are connected to the first air outlet pipe 61, the second air outlet pipe 62, and the third air outlet pipe 63 through channels 1 and 2, respectively. The channels 3 of the three-way valve 71 , the second three-way valve 72 , and the third three-way valve 73 are connected by the detection pipe 10 and merged into the exhaust pipe 15 . In this embodiment, the front-to-rear direction is the flow direction of the airflow along the pipe.

The device also includes a pressure display and control device, the pressure display and control device includes a display 11 and a system controller 12, the system controller 12 is connected to the first exhaust valve 601, the second exhaust valve 601, the pressure reducing valve 2, the intake air The valve 3, the first three-way valve 71, the second three-way valve 72, the third three-way valve 73, the pressure sensor 4, the first flowmeter 81, the second flowmeter 82, and the third flowmeter 83 are signally connected, and the display 11 In signal connection with the system controller 12 , the display 11 is used to display the detection data of the pressure sensor 4 , the first flowmeter 81 , the second flowmeter 82 and the third flowmeter 83 . The system controller 12 is used to control the first exhaust valve 601, the second exhaust valve 601, the pressure reducing valve 2, the intake valve 3, the first three-way valve 71, the second three-way valve 72, and the third three-way valve The system controller 12 will record and process the measurement results of the pressure sensor 4 , the first flow meter 81 , the second flow meter 82 , and the third flow meter 83 as required.

An exhaust port 16 is provided at the end of the exhaust pipe 15 , and an intake port 17 is provided on the gas storage pipe 14 to communicate with the nitrogen cylinder 1 . There are five interfaces on the device in this embodiment: an air intake port 17 , a first external interface 91 , a second external interface 92 , a third external interface 93 and an exhaust port 16 . The input end of the air inlet port 17 is connected to the external nitrogen cylinder 1 to provide airtight pressure maintaining gas for the entire system. The first external interface 91 corresponds to the hydrogen circuit pipeline of the fuel cell system 13 and is used to detect the tightness of the hydrogen circuit; the second external interface 92 corresponds to the air circuit pipeline of the fuel cell system 13, which is used to detect the air tightness of the air circuit; the third external interface 93 corresponds to the cooling water pipeline of the fuel cell system 13, which is used to detect the air tightness of the cooling water circuit. The first external interface 91, the second external interface 92, and the third external interface 93 are equipped with pipe diameter conversion interfaces of different pipe diameters, which can be adapted to pipelines of different pipe diameters of the fuel cell system 13, and there is no need to distinguish between the air path and the hydrogen path. It can be connected to the three cavities of hydrogen, air and water in the fuel cell system 13 arbitrarily, and has strong versatility. Exhaust port 16 is connected to the atmosphere outside the system for excess gas exhaust.

The gas enters the intake valve 3 after passing through the secondary pressure reducing valve 2. The pressure reducing valve 2 is mainly used to decompress and adjust the high-pressure nitrogen in the nitrogen cylinder 1, and supply it to the fuel cell system 13 for air tightness testing to avoid excessive gas pressure. Damage to the fuel cell stack. The intake valve 3 mainly controls the opening and closing of the intake circuit.

The gas storage device 5 is mainly used to ensure the consistency of the air pressure of the three chambers of the hydrogen circuit, the air circuit and the water circuit. The opening of channel 1 and channel 2 of the first three-way valve 71 is mainly used for nitrogen to enter the hydrogen chamber, the opening of channel 2 and channel 3 is mainly used for the gas in the hydrogen chamber to discharge the atmosphere, and the opening of channel 1 and channel 2 of the second three-way valve 72 is mainly used for opening. When nitrogen enters the air cavity, the opening of channel 2 and channel 3 is mainly used for the gas in the air cavity to discharge the atmosphere. The third three-way valve 73 is opened mainly for nitrogen entering the water cavity, and the opening of channel 2 and channel 3 is mainly used for The gas in the water chamber is exhausted to the atmosphere.

The pressure sensor 4 is used to monitor the pressure in the gas storage device 5. When the pressure value in the gas storage device 5 does not reach the threshold value P _t , the pressure reducing valve 2 is adjusted to increase the pressure in the gas storage device 5. If the pressure value exceeds the threshold value At P _t , the first exhaust valve 601 is opened to discharge excess gas, so that the pressure is controlled within a certain range. It is ensured that the pressures entering the three chambers of the hydrogen circuit, the air circuit and the water circuit of the fuel cell system are within an appropriate range, and the fuel cell will not be damaged due to excessive pressure.

The first flow meter 81 , the second flow meter 82 and the third flow meter 83 are mainly used to monitor the gas flow value in each chamber circuit.

In the air pressure display and control device, the display 11 can display the air pressure value in the air storage device 5, which is convenient for the operator to check the air pressure at any time. The control device 12 controls the three-chamber pressure-keeping and air-tightness automatic detection equipment of the entire fuel cell system. .

The present invention also provides a detection method for the above-mentioned three-chamber pressure-maintaining and air-tightness automatic detection equipment of the fuel cell system, including the external leakage and pressure-maintaining detection working mode, the hydrogen cavity and the air cavity inter-connection detection work mode, and the air cavity and the water cavity inter-connection detection work. model;

Before starting each working mode, ensure that the gas storage pipeline 14 and the nitrogen cylinder 1, as well as the first gas outlet pipe 61, the second gas outlet pipe 62, and the third gas outlet pipe 63 are respectively connected with the fuel cell hydrogen chamber, air chamber and water chamber pipelines in a sealed connection , the first exhaust valve 601 , the second exhaust valve 601 , the pressure reducing valve 2 , and the intake valve 3 are in a closed state.

Mode 1. External leakage and pressure-holding detection working mode, the specific steps are as follows:

Step 1: System initialization, the counter is cleared and the counter is turned on,

Step 2: Open the intake valve 3, slowly adjust the pressure reducing valve 2, and let the nitrogen in the nitrogen cylinder 1 decompress and enter the gas storage device 5;

Step 3: Open the first three-way valve 71 channel 1 and channel 2, the second three-way valve 72 channel 1 and channel 2, the third three-way valve 73 channel 1 and channel 2, inflate each chamber, and three outlet pipes The upward airflow direction is shown in Figure 3;

Step 4: The pressure value in the gas storage device 5 is detected by the pressure sensor 4, and the pressure in the gas storage device 5 is adjusted to the threshold value Pt (the maximum allowable pressure value of the stack) through the pressure reducing valve 2 and the first exhaust valve 601. The specific operation In order to compare the pressure value of the pressure sensor 4 with the threshold value _Pt , when the pressure value is lower than the threshold value _Pt , adjust the pressure reducing valve 2 to pressurize, and when the pressure value is higher than the threshold value _Pt , open the first exhaust valve 601 to reduce pressure , the system can use PID algorithm to achieve pressure control, but not limited to PID algorithm;

Step 5: close the intake valve 3 and the first exhaust valve 601, after the duration T1, the pressure value in the gas storage device 5 is detected and recorded by the pressure sensor 4, and the counter counts once;

Step 6: Adjust the pressure reducing valve 2 to zero point, open the first exhaust valve 601 again, discharge the gas inside the system, and reduce the internal pressure of the stack to the same atmospheric pressure;

Step 7: Repeat the above steps 2-6 for a total of n times (n is a positive integer, which can be set by yourself), and obtain and record a total of n pressure values of P1, P2...Pn detected by the pressure sensor 4;

Step 8: Calculate the differential pressure ΔP=Pt-(P1+P2+…Pn)/n, the set value ΔP _max in this embodiment is 10kPa,

If △P<10kPa, it means that the external leakage detection of the three cavities is qualified, and the external sealing performance of each cavity of the fuel cell stack is good.

If △P ≥ 10kPa, it means that the external leakage detection of the three chambers is unqualified, and the system is alarmed.

Mode 2: Hydrogen cavity and air cavity mutual detection working mode

Step 1: System initialization, the counter is cleared and the counter is turned on,

Step 2: Open the intake valve 3, slowly adjust the pressure reducing valve 2, and let the nitrogen in the nitrogen cylinder 1 decompress and enter the gas storage device 5;

Step 3: Open the channels 1 and 2 of the first three-way valve 71, the channels 2 and 3 of the second three-way valve 72, and the channels 2 and 3 of the third three-way valve 73 to fill the entire hydrogen chamber with nitrogen;

Step 4: The pressure value in the gas storage device 5 is detected by the pressure sensor 4, and the pressure in the gas storage device 5 is adjusted to be a threshold value P _H2 (maximum pressure difference between the hydrogen chamber and the air chamber through the pressure reducing valve 2 and the first exhaust valve 601) The specific operation is to compare the pressure value in the gas storage device 5 measured by the pressure sensor 4 with the threshold value P _H2 , and when the pressure value is lower than the threshold value P _H2 , adjust the pressure reducing valve 2 to pressurize , when the pressure value is higher than the threshold value P _H2 , open the first exhaust valve 601 to reduce pressure, and the system can use the PID algorithm to achieve pressure control but is not limited to the PID algorithm;

Step 5: close the first exhaust valve 601, open the second exhaust valve 602, the airflow directions on the three air outlet pipes are shown in Figure 4, the air flow value is detected and recorded by the second flow meter 82, and the counter counts once;

Step 6: Adjust the pressure reducing valve 2 to zero point, open the first exhaust valve 601 again, discharge the gas inside the system, and reduce the internal pressure of the stack to the same atmospheric pressure;

Step 7: Repeat the above steps 2-6 for a total of n times (n is a positive integer, which can be set by yourself), and obtain and record a total of n air flow values of Fair1, Fair2...Fairn detected by the second flow meter 82;

Step 8: Calculate the average flow rate Fair=(Fair1+Fair2+...Fairn)/n, the set value Fair _max in this embodiment is 145ml/min,

If Fair<145ml/min, it means that the hydrogen chamber and the air chamber are tested in series, and the fuel cell stack membrane is well sealed.

If Fair ≥ 145ml/min, it means that the hydrogen chamber and the air chamber fail to pass the test of each other, and the system will be alarmed.

Mode 3. The working mode of the air cavity and water cavity mutual series detection is:

Step 1: System initialization, the counter is cleared and the counter is turned on,

Step 2: Open the intake valve 3, slowly adjust the pressure reducing valve 2, and let the nitrogen in the nitrogen cylinder 1 decompress and enter the gas storage device 5;

Step 3: Open the first three-way valve 71 channel 1 and channel 2, the second three-way valve 72 channel 1 and channel 2, the third three-way valve 73 channel 2 and channel 3, and let nitrogen fill the entire hydrogen chamber;

Step 4: Adjust the pressure in the gas storage device 5 to a threshold value P _t (the maximum allowable pressure value of the stack) through the pressure reducing valve 2 and the first exhaust valve 601; the specific operation is to measure the gas storage device 5 measured by the pressure sensor 4 The internal pressure value is compared with the threshold value P _t . When the pressure value is lower than the threshold value P _t , the pressure reducing valve 2 is adjusted to pressurize. When the pressure value is higher than the threshold value P _t , the first exhaust valve 601 is opened to reduce pressure. PID algorithm realizes pressure control but is not limited to PID algorithm;

Step 5: close the first exhaust valve 601 and open the second exhaust valve 602 at the same time, the airflow directions on the three air outlet pipes are shown in Figure 5, the water flow value is detected and recorded by the third flow meter 83, and the counter counts once;

Step 6: Adjust the pressure reducing valve 2 to zero, open the first exhaust valve 601 again, discharge the gas inside the device, and reduce the internal pressure of the stack to the same as the atmospheric pressure;

Step 7: Repeat the above steps 2-6 for a total of n times (n is a positive integer, which can be set by yourself), and obtain and record a total of n flow values of Fwt1, Fwt2...Fwtn detected by the third flow meter 83;

Step 8: Calculate the average flow rate Fwt=(Fwt1+Fwt2+...Fwtn)/n, the set value Fwt _max in this embodiment is 10ml/min,

If Fwt<10ml/min, it means that the air cavity and the water cavity are tested in series, and the sealing performance between the fuel cell stack bipolar plate and the gasket is good.

If Fwt≥10ml/min, it means that the air chamber and water chamber fail to pass the mutual test, and alarm to the system.

The system controller 12 can be set to automatically enter the second mode after the first mode is completed, and then proceed to the third mode to directly complete the air tightness detection of the entire fuel cell system 13 .

Claims (8)

1. An automatic detection device for three-cavity pressure-maintaining air tightness of a fuel cell system is characterized by comprising an air storage device (5), the gas storage device (5) is provided with a gas storage pipeline (14) communicated with the nitrogen cylinder (1), a pressure reducing valve (2) and an air inlet valve (3) are arranged on the air storage pipeline (14) along the air inlet direction, three air outlet pipelines (6) which are connected in parallel are arranged on the air storage device (5) and respectively correspond to three cavities of a fuel cell system (13), a three-way valve (7), a flowmeter (8) and an external interface (9) are arranged on each air outlet pipeline (6) along the air outlet direction, the gas storage device (5) is also provided with a pressure sensor (4) and an exhaust pipeline (15), and a first exhaust valve (601) is arranged on the exhaust pipeline (15), and a detection pipeline (10) which is communicated with each other and used for detecting leakage between chambers of the fuel cell system is also arranged on the three-way valve (7) of each exhaust pipeline (6).

2. The three-cavity pressure-maintaining air-tightness automatic detection device of the fuel cell system according to claim 1, wherein the three parallel air outlet pipes (6) are a first air outlet pipe (61), a second air outlet pipe (62), and a third air outlet pipe (63), respectively, the first air outlet pipe (61) is provided with a first three-way valve (71), a first flow meter (81), and a first external interface (91) in sequence along the air outlet direction, the second air outlet pipe (62) is provided with a second three-way valve (72), a second flow meter (82), and a second external interface (92) in sequence along the air outlet direction, and the third air outlet pipe (63) is provided with a third three-way valve (73), a third flow meter (83), and a third external interface (93) in sequence along the air outlet direction;

first three-way valve (71), second three-way valve (72), third three-way valve (73) are wherein two passageways and first pipeline (61), the second pipeline (62), the third pipeline (63) of giving vent to anger and are connected, detection pipeline (10) set up second discharge valve (602) and lead to behind first discharge valve (601) on exhaust duct (15) after combining another passageway connection of first three-way valve (71), second three-way valve (72), third three-way valve (73).

3. The three-cavity pressure-maintaining air-tightness automatic detection device of the fuel cell system according to claim 2, wherein an air inlet port (17) is arranged on the air storage pipeline (14) and is correspondingly connected with the nitrogen cylinder (1), and an air outlet port (16) is arranged at the end of the air outlet pipe (15) and is communicated with the atmosphere.

4. The three-chamber pressure-maintaining airtightness automatic detection apparatus according to claim 2, further comprising a pressure display and control device, the pressure display and control device comprising a display (11) and a system controller (12), the system controller (12) being in signal connection with the first exhaust valve (601), the second exhaust valve (601), the pressure reducing valve (2), the intake valve (3), the first three-way valve (71), the second three-way valve (72), the third three-way valve (73), the pressure sensor (4), the first flow meter (81), the second flow meter (82), and the third flow meter (83), the display (11) being in signal connection with the system controller (12) for displaying detection data of the pressure sensor (4), the first flow meter (81), the second flow meter (82), and the third flow meter (83).

5. A testing method of the three-chamber pressure-maintaining airtightness automatic testing apparatus for the fuel cell system according to any one of claims 2 to 4, comprising an external leakage pressure-maintaining testing operation mode, a hydrogen gas chamber and air chamber series testing operation mode, and an air chamber and water chamber series testing operation mode;

before the working mode is started, the gas storage pipeline (14) and the nitrogen cylinder (1) as well as the first gas outlet pipeline (61), the second gas outlet pipeline (62) and the third gas outlet pipeline (63) are respectively in sealing connection with a hydrogen cavity, an air cavity and a water cavity pipeline of the fuel cell, and the first exhaust valve (601), the second exhaust valve (602), the pressure reducing valve (2) and the air inlet valve (3) are in a closed state;

the external leakage pressure maintaining detection working mode is as follows:

inflation and pressure regulation: opening the air inlet valve (3), slowly adjusting the pressure reducing valve (2), and reducing the pressure of the nitrogen in the nitrogen cylinder (1) and then entering the gas storage device (5); controlling a first three-way valve (71), a second three-way valve (72) and a third three-way valve (73) to lead the gas storage device (5) and the fuel cell system to be communicated to charge each chamber; the pressure sensor (4) detects the pressure in the gas storage device (5), and the pressure in the gas storage device (5) is regulated to be stabilized to be a threshold value P through the pressure reducing valve (2) and the first exhaust valve (601)_t；

And (3) detecting data: closing the air inlet valve (3) and the first air outlet valve (601), after the duration time is T1, detecting and recording the pressure value in the air storage device (5) through the pressure sensor (4), adjusting the pressure reducing valve (2) to the zero point, no air is introduced into the air storage device (5), opening the first air outlet valve (601) again, discharging the gas in the equipment, reducing the air pressure in the galvanic pile to be consistent with the atmospheric pressure, repeating the steps for n times, and obtaining the recorded P1, P2 … Pn and n pressure values;

test result, calculating pressure difference △ P ═ P_t-(P1+P2+…Pn)/n，

If △ P is less than the set value △ P_maxThen the three-cavity external leakage detection is qualified,

if △ P is more than or equal to the set value △ P_maxAnd then the three-cavity external leakage detection is unqualified.

6. The method for detecting the three-cavity pressure-maintaining airtightness automatic detection apparatus for the fuel cell system according to claim 5, wherein the mutually serially detecting operation mode steps of the hydrogen gas cavity and the air cavity are:

inflation and pressure regulation: opening the air inlet valve (3), slowly adjusting the pressure reducing valve (2), and introducing the nitrogen into the air storage device (5) after reducing the pressure; the first three-way valve (71) is controlled to lead the gas storage device (5) and the fuel cell system to be communicated to inflate the hydrogen cavity, and the control is carried outThe second three-way valve (72) and the third three-way valve (73) lead the fuel cell system to be communicated with the detection pipeline (10); the pressure sensor (4) detects the pressure in the gas storage device (5), and the pressure in the gas storage device (5) is regulated to be stabilized to be a threshold value P through the pressure reducing valve (2) and the first exhaust valve (601)_H2；

And (3) detecting data: closing the first exhaust valve (601), opening the second exhaust valve (602), and detecting and recording an air path flow value through a second flowmeter (82); adjusting the pressure reducing valve (2) to a zero point, no air is fed into the air storage device (5), opening the first exhaust valve (601) again, exhausting the air in the equipment, reducing the air pressure in the galvanic pile to be consistent with the atmospheric pressure, repeating the steps for n times, and obtaining n recorded flow values of Fair1 and Fair2 … Fairn;

and (4) testing results: calculating the average flow value Fair ═ (Fair1+ Fair2+ … Fairn)/n,

if Fair is less than the set value Fair_maxThen the detection of the hydrogen gas cavity and the air cavity is qualified,

if Fair is more than or equal to the set value Fair_maxAnd the hydrogen cavity and the air cavity are mutually tested in series to be unqualified.

7. The method of detecting a three-chamber pressure-maintaining airtightness automatic detection apparatus for a fuel cell system according to claim 5,

the working mode of the mutual serial detection of the air cavity and the water cavity is as follows:

inflation and pressure regulation: opening the air inlet valve (3), slowly adjusting the pressure reducing valve (2), and introducing the nitrogen into the air storage device (5) after reducing the pressure; controlling a first three-way valve (71) and a second three-way valve (72) to lead the gas storage device (5) and the fuel cell system to be communicated to charge the hydrogen chamber and the air chamber, and controlling a third three-way valve (73) to lead the fuel cell system and the detection pipeline (10) to be communicated; the pressure sensor (4) detects the pressure in the gas storage device (5), and the pressure in the gas storage device (5) is regulated to be stabilized to be a threshold value P through the pressure reducing valve (2) and the first exhaust valve (601)_t；

And (3) detecting data: simultaneously closing the first exhaust valve (601), opening the second exhaust valve (602), and detecting and recording a waterway flow value through a third flowmeter (83); adjusting the pressure reducing valve (2) to a zero point, no air enters the air storage device (5), opening the first exhaust valve (601) again, exhausting the air in the system, reducing the air pressure in the galvanic pile to be consistent with the atmospheric pressure, repeating the steps for n times, and acquiring n recorded flow values of Fwt1 and Fwt2 … Fwtn;

and (4) testing results: the calculated average flow Fwt is (Fwt1+ Fwt2+ … Fwtn)/n,

if Fwt < the set value Fwt_maxThen the detection of the air cavity and the water cavity is qualified,

if Fwt is more than or equal to the set value Fwt_maxAnd then the detection of the air cavity and the water cavity which are mutually connected in series is unqualified.

8. The method for detecting the three-chamber pressure-maintaining airtightness automatic detection apparatus of the fuel cell system according to claim 5, wherein the pressure in the gas storage device (5) is regulated to be stabilized at the threshold value P_tThe specific operation is as follows: the pressure value measured by the pressure sensor (4) is compared with a threshold value P_tComparing when the pressure value is lower than the threshold value P_tWhen the pressure is needed, the pressure reducing valve (2) is adjusted to pressurize; when the pressure value is higher than the threshold value P_tWhen the pressure is reduced, the first exhaust valve (601) is opened to reduce the pressure.

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