A test device and method for simulating the impact of external foreign matter on fuel cells

Abstract

The present invention relates to a testing device and method for simulating the impact of external foreign matter on a fuel cell, wherein the device includes: a first gas supply source and a second gas supply source, which respectively provide an oxidizing gas and a reducing gas; a first pipeline and a second pipeline, the first pipeline connecting the first gas supply source and the oxidant inlet of the fuel cell stack, and the second pipeline connecting the second gas supply source and the reducing agent inlet of the fuel cell stack; two foreign matter placement chambers, respectively arranged in the first pipeline and the second pipeline, the foreign matter placement chambers including a first joint, a second joint and a filter membrane, the first joint and the second joint being connected to the gas supply source and the fuel cell stack, respectively, and the filter membrane being arranged between the first joint and the second joint. Compared with the existing technology, the present invention has the advantages of low testing cost and convenient and fast testing.

Description

Technical Field

[0001] The present invention relates to the field of fuel cell testing, and in particular to a testing device and method for simulating the influence of external foreign matter on a fuel cell. Background Art

[0002] Proton exchange membrane fuel cells (PEMFCs) have the characteristics of high energy conversion efficiency, fast response speed, good low-temperature start-up performance, no pollution, and low emissions. They have very broad application prospects in fixed power stations, backup power supplies, transportation, aerospace, and military industries. In particular, their application in fuel cell vehicles has attracted much attention. Therefore, proton exchange membrane fuel cell technology, as a green energy technology, is receiving more and more attention.

[0003] In order to maintain the reaction of the proton exchange membrane fuel cell, the gas supply system continuously delivers the fuel and oxidant required for the electrochemical reaction to the fuel cell, and at the same time, the reaction waste heat is discharged through the cooling cycle heat dissipation system to ensure that the fuel cell operates at the optimal temperature. When there is a power demand, the gas supply system and the cooling cycle heat dissipation system coordinate and cooperate to inject the reaction gas and coolant into the fuel cell, and the battery will continuously provide electrical energy output. However, in actual use, due to the influence of the fuel cell system components themselves, aging or failure (such as air compressor failure, foreign matter leakage from pipes or related accessories, etc.), foreign matter of different types and sizes will enter the battery, posing a huge challenge to the electrical output performance and reliability of the fuel cell. In order to simulate the impact of these foreign matter leakage on the performance of the battery stack, the existing technology mostly disassembles the battery stack and puts the foreign matter into the battery stack or injects the foreign matter into the battery stack through the gas supply system. This is not only cumbersome and complicated to operate, but also causes permanent contamination of the gas supply system, and it is impossible to repeat the experiment to verify the impact of different foreign matter on performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a test device and method for simulating the impact of external foreign matter on fuel cells. By configuring a foreign matter placement chamber, foreign matter to be verified can be placed in the foreign matter placement chamber for testing. This eliminates the need to build complex equipment and pipelines, and will not damage the fuel cell. Continuous testing of multiple foreign objects can be performed, greatly reducing testing costs and improving testing efficiency.

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

[0006] A test device for simulating the impact of foreign matter on a fuel cell, comprising:

[0007] The first gas supply source and the second gas supply source provide an oxidizing gas and a reducing gas, respectively;

[0008] a first pipeline and a second pipeline, wherein the first pipeline connects a first gas supply source and an oxidant inlet of the fuel cell stack, and the second pipeline connects a second gas supply source and a reductant inlet of the fuel cell stack;

[0009] Two foreign matter placement bins are respectively arranged in the first pipeline and the second pipeline. The foreign matter placement bins include a first joint, a second joint and a filter membrane. The first joint and the second joint are respectively connected to the gas supply source and the fuel cell stack. The filter membrane is arranged between the first joint and the second joint.

[0010] The first joint and the second joint are both reducer joints, and the radial cross-sectional area gradually decreases from the side close to the filter membrane to the side far away from the filter membrane.

[0011] The foreign matter placement bin further includes a clamp, and the filter membrane is sealed by the clamp after being clamped between the first joint and the second joint.

[0012] A method for testing the above-mentioned testing device comprises:

[0013] Step S1: In an initial state, purging the cathode and anode of the fuel cell stack, wherein the initial state is a state where no foreign matter is placed in the foreign matter placement chamber;

[0014] Step S2: activating the fuel cell stack;

[0015] Step S3: After the purge is completed, the fuel cell stack is subjected to a polarization performance test, a cyclic voltammetry performance test, and a hydrogen permeation current test, and the test results are obtained;

[0016] Step S4: After the foreign matter to be verified is placed in the foreign matter placement chamber, the fuel cell stack is subjected to a polarization performance test, a cyclic voltammetry performance test, and a hydrogen permeation current test, and the test results are obtained.

[0017] The method further comprises:

[0018] Step S5: After cleaning the foreign matter placement chamber and replacing the foreign matter to be verified therein, the fuel cell stack is subjected to a polarization performance test, a cyclic voltammetry performance test, and a hydrogen permeation current test, and the test results are obtained.

[0019] The step S1 specifically includes:

[0020] Step S11: purging the cathode and anode with wet nitrogen;

[0021] Step S12: using humidified reducing gas to simultaneously purge the cathode and anode of the fuel cell stack.

[0022] The step S2 specifically includes:

[0023] Step S21: adjusting the temperature of the fuel cell stack to 50-80° C.;

[0024] Step S22: introducing oxidizing gas into the cathode of the fuel cell stack and reducing gas into the anode, connecting the load, and continuously increasing the current density of the fuel cell stack to 1000-2000 mA / cm 2 , and then reduce the load to 0 after balancing at this current density for a certain period of time;

[0025] Step S23: Continue to increase the current density of the fuel cell stack to 1000-2000 mA / cm 2 ;

[0026] Step S24: Repeat step S23 multiple times until the output voltage of the fuel cell stack no longer increases, completing the activation of the fuel cell stack.

[0027] The polarization performance test process is as follows: hydrogen and air are used as reaction gases, the hydrogen stoichiometric ratio and the air stoichiometric ratio are both 2, the battery operating temperature is 80°C, the cathode and anode humidification temperatures are both 60°C, the battery operating pressure is 80kPa(g), the current output is controlled by adjusting the electronic load, the voltage value is recorded, and each current density point is stably operated for 5 minutes to obtain the polarization curve performance.

[0028] The process of the cyclic voltammetry performance test is as follows: humidified nitrogen is introduced into the cathode side of the battery with a stoichiometric ratio of 2 and a humidification temperature of 80°C, and hydrogen is introduced into the anode side with a stoichiometric ratio of 2 and a humidification temperature of 80°C. The battery operating temperature is 80°C, and a cyclic voltammetry test is performed with a potential scan range of 0-1.0V and a scan rate of 20mV / s, and a cyclic voltammetry curve is obtained.

[0029] The process of the hydrogen permeation current test is as follows: nitrogen is introduced into the cathode and hydrogen is introduced into the anode, the gas flow rate of the cathode and anode is 200 ml / min, the gas humidification temperature is 80°C, and the battery operating temperature is 80°C. The hydrogen permeation current test is performed on the above battery system with a potential scanning range of 0.09-0.50V and a scanning rate of 2mV / s. The permeability of the proton exchange membrane is obtained by comparing the hydrogen permeation current corresponding to 0.45V.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. By configuring a foreign body placement chamber, foreign bodies to be verified can be placed in the chamber for testing. This eliminates the need to build complex equipment and pipelines, and will not damage the fuel cell. Continuous testing of multiple foreign bodies can be performed, greatly reducing testing costs.

[0032] 2. Both the first joint and the second joint are reducer joints, which can provide a larger foreign matter placement chamber, thereby increasing the adjustment range of the amount of foreign matter placed and improving the scope of application.

[0033] 3. The filter membrane is clamped by two joints and clamped with a clamp, which has little effect on fluid performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the present invention;

[0035] Figure 2 This is a schematic structural diagram of a foreign matter placement bin according to an embodiment of the present invention;

[0036] Among them: 1. first gas supply source, 2. second gas supply source, 3. fuel cell stack, 4. first pipeline, 5. second pipeline, 6. foreign matter placement bin, 7. foreign matter placement bin, 61. first connector, 62. second connector, 63. filter membrane. DETAILED DESCRIPTION

[0037] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0038] A fuel cell test device that simulates foreign matter, such as Figure 1 and Figure 2 Shown, including:

[0039] The first gas supply source and the second gas supply source provide an oxidizing gas and a reducing gas, respectively;

[0040] a first pipeline and a second pipeline, the first pipeline connecting the first gas supply source and the oxidant inlet of the fuel cell stack, and the second pipeline connecting the second gas supply source and the reductant inlet of the fuel cell stack;

[0041] Two foreign matter placement bins are respectively arranged in the first pipeline and the second pipeline. The foreign matter placement bins include a first joint, a second joint and a filter membrane. The first joint and the second joint are respectively connected to the gas supply source and the fuel cell stack. The filter membrane is arranged between the first joint and the second joint.

[0042] By configuring a foreign object placement chamber, foreign objects to be verified can be placed in the chamber for testing. This eliminates the need to build complex equipment and pipelines, and will not damage the fuel cell. Continuous testing of multiple foreign objects can be performed, greatly reducing testing costs.

[0043] like Figure 2As shown, the first joint and the second joint are both reducers, and the radial cross-sectional area gradually decreases from the side close to the filter membrane to the side away from the filter membrane, so that a larger foreign matter placement bin can be provided, thereby increasing the adjustment range of the amount of foreign matter placed, allowing for the placement of more types of foreign matter, and improving the scope of application.

[0044] The foreign body placement chamber also includes a clamp. After the filter membrane is clamped between the first joint and the second joint, it is sealed by the clamp. The filter membrane is clamped by two joints and tightened with the clamp, which has little impact on fluid performance.

[0045] As in the test method of the test equipment described above, before starting the test, the fuel cell is placed on the test bench, and the foreign matter placement chamber is installed at the front end of the fuel gas and oxidant gas pipelines of the test bench.

[0046] Then the testing process begins, including:

[0047] Step S1: In an initial state, the cathode and anode of the fuel cell stack are purged, wherein the initial state is a state where no foreign matter is placed in the foreign matter placement chamber; Step S1 specifically includes:

[0048] Step S11: purging the cathode and anode with wet nitrogen to reduce the hydrogen-air interface;

[0049] Step S12: A humidified reducing gas is used to simultaneously purge the cathode and anode of the fuel cell stack. The reducing gas is pure hydrogen, with an operating pressure of 0-80 kPa, preferably 30-60 kPa, a flow rate of (0.5-1*n) slpm, where n is the number of fuel cell stack cells, n≥1, and a humidity of 30-100%, preferably 60-100%, for a purge time of 30-60 minutes. Appropriate pressure allows for more complete reduction of the fuel cell catalyst. In theory, a higher gas flow rate is better, but this results in additional power loss. The humidity is set to prevent the fuel cell proton exchange membrane from drying out during the purge process, which can reduce its lifespan.

[0050] Step S2: Activate the fuel cell. Step S2 specifically includes: Step S21: Purge the cathode and anode with wet nitrogen, and then adjust the temperature of the fuel cell stack to 50-65°C; Step S22: Pass an oxidizing gas into the cathode of the stack and a reducing gas into the anode. In this embodiment, the oxidizing gas is air and the reducing gas is hydrogen. Connect the load and continuously increase the current density of the fuel cell stack to 1000-1800 mA / cm 2 , and then reduce the load to 0 after balancing at this current density for a certain period of time; Step S23: continuously increase the current density of the fuel cell stack to 1000-1800 mA / cm 2; Step S24: Repeat step S23 multiple times until the output voltage of the fuel cell stack no longer increases, completing the activation of the fuel cell stack.

[0051] During this process, the cathode stoichiometric ratio is 1.8-2.5, and the anode stoichiometric ratio is 1.1-1.5. The stoichiometric ratio is the ratio of the gas flow supplied to the fuel cell to the gas flow actually consumed by the fuel cell. Theoretically, the higher the gas flow, the better, but it will cause other additional power losses.

[0052] Step S3: After the purge is completed, the fuel cell stack is subjected to a polarization performance test, a cyclic voltammetry performance test, and a hydrogen permeation current test, and the test results are obtained;

[0053] Step S4: After the foreign matter to be verified is placed in the foreign matter placement chamber, the fuel cell stack is subjected to a polarization performance test, a cyclic voltammetry performance test, and a hydrogen permeation current test, and the test results are obtained.

[0054] Step S5: After cleaning the foreign matter storage compartment and replacing the foreign matter to be verified, the fuel cell stack is tested for polarization performance, cyclic voltammetry, and hydrogen permeation current, and the test results are obtained. Specifically, the foreign matter to be verified can include metal, graphite, possible precipitates from rubber products, possible precipitates from system rubber piping, possible precipitates from system metal piping, and foreign matter that may be introduced by the system air compressor and hydrogen circulation system.

[0055] The process of polarization performance test is as follows: hydrogen and air are used as reaction gases, the hydrogen stoichiometric and air stoichiometric ratios are both 2, the battery operating temperature is 80°C, the cathode and anode humidification temperatures are both 60°C, the battery operating pressure is 80kPa(g), the current output is controlled by adjusting the electronic load, the voltage value is recorded, and each current density point is stably operated for 5 minutes to obtain the polarization curve performance.

[0056] The process of cyclic voltammetry performance test is as follows: humidified nitrogen gas at 60 kPa, a stoichiometric ratio of 2, and a humidification temperature of 80°C is introduced into the cathode side of the battery as a research electrode, and hydrogen gas at 60 kPa, a stoichiometric ratio of 2, and a humidification temperature of 80°C is introduced into the anode side as a reference electrode and counter electrode. The battery operating temperature is 80°C, and cyclic voltammetry test is performed with a potential scanning range of 0-1.0 V and a scanning rate of 20 mV / s. The integral area of ​​the hydrogen desorption zone is calculated through the obtained cyclic voltammetry curve, and the change in its electrochemical active area is further calculated.

[0057] The process of hydrogen permeation current test is as follows: nitrogen is introduced into the cathode and hydrogen is introduced into the anode. The gas flow rates of the cathode and anode are both 200 ml / min, the gas humidification temperature is both 80°C, and the battery operating temperature is 80°C. The hydrogen permeation current test of the above battery system is carried out with a potential scanning range of 0.09-0.50V and a scanning rate of 2mV / s. The permeability of the proton exchange membrane is obtained by comparing the hydrogen permeation current corresponding to 0.45V.

Claims

1. A testing method for testing equipment that simulates the impact of external foreign matter on a fuel cell, characterized in that: The testing equipment includes: The first gas supply source and the second gas supply source provide an oxidizing gas and a reducing gas, respectively; a first pipeline and a second pipeline, wherein the first pipeline connects a first gas supply source and an oxidant inlet of the fuel cell stack, and the second pipeline connects a second gas supply source and a reductant inlet of the fuel cell stack; Two foreign matter placement chambers are provided in the first pipeline and the second pipeline, respectively. The foreign matter placement chambers include a first joint, a second joint, and a filter membrane. The first joint and the second joint are connected to the gas supply source and the fuel cell stack, respectively. The filter membrane is provided between the first joint and the second joint. The test method includes: Step S1: In an initial state, purging the cathode and anode of the fuel cell stack, wherein the initial state is a state where no foreign matter is placed in the foreign matter placement chamber; Step S2: activating the fuel cell stack; Step S3: After the purge is completed, the fuel cell stack is subjected to a polarization performance test, a cyclic voltammetry performance test, and a hydrogen permeation current test, and the test results are obtained; Step S4: After the foreign matter to be verified is placed in the foreign matter placement chamber, the fuel cell stack is subjected to a polarization performance test, a cyclic voltammetry performance test, and a hydrogen permeation current test, and the test results are obtained.

2. The testing method according to claim 1, wherein: The first joint and the second joint are both reducer joints, and the radial cross-sectional area gradually decreases from the side close to the filter membrane to the side far away from the filter membrane.

3. The testing method according to claim 1, wherein: The foreign matter placement bin further includes a clamp, and the filter membrane is sealed by the clamp after being clamped between the first joint and the second joint.

4. The testing method according to claim 1, wherein: The method further comprises: Step S5: After cleaning the foreign matter placement chamber and replacing the foreign matter to be verified therein, the fuel cell stack is subjected to a polarization performance test, a cyclic voltammetry performance test, and a hydrogen permeation current test, and the test results are obtained.

5. The testing method according to claim 1, wherein: The step S1 specifically includes: Step S11: purging the cathode and anode with wet nitrogen; Step S12: using humidified reducing gas to simultaneously purge the cathode and anode of the fuel cell stack.

6. The testing method according to claim 1, wherein: The step S2 specifically includes: Step S21: adjusting the temperature of the fuel cell stack to 50-80°C; Step S22: introducing oxidizing gas into the cathode of the fuel cell stack and reducing gas into the anode, connecting the load, and continuously increasing the current density of the fuel cell stack to 1000-2000 mA / cm 2 , and then reduce the load to 0 after balancing at this current density for a certain period of time; Step S23: Continue to increase the current density of the fuel cell stack to 1000-2000 mA / cm 2 ; Step S24: Repeat step S23 multiple times until the output voltage of the fuel cell stack no longer increases, completing the activation of the fuel cell stack.

7. The testing method according to claim 1, wherein: The polarization performance test process is as follows: hydrogen and air are used as reaction gases, the hydrogen stoichiometric ratio and the air stoichiometric ratio are both 2, the battery operating temperature is 80°C, the cathode and anode humidification temperatures are both 60°C, the battery operating pressure is 80kPa, the current output is controlled by adjusting the electronic load, the voltage value is recorded, and each current density point is stably operated for 5 minutes to obtain the polarization curve performance.

8. The testing method according to claim 1, wherein: The process of the cyclic voltammetry performance test is as follows: humidified nitrogen is introduced into the cathode side of the battery with a stoichiometric ratio of 2 and a humidification temperature of 80°C, and hydrogen is introduced into the anode side with a stoichiometric ratio of 2 and a humidification temperature of 80°C. The battery operating temperature is 80°C, and a cyclic voltammetry test is performed with a potential scan range of 0-1.0V and a scan rate of 20mV / s, and a cyclic voltammetry curve is obtained.

9. The testing method according to claim 1, wherein: The process of the hydrogen permeation current test is as follows: nitrogen is introduced into the cathode and hydrogen is introduced into the anode, the gas flow rates of the cathode and anode are both 200 ml / min, the gas humidification temperature is both 80°C, the battery operating temperature is 80°C, and the fuel cell stack is tested for hydrogen permeation current. The potential scanning range is 0.09-0.50V, the scanning rate is 2mV / s, and the permeability of the proton exchange membrane is obtained by comparing the hydrogen permeation current corresponding to 0.45V.

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