Fuel cell start-stop life test equipment and test method

Abstract

The present invention provides a fuel cell start-stop life test device and a test method, wherein the test device comprises a hydrogen supply system, a nitrogen supply system, an air supply system and a start-stop control system, wherein the hydrogen supply system, the nitrogen supply system and the air supply system are communicatively connected to the start-stop control system, and the start-stop control system formulates a start-stop strategy; so that the start-stop control system controls the nitrogen supply system to pass nitrogen into the hydrogen inlet end of the fuel cell stack when the fuel cell stack is shut down based on the start-stop strategy, and controls the air supply system to pass air into the hydrogen inlet end of the fuel cell stack, so that the anode of the fuel cell stack is filled with air, and when the fuel cell stack is started, a hydrogen-air interface is formed at the anode of the fuel cell stack, and the air supply system is controlled to pass air to the air inlet end of the fuel cell stack, so as to simulate the start-stop of the fuel cell stack under normal operating conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a fuel cell start-stop life test device and a test method. Background Art

[0002] Proton exchange membrane fuel cell is a power generation device that converts chemical energy into electrical energy using hydrogen as a carrier. It has the advantages of low reaction temperature, fast dynamic response speed, high reaction efficiency, and high power density, and has broad application prospects in the field of transportation. During the start-up / shutdown operation of the fuel cell, the degradation of the membrane electrode assembly (MEA) of the proton exchange membrane fuel cell is mainly due to the corrosion of the carbon carrier and the dissolution / migration / aggregation of the cathode platinum catalyst.

[0003] The start-stop process of the fuel cell is one of the main factors that reduce the life of the fuel cell. When a vehicle using a fuel cell is parked for a long time, or when the fuel cell is not started for a long time, the cathode vent cannot be completely sealed, and the air diffuses from the cathode to the anode through the membrane, so that the anode and cathode flow fields will eventually be filled with air. If hydrogen is supplied to the anode flow field of the fuel cell when the fuel cell is started, a hydrogen / air boundary will be generated in the anode flow field, and a high potential of 1.44V or twice the open circuit voltage (OCV) will exist locally in the air facing the cathode in the anode flow field. Under the above conditions, the high potential generated locally at the cathode will accelerate the corrosion dissolution / migration / agglomeration of the carbon support of the platinum catalyst. In other words, the start-stop process of the fuel cell accelerates the degradation of the local cathode due to the presence of the hydrogen / air boundary.

[0004] In order to solve the above problems, the prior art avoids the high potential by applying a starting resistor. However, in the prior art, the closing time point and size of the starting resistor and the control method of hydrogen at the time of starting all have an impact on the life of the fuel cell stack. Summary of the invention

[0005] A major advantage of the present invention is that it provides a fuel cell start-stop life test device and test method, wherein the fuel cell start-stop life test device can be used to verify the fuel cell start-stop strategy, which is beneficial to optimize the fuel cell engine start-stop control strategy.

[0006] Another advantage of the present invention is that it provides a fuel cell start-stop life test device and test method, wherein the fuel cell start-stop life test device can be used to test the impact of different start-stop strategies on the life of the fuel cell and optimize the fuel cell engine start-stop control strategy.

[0007] Another advantage of the present invention is that it provides a fuel cell start-stop life test device and test method, wherein the fuel cell start-stop life test device can simulate the impact of different start-stop strategies on the life of the fuel cell under different operating conditions, and can guide the development of start-stop strategies for fuel cells in different fields of application.

[0008] Another advantage of the present invention is to provide a fuel cell start-stop life test device and a test method, wherein the fuel cell start-stop life test device can be used to develop a fuel cell start-stop strategy and find the optimal start-up resistance and start-up time.

[0009] Another advantage of the present invention is that it provides a fuel cell start-stop life test device and test method, wherein the fuel cell startup life test device can first use nitrogen to purge the fuel cell anode during the shutdown phase to remove hydrogen, and then introduce air into the fuel cell anode through a branch of the air port for a certain period of time to allow the air to quickly fill the anode, simulating the diffusion of cathode air to the anode after the fuel cell is shut down.

[0010] Another advantage of the present invention is to provide a fuel cell start-stop life test device and test method, wherein when the fuel cell is started, hydrogen is introduced into the anode to form a hydrogen-air interface with the control inside. Cyclic start-stop test draws multiple curves of the influence of start-stop on life under different temperature and humidity conditions, and finds the optimal start-stop state according to the curve.

[0011] Other advantages and features of the present invention will become more apparent from the following detailed description and may be realized by means of the instrumentalities and combinations particularly pointed out in the appended claims.

[0012] According to one aspect of the present invention, a fuel cell start-stop life test device of the present invention, which can achieve the aforementioned objectives and other objectives and advantages, is suitable for testing a fuel cell stack, and the test device comprises:

[0013] a hydrogen supply system;

[0014] a nitrogen supply system;

[0015] an air supply system; and

[0016] A start-stop control system, wherein the hydrogen supply system, the nitrogen supply system and the air supply system are communicatively connected to the start-stop control system, and the start-stop control system formulates a start-stop strategy; so that the start-stop control system controls the nitrogen supply system to pass nitrogen into the hydrogen inlet of the fuel cell stack based on the start-stop strategy when the fuel cell stack is shut down, and the anode of the fuel cell stack is purged with nitrogen; the start-stop control system controls the air supply system to pass air into the hydrogen inlet of the fuel cell stack so that the anode of the fuel cell stack is filled with air; when the fuel cell stack is started, the start-stop control system controls the hydrogen supply system to pass hydrogen into the hydrogen inlet of the fuel cell stack to form a hydrogen-air interface at the anode of the fuel cell stack, and controls the air supply system to pass air to the air inlet of the fuel cell stack to simulate the start-stop of the fuel cell stack under normal operating conditions.

[0017] According to at least one embodiment of the present invention, the testing equipment further includes a thermal management system, wherein the thermal management system is electrically connected to the start-stop control system, and the start-stop control system controls the thermal management system based on the start-stop strategy to simulate the temperature of the fuel cell when starting and stopping.

[0018] According to at least one embodiment of the present invention, the hydrogen supply system includes a hydrogen source, a hydrogen supply pipeline connected to the hydrogen source, at least one pressure controller and a flow controller arranged on the hydrogen supply pipeline, wherein one end of the hydrogen supply pipeline of the hydrogen supply system is conductively connected to a hydrogen inlet end of the fuel cell stack.

[0019] According to at least one embodiment of the present invention, the hydrogen supply system further includes a hydrogen humidifier, which is arranged in the hydrogen supply pipeline, and the hydrogen humidifier controls the humidity of the hydrogen leading to the fuel cell stack based on the control strategy of the start-stop control system.

[0020] According to at least one embodiment of the present invention, the nitrogen supply system includes a nitrogen source and a nitrogen supply pipeline connected to the nitrogen source, wherein one end of the nitrogen supply pipeline is connected to the nitrogen source, and the other end of the nitrogen supply pipeline is conductively connected to the hydrogen inlet end of the fuel cell stack.

[0021] According to at least one embodiment of the present invention, the air supply system includes an air source, an air supply pipe, an air pressure controller and an air flow controller, wherein the air source is connected to one end of the air supply pipe, and the other end of the air supply pipe can be connected to the fuel cell stack.

[0022] According to at least one embodiment of the present invention, the air supply conduit includes a hydrogen inlet branch and an air inlet branch, wherein an inlet end of the hydrogen inlet branch is conductively connected to the hydrogen inlet end of the fuel cell stack, and one end of the air inlet branch is conductively connected to the air inlet end of the fuel cell stack.

[0023] According to at least one embodiment of the present invention, the air supply system further includes an air humidifier, which is disposed in the air supply pipe and is used to adjust the humidity of the air in the air supply pipe.

[0024] According to at least one embodiment of the present invention, the testing equipment further includes an electronic load, wherein the electronic load can be electrically connected to the fuel cell stack, and the electronic load is communicatively connected to the start-stop control system, and the start-stop control system controls the electronic load based on a set start-stop control strategy to simulate the actual operating environment of the fuel cell stack.

[0025] According to at least one embodiment of the present invention, the electronic load includes an electronic load circuit, a current sensor disposed in the electronic load circuit, at least one detection resistor, and at least one contactor for controlling the detection resistor.

[0026] According to at least one embodiment of the present invention, the electronic load circuit further includes a first load branch and a second load branch, and the detection resistor further includes at least a first resistor and a second resistor, wherein the first resistor is arranged in the first load branch, and the second resistor is arranged in the second load branch, wherein the resistance value of the first resistor is greater than the resistance value of the second resistor.

[0027] According to at least one embodiment of the present invention, the electronic load of the testing equipment further includes at least one single-cell inspection device, wherein the single-cell inspection device can be electrically connected to the fuel cell stack, and the start / stop working status of each battery unit of the stack can be detected by the single-cell inspection device.

[0028] According to another aspect of the present invention, the present invention further provides a fuel cell start-stop life test method, wherein the test method comprises the following steps:

[0029] (1) In a shutdown state, nitrogen is passed to the hydrogen inlet of a battery stack to be tested, and the anode of the battery stack is purged with nitrogen to remove hydrogen;

[0030] (2) introducing air into the hydrogen inlet of the fuel cell stack so that the air fills the anode of the fuel cell stack;

[0031] (3) introducing hydrogen into the hydrogen inlet of the fuel cell stack so as to form a hydrogen-air interface at the anode of the fuel cell stack;

[0032] (4) Air is introduced into an air inlet end of the fuel cell stack, the fuel cell stack is started, and then shut down to complete a start-stop test.

[0033] According to at least one embodiment of the present invention, the test method further includes the steps of: formulating a start-stop strategy, and cyclically executing steps (1) to (4) according to the start-stop strategy, and detecting the degree of life decay of the fuel cell stack, and obtaining the decay curve of the fuel cell according to the start-stop strategy and the number of test cycles.

[0034] According to at least one embodiment of the present invention, in step (3) and step (4) of the test method, the temperature and humidity of the fuel cell stack are adjusted by introducing hydrogen and air according to the set start-stop strategy to comply with the start-stop strategy of the fuel cell stack.

[0035] According to at least one embodiment of the present invention, the test method further comprises the following steps: based on the start-stop strategy, starting a thermal management system, whereby the thermal management system controls the temperature of the fuel cell stack based on the start-stop strategy.

[0036] According to at least one embodiment of the present invention, the test method further includes the steps of: turning on a first load branch of an electronic load electrically connected to the battery stack, and disconnecting a second load branch of the electronic load, to perform a single starting resistance test.

[0037] According to at least one embodiment of the present invention, the testing method further includes the steps of: when the total voltage of the fuel cell stack reaches a set value, turning on the second load branch of the electronic load electrically connected to the fuel cell stack, and disconnecting the first load branch of the electronic load, to perform a dual starting resistance test.

[0038] Further objects and advantages of the present invention will be fully apparent from an understanding of the following description and the accompanying drawings.

[0039] These and other objects, features and advantages of the present invention will be more fully understood from the following detailed description, accompanying drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1A It is an overall schematic diagram of a fuel cell start-stop life test device according to a first preferred embodiment of the present invention.

[0041] Figure 1B Schematic diagram of the system framework of the fuel cell start-stop life test equipment according to the first preferred embodiment of the present invention.

[0042] Figure 2 It is a schematic diagram of a curve showing the influence of start-stop on the life of a fuel cell stack when detecting the effect of start-stop on the life of a fuel cell stack according to the fuel cell start-stop life test equipment according to the first preferred embodiment of the present invention.

[0043] Figure 3 Schematic diagram of an electronic load of the fuel cell start-stop life test device according to the first preferred embodiment of the present invention.

[0044] Figure 4 It is a flow chart of the fuel cell start-stop life test method according to the first preferred embodiment of the present invention. DETAILED DESCRIPTION

[0045] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0046] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0047] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0048] Referring to the accompanying drawings of the present invention Figures 1A to 3As shown, a fuel cell start-stop life test device and a test method according to the first preferred embodiment of the present invention are explained in the following description. The fuel cell start-stop life test device is used to simulate the use scenario of a fuel cell, and detect the service life of a stack 100 of the fuel cell according to the set use scenario. The fuel cell start-stop life test device can set different start-stop strategies for the stack 100 to be tested, and verify the start-stop life attenuation of the stack 100 according to the set start-stop strategy. For example, based on the set start-stop strategy, the stack 100 to be tested is verified to be started and stopped 200 times, 400 times, and 800 times. The degree of attenuation of the stack 100 to be tested, so as to formulate an optimized start-stop strategy suitable for the stack 100. In short, this device can simulate the impact of different start-stop strategies on the life of fuel cells under different working conditions, and can guide the development of start-stop strategies for fuel cells in different fields.

[0049] like Figure 1A and Figure 1B As shown, the fuel cell start-stop life test equipment includes a hydrogen supply system 10, a nitrogen supply system 20, an air supply system 30, a thermal management system 40, and a start-stop control system 50, wherein the hydrogen supply system 10, the nitrogen supply system 20, the air supply system 30 and the thermal management system 40 are respectively communicatively connected to the start-stop control system 50, and the start-stop control system 50 controls the working states of the hydrogen supply system 10, the nitrogen supply system 20, the air supply system 30 and the thermal management system 40 based on a set start-stop control strategy.

[0050] In detail, the start-stop control system 50 sets at least one corresponding start-stop strategy based on the battery stack 100 to be tested, and controls the hydrogen supply system 10, the nitrogen supply system 20, the air supply system 30 and the thermal management system 40 according to the set start-stop strategy to simulate the start-stop environment of the battery stack 100 under working conditions. As an example, the battery stack 100 of the fuel cell is suitable for a fuel cell engine of an electric vehicle, wherein the start-stop control system 50 simulates a normal working environment of the battery stack 100 according to the usage scenario of the battery stack 100, and tests the effect of the start-stop of the battery stack 100 on the life of the battery stack 100 under the simulated environment.

[0051] The start-stop strategy set by the start-stop control system 50 includes the temperature, humidity, hydrogen-air interface state, etc. during the start-stop process. The hydrogen supply system 10 is conductively connected to the battery stack 100 to be tested, and is used to provide the hydrogen required for detection for the battery stack 100 of the fuel cell. The hydrogen supply system 10 provides hydrogen of a specific temperature, specific humidity, specific pressure and specific flow rate to the battery stack 100 of the fuel cell based on the start-stop strategy set by the start-stop control system 50. When the start-stop strategy set by the start-stop control system 50 changes, the start-stop control system 50 controls the hydrogen supply system 10 to adjust the temperature, humidity, gas pressure and gas flow rate of the hydrogen supply to simulate the start-stop working environment of the battery stack 100 under different hydrogen supply conditions.

[0052] The hydrogen supply system 10 includes a hydrogen source 11, a hydrogen supply pipeline 12 connected to the hydrogen source 11, and at least one pressure controller 13 and a flow controller 14 arranged on the hydrogen supply pipeline 12, wherein one end of the hydrogen supply pipeline 12 of the hydrogen supply system 10 is connected to the hydrogen source 11, and the other end of the hydrogen supply pipeline 12 is conductively connected to a hydrogen inlet end of the fuel cell stack 100. The hydrogen supply system 10 controls the hydrogen pressure from the hydrogen supply pipeline 12 to the fuel cell stack 100 by the pressure controller 13 based on the start-stop strategy set by the start-stop control system 50, and controls the hydrogen flow from the hydrogen supply pipeline 12 to the fuel cell stack 100 by the flow controller 14.

[0053] Preferably, in this preferred embodiment of the present invention, the pressure controller 13 of the hydrogen supply system 10 is implemented as a pressure reducing valve, and the pressure controller 13 controls the pressure of the hydrogen in the hydrogen supply pipeline 12. Preferably, the flow controller 14 controls the amount of hydrogen by controlling the flow of hydrogen from the hydrogen supply pipeline 12 to the fuel cell stack 100. Optionally, the flow direction controller 14 is implemented as a quality controller, wherein the flow controller 14 controls the total amount of hydrogen to the fuel cell stack 100 by controlling the quality of hydrogen.

[0054] The hydrogen supply system 10 further includes a one-way controller 15, which is disposed in the hydrogen supply pipeline 12, and the one-way controller 15 controls the flow direction of hydrogen in the hydrogen supply pipeline 12. In other words, the one-way controller 15 is used to control the flow of hydrogen in the hydrogen supply pipeline 12 from the hydrogen source 11 to the fuel cell stack 100. Preferably, in this preferred embodiment of the present invention, the one-way controller 15 is implemented as a one-way valve.

[0055] The hydrogen supply system 10 further includes a hydrogen humidifier 16 , which is disposed in the hydrogen supply pipeline 12 , and controls the humidity of the hydrogen flowing to the fuel cell stack 100 based on the control strategy of the start-stop control system 50 .

[0056] The nitrogen supply system 20 includes a nitrogen source 21 and a nitrogen supply pipeline 22 connected to the nitrogen source 21, wherein one end of the nitrogen supply pipeline 22 is connected to the nitrogen source 21, and the other end of the nitrogen supply pipeline 22 is conductively connected to the hydrogen inlet of the fuel cell stack 100. The nitrogen supply system 20 is used for fuel cell anode purge to prevent the formation of hydrogen-air interface.

[0057] The nitrogen supply system 20 further includes a one-way control valve 23, wherein the one-way control valve 23 is arranged on the nitrogen supply pipeline 22, wherein the one-way control valve 23 prevents the backflow of hydrogen or nitrogen in the fuel cell stack 100. In other words, the nitrogen supply pipeline 22 of the nitrogen supply system is connected with the common light pipeline 12 of the hydrogen supply system 10, and when the hydrogen supply system 10 stops supplying hydrogen to the fuel cell stack 100, nitrogen is introduced into the fuel cell stack 100 by the nitrogen supply system 20, and the anode of the fuel cell stack 100 is purged with nitrogen, thereby preventing the anode of the fuel cell stack 100 from forming a hydrogen-air interface.

[0058] The air supply system 30 provides air of specific temperature, specific humidity, specific pressure and specific flow rate to the stack 100 of the fuel cell based on the start-stop strategy set by the start-stop control system 50. When the start-stop strategy set by the start-stop control system 50 changes, the start-stop control system 50 controls the air supply system 10 to adjust the temperature, humidity, gas pressure and gas flow rate of the air supply to simulate the start-stop working environment of the stack 100 under different air supply conditions. In addition, the air supply system 30 is also connected to the hydrogen inlet end of the stack 100 to simulate the diffusion of air to the anode side of the fuel cell to form a hydrogen-air interface.

[0059] The air supply system 30 includes an air source 31, an air supply pipeline 32, an air pressure controller 33 and an air flow controller 34, wherein the air source 31 is connected to one end of the air supply pipeline 32, and the other end of the air supply pipeline 32 can be connected to the fuel cell stack 100. The air is led to the air inlet end and / or the hydrogen inlet end of the fuel cell stack 100 by the air source 31 through the air supply pipeline 32. The air pressure controller 33 and the air flow controller 34 are arranged in the air supply pipeline 32, and the air pressure controller 33 controls the air pressure of the air supply pipeline 32 leading to the fuel cell stack 100. The air flow direction controller 34 is used to control the air flow or quality of the air supply pipeline 32 leading to the fuel cell stack 100.

[0060] It is worth mentioning that, in this preferred embodiment of the present invention, the air pressure controller 33 is preferably a pressure reducing valve, and the air flow controller 34 can also be implemented as a mass controller.

[0061] The air supply pipeline 32 of the air supply system 30 includes a hydrogen inlet branch 321 and an air inlet branch 322, wherein the inlet end of the hydrogen inlet branch 321 is conductively connected to the hydrogen inlet end of the fuel cell stack 100, and one end of the air inlet branch 322 is conductively connected to the air inlet end of the fuel cell stack 100. The air supply system 30 controls the hydrogen inlet branch 321 and / or the air inlet branch 322 of the air supply pipeline 32 to be conductive based on the control strategy of the start-stop control system 50, so as to simulate the working environment of the fuel cell stack 100 under different working conditions.

[0062] It can be understood that when the hydrogen inlet branch 321 of the air supply pipeline 32 is turned on, that is, the air source 31 passes air to the hydrogen inlet end of the fuel cell stack 100 through the hydrogen inlet branch 321 of the air supply pipeline 32, so as to simulate the hydrogen-air interface formed in the fuel cell stack 100 when the fuel cell is shut down for a long time. When the air inlet branch 322 of the air supply pipeline 32 is turned on, that is, the air source 31 passes air to the air inlet end of the fuel cell stack 100 through the air inlet branch 322 of the air supply pipeline 32, the oxygen required for the normal operation of the fuel cell stack 100 is provided.

[0063] The air supply system 30 further includes at least one gate valve 35, wherein the gate valve 35 is arranged at the hydrogen inlet branch 321 of the air supply pipeline 32, wherein the gate valve 35 is used to control the air supply system 30 to pass air into the fuel cell stack 100. In short, the gate valve 35 is used to control the on-off of the hydrogen inlet branch 321 of the air supply pipeline 32. When the gate valve 35 is opened, the hydrogen inlet branch 321 of the air supply pipeline 32 is conducted; when the gate valve 35 is closed, the hydrogen inlet branch 321 of the air supply pipeline 32 is closed. It is worth mentioning that when the gate valve 35 is opened based on the control signal of the start-stop control system 50, the control supply system 30 passes air to the hydrogen inlet end of the fuel cell stack 100 to simulate the diffusion of air to the anode side of the fuel cell to form a hydrogen-air interface. By controlling the opening time of the gate valve 35 and controlling the pressure and flow rate of the air in the air supply pipe 32 of the air supply system 30, the formation of the hydrogen-air interface can be controlled to simulate the working environment of the fuel cell under a real working environment.

[0064] The air supply system 30 further includes an air humidifier 36, which is disposed in the air supply pipe 32 and is used to adjust the humidity of the air in the air supply pipe 32. Preferably, in this preferred embodiment of the present invention, the air humidifier 36 is disposed in the air inlet branch 322 of the air supply pipe 32.

[0065] The thermal management system 40 is conductively connected to the fuel cell stack 100 , wherein the thermal management system 40 adjusts the temperature of the fuel cell stack 100 based on the control instruction of the start-stop control system 50 to simulate different temperatures of the fuel cell stack 100 .

[0066] In detail, the thermal management system 40 includes a heat exchange pipe 41, a heat exchanger 42 arranged on the heat exchange pipe 41, a water pump 43 and a heater 44, wherein the heat exchange pipe 41 is conductively connected to a water inlet and a water outlet of the fuel cell stack 100, and the heat exchange pipe 41 and the fuel cell stack 100 form a heat exchange passage, and the temperature of the fuel cell stack 100 is adjusted through the heat exchange passage.

[0067] The heat exchanger 42, the water pump 43 and the heater 44 are connected in series to the heat exchange pipe 41, wherein the heat exchanger 42 is used to reduce the temperature of the heat exchange medium in the thermal management system 40, and reduce the temperature of the fuel cell stack 100 through the heat exchange medium. The thermal management system 40 further includes a radiator 45, wherein the radiator 45 is arranged on the heat exchanger 42, and the radiator 45 assists the heat exchanger 42 in reducing the temperature of the heat exchange medium. Preferably, in this preferred embodiment of the present invention, the radiator 45 is implemented as a fan.

[0068] It is worth mentioning that, in this preferred embodiment of the present invention, the water pump 43 provides circulation power for the heat exchange medium, wherein the water pump 43 passes the heat exchange medium from the heater to the fuel cell stack 100. The heater 44 is used to heat the heat exchange medium to increase the temperature of the fuel cell stack 100 through the heat exchange medium.

[0069] like Figure 1A and Figure 3 The fuel cell start-stop life test equipment further includes an electronic load 60, wherein the electronic load 60 can be electrically connected to the fuel cell stack 100, and the electronic load 60 is communicatively connected to the start-stop control system 50, and the start-stop control system 50 controls the electronic load 60 based on a set start-stop control strategy to simulate the actual operating environment of the fuel cell stack 100.

[0070] The electronic load 60 can be adjusted to be connected to the positive and negative electrodes of the battery stack 100 with different resistances, and simulate the start-stop resistance of the battery stack 100 under real working conditions. In detail, the electronic load 60 includes an electronic load circuit 61, a current sensor 62 arranged in the electronic load circuit 61, at least one detection resistor 63 and at least one contactor 64 for controlling the detection resistor 63. It can be understood that the user current sensor 62, the detection resistor 63 and the contactor 64 are connected in series between the positive and negative electrodes of the battery stack 100 through the electronic load circuit 61.

[0071] The current sensor 62 is used to detect the current change of the electronic load circuit 61 during the start-stop test of the fuel cell stack 100 to reflect the current change of the fuel cell stack 100 under the simulated working condition.

[0072] The electronic load circuit 61 further includes a first load branch 611 and a second load branch 612, and the detection resistor 63 further includes at least a first resistor 631 and a second resistor 632, wherein the first resistor 631 is arranged in the first load branch 611, and the second resistor 632 is arranged in the second load branch 612. Preferably, in this preferred embodiment of the present invention, the first resistor 631 and the second resistor 632 have different resistance values, and the first resistor 631 and the second resistor 632 are arranged in parallel in the electronic load circuit 61. The contactor 64 includes a first contactor 641 and a second contactor 642, wherein the first contactor 641 is connected in series with the first resistor 631 of the detection resistor 63, and the second contactor 642 is connected in series with the second resistor 632. In other words, in this preferred embodiment of the present invention, the first contactor 641 is used to control the on-off of the first load branch 611, and the second contactor 642 is used to control the on-off of the second load branch 612.

[0073] It is worth mentioning that in this preferred embodiment of the present invention, the start-stop control system 50 controls the opening and closing of the first contactor 641 and / or the second contactor 642 of the contactor 64 based on the set start-stop control strategy to simulate the start-stop working resistance of the battery stack 100 under different working conditions.

[0074] The electronic load 60 further includes at least one single cell inspection device 65 , wherein the single cell inspection device 65 can be electrically connected to the fuel cell stack 100 , and the start / stop working status of each battery unit of the fuel cell stack 100 can be detected by the single cell inspection device 65 .

[0075] The fuel cell start-stop life test equipment sets different working conditions, such as the start-stop control system 50 simulates the start-stop conditions of the fuel cell stack under normal working conditions based on a specific fuel cell stack start-stop condition, such as a specific fuel cell stack temperature, humidity, hydrogen pressure, hydrogen-air interface, and the resistance value of the electronic load, and the start-stop control system 50 controls the start-stop detection of the fuel cell stack 100 according to the set specific start-stop conditions. As an example, in this preferred embodiment of the present invention, the start-stop control system repeatedly starts and stops the fuel cell stack 100 to be tested based on the set specific fuel cell stack start-stop condition, and detects the performance degradation and life shortening of the fuel cell stack 100.

[0076] Through experiments, the start-stop attenuation curve of the fuel cell under different working conditions is found to guide the optimal start-up and shutdown conditions of the fuel cell in the application. In order to accelerate the life test, the hydrogen supply system 10 and the air supply system 20 can create different temperature and humidity environments for the stack 100 of the fuel cell, wherein the thermal management system 40 can create different stack temperatures for the stack 100 of the fuel cell. During the shutdown stage, the nitrogen supply system 20, based on the control instructions of the start-stop control system 50, directs nitrogen to the hydrogen inlet end of the stack 100, that is, the fuel cell anode, and removes hydrogen from the stack 100 through nitrogen.

[0077] The air supply system 30 directs air to the hydrogen inlet of the stack 100 within a certain period of time based on the control instructions of the start-stop control system 50, so that the air quickly fills the anode of the fuel cell to simulate the diffusion of cathode air to the anode after the fuel cell is shut down. When the fuel cell is started, the hydrogen supply system 10 directs hydrogen to the anode of the stack 100 based on the control instructions of the start-stop control system 50 to form a hydrogen-air interface with the air inside. The cyclic start-stop test depicts the influence curves of start-stop on life under multiple different temperature and humidity conditions, and finds the optimal start-stop state based on the curve.

[0078] like Figure 3 As shown, the fuel cell start-stop life test equipment obtains a start-stop life curve corresponding to the fuel cell based on the set start-stop conditions. As the number of start-stop cycles accumulates, the fuel cell life gradually decreases, and the anode (cathode) activation area of ​​the stack 100 gradually decreases.

[0079] It is worth mentioning that in this preferred embodiment of the present invention, the start-stop control system 50 simulates the start-stop conditions of the fuel cell under real working conditions based on the set specific start-stop conditions. Preferably, the start-stop control system 50 controls the working state of the contactor 64 of the electronic load 60 to limit the high potential during the start-stop process of the fuel cell stack 100 to protect the fuel cell stack 100.

[0080] It is worth mentioning that the proton exchange membrane fuel cell starts up very quickly. After the reaction gas (hydrogen) is introduced into the stack 100 to be tested, the voltage of each single cell of the stack 100 quickly rises to an open circuit voltage greater than 0.95V. Under the high potential of the open circuit voltage, the carbon support material of the cathode catalyst layer of the stack 100 of the fuel cell will undergo oxidation corrosion, causing the stack performance to decay and the life to be shortened. Therefore, it is necessary to limit the high starting potential during the stack startup process to protect the stack performance.

[0081] The fuel cell start-stop life test equipment controls the contactor 64 of the electronic load 60 based on the set start-stop conditions, and the start-stop control system 50 enables the fuel cell stack 100 to perform a single start-up resistance test and a double start-up resistance test to limit the start-up high voltage during the fuel cell stack startup process.

[0082] In order to prevent serious reverse polarity phenomenon, when the fuel cell start-stop life test equipment tests the stack 100 to be tested based on the set start-stop conditions, a resistor with a larger resistance value can be selected in the first stage. At this time, the discharge current of the stack is relatively small, and it is not easy to have local hydrogen deficiency at the anode, which leads to the occurrence of reverse polarity phenomenon. It is worth mentioning that the discharge resistor can allow a single cell with a higher voltage to discharge a larger current, play a role in balancing the voltage, and effectively avoid large differences in single cell voltage. The test plan can perform a load start test under a large resistance.

[0083] In detail, when the start-stop control system 50 controls the battery stack 100 to perform a single starting resistance test, the start-stop control system 50 controls the first contactor 641 of the contactor 64 to close, and the second contactor 642 to open, so that the first load branch 611 is turned on and the second load branch 612 is turned off. It is worth mentioning that in this preferred embodiment of the present invention, the resistance of the first resistor 631 is greater than the resistance of the second resistor 632. In other words, during the single starting resistance test, the start-stop control system 50 selects the first load branch 611 to be turned on.

[0084] The start-stop control system 50 controls the stack 100 to perform a dual start-up resistance test. In addition, in order to significantly reduce the start-up high potential of the stack, after the total voltage of the stack reaches a set value, the on-resistance can be reduced to a smaller resistance so as to discharge quickly. This not only avoids the occurrence of reverse polarity, but also achieves the purpose of quickly reducing the open circuit voltage.

[0085] After the start-stop control system 50 controls the battery stack 100 to perform a single starting resistance test, the start-stop control system 50 controls the first contactor 641 of the contactor 64 to be disconnected, and controls the second contactor 642 to be closed, so that the first load branch 611 is disconnected and the second load branch 512 is turned on. Optionally, in other optional embodiments of the present invention, the start-stop control system 50 controls the first contactor 641 and / or the second contactor 642 of the contactor 64 to be in a closed state at the same time, so as to discharge quickly, which not only avoids the occurrence of reverse polarity, but also achieves the purpose of quickly reducing the open circuit voltage.

[0086] It is worth mentioning that after the fuel cell start-stop life test equipment completes a test on the fuel cell stack 100, the start-stop control system 50 controls the disconnection of each system in the opposite way to the start-up method, so as to shut down the fuel cell stack 100. In short, in this preferred embodiment of the present invention, the shutdown strategy test of the test equipment is the inverse method of the startup strategy test.

[0087] According to the start-stop life test strategy set by the start-stop control system, the start-stop control system 50 controls the stack 100 to perform a cycle test under the same conditions, and the test results are statistically converted into a fuel cell start-stop attenuation curve to guide the optimal start and stop conditions of the fuel cell in the application. It is worth mentioning that after the fuel cell start-stop life test equipment performs a start-stop life test on the stack 100 under the same test strategy conditions, it switches to different start-stop test conditions, replaces the new stack 100, and continues testing according to the new start-stop test conditions in order to find a suitable start-stop strategy.

[0088] like Figure 4 The test method of the fuel cell start-stop life test device is shown, wherein the test method comprises the following steps:

[0089] (1) In a shutdown state, nitrogen is passed to the hydrogen inlet of a battery stack 100 to be tested, and the anode of the battery stack 100 is purged with nitrogen to remove hydrogen;

[0090] (2) introducing air into the hydrogen inlet of the fuel cell stack 100 so that the air fills the anode of the fuel cell stack 100;

[0091] (3) introducing hydrogen into the hydrogen inlet of the fuel cell stack 100 so as to form a hydrogen-air interface at the anode of the fuel cell stack 100; and

[0092] (4) Air is introduced into an air inlet of the fuel cell stack, the fuel cell stack 100 is started, and then shut down to complete a start-stop test.

[0093] According to the above-mentioned test method of the present invention, the above-mentioned test method further includes the steps of: formulating a start-stop strategy, and cyclically executing the steps (1) to (4) according to the start-stop strategy, and detecting the degree of life attenuation of the fuel cell stack 100, and obtaining the attenuation curve of the fuel cell according to the start-up strategy and the number of test cycles.

[0094] In step (3) and step (4) of the above test method, according to the set start-stop strategy, the temperature and humidity of the fuel cell stack 100 are adjusted by introducing hydrogen and air to comply with the start-stop strategy of the fuel cell stack 100. In step (3) of the above test method, the following steps are further included: based on the start-stop strategy, a thermal management system 40 is started, whereby the thermal management system 40 controls the temperature of the fuel cell stack 100 based on the start-stop strategy.

[0095] According to the above test method of the present invention, the above test method further includes the step of: turning on a first load branch 611 of an electronic load 60 electrically connected to the battery stack 100, and disconnecting a second load branch 612 of the electronic load 60, to perform a single startup resistance test. According to the above test method of the present invention, the above test method further includes the step of: when the total voltage of the battery stack 100 reaches a set value, turning on the second load branch 612 of the electronic load 60 electrically connected to the battery stack 100, and disconnecting the first load branch 611 of the electronic load 60, to perform a dual startup resistance test.

[0096] It should be understood by those skilled in the art that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A fuel cell start-stop life test device, suitable for testing a fuel cell stack, characterized in that: The test equipment includes: a hydrogen supply system; a nitrogen supply system; an air supply system; and A start-stop control system, wherein the hydrogen supply system, the nitrogen supply system and the air supply system are communicatively connected to the start-stop control system, and the start-stop control system formulates a start-stop strategy; so that the start-stop control system controls the nitrogen supply system to pass nitrogen into the hydrogen inlet end of the fuel cell stack based on the start-stop strategy when the fuel cell stack is shut down, and purges the anode of the fuel cell stack with nitrogen; the start-stop control system controls the air supply system to pass air into the hydrogen inlet end of the fuel cell stack after removing the hydrogen in the anode of the fuel cell stack, so that the anode of the fuel cell stack is filled with air, so as to simulate the state of cathode air diffusing to the anode after the fuel cell is shut down for a long time; when the fuel cell stack is started, the start-stop control system controls the hydrogen supply system to pass hydrogen into the hydrogen inlet end of the fuel cell stack to form a hydrogen-air interface at the anode of the fuel cell stack, and controls the air supply system to pass air to the air inlet end of the fuel cell stack, so as to simulate the start-stop of the fuel cell stack under normal operating conditions.

2. The test equipment according to claim 1, wherein the test equipment further comprises a thermal management system, wherein the thermal management system is electrically connected to the start-stop control system, and the start-stop control system controls the thermal management system based on the start-stop strategy to simulate the temperature of the fuel cell when starting and stopping.

3. The testing equipment according to claim 1, wherein the hydrogen supply system comprises a hydrogen source, a hydrogen supply pipeline connected to the hydrogen source, at least one pressure controller and a flow controller arranged on the hydrogen supply pipeline, wherein one end of the hydrogen supply pipeline of the hydrogen supply system is conductively connected to a hydrogen inlet end of the fuel cell stack.

4. The test equipment according to claim 3, wherein the hydrogen supply system further comprises a hydrogen humidifier, which is arranged in the hydrogen supply pipeline, and the hydrogen humidifier controls the humidity of the hydrogen leading to the fuel cell stack based on the control strategy of the start-stop control system.

5. The testing equipment according to claim 1, wherein the nitrogen supply system comprises a nitrogen source and a nitrogen supply pipeline connected to the nitrogen source, wherein one end of the nitrogen supply pipeline is connected to the nitrogen source, and the other end of the nitrogen supply pipeline is conductively connected to the hydrogen inlet end of the fuel cell stack.

6. The testing equipment according to claim 1, wherein the air supply system comprises an air source, an air supply pipe, an air pressure controller and an air flow controller, wherein the air source is connected to one end of the air supply pipe, and the other end of the air supply pipe can be connected to the fuel cell stack.

7. The test equipment according to claim 6, wherein the air supply conduit comprises a hydrogen inlet branch and an air inlet branch, wherein an inlet end of the hydrogen inlet branch is conductively connected to the hydrogen inlet end of the fuel cell stack, and one end of the air inlet branch is conductively connected to the air inlet end of the fuel cell stack.

8. The testing device according to claim 7, wherein the air supply system further comprises an air humidifier, the air humidifier being disposed in the air supply duct and being used to adjust the humidity of the air in the air supply duct.

9. The test equipment according to claim 7, wherein the test equipment further comprises an electronic load, wherein the electronic load can be electrically connected to the fuel cell stack, and the electronic load is communicatively connected to the start-stop control system, and the start-stop control system controls the electronic load based on a set start-stop control strategy to simulate the actual operating environment of the fuel cell stack.

10. The testing device according to claim 9, wherein the electronic load comprises an electronic load circuit, a current sensor disposed in the electronic load circuit, at least one detection resistor and at least one contactor for controlling the detection resistor.

11. The test device according to claim 10, wherein the electronic load circuit further includes a first load branch and a second load branch, and the detection resistor further includes at least a first resistor and a second resistor, wherein the first resistor is set in the first load branch, and the second resistor is set in the second load branch, wherein the resistance value of the first resistor is greater than the resistance value of the second resistor.

12. The testing equipment according to claim 11, wherein the electronic load of the testing equipment further comprises at least one single-cell inspection device, wherein the single-cell inspection device can be electrically connected to the fuel cell stack, and the start / stop working status of each battery unit of the stack is detected by the single-cell inspection device.

13. A fuel cell start-stop life test method, characterized in that: The test method comprises the following steps: (1) In a shutdown state, nitrogen is passed to the hydrogen inlet of a battery stack to be tested, and the anode of the battery stack is purged with nitrogen to remove hydrogen; (2) after removing the hydrogen from the anode of the fuel cell stack, introducing air into the hydrogen inlet of the fuel cell stack so that the air fills the anode of the fuel cell stack, thereby simulating the state in which the air diffuses into the anode after the fuel cell is shut down for a long time; (3) When the fuel cell is started, hydrogen is introduced into the hydrogen inlet of the fuel cell stack so as to form a hydrogen-air interface at the anode of the fuel cell stack; as well as (4) Air is introduced into an air inlet end of the fuel cell stack, the fuel cell stack is started, and then shut down to complete a start-stop test.

14. The test method according to claim 13, wherein the test method further comprises the steps of: formulating a start-stop strategy, and cyclically executing steps (1) to (4) according to the start-stop strategy, and detecting the degree of life attenuation of the fuel cell stack, and obtaining the attenuation curve of the fuel cell according to the start-stop strategy and the number of test cycles.

15. The test method according to claim 14, wherein in step (3) and step (4) of the test method, the temperature and humidity of the fuel cell stack are adjusted by introducing hydrogen and air according to the set start-stop strategy to comply with the start-stop strategy of the fuel cell stack.

16. The test method according to claim 14, wherein the test method further comprises the following steps: Based on the start-stop strategy, a thermal management system is started, whereby the thermal management system controls the temperature of the fuel cell stack based on the start-stop strategy.

17. The test method according to claim 14, wherein the test method further comprises the steps of: turning on a first load branch of an electronic load electrically connected to the battery stack, and disconnecting a second load branch of the electronic load, to perform a single starting resistance test.

18. The test method according to claim 17, wherein the test method further comprises the step of: when the total voltage of the battery stack reaches a set value, turning on the second load branch of the electronic load electrically connected to the battery stack, and disconnecting the first load branch of the electronic load, to perform a dual start-up resistance test.

Images