Activation device of proton exchange membrane fuel cell stack and application thereof

Abstract

The present application relates to a kind of proton exchange membrane fuel cell stack activation device and its application.The device includes the following units: gas supply unit for supplying nitrogen, air and hydrogen;Gas heating and humidifying unit for hydrogen or air heating and humidifying;Cooling liquid unit for cooling fuel cell stack;Control unit for temperature, liquid level and valve control;The gas supply unit is communicated with gas heating and humidifying unit, and the gas heating and humidifying unit is communicated with fuel cell stack by stack connection unit, and the cooling liquid unit is communicated with fuel cell stack, and the control unit is connected with gas heating and humidifying unit and cooling liquid unit.Compared with prior art, the present application can replace fuel cell test platform to carry out activation, partially release the resource of fuel cell test platform, and improve production efficiency.

Description

Technical Field

[0001] This invention relates to the field of fuel cells, and more specifically to an activation device for a proton exchange membrane fuel cell stack and its application. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs) are promising energy conversion devices that typically generate electricity through the electrochemical reaction between hydrogen (H2) and oxygen (O2) on both sides of the membrane electrode assembly (MEA). Therefore, the MEA is the core component of a PEMFC stack, and its performance determines the stack's output performance. Activation of a PEMFC stack involves activating the platinum catalyst in the MEA and typically includes the following processes: 1) humidification of the proton exchange membrane; 2) establishment of mass transport channels; 3) optimization of the electrode structure; and 4) improvement of the activity and utilization rate of the catalyst layer.

[0003] Newly manufactured or long-stored proton exchange membrane fuel cell stacks require activation treatment before official commissioning to humidify the proton exchange membrane, activate the platinum catalyst, and improve MEA performance. Additionally, fuel cells used in vehicles for extended periods may become contaminated, such as by antifreeze contamination, leading to deterioration of MEA performance. To ensure continued use of the stack in vehicles, activation methods can be used to remove contaminants and restore MEA performance.

[0004] Traditional activation methods often employ techniques such as current-loaded activation, constant-current activation, or hydrogen pump activation. For example, Chinese patent CN201810170394.3 provides a method and apparatus for constant-current activation. This involves loading the fuel cell stack to 300A under different set conditions, running it for a period of time, then reducing the load to 0A. The set conditions are then changed, and the stack is again loaded to 300A for a period of time before being reduced to 0A. This process is repeated several times until the average voltage no longer increases. These traditional activation methods all require the activation device to have an electronic load and a CVM (Continuous Voltage Monitor) sensor. Summary of the Invention

[0005] The purpose of this invention is to overcome at least one of the defects in the prior art by providing an activation device for a proton exchange membrane fuel cell stack and its application. This device can activate the proton exchange membrane fuel cell through dual-space dual-hydrogen purging. Furthermore, the dual-space dual-hydrogen purging activation method employed in this device requires no electronic load, no monitoring of the cell voltage, and offers flexible activation time. Compared to commonly used fuel cell testing platforms, this device eliminates the need for electronic loads and voltage monitoring devices, freeing up testing resources and saving manpower and material resources.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] One objective of this invention is to provide an activation device for a proton exchange membrane fuel cell stack, the device comprising the following units:

[0008] Gas supply unit for supplying nitrogen, air and hydrogen;

[0009] Gas heating and humidification unit for heating and humidifying hydrogen or air;

[0010] Coolant unit used to cool fuel cell stacks;

[0011] Control unit for controlling level gauges, controllers and sensors in gas supply units, gas heating and humidification units and coolant units;

[0012] Stack connection unit for connecting fuel cell stacks;

[0013] The gas supply unit is connected to the gas heating and humidification unit, the gas heating and humidification unit is connected to the fuel cell stack, and the coolant unit is connected to the fuel cell stack.

[0014] Furthermore, the gas supply unit includes a nitrogen pipeline, an air pipeline, and a hydrogen pipeline. The nitrogen pipeline and the air pipeline are connected by a branch containing a gas valve and / or a check valve; the nitrogen pipeline and the hydrogen pipeline are connected by a branch containing a gas valve and / or a check valve; and the hydrogen pipeline and the air pipeline are connected.

[0015] Furthermore, the nitrogen pipeline, air pipeline, and hydrogen pipeline converge into a single pipeline leading to the gas humidifier.

[0016] Furthermore, the gas heating and humidification unit includes a gas humidifier and a heating and humidification water tank that are connected in a cycle to each other, and the gas humidifier is connected to the fuel cell stack.

[0017] Furthermore, the gas heating and humidification unit also includes a small circulation loop containing valves, a level gauge, valves, a pump, a controller, and sensors. The gas heating and humidification unit also includes a heating and humidification water tank, a heating and humidification water tank replenishment solenoid valve, a heating and humidification unit water pump, a heating and humidification temperature controller, a temperature sensor, and a flow sensor.

[0018] Furthermore, the coolant unit includes a coolant heating tank that is circulated and connected to the fuel cell stack.

[0019] Furthermore, the coolant unit also includes a small circulation loop containing valves, a level gauge, valves, a pump, a controller, and sensors.

[0020] Coolant tank level gauge, coolant tank water replenishment solenoid valve, coolant unit water pump, coolant temperature controller, coolant temperature sensor, coolant pressure sensor, and coolant flow sensor.

[0021] The coolant heating tank and coolant pump are located between the coolant heating tank and the fuel cell stack.

[0022] Furthermore, the fuel cell stack has a stack inlet pipe connected to a gas humidifier, a stack tailpipe connected to a water vapor separator, a coolant inlet pipe connected to a coolant heating water tank, and a coolant outlet pipe.

[0023] Furthermore, the gas heating and humidification unit also includes a heating and humidification temperature controller, a heating and humidification water tank level gauge, and a heating and humidification water tank water replenishment solenoid valve.

[0024] Furthermore, the coolant unit also includes a coolant temperature controller, a coolant tank level gauge, and a coolant tank water replenishment solenoid valve.

[0025] Furthermore, the control unit is connected to the heating and humidifying temperature controller, the heating and humidifying water tank level gauge, the heating and humidifying water tank water replenishment solenoid valve, the coolant temperature controller, the coolant water tank level gauge, and the coolant water tank water replenishment solenoid valve.

[0026] Furthermore, the fuel cell stack connection unit includes a stack air inlet pipe, a stack tailpipe pipe, a coolant inlet interface, and a coolant outlet interface.

[0027] A second objective of this invention is the application of an activation device for a proton exchange membrane fuel cell stack as described above. This device is used for the activation of a proton exchange membrane fuel cell stack and includes the following steps:

[0028] The fuel cell stack is preheated with coolant until it reaches the specified temperature;

[0029] Nitrogen gas is used to purge the pipelines and the cathode and anode of the fuel cell stack to prevent hydrogen-air mixing;

[0030] After purging the cathode and anode of the fuel cell stack with heated and humidified air, nitrogen is used again to purge the pipelines and the cathode and anode of the fuel cell stack to prevent hydrogen-air mixing.

[0031] After purging the cathode and anode of the fuel cell stack with heated and humidified hydrogen, nitrogen is used again to purge the pipelines and the cathode and anode of the fuel cell stack to prevent hydrogen-air mixing, thus completing the activation process.

[0032] Furthermore, the coolant temperature is a set temperature ±2℃.

[0033] Compared with existing technologies, the present invention can replace the fuel cell test platform for activation, partially freeing up the resources of the fuel cell test platform and improving production efficiency. In addition, the device has the advantages of simple and convenient operation, low error rate, simple structure, and low maintenance cost. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the proton exchange membrane fuel cell activation device in this invention;

[0035] Figure 2 This is a structural diagram of the proton exchange membrane fuel cell activation device in this invention;

[0036] The labels in the diagram indicate: 11-Hydrogen external supply valve; 21-Air external supply valve; 31-Nitrogen external supply valve; 12-Hydrogen pressure regulating valve; 22-Air pressure regulating valve; 32-Nitrogen pressure regulating valve; 13-Hydrogen gas flow meter; 23-Air gas flow meter; 33-Nitrogen gas flow meter; 14-Hydrogen check valve; 24-Air check valve; 34-Nitrogen to hydrogen check valve; 35-Nitrogen to air check valve; 36-Nitrogen to hydrogen valve; 37-Nitrogen to air valve; 41-Gas humidifier; 42-Heated humidifier water tank. ; 43-Heating and humidifying water tank level gauge; 44-Heating and humidifying water tank makeup solenoid valve; 45-Heating and humidifying unit water pump; 46-Heating and humidifying temperature controller; 47-Temperature sensor; 48-Flow sensor; 52-Coolant heating water tank; 53-Coolant water tank level gauge; 54-Coolant water tank makeup solenoid valve; 55-Coolant unit water pump; 56-Coolant temperature controller; 57-Coolant temperature sensor; 58-Coolant pressure sensor; 59-Coolant flow sensor; 61-Gas inlet valve; 62-Gas outlet valve; 63-Gas inlet pressure gauge. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0038] Example

[0039] An activation device for a proton exchange membrane fuel cell stack, such as Figure 1 As shown, the device includes the following units: a gas supply unit for supplying nitrogen, air and hydrogen; a gas heating and humidification unit for heating and humidifying hydrogen or air; a coolant unit for cooling the fuel cell stack; a stack connection unit for connecting the fuel cell stack; and a control unit for controlling the level gauge, controller and sensor.

[0040] The gas supply unit includes a hydrogen peripheral supply valve 11, an air peripheral supply valve 21, a nitrogen peripheral supply valve 31, a hydrogen pressure regulating valve 12, an air pressure regulating valve 22, a nitrogen pressure regulating valve 32, a hydrogen gas flow meter 13, an air gas flow meter 23, a nitrogen gas flow meter 33, a hydrogen check valve 14, an air check valve 24, a nitrogen-to-hydrogen check valve 34, a nitrogen-to-air check valve 35, a nitrogen-to-hydrogen valve 36, and a nitrogen-to-air valve 37. The gas supply unit is connected to a gas heating and humidification unit, which is connected to the fuel cell stack via a fuel cell stack connection unit. The coolant unit is interconnected with the fuel cell stack. The control unit is connected to both the gas heating and humidification unit and the coolant unit. The gas supply unit includes nitrogen, air, and hydrogen pipelines. Nitrogen enters the air pipeline via the nitrogen-to-air valve 37, and nitrogen enters the hydrogen pipeline via the nitrogen-to-hydrogen valve 36. The gas heating and humidification unit includes a gas humidifier 41, a heating and humidification water tank 42, a heating and humidification water tank level gauge 43, a heating and humidification water tank water replenishment solenoid valve 44, a heating and humidification unit water pump 45, a heating and humidification temperature controller 46, a temperature sensor 47, and a flow sensor 48. The gas humidifier 41 and the heating and humidification water tank 42 are interconnected. The coolant unit includes a coolant heating water tank 52, a coolant water tank level gauge 53, a coolant water tank water replenishment solenoid valve 54, a coolant unit water pump 55, a coolant temperature controller 56, a coolant temperature sensor 57, a coolant pressure sensor 58, and a coolant flow sensor 59. The coolant unit water pump 55 is located between the coolant heating water tank 52 and the fuel cell stack. The stack connection unit includes a stack air inlet pipe, a stack exhaust pipe, a coolant inlet interface, and a coolant outlet interface. The control unit is connected to the heating and humidifying temperature controller 46, the heating and humidifying water tank level gauge 43, the heating and humidifying water tank water replenishment solenoid valve 44, the coolant temperature controller 56, the coolant water tank level gauge 53, and the coolant water tank water replenishment solenoid valve 54.

[0041] like Figure 2 As shown, the fuel cell stack is connected to the gas heating and humidification unit through two fuel cell stack inlet pipes. The pipes include a gas inlet valve 61 and a gas inlet pressure gauge 63, as well as a water vapor separator connected to the device through two fuel cell stack tailpipe pipes. The pipes include a gas outlet valve 62. The coolant unit is connected to the coolant inlet and outlet ports of the fuel cell stack through two pipes, realizing the circulation of coolant between the water tank and the fuel cell stack.

[0042] After the fuel cell stack is installed, the coolant temperature is preset before activation begins, and the coolant is circulated into the fuel cell to preheat the stack. When the coolant temperature controller 56 detects that the coolant temperature has reached 50-65°C, it stops heating and maintains the coolant temperature stable within ±2°C of the set temperature. The coolant unit pump 55 continuously operates to circulate the coolant between the water tank and the fuel cell stack, thereby controlling the internal temperature of the fuel cell.

[0043] Before introducing hydrogen or air, the external supply valve 31 for pure nitrogen gas, as well as the nitrogen-to-hydrogen valve 36 and nitrogen-to-air valve 37, are opened. The depressurized nitrogen purges the pipelines and the cathode and anode of the fuel cell stack to prevent hydrogen-air mixing. During activation, the externally supplied air, after depressurization, enters the gas humidifier 41 for heating and humidification to reach the set temperature and humidity. Its operating pressure is 50 kPa, flow rate is 1.5*n slpm (n is the number of fuel cell stack cells, n≥1), humidity is 60%, and purging time is 45 min. The humidified and heated air simultaneously purges the cathode and anode of the fuel cell stack through the stack connection unit. After purging for 45 min, the external supply valve 31 for pure nitrogen gas and the nitrogen-to-air valve 37 are opened again to purge the pipelines and the cathode and anode of the fuel cell stack to prevent hydrogen-air mixing. Similarly, high-pressure pure hydrogen, after depressurization, enters the humidifier for heating and humidification to reach the set temperature and humidity. Humidified and heated hydrogen gas enters the fuel cell stack cathode and anode for purging via the stack connection unit. Its operating pressure is 50 kPa, flow rate is 0.8 * n slpm (where n is the number of fuel cell stack cells, n ≥ 1), and humidity is 60%. After purging for 45 minutes, the hydrogen external supply valve 11 is closed, and the pure nitrogen external supply valve 31 and the nitrogen-to-hydrogen line valve 36 are reopened to purge the pipelines and the fuel cell stack cathode and anode, preventing hydrogen-air mixing.

[0044] After the above purging is completed, nitrogen gas is used to purge the cathode and anode to reduce the hydrogen-air interface. The stack temperature is controlled at 50-65°C. Air is introduced into the fuel cell cathode and hydrogen into the anode. The load is connected, with a cathode metering ratio of 2.5 and an anode metering ratio of 1.5. The load is gradually increased to 1300 mA / cm at a loading rate of 10 A / s. 2 The current density is then balanced for a certain period of time until the output voltage of the fuel cell no longer increases, at which point the activation is complete.

[0045] Compared with existing technologies, this invention does not require an electronic load, does not require monitoring of battery voltage, and has controllable activation time, saving manpower and resources.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An activation device for a proton exchange membrane fuel cell stack, characterized in that, The device consists of the following units: Gas supply unit for supplying nitrogen, air and hydrogen; Gas heating and humidification unit for heating and humidifying hydrogen or air; Coolant unit used to cool fuel cell stacks; The gas supply unit is connected to the gas heating and humidification unit, the gas heating and humidification unit is connected to the fuel cell stack, and the coolant unit is connected to the fuel cell stack. The gas supply unit includes a nitrogen pipeline, an air pipeline, and a hydrogen pipeline. The nitrogen pipeline and the air pipeline are connected by a branch containing a gas valve and / or a check valve; the nitrogen pipeline and the hydrogen pipeline are connected by a branch containing a gas valve and / or a check valve; and the hydrogen pipeline and the air pipeline are connected. The gas heating and humidification unit includes a gas humidifier (41) and a heating and humidification water tank (42) that are connected in a cycle to each other. The gas humidifier (41) is connected to the fuel cell stack. The coolant unit includes a coolant heating water tank (52) that is circulatedly connected to the fuel cell stack. This device is used for the activation of proton exchange membrane fuel cell stacks and includes the following steps: The fuel cell stack is preheated with coolant until it reaches the specified temperature; Nitrogen gas is used to purge the pipelines and the cathode and anode of the fuel cell stack to prevent hydrogen-air mixing; After purging the cathode and anode of the fuel cell stack with heated and humidified air, nitrogen is used again to purge the pipelines and the cathode and anode of the fuel cell stack to prevent hydrogen-air mixing. After purging the cathode and anode of the fuel cell stack with heated and humidified hydrogen, nitrogen is used again to purge the pipelines and the cathode and anode of the fuel cell stack to prevent hydrogen-air mixing, thus completing the activation process.

2. The activation device for a proton exchange membrane fuel cell stack according to claim 1, characterized in that, The nitrogen pipeline, air pipeline and hydrogen pipeline are combined into one pipeline, which leads to the gas humidifier (41).

3. The activation device for a proton exchange membrane fuel cell stack according to claim 1, characterized in that, The gas heating and humidification unit also includes a small circulation loop containing valves.

4. The activation device for a proton exchange membrane fuel cell stack according to claim 1, characterized in that, The coolant unit also includes a small circulation loop containing valves.

5. The activation device for a proton exchange membrane fuel cell stack according to claim 1, characterized in that, The fuel cell stack has a stack inlet pipe connected to a gas humidifier (41), a stack tailpipe connected to a water vapor separator, a coolant inlet pipe connected to a coolant heating tank (52), and a coolant outlet pipe.

6. The activation device for a proton exchange membrane fuel cell stack according to claim 1, characterized in that, The coolant temperature is set at ±2℃.

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