Fuel cell cold start anode purging device and purging method

[0042] Example 1

[0043] In a typical implementation of the present invention, such as figure 1 As shown, a fuel cell cold-start anode purging device includes a nitrogen purging system connected to a hydrogen circulation system. The nitrogen purging system adopts nitrogen purging. The system includes a nitrogen tank 9 and a second solenoid valve 10 connected in sequence , The second pressure reducing valve 11, the second flow meter 12, the second flow meter 12 is connected with the first integrated temperature, pressure and humidity sensor 13 in the hydrogen circulation system, and further connected with the inlet of the fuel cell stack 14.

[0044] The nitrogen purge system also includes a second integrated temperature, pressure and humidity sensor 15 and a three-way valve 17. The second integrated temperature, pressure and humidity sensor 15 is connected to the inlet of the three-way valve 17. The three-way valve 17 is a three-way solenoid valve. The inlet of the valve is connected to the fuel cell stack 14 via the second integrated temperature, pressure and humidity sensor 15, the outlet of the three-way solenoid valve is respectively communicated with the gas-liquid separator 18 and the liquid storage tank 20 (external environment), and the check valve 8 is also connected with The pressure relief valve 16 is connected, and the pressure relief valve 16 is connected to the external environment through the liquid storage tank 20, and a solenoid valve 19 is also provided between the gas-liquid separator 18 and the liquid storage tank 20 to control the separation of the gas-liquid separator 18 The liquid flows back into the liquid storage tank 20, and the gas-liquid separator 18 is connected to the hydrogen ejector/circulation pump 6 for sending the excess hydrogen discharged from the fuel cell stack back to the hydrogen circulation system.

[0045] The hydrogen circulation system includes a hydrogen tank 1, a first solenoid valve 2, a first pressure reducing valve 3, a first flow meter 4, a pressure sensor 5, a hydrogen ejector/circulation pump 6, a surge tank 7, a check Valve 8 and first integrated temperature, pressure and humidity sensor 13, fuel cell stack 14, second integrated temperature, pressure and humidity sensor 15, three-way valve 17, gas-liquid separator 18, first integrated temperature, pressure and humidity sensor 13 and second integrated temperature and pressure sensor The integrated wet sensor 15 is connected to the inlet and outlet of the fuel cell stack 14 respectively.

[0046] Among them, it should be noted that the liquid storage tank 20 includes a shell, the top of the shell is provided with a gas outlet, and the bottom is provided with a liquid outlet. After the gas-liquid mixture enters the shell, the liquid collides with the inner wall of the shell and flows to the bottom of the shell. The liquid outlet flows out, and the gas in the gas-liquid mixture is discharged through the gas outlet; or, the liquid storage tank is a liquid storage tank, and the liquid storage tank is equipped with a switch, and the switch is turned on regularly, so that the liquid water is drained in time after purging.

[0047] The hydrogen circulation system and the nitrogen purge system are both connected to the fuel cell stack for purging the fuel cell stack. The first integrated temperature, pressure and humidity sensor and the second integrated temperature, pressure and humidity sensor are used to detect fuel cell power respectively. The temperature, pressure, and humidity on the inlet and outlet sides of the reactor can be used to control the opening or closing of the nitrogen purge system to ensure the purge effect.

[0048] It should be noted that the first integrated temperature, pressure and humidity sensor and the second integrated temperature, pressure and humidity sensor can be replaced with corresponding temperature, pressure and humidity sensors.

[0049] The pressure of the gas after the first pressure reducing valve and the second pressure reducing valve are decompressed shall not exceed 0.5MPa.

[0050] The hydrogen tank uses a standard 35MPa hydrogen storage bottle or 70MPa hydrogen storage bottle. The position of hydrogen ejector/circulation pump preferentially adopt hydrogen ejector.

[0051] Example 2

[0052] A fuel cell cold-start anode purging method adopts the fuel cell cold-start anode purging device described in Embodiment 1, and includes the following contents:

[0053] When the fuel cell is shut down, it can be switched to the nitrogen purge system immediately. The first solenoid valve in the hydrogen circulation system is closed, and the second solenoid valve in the nitrogen purge system is opened to turn on the nitrogen purge system; when the fuel cell starts, the first pass The cooling water of the fuel cell heat dissipation system heats the fuel cell stack. When the temperature of the cooling water reaches the set value, the nitrogen purge system is turned on; after being released from the nitrogen tank, the nitrogen flows through the second solenoid valve and the second pressure reducing valve , The second flow meter, the first integrated temperature, pressure and humidity sensor, the purged fuel cell stack, and the second integrated temperature, pressure and humidity sensor reach the three-way solenoid valve 17, which is connected to the gas-liquid separator 18. The outlet is closed, the outlet to the liquid storage tank is opened, the nitrogen gas flows through the liquid storage tank and then discharged to the outside environment, and the liquid water recovered to the liquid storage tank is regularly discharged from the system. After the nitrogen purge system is over, the outlet communicating with the three-way valve and the gas-liquid separator is opened, and the outlet to the liquid storage tank is closed. At this time, the next round of hydrogen circulation system opens, and the excess hydrogen discharged from the fuel cell stack flows through the gas The liquid separator is sent to the hydrogen circulation system for reuse.

[0054] Among them, each solenoid valve, flow meter, pressure sensor, the first integrated temperature, pressure and humidity sensor, the second integrated first temperature, pressure and humidity sensor, the three-way valve, and the hydrogen ejector/circulation pump are all connected to the controller. The PLC controller is used to control the timely opening or closing of various structural parts.

[0055] When the fuel cell is shut down, the hydrogen circulation system is closed and the nitrogen purge system bypass is opened immediately; when the fuel cell is started, when the cooling water temperature reaches 5-15 ℃ or more, the nitrogen purge system can be opened.

[0056] In addition, when the fuel cell is shut down, when any of the following two conditions is met, the nitrogen purge system is closed:

[0057] 1) The temperature of the nitrogen at the outlet of the hydrogen side of the fuel cell stack is lower than 40-50℃ and the relative humidity is lower than 20-40%, ensuring the energy consumption and cost performance of the purging device;

[0058] 2) Purge time is greater than 3~10min;

[0059] When the fuel cell is started, when the nitrogen purge system purge time reaches 1 to 2 minutes, the nitrogen purge system is closed. At this time, most of the liquid water in the flow channel of the fuel cell stack and the porous electrode has been purged out of the fuel cell Electric pile.