Gas humidifying device for fuel cell test

The invention provides a gas humidifying device for fuel cell testing, belongs to the technical field of fuel cells, and solves the problems that in the prior art, the gas humidity is difficult to adjust quickly according to the operation requirement of a galvanic pile and the application range is limited. The device is suitable for all working condition points and comprises a gas humidifying tank, a first tank body filled with constant-temperature hot water, a second tank body filled with constant-temperature cold water, a first water pump, a second water pump and a controller. A heater and a cooling plate are arranged in the gas humidifying tank, the first water inlet is connected with the first tank body through a first water pump to form a coarse adjustment temperature rising branch, and the second water inlet is connected with the second tank body through a second water pump to form a coarse adjustment cooling branch. The control method comprises the following steps: determining a dew point temperature c