Fuel cell stack cathode humidity control system and control method thereof

Abstract

The invention discloses a fuel cell stack cathode humidity control system and a control method thereof.The fuel cell stack cathode humidity control system comprises an air source, a stack and a controller, and an air compressor, a first radiator and a humidifier are sequentially arranged between the air source and a stack cathode inlet in the air flow direction; an air supply bypass valve is arranged between the air outlet of the first radiator and the cathode inlet of the electric pile, a second radiator and an exhaust bypass valve which are connected in parallel are arranged between the cathode outlet of the electric pile and the wet side inlet of the humidifier, and the wet side outlet of the humidifier is connected with the outside atmosphere. The controller is used for analyzing the air temperature at the cathode inlet of the electric pile, and the output end of the controller is connected with the air supply bypass valve, the exhaust bypass valve and the second radiator. The air temperature and humidity at the cathode inlet of the electric pile are adjusted by adjusting the air temperature at the wet side inlet of the humidifier, so that the humidity requirement of the electric pile is met.

Description

technical field [0001] The invention belongs to the technical field of fuel cell humidity control, and in particular relates to a fuel cell stack cathode humidity control system and a control method thereof. Background technique [0002] The fuel of the fuel cell is hydrogen, the combustion gas is oxygen, and the product is clean water. The fuel cell itself does not produce carbon monoxide and carbon dioxide, nor does it emit sulfur and particulates. Therefore, hydrogen fuel cell vehicles are truly zero-emission, zero-emission. polluted car. [0003] Humidity is very important to fuel cells. Improper control will seriously affect the performance and life of fuel cells. Too low intake air humidity will easily lead to drying of membrane electrodes, and then the conductivity of fuel cells will decrease. The gas transfer is blocked, and the air side of the current fuel cell is basically humidified by an external humidifier to increase the air humidity. [0004] As the operatin...

AI Technical Summary

Problems solved by technology

[0003] Humidity is very important to fuel cells. Improper control will seriously affect the performance and life of fuel cells. Too low air intake humidity will easily cause the membrane electrode to dry out, thereby reducing the conductivity of the fuel cell. Excessive intake air humidity will easily cause water flooding. The gas transfer is blocked, and the air side of the current fuel cell is basically humidified by an external humidifier to increase the air humidity

[0004] With the increase of the operating temperature of the fuel cell system, especially during high-power operation, the inlet temperature of the dry side of the humidifier (equal to the inlet temperature of the stack cooling water) and the inlet temperature of the wet side of the humidifier (equal to the outlet temperature of the stack cooling water Relatively high), the relative humidity decreases, resulting in a decrease in the efficiency of the humidifier, and a decrease in the relative humidity of the dry outlet of the humidifier, which cannot meet the humidity requirements of the fuel cell system

Images