Humidification system and method for fuel cell, and fuel cell system

Abstract

The invention relates to a humidification system and method for a fuel cell, and a fuel cell system. The humidification system comprises a voltage and current sensor, which is connected with the poweroutput end of a fuel cell stack and used for collecting the output current and the output voltage of the fuel cell stack; an air flow meter, which is arranged on an air inlet pipeline of an air supply system of a fuel cell stack system and used for collecting air flow signals entering the fuel cell stack; an exhaust tail gas circulation valve, with one end connected with the outlet of the air supply system of the fuel cell stack system and the other end connected with the air inlet of an air compressor of the air inlet pipeline; and a humidity controller, which is separately connected with the voltage and current sensor, the air flow meter and the exhaust tail gas circulation valve and used for estimating the internal resistance of the fuel cell stack according to the output current and the output voltage of the fuel cell stack and adjusting the openness of the exhaust tail gas circulation valve according to both the internal resistance of the fuel cell stack and the flow of air entering the fuel cell stack. Compared with the prior art, the humidification system of the invention has the advantages of high integration level, low cost, small size and the like.

Description

Technical field [0001] The invention relates to a fuel cell humidification system, in particular to a fuel cell humidification system, method and fuel cell system. Background technique [0002] Fuel cell water management is extremely important to fuel cell performance, efficiency, cold start and life. During the operation of the fuel cell, the proton exchange membrane needs to bind water to maintain the conductivity of protons. Too little water will increase the internal resistance of the fuel cell; if the water content is too much, it will cause the cathode to flood. The ohmic resistance of a fuel cell is an important parameter during the operation of the fuel cell, and it reflects the internal operating state of the fuel cell. From a short span of time, there is a great relationship between the change of ohmic resistance and the humidity change of the proton exchange membrane. The humidity of the membrane can be indirectly estimated by estimating the ohmic resistance, which is...

AI Technical Summary

Problems solved by technology

Existing fuel cell humidification methods include liquid water injection humidification, temperature rise humidification, liquid water injection humidification, and permeable membrane humidification, etc. Although these external humidification schemes improve the performance of fuel cells, they increase the fuel consumption. The volume of the entire system of the battery may increase additional energy consumption, and the disadvantage of not being able to adjust the humidity

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