Humidity control method for proton exchange membrane fuel cell system

Abstract

A humidity control method for a proton exchange membrane fuel cell system is used for a hydrogen fuel cell which at least comprises a cathode into which oxygen or air is introduced as a reaction raw material, an anode into which hydrogen is introduced as a reaction raw material, and an exchange membrane which separates the cathode from the anode and is only selectively permeable to specific ions, comprising the following steps: alternately humidifying air conveyed to a cathode of a battery and hydrogen conveyed to an anode of the battery based on battery work, so that corresponding humidified gas enters corresponding electrodes to humidify the humidity in the electrodes, all water used for humidification comes from water generated by the cathode or anode reaction, so that the humidity control flow of the fuel cell is completely self-sufficient at least in water resource.

Description

technical field [0001] The invention relates to the field of fuel cell operating condition control, in particular to a humidity control method for a proton exchange membrane fuel cell system. Background technique [0002] The general structure of a proton exchange membrane fuel cell (PEMFC) consists of a membrane electrode, a sealing ring, and a flow field plate with an air guide channel, in which the membrane electrode has a greater demand for controlling the internal humidity of the battery, that is, the humidity in the battery has a great influence on the battery. Heap performance has a big impact. If the water content is not enough, the conductivity of the proton membrane will deteriorate; within a certain range, the humidity or the water content of the proton membrane will be positively correlated with the conductivity of the membrane; Membrane conductivity. Therefore, it is necessary to maintain a suitable humidity to effectively improve the performance of the stack,...

AI Technical Summary

Problems solved by technology

The former essentially uses an external humidifier to humidify the reaction raw material gas before it is sent into the stack, and increases the humidity of the raw material from the source, but this solution has higher requirements for external humidification equipment and higher use costs; the latter uses Change the structure of the bipolar plate and diffusion layer inside the stack, and use a special porous carbon plate or material to allow the water introduced from the outside of the stack to diffuse the moisture generated by the cathode to the inside of the mold or the anode. The main changes in this method are The internal structure of the electric stack, and the added internal humidification components need to withstand the high working temperature, electric field and working pressure in the electric stack, and there are certain problems of service life and reliability

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