Cold purging method of fuel cell system

Abstract

The invention provides a cold purging method of a fuel cell system. The cold purging method of the fuel cell system comprises the following steps: receiving a shutdown instruction of the fuel cell system; carrying out purging according to a preset first temperature and a preset first time duration; purging according to a preset second temperature and a preset second time duration, wherein the second temperature is lower than the first temperature; and shutting down the fuel cell system. The method has the advantages that high-temperature and low-temperature two-section purging is carried out, high-temperature moisture can be further condensed through low-temperature purging, high-humidity gas is prevented from being condensed and frozen after being cooled after high-temperature purging, and purging can be more complete; a fan and a water pump can work at a relatively large duty ratio, so that the temperature of cooling liquid is rapidly reduced; a circulating pump can continuously operate in the cold start-up process, the phenomena of clamping stagnation and stalling do not exist in the process, hydrogen needed by reaction and sufficient humidity can be well provided for the fuel cell stack, and success of cold start-up of the system is facilitated.

Description

technical field [0001] The invention relates to a purging method, in particular to a cold purging method for a fuel cell system. Background technique [0002] The hydrogen fuel cell system vehicle technology is becoming more and more mature. As a new energy vehicle with zero pollution and zero emission, more and more hydrogen fuel cell system vehicles have entered the transportation system and have been widely recognized by the public. Fuel cell system vehicles use hydrogen as fuel. Through the fuel engine, the chemical energy is efficiently converted into electric energy to drive the vehicle. The whole process only discharges pure water. Therefore, it is the most ideal energy-saving and environment-friendly zero for replacing traditional fossil fuel vehicles in the near future. Emissions vehicles. [0003] In the case of fuel cells without special treatment or auxiliary tools, in the working environment below 0°C, the water generated by the reaction on the cathode side is ...

AI Technical Summary

Problems solved by technology

However, due to the structural characteristics of the circulating pump itself, especially the claw-type circulating pump, it is easy to freeze at the joint of the claws, and the shell of the circulating pump is made of metal, which conducts heat quickly. According to relevant experiments, if three drops of water freeze at the joint of the claws, it will It will cause the circulation pump to fail to start at low temperature

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