Shutdown control method of fuel cell system, fuel cell system and vehicle

Abstract

The invention relates to the field of fuel cells, in particular to a shutdown control method of a fuel cell system, the fuel cell system and a vehicle. The method comprises the following steps: closing an inlet / outlet at the air side of the fuel cell stack, and keeping the pressure at the hydrogen side of the fuel cell stack constant; switching on an output circuit of the fuel cell stack, and obtaining hydrogen accumulated flow input from the hydrogen side; and determining whether to close the fuel cell system according to the relationship between the hydrogen accumulated flow and a preset threshold value. According to the invention, the contradiction that the fuel cell system is insufficient in shutdown oxidation gas consumption and short in standing time and is high in tail discharge hydrogen concentration of next startup in the shutdown oxidation gas consumption process is solved; and it can be guaranteed that shutdown control meets the safety of oxygen consumption and hydrogen emission in the whole life cycle and under the abnormal condition.

Description

technical field [0001] The invention relates to the field of fuel cells, in particular to a fuel cell system shutdown control method, a fuel cell system, and a vehicle. Background technique [0002] Proton exchange membrane fuel cells have been widely studied and applied due to their pollution-free and high conversion rates. Generally, the voltage of fuel cell cells is usually less than 1V. In practical applications, hundreds of cells need to be connected in series to form a fuel cell stack, and matched with corresponding peripheral accessories to form a fuel cell system. [0003] Since the hydrogen-oxygen interface can lead to the attenuation of the fuel cell system, in order to avoid the hydrogen-oxygen interface phenomenon when starting up, it is necessary to continuously consume the oxygen infiltrated from the outside; and it is also necessary to ensure that there is a reducing environment inside the stack when the power is turned off. Oxygen in the fuel cell system may...

AI Technical Summary

Problems solved by technology

However, if the processing time is too long, too much hydrogen will be generated at the cathode, which may lead to excessive hydrogen concentration in the next exhaust; if the processing time is too short, there will be too much unconsumed oxygen, which will not achieve the consumption of oxygen and long-term static sealing the goal of

Moreover, with the increase of the stack usage time, the amount of hydrogen air leakage will continue to increase, which will accelerate the generation rate of hydrogen gas in the cathode during the above process, resulting in misjudgment of the parameter voltage or pressure when the oxygen consumption is stopped.

[0005] In addition, the patent application with the publication number CN109786788A discloses a fuel cell system, and its technical solution is to use the total voltage or air side pressure as the oxygen consumption process However, this technical solution cannot achieve the purpose of fully consuming oxygen and residual hydrogen, especially in the case of hydrogen air leakage, the judgment deviation of the stop processing time is relatively large

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