A fuel cell system and shutdown control method thereof

Abstract

The invention provides a fuel cell system and a shutdown control method thereof. The fuel cell system includes: an electric pile, the negative electrode of the electric pile is communicated with one end of an air transportation pipeline, and an air outlet of the electric pile is communicated with one end of an air discharge pipeline. The system is characterized in that it also includes a first air valve disposed on the air transportation pipeline and a second air valve arranged on the air discharge pipeline; an A end of a hydrogen air pressure balancing tank is communicated with the air outlet of the electric pile in the fuel cell system, a B end of the hydrogen air pressure balancing tank is communicated with a hydrogen outlet of the electric pile in the fuel cell system. In the hydrogen air pressure balancing tank, the A end and the B end are sealed and separated by a movable baffle. A discharge resistor is connected between a positive electrode and a negative electrode of the electric pile in series. The fuel cell system can solve the problem that after shutdown of a fuel cell, a hydrogen air interface can appear on the electrode after hydrogen-oxygen mixing occurs at the negative electrode or positive electrode, thus ensuring the electric pile performance, and prolonging the service life of the fuel cell.

Description

technical field [0001] The invention relates to a vehicle-mounted fuel cell technology, in particular to a fuel cell system and a shutdown control method. Background technique [0002] The vehicle fuel cell system includes: hydrogen pipes and air pipes respectively connected to the electric stack, and the hydrogen and air entering the electric stack react in the electric stack to provide energy. However, after the vehicle fuel cell is shut down, the hydrogen side pressure in the stack is usually greater than the air side pressure. Trace amounts of hydrogen gas can be detected in the air-side cavity of the stack due to the seepage effect. For this reason, the trace amount of hydrogen in the air-side cavity reacts with the oxygen in the air in the cavity on the surface of the stack catalyst, resulting in the loss of catalyst carrier carbon in the stack, resulting in the accumulation of catalyst in the stack and the decrease of specific surface area. Ultimately, the performan...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the defects in the prior art, the present invention provides a fuel cell system and shutdown control method, which can solve the problem of hydrogen leaking from the stack to the air side cavity after the fuel cell shutdown, thereby ensuring the performance of the stack and prolonging the Fuel Cell Lifespan

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