Method for lowering peak concentration of exhaust hydrogen of fuel battery system

Abstract

The invention discloses a method for lowering peak concentration of exhaust hydrogen of a fuel battery system, which comprises steps as follows: air of the fuel battery system is continuously and stably discharged into a hydrogen slow release cavity through a cathode exhaust outlet by an air guide tube; hydrogen of the fuel battery system is discharged into a hydrogen slow release cavity through an anode exhaust outlet by a hydrogen guide tube, and is subjected to slow release by the air in the hydrogen slow release cavity; and after the hydrogen is discharged into a mixing cavity from the hydrogen slow release cavity by the slow release gas subjected to slow release, purging air from another way led out by the cathode exhaust outlet of the fuel battery system performs continuous and stable purging on the slow release gas to further lower the concentration of the hydrogen in the slow release gas, and the hydrogen is discharged from a discharge port of the mixing cavity. On the premise of not changing the fuel battery system, the anode exhaust hydrogen, which is discharged by pulses or discharged by combination of continuous discharge and pulse discharge, is buffered, diluted and subjected to purging mixing with cathode gas, thereby lowering the hydrogen to explosion limit below.

Description

technical field [0001] The present invention relates to the exhaust hydrogen technology of vehicle and non-vehicle fuel cell systems, more specifically, it relates to a method for reducing the hydrogen explosion limit of the peak hydrogen concentration in the tail exhaust of fuel cell systems for vehicles and non-vehicles, so as to meet the safety emission requirements Methods. Background technique [0002] As a clean and efficient energy conversion technology, fuel cells have attracted widespread attention in recent years. Among them, the most widely used proton exchange membrane fuel cell is referred to as PEMFC, which uses hydrogen as the anode fuel. The hydrogen utilization rate must generally be controlled within the range of 95%, and the rest is exhausted in the form of pure hydrogen or a mixture of hydrogen and water vapor. Lose. Hydrogen is a flammable and explosive gas, and its explosion limit in air is 4%-74.2%. The hydrogen-air mixture in this range may explode ...

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Problems solved by technology

However, the anode tail gas with pulse-changing discharge has a large hydrogen flow at the moment of pulse discharge. The air flow rationed to maintain the best working condition of the fuel cell is not enough to dilute the hydrogen below the explosion limit. Simply increase the cathode air volume to The method will affect the performance of the fuel cell and reduce the efficiency of the fuel cell system

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