Anode gas purification control method for proton exchange membrane fuel cell

Abstract

The invention discloses an anode gas purification control method for a proton exchange membrane fuel cell. The method comprises the steps of constructing an anode water management structure, and controlling the anode water management structure to work by utilizing an anode nitrogen concentration observer; controlling the hydrogen flow through a hydrogen circulating pump to take away liquid water contained in gas in a fuel cell stack and remove the liquid water through a second water-vapor separator, and removing the liquid water condensed and separated from gas through a first water-vapor separator; adopting an anode nitrogen concentration observer to process to obtain a nitrogen concentration observation value, using a purification duration process model to obtain purification duration time, when the nitrogen concentration observation value reaches a nitrogen concentration threshold value, opening a purification valve, and discharging nitrogen; and closing the purification valve afterthe purification duration, and entering the next period. The optimization problem of the gas purification process of an anode loop of a proton exchange membrane fuel cell engine system is solved, andthe hydrogen utilization rate of the fuel cell system can be greatly improved on the basis of ensuring the service life of an electric pile.

Description

technical field [0001] The invention belongs to a fuel cell treatment control method in the field of fuel cell application, and in particular relates to a method for purifying anode gas of a proton exchange membrane fuel cell based on online observation of nitrogen concentration. Background technique [0002] In order to improve the hydrogen utilization rate of the proton exchange membrane fuel cell system, the anode system works in dead-end mode. However, with the operation of the fuel cell system in this working mode, the nitrogen in the cathode and the liquid water produced will permeate through the anode through transmembrane transport. On the other hand, too much nitrogen will reduce the partial pressure of anode hydrogen and affect the overall performance of the stack. Therefore, periodic purification treatment is required to discharge excess water and hydrogen from the anode. [0003] At present, the purge trigger method adopted by the engine system is time-based, a...

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Problems solved by technology

However, under this technical solution, on the one hand, water flooding and nitrogen concentration will be excluded during the calibration process. In many cases, the purification will be turned on even when the nitrogen concentration is very low for drainage, resulting in unnecessary waste of hydrogen; on the other hand On the one hand, when the current output of the stack changes, it will lead to problems such as difficult selection of purification time

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