Cathode exhaust recirculating system for proton exchange membrane fuel cell

Abstract

An air system for a proton exchange membrane fuel cell belongs to the technical field of new energy automobiles, and is characterized in that an exhaust recirculating loop is used to lead the gas exhausted from a cathode outlet of a galvanic pile into an inlet loop of the galvanic pile again. According to the invention, the total flow, total pressure and oxygen flow entering into the galvanic pile can be adjusted independently, and the water logging or membrane drying of the galvanic pile can be effectively avoided while the monolithic voltage of the galvanic pile is limited; during the shutdown period, liquid water inside the galvanic pile can be dried quickly, so as to prevent the galvanic pile from being damaged caused by freezing of water residual inside the galvanic pile under the condition of low temperature; during the shutdown period, the whole pipeline can be filled with nitrogen, so as to prevent oxygen from entering into the anode to corrode the galvanic pile with long-term shutdown; and the fresh air amount entering into the system is reduced, and the load of the mechanical and chemical filter is reduced. The measures can effectively improve the service life and the durability of the fuel cell, and meanwhile, as the radiating and humidifying by-pass governing is led in, the machine warming speed of the galvanic pile under the condition of low temperature can be increased.

Description

technical field [0001] The invention relates to an air system of a proton exchange membrane fuel cell, in particular to an air system of an advanced proton exchange membrane fuel cell which introduces cathode exhaust gas recirculation technology, and belongs to the technical field of new energy vehicles. Background technique [0002] Proton Exchange Membrane Fuel Cell (PEMFC for short) is particularly favored by people for its advantages of high efficiency and zero emission. The fuel cell power generation system is an electrochemical device that directly converts chemical energy into electrical energy. The energy conversion process is not limited by the Carnot cycle, and the theoretical efficiency is relatively high. The fuel it consumes is hydrogen, the reaction product is water, and the harmful emissions are zero. It is one of the cleanest energy sources. Therefore, the fuel cell power generation system can be used in fields such as backup power stations, electric vehicle...

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Problems solved by technology

[0009] as attached figure 1 Another disadvantage of the air system shown is that, in order to ensure the functions such as stack drainage, more air from the atmosphere needs to enter the stack. Due to the presence of impurities such as particles and sulfur in the atmosphere, these impurities will accelerate the attenuation of the stack; therefore Special mechanical and chemical filters are required to filter out these impurities; increased air flow means increased volume and cost of mechanical and chemical filters, or accelerated decay of their effective life

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