Recirculating loop for fuel cell

Abstract

The invention relates to a recirculating loop (11R or 12Ra) for a gas circuit of a fuel cell (1a), which recirculating loop forms a connection duct beginning at the outlet of one of the two anode or cathode circuits of the fuel cell stack (1) and terminating on one of the two supply circuits, either on the fuel-gas supply duct (11A) or on the oxidant-gas supply duct (12A). The recirculating loop recirculates the gas contained in the anode or cathode circuits of the fuel cell, said recirculating loop comprising a pump (115 or 125) for recirculating said gas. The recirculating loop comprises a multi-way valve (119 or 129) that divides the loop into a first section (11R1 or 12R1) and a second section (11R2a or 12R2a), said multi-way valve having: a first stable operating position which establishes continuity between the first and second sections of the loop; and a second stable operating position which simultaneously interrupts the continuity between the first and second sections of the recirculating loop and brings said recirculating loop into contact with the atmosphere, by moving the multi-way valve.

Description

technical field [0001] The present invention relates to fuel cell stacks, more particularly, but not exclusively, to fuel cell stacks of the type having an electrolyte in the form of a polymer membrane (ie PEFC (Polymer Electrolyte Fuel Cell)). Background technique [0002] Fuel cell stacks are known to be able to generate electrical energy directly by electrochemical redox reactions starting from hydrogen (fuel) and oxygen (oxidant), without going through a mechanical energy conversion step. The technology seems promising, especially for motor vehicle applications. A fuel cell stack typically includes a series of individual parts, each consisting essentially of an anode and a cathode separated by a polymer membrane that enables the passage of ions from the anode to the cathode. In the case of a "dead end" line, that is, the line is not normally open at ambient conditions, which is usually the case for the anode circuit, and also for the cathode of a battery intended to ope...

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to succeed in providing a close control of gas recirculation and purge, or venting to atmosphere, both of which are necessary, regardless of the stage or state of operation during start-up or extinction. No additional pumps, which are relatively bulky and expensive pieces of equipment

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