Fuel cell system
First Claim
1. A fuel cell system comprising:
- a fuel cell having a membrane-electrode assembly in which both surfaces of an electrolyte membrane are sandwiched between a pair of catalyst layers, the fuel cell being supplied with reactant gas to generate electric power through an electrochemical reaction of the reactant gas;
an impedance calculation part is programmed to calculate a first impedance which is an impedance of the fuel cell in a first frequency range and which corresponds to resistance of the electrolyte membrane, and also calculates a second impedance which is an impedance of the fuel cell in a second frequency range which is lower than the first frequency range;
the second impedance corresponding to the sum of resistance of the electrolyte membrane and resistance of the catalyst layer; and
a water content calculation part is programmed to calculate a differential impedance which is a difference between the second impedance and the first impedance, and, by referring to a correlation between the differential impedance and water content of the catalyst layer, the correlation having been stored in a memory in advance, calculates the water content of the catalyst layer that corresponds to the calculated differential impedance.
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Accused Products
Abstract
The degree of dryness in a fuel cell can be judged more accurately. A system has: an impedance calculation part that calculates an impedance of a fuel cell, extracts from the calculated impedance a high-frequency impedance which is an impedance in a high frequency range and a low-frequency impedance which is an impedance in a low frequency range, and subtracts the high-frequency impedance from the low-frequency impedance to calculate a differential impedance; a water content calculation part that calculates the water content of an electrolyte membrane using the high-frequency impedance and calculates the water content of a catalyst layer using the differential impedance; and a water content control part that performs water content recovery processing to increase the water content of the catalyst layer if the water content of the catalyst layer is smaller than a predetermined water content.
4 Citations
4 Claims
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1. A fuel cell system comprising:
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a fuel cell having a membrane-electrode assembly in which both surfaces of an electrolyte membrane are sandwiched between a pair of catalyst layers, the fuel cell being supplied with reactant gas to generate electric power through an electrochemical reaction of the reactant gas; an impedance calculation part is programmed to calculate a first impedance which is an impedance of the fuel cell in a first frequency range and which corresponds to resistance of the electrolyte membrane, and also calculates a second impedance which is an impedance of the fuel cell in a second frequency range which is lower than the first frequency range;
the second impedance corresponding to the sum of resistance of the electrolyte membrane and resistance of the catalyst layer; anda water content calculation part is programmed to calculate a differential impedance which is a difference between the second impedance and the first impedance, and, by referring to a correlation between the differential impedance and water content of the catalyst layer, the correlation having been stored in a memory in advance, calculates the water content of the catalyst layer that corresponds to the calculated differential impedance. - View Dependent Claims (2, 3, 4)
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Specification