Freezing detection method for fuel cell
AssigneeCanon Kabushiki Kaisha
InventorsAkira Morita, Jun Yamamoto, Kazuyuki Ueda, Taihei Mukaide
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Abstract
In a method for detecting the freezing of water within a fuel cell, precise detection can be performed using a phenomenon specific to the time when water starts to freeze to allow a reduction in erroneous activation. Detection at an early stage after the start of freezing is allowed, and hence measures can be taken against an output reduction before the water within the fuel cell completely freezes.
Claims20
A freezing detection method for a fuel cell unit for detecting a start of freezing of water within the fuel cell unit, comprising:
- a first step of determining whether or not at least one of a time differential value of an output measurement value of the fuel cell unit and a secondary time differential value thereof is a positive predetermined value or more;
- and
- a second step of determining, when at least one of the time differential value of the output measurement value and the secondary time differential value thereof is the positive predetermined value in the first step, whether or not at least one of the time differential value of the output measurement value and the secondary time differential value thereof subsequently change to a negative value.
A freezing detection method for a fuel cell unit for detecting a start of freezing of water within the fuel cell unit, comprising:
- a first step of determining whether or not a cell resistance of the fuel cell unit decreases by an amount not less than a predetermined amount of change;
- and
- a second step of determining, when the cell resistance decreases by an amount not less than the predetermined amount of change in the first step, whether or not at least one of a time differential value of the cell resistance and the secondary time differential value thereof reaches a negative predetermined value.
A freezing detection method for a fuel cell unit for detecting a start of freezing of water within the fuel cell unit, comprising, determining whether or not a cell fastening pressure of the fuel cell unit increases by an amount not less than a predetermined amount of change.
Dependencies are inferred from the claim text.