US 7,442,452 B2 · Fuel cell system and gas leak detection method

Abstract

When a command for stopping electric generation by a fuel cell is issued, shutoff valves are closed (at time t1), and then a time-dependent change in pressure (P) in a closed passage area including the fuel cell is detected. A pressure change speed (dP1, i.e., an inclination of L1) when the pressure (P) is in a first pressure range (Ra) in the vicinity of atmospheric pressure and a pressure change speed (dP2, i.e., an inclination of L2) when the pressure (P) is in a second pressure range (Rb) that is on a high pressure side of the first pressure range (Ra) are detected, and both the pressure change speeds (dP1, dP2) are compared with each other. When a difference between both the pressure change speeds (dP1, dP2) is equal to or larger than a predetermined value (Pc), it is determined that there is a hole in an electrolyte membrane of the fuel cell.

Claims20

Dependent claims

A fuel cell system which includes a fuel cell;

a supply passage that supplies hydrogen gas to the fuel cell;
a discharge passage that discharges the hydrogen gas from the fuel cell;
at least one valve element which is located in a predetermined portion in at least one of the supply passage and the discharge passage, and which closes off a hydrogen passage in the fuel cell;
and control means for performing control that closes the at least one valve element, the fuel cell system comprising:
pressure detection means for detecting pressure in the hydrogen passage;
and
leak determination means for performing analysis of a change in the pressure detected by the pressure detection means when the at least one valve element is closed by the control means, and determining whether there is a leak of the hydrogen gas based on a result of the analysis.

4 more elements

A gas leak detection method for detecting a hydrogen gas leak in a fuel cell system which includes a fuel cell;

a supply passage that supplies hydrogen gas to the fuel cell;
a discharge passage that discharges the hydrogen gas from the fuel cell;
and at least one valve element which is located in a predetermined portion in at least one of the supply passage and the discharge passage, and which closes off a hydrogen passage in the fuel cell, the method comprising the steps of:
(a) closing the at least one valve element;
(b) detecting pressure in the hydrogen passage in the fuel cell;
and
(c) performing analysis of a change in the pressure detected in the step (b) when the at least one valve element is closed in the step (a), and determining whether there is a leak of the hydrogen gas based on a result of the analysis.

4 more elements

Dependencies are inferred from the claim text.

Fuel cell system and gas leak detection method

Life of this patent

Fuel cell system and gas leak detection method

Life of this patent

Abstract

Claims20