Method and apparatus for locating internal transfer leaks within fuel cell stacks
AssigneeBallard Power Systems Inc.
InventorStephen John Pratt
Life of this patent
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Abstract
A method for locating an internal transfer leak in a fuel cell stack by applying a substantially constant gas pressure difference between a first fluid stream passage and a second fluid stream passage, wherein gas pressure in the second fluid stream passage is higher than gas pressure in the first fluid stream passage. A test gas is supplied to the second fluid stream passage and a test liquid is supplied to the first fluid stream passage. A parameter indicative of flow rate of the test gas exiting the first fluid stream passage is measured as the test liquid fills the first fluid stream passage. An apparatus for locating an internal transfer leak in a fuel cell stack is also provided.
Claims25
Method for locating an internal transfer leak between an oxidant stream passage and a fuel stream passage of a fuel cell stack, the method comprising:
- a) positioning the fuel cell stack so that water directed to the fuel stream passage fills channels of fuel flow field plates in successive individual fuel cell assemblies;
- b) directing air to the oxidant stream passage;
- c) maintaining gas pressure inside the oxidant stream passage at a substantially constant value greater than ambient atmospheric pressure;
- d) maintaining gas pressure inside the fuel stream passage substantially constant at ambient atmospheric pressure;
- e) directing water to the fuel stream passage;
- f) measuring flow rate of air exiting the fuel stream passage as the water fills the fuel stream passage;
- and
- g) ascertaining a water level position inside the fuel stream passage as the water fills the fuel stream passage.
A method for locating an internal transfer leak in a fuel cell stack, the method comprising:
- a) applying a substantially constant gas pressure difference between a first fluid stream passage and a second fluid stream passage, wherein gas pressure in the second fluid stream passage is higher than gas pressure in the first fluid stream passage;
- b) supplying a test gas to the second fluid stream passage;
- c) supplying a test liquid to the first fluid stream passage;
- and
- d) measuring a parameter indicative of flow rate of the test gas exiting the first fluid stream passage as the test liquid fills the first fluid stream passage.
An apparatus for locating an internal transfer leak in a fuel cell stack, comprising:
- a) a liquid supply system adapted to supply a test liquid to a first fluid stream passage;
- b) a gas supply system adapted to supply a test gas to a second fluid stream passage;
- and
- c) a measuring instrument adapted to measure a parameter indicative of flow rate of the test gas exiting the first fluid stream passage as the test liquid fills the first fluid stream passage.
Dependencies are inferred from the claim text.