Fuel dissipater for pressurized fuel cell generators
AssigneeSiemens Westinghouse Power Corporation
InventorsRichard A. Basel, John E. King
Life of this patent
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Abstract
An apparatus and method are disclosed for eliminating the chemical energy of fuel remaining in a pressurized fuel cell generator (10) when the electrical power output of the fuel cell generator is terminated during transient operation, such as a shutdown; where, two electrically resistive elements (two of 28, 53, 54, 55) at least one of which is connected in parallel, in association with contactors (26, 57, 58, 59), a multi-point settable sensor relay (23) and a circuit breaker (24), are automatically connected across the fuel cell generator terminals (21, 22) at two or more contact points, in order to draw current, thereby depleting the fuel inventory in the generator.
Claims16
A fuel cell generator comprising:
- solid oxide electrolyte fuel cell stacks acting on pressurized hydrogen and carbon monoxide-containing fuel and pressurized oxygen-containing oxidant to provide electrical energy, in which the stacks have positive and negative terminals;
- a stack energy dissipater which operates on amplitude proportioning of a resistance load, comprising an electrical resistance load, said electrical resistance load comprising an array of at least two cooled, electrically connected resistors controlled by a voltage-sensitive multi-settable point relay, where individual switching contactors allowing for variable resistance loads are disposed between the array and a circuit breaker;
- and
- where the circuit breaker is in electrical contact with the positive terminal and each of the resistors in the array is in electrical contact with the negative terminal, so that the energy dissipater can draw current, in order to consume hydrogen and carbon monoxide-containing fuel stored within the generator during a shutdown.
A method of dissipating energy during shutdown of a pressurized fuel cell generator comprising:
- converting pressurized hydrogen and carbon monoxide-containing fuel and pressurized oxygen-containing oxidant to electrical energy in a fuel cell generator;
- shutting down the fuel cell generator;
- drawing current from the fuel cell generator after the generator shuts down utilizing a stack energy dissipater containing at least three resistors having a resistance load, thereby to consume at least a portion of the hydrogen and carbon monoxide containing fuel remaining in the generator and to convert the fuel to oxidized products thereby to substantially prevent overheating of the generator, utilizing an array of the at least three resistors to amplitude proportion a resistance load in the stack energy dissipater;
- and
- wherein the fuel cell generator contains solid oxide electrolyte fuel cell stacks having positive and negative terminals, where the stack energy dissipater which operates on amplitude proportioning of a resistance load is effective to draw current from the fuel cell generator after shutdown by means of the array of at least three resistors controlled by a voltage-sensitive multi-settable point relay where individual switching contactors allowing for variable resistance loads are disposed between the array and a circuit breaker, and where the fuel and the oxidant are pressurized to between 151.6 kPa and 1013 kPA.
Dependencies are inferred from the claim text.