Electrochemical load management system for transportation applications
First Claim
1. A fuel cell power system for a vehicle comprising a fuel cell stack designed to operate using hydrogen gas as fuel and air as the oxidant during periods of normal power output, the system comprising the fuel cell stack;
- means for providing hydrogen under pressure to the fuel cell; and
air means for supplying pressurized air as an oxidant gas for the fuel cell stack;
wherein the improvement comprises;
the fuel cell stack being designed to operate at a pressure of not more than about 30 psig above atmospheric pressure, and at a temperature below the boiling point of water at ambient pressure, and further comprising elevated pressure oxygen storage means to store substantially pure oxygen under elevated pressure;
valve means in fluid flow connection between the oxygen storage means and the air means, and means responsive to an amperage output from the fuel cell stack above a set level, for opening the valve so as to add pure oxygen to the supply of pressurized air fed to the fuel cell stack, to enrich the air fed to the fuel cell stack to contain at least 30% but not more than 60% oxygen by volume during periods when the amperage output is above a set level.
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Accused Products
Abstract
A load management system for hydrogen-oxygen fuel cells is provided, for powering vehicles. The load management system operates such that under normal load conditions air is provided as the oxidizing agent for the hydrogen fuel. At high output conditions the air supply is enriched with additional oxygen. The system comprises means responsive to the amperage output from the fuel cell stack to activate valve means for the addition of pure oxygen into the air inlet line. There is also provided means for electrolyzing water to produce pure hydrogen and pure oxygen gas, which may be recyclable to the fuel cell.
136 Citations
19 Claims
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1. A fuel cell power system for a vehicle comprising a fuel cell stack designed to operate using hydrogen gas as fuel and air as the oxidant during periods of normal power output, the system comprising the fuel cell stack;
- means for providing hydrogen under pressure to the fuel cell; and
air means for supplying pressurized air as an oxidant gas for the fuel cell stack;
wherein the improvement comprises;
the fuel cell stack being designed to operate at a pressure of not more than about 30 psig above atmospheric pressure, and at a temperature below the boiling point of water at ambient pressure, and further comprising elevated pressure oxygen storage means to store substantially pure oxygen under elevated pressure;
valve means in fluid flow connection between the oxygen storage means and the air means, and means responsive to an amperage output from the fuel cell stack above a set level, for opening the valve so as to add pure oxygen to the supply of pressurized air fed to the fuel cell stack, to enrich the air fed to the fuel cell stack to contain at least 30% but not more than 60% oxygen by volume during periods when the amperage output is above a set level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- means for providing hydrogen under pressure to the fuel cell; and
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14. The fuel cell power system for a vehicle comprising a fuel cell stack which is operated by hydrogen gas fuel and air during normal power intervals and oxygen enriched air to contain at least 30% but not more than 60% oxygen by volume during peak power intervals, a fuel cell stack having a plurality of cells, each cell comprising an anode and a cathode separated by an ion-exchange membrane;
- means for providing hydrogen under pressure to the fuel cell stack;
means for supplying air under pressure as an oxidant gas for the fuel cell stack;
the fuel cell stack is designed to operate at an increased pressure of not more than about 30 psig and at a temperature below the boiling point of water at ambient pressure; and
an electrolyzer for electrolyzing water to produce hydrogen and oxygen;
means to supply an electrolysis current to the electrolyzer;
conduit means to carry the oxygen from the electrolyzer to the elevated pressure storage means;
a water reservoir in fluid flow connection between the fuel cell stack and the electrolyzer; and
a pressure pump for pressurizing water from the reservoir and feeding the pressurized water to the electrolizer at a pressure greater than that in the oxygen storage means. - View Dependent Claims (15)
- means for providing hydrogen under pressure to the fuel cell stack;
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16. In a process for galvanically generating electricity, the process comprising separately passing hydrogen gas and air through a stack of ion-exchange membrane fuel cells, to generate electrical current and by-product water, and removing the by-product water;
- wherein the improvement comprises feeding the air and hydrogen gas to the fuel cell stack at a pressure of not greater than about 30 psig and at a temperature below the ambient boiling point of water, and further providing pure oxygen gas which is admixed with the air fed to the fuel cell stack so that oxygen enriched air is fed to the fuel cell stack when the amperage output from the fuel cell stack is above a set level, wherein the proportion of oxygen in the oxygen enriched air is not greater than about 60% but not less than about 30% by volume.
- View Dependent Claims (17, 18, 19)
Specification