Intermittent cooling of fuel cell
AssigneeGeneral Motors Corporation
InventorMartin Monroe Hoch
Life of this patent
Estimating the term…
Abstract
Process for improving the efficiency of a fuel cell system having a liquid coolant and a pump circulating the coolant through the fuel cell and a heat exchanger that extracts heat from the coolant. Improved efficiency is achieved by intermittently shutting off the pump when the fuel cell is operating at less than 25% of its “full power” design point.
Claims10
A process for improving the efficiency of a fuel cell system that includes a fuel cell having an anode and a cathode and is designed for full power operation at a certain current density, a liquid coolant flowing through said fuel cell, a heat exchanger for extracting heat from said coolant, and a pump energized by said fuel cell for pumping said coolant between said fuel cell and said heat exchanger, said process comprising the steps of:
- supplying fuel to said anode;
- supplying oxidant to said cathode;
- drawing current from said fuel cell at a current density less then 25% of said full power current density;
- while drawing said current, discontinuing said pumping for an interval of time;
- allowing the temperature of said fuel cell to rise during said interval to a temperature that does not degrade the performance of said fuel cell;
- and starting said pumping at the end of said interval;
- whereby the efficiency of said system is increased by eliminating the parasitic load of said pump on said system during said interval.
A process for improving the efficiency of a fuel cell system including a PEM fuel cell having an anode and a cathode and is designed for full power operation at a certain current density, a liquid coolant flowing through said fuel cell, a heat exchanger for extracting heat from said coolant, and a pump energized by said fuel cell for pumping said coolant between said fuel cell and said heat exchanger, said process comprising the steps of:
- supplying fuel to said anode;
- supplying oxidant to said cathode;
- drawing current from said fuel cell at a current density less then about 0.2 A/cm2;
- while drawing said current, discontinuing said pumping for an interval of time;
- allowing the temperature of said fuel cell to rise during said interval;
- to a temperature that does not degrade the performance of said fuel cell;
- and starting said pumping at the end of said interval;
- whereby the efficiency of said system is increased by eliminating the parasitic load of said pump on said system during said interval.
A process for improving the efficiency of a fuel cell system that includes a fuel cell having an anode and a cathode and is designed for full power operation at a certain current density, a liquid coolant flowing through said fuel cell, a heat exchanger for extracting heat from said coolant, a motor-driven fan energized by said fuel cell for blowing air through said heat exchanger, and a pump energized by said fuel cell for pumping said coolant between said fuel cell and said heat exchanger, said process comprising the steps of:
- supplying fuel to said anode;
- supplying oxidant to said cathode;
- drawing current from said fuel cell at a current density less then 25% of said full power current density;
- while drawing said current, shutting off said pump and said motor-driven fan for an interval of time;
- allowing the temperature of said fuel cell to rise during said interval to a temperature that does not degrade the performance of said fuel cell;
- and starting said pumping at the end of said interval;
- whereby the efficiency of said system is increased by eliminating the parasitic load of said pump and said fan on said system during said interval.
Dependencies are inferred from the claim text.