FUEL CELL ANODE PURGE SYSTEMS AND METHODS
First Claim
1. A method of purging liquid from an anode flow field of at least one of one or more fuel cells, each of the one or more fuel cells having an anode region and a cathode region, the method comprising:
- electrically coupling each of the one or more fuel cells to an energy consuming device that applies an applied load to the one or more fuel cells;
delivering a fuel stream to the anode region, and an oxidant stream to the cathode region, of each of the one or more fuel cells, whereby a purge stream is emitted from the anode region of each of the one or more fuel cells, and the one or more fuel cells generate an electrical output that satisfies at least a portion of the applied load; and
electrically isolating at least one of the one or more fuel cells from the applied load for a temporary period of time without substantially altering the flow rate of the fuel stream delivered to the anode region of each isolated fuel cell, wherein the period of time is sufficient to cause the flow rate of the purge stream emitted from the anode region of each isolated fuel cell to increase in magnitude to expel from the anode region of each isolated fuel cell a substantial portion of any liquid that has collected in the anode flow field of each isolated fuel cell.
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Accused Products
Abstract
Systems and methods of purging liquid from an anode flow field of a fuel cell having an anode region and a cathode region. A fuel cell is electrically coupled to an energy consuming device that applies a load to the fuel cell. A fuel stream is delivered to the anode region, and an oxidant stream to the cathode region, thereby causing an anode purge stream to be emitted from the anode region, and causing the fuel cell to generate an electrical output that satisfies at least a portion of the electrical load. The fuel cell is then electrically isolated from the applied load for a temporary period of time without substantially altering the flow rate of the fuel stream delivered to the anode region. The period of time is sufficient to cause the flow rate of the purge stream emitted from the anode region to increase in magnitude to expel from the anode region a substantial portion of any liquid that has collected in the anode flow field.
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Citations
30 Claims
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1. A method of purging liquid from an anode flow field of at least one of one or more fuel cells, each of the one or more fuel cells having an anode region and a cathode region, the method comprising:
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electrically coupling each of the one or more fuel cells to an energy consuming device that applies an applied load to the one or more fuel cells; delivering a fuel stream to the anode region, and an oxidant stream to the cathode region, of each of the one or more fuel cells, whereby a purge stream is emitted from the anode region of each of the one or more fuel cells, and the one or more fuel cells generate an electrical output that satisfies at least a portion of the applied load; and electrically isolating at least one of the one or more fuel cells from the applied load for a temporary period of time without substantially altering the flow rate of the fuel stream delivered to the anode region of each isolated fuel cell, wherein the period of time is sufficient to cause the flow rate of the purge stream emitted from the anode region of each isolated fuel cell to increase in magnitude to expel from the anode region of each isolated fuel cell a substantial portion of any liquid that has collected in the anode flow field of each isolated fuel cell. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A fuel cell system, comprising:
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a fuel cell configured to consume a fuel and an oxidant to generate an electrical output when an applied load is applied to the fuel cell by an energy consuming device, the fuel cell comprising an anode region including an anode inlet configured to receive a fuel stream into the anode region, an anode flow field configured to transport fuel through portions of the anode region, and an anode outlet configured to emit a purge stream from the anode region, the fuel cell being configured for use in at least; a non-isolated state, wherein the load is applied to the fuel cell, and the fuel stream is delivered to the anode inlet at a selected flow rate, and whereby the purge stream is emitted from the anode outlet on at least one of an intermittent and a periodic basis; and an isolated state, wherein the fuel cell is isolated from the applied load, and the fuel stream is delivered to the anode inlet flow at a rate that is at least substantially the same as the selected flow rate, and whereby the purge stream is emitted from the anode outlet on at least one of an intermittent and a periodic basis; and a controller configured to change the configuration of the fuel cell from the non-isolated state to the isolated state for a momentary period of time and then return the fuel cell to the non-isolated state, whereby the period of time is sufficient to cause the flow rate of the purge stream to increase in magnitude to expel, through the anode outlet, a substantial portion of any liquid that has collected in the anode flow field. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A fuel cell system, comprising:
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a fuel cell configured to consume a fuel and an oxidant to generate an electrical output when an applied load is applied to the fuel cell by an energy consuming device, the fuel cell comprising an anode region including an anode inlet configured to receive a fuel stream into the anode region, an anode flow field configured to transport fuel through portions of the anode region, and an anode outlet configured to emit a purge stream from the anode region; and means for expelling liquid from the anode region by periodically isolating the fuel cell from the applied load for a momentary period of time while continuing to deliver fuel to the anode inlet, wherein the momentary period of time is sufficient to cause an increase in the flow rate of the purge stream to expel accumulated liquid from the anode flow field through the anode outlet. - View Dependent Claims (30)
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Specification