초록 ▼

A fuel cell module is provided having a fuel cell stack, a parasitic load connectable across the electrodes, and a reactant reservoir for storing an amount of a first reactant such as hydrogen. When the fuel cell module is shutdown, the stored amount of the first reactant can be drawn to react with

A fuel cell module is provided having a fuel cell stack, a parasitic load connectable across the electrodes, and a reactant reservoir for storing an amount of a first reactant such as hydrogen. When the fuel cell module is shutdown, the stored amount of the first reactant can be drawn to react with an amount of a second reactant (e.g., oxygen in air) remaining in the stack to electrochemically consume the first and second reactants, thereby leaving a mixture that substantially comprises a non-reactive agent (e.g., nitrogen), thereby passively blanketing the electrodes. The parasitic load limits the voltage of the fuel cell stack and induces the electrochemical consumption of the first and second reactants remaining in the stack during shutdown. A pressure gradient between the electrodes and an optional check valve may allow for movement of the non-reactive agent between electrodes. A process related to said fuel cell module is also provided.

대표청구항 ▼

I claim: 1. A fuel cell module, for use with hydrogen as a first reactant and air, including oxygen as a second reactant and nitrogen as a non-reactive agent, the fuel cell module comprising: a fuel cell stack including at least one fuel cell, each fuel cell including an anode electrode, a cathode

I claim: 1. A fuel cell module, for use with hydrogen as a first reactant and air, including oxygen as a second reactant and nitrogen as a non-reactive agent, the fuel cell module comprising: a fuel cell stack including at least one fuel cell, each fuel cell including an anode electrode, a cathode electrode and an electrolyte medium, comprising a proton exchange membrane, arranged between the anode electrode and the cathode electrode, wherein during normal operation the anode electrode is provided with the first reactant and the cathode electrode is provided with air; a parasitic load that is connectable across the anode and the cathode electrodes; and, a reactant reservoir, connectable to the anode electrode of each fuel cell, for storing an amount of the first reactant suitable for a shutdown process of the fuel cell module, whereby, in use when the fuel cell module is shutdown, the stored amount of the first reactant is drawn from the reactant reservoir and electrochemically reacts with an amount of the second reactant remaining in the fuel cell module, to electrochemically consume all of the amounts of the first and second reactants, thereby leaving a second mixture that substantially comprises the non-reactive agent wherein the fuel cell stack comprises: a cathode inlet port for supplying the first mixture to the cathode electrodes; a cathode outlet port for evacuating un-reacted amounts of the second reactant, amounts of the non-reactive agent and exhaust products from the cathode electrodes; an anode inlet port, fluidly connectable to the reactant reservoir, and for supplying the first reactant to the anode electrodes; and, an anode outlet port for evacuating un-reacted amounts of the first reactant and exhaust products from the anode electrodes; wherein the fuel cell module further comprises: a hydrogen supply port; an anode input valve, connectable between the hydrogen supply port and the reactant reservoir, for cutting-off a flow of hydrogen from the hydrogen supply port to the anode inlet port during the shutdown process; and a check valve connectable between the cathode inlet port and the anode inlet port; wherein the check valve opens at a predetermined pressure differential between an internal pressure in the cathode electrodes and an internal pressure in the anode electrodes, and remains closed when the internal pressures are approximately the same. 2. A process for shutting down a fuel cell, the fuel cell including a first electrode, a second electrode and an electrolyte membrane arranged between the first and second electrodes, wherein during normal operation the first electrode is provided with a first reactant and the second electrode is provided with a first mixture containing a second reactant and a non-reactive agent, the process comprising: stopping an inflow of the first reactant into the first electrode; cutting-off power to supporting elements of the fuel cell; drawing current through a parasitic load connectable across the first arid second electrodes; providing a pre-stored near stoichiometric amount of a first reactant for the electrochemical consumption of a remaining amount of a second reactant; and, permitting a delayed inflow of an amount of the first mixture into the second electrode; wherein the near stoichiometric amount of the first reactant electrochemically reacts with the remaining amount of the second reactant, thereby leaving a second mixture that substantially comprises the non-reactive agent. 3. A fuel cell module comprising: A fuel cell stack including at least one fuel cell, each fuel cell including an anode electrode and the cathode electrode, wherein during normal operation the anode electrode is provided with a first reactant and the cathode electrode is provided with a first mixture containing a second reactant and a non-reactive agent; a parasitic load that is connectable across the anode and the cathode electrodes; and, a reactant reservoir, connectable to the anode electrode, for storing an amount of the first reactant suitable for a shutdown process of the fuel cell module, whereby, in use when the fuel cell module is shutdown, the stored amount of the first reactant is drawn from the reactant reservoir and electrochemically reacts with an amount of the second reactant remaining in the fuel cell module, to electrochemically consume all of the amounts of the first and second reactants, thereby leaving a second mixture that substantially comprises the non-reactive agent, wherein the reactant reservoir is sized such that the amount of the first reactant stored in the reactant reservoir is less than enough to electrochemically consume the entire amount of the second reactant remaining in the fuel cell module during the shutdown process so as to deter other undesired reactions from occurring, and refillable during the shutdown process so that almost all of the remaining amount of the second reactant is electrochemically consumed by additional amounts of the first reactant added to the reactant reservoir during the shutdown process. 4. A fuel cell module according to claim 3, wherein the fuel cell stack comprises: a cathode inlet port for supplying the first mixture to the cathode electrodes; a cathode outlet port for evacuating un-reacted amounts of the second reactant, amounts of the non-reactive agent and exhaust products from the cathode electrodes; an anode inlet port, fluidly connectable to the reactant reservoir, and for supplying the first reactant to the anode electrodes; and, an anode outlet port for evacuating un-reacted amounts of the first reactant and exhaust products from the anode electrodes. 5. A fuel cell module according to claim 4, wherein the electrolyte medium is a Proton Exchange Membrane (PEM). 6. A fuel cell module according to claim 3, further comprising a flow control device connectable to the anode electrode for regulating a flow of the first reactant delivered to the anode electrode. 7. A fuel cell module according to claim 3, wherein the reactant reservoir is one of a vessel, a pressurized vessel and a length of tubing. 8. A fuel cell module according to claim 3, wherein the parasitic load includes at least one of internal resistances of the fuel cell module and an external resistance element. 9. A fuel cell module comprising: a fuel cell stack including at least one fuel cell, each fuel cell including an anode electrode, a cathode electrode and an electrolyte medium arranged between the anode electrode and the cathode electrode, wherein during normal operation the anode electrode is provided with a first reactant and the cathode electrode is provided with a first mixture containing a second reactant and a non-reactive agent; a parasitic load that is connectable across the anode and the cathode electrodes; and, a reactant reservoir, connectable to the anode electrode, for storing an amount of the first reactant suitable for a shutdown process of the fuel cell module, whereby, in use when the fuel cell module is shutdown, the stored amount of the first reactant is drawn from the reactant reservoir and electrochemically reacts with an amount of the second reactant remaining in the fuel cell module, to electrochemically consume all of the amounts of the first and second reactants, thereby leaving a second mixture that substantially comprises the non-reactive agent, wherein the reactant reservoir is sized such that a near stoichiometric amount of the first reactant stored in the reactant reservoir to electrochemically consume the amount of the second reactant remaining in the fuel cell module during the shutdown process so as to deter other undesired reactions from occurring and cause respective pressure drops within the fuel cell module as the remaining amounts of the first and second reactants are electrochemically consumed. 10. A fuel cell module according to claim 9, wherein the fuel cell stack comprises: a cathode inlet port for supplying the first mixture to the cathode electrodes; a cathode outlet port for evacuating un-reacted amounts of the second reactant, amounts of the non-reactive agent and exhaust products from the cathode electrodes; an anode inlet port, fluidly connectable to the reactant reservoir, and for supplying the first reactant to the anode electrodes; and, an anode outlet port for evacuating un-reacted amounts of the first reactant and exhaust products from the anode electrodes. 11. A fuel cell module according to claim 10, wherein the electrolyte medium is a Proton Exchange Membrane (PEM). 12. A fuel cell module according to claim 11, wherein the first reactant is hydrogen, the second reactant is oxygen carried in the air and the non-reactive agent is nitrogen carried in the air. 13. A fuel cell module according to claim 12, further comprising: a hydrogen supply port; and, an anode input valve, connectable between the hydrogen supply port and the reactant reservoir, for cuffing-off a flow of hydrogen from the hydrogen supply port to the anode inlet port during the shutdown process. 14. A fuel cell module according to claim 13, further comprising an anode output valve, connectable to the anode outlet port, for sealingly closing off the anode outlet port during the shutdown process. 15. A fuel cell module according to claim 13, further comprising a blower, connectable between the cathode inlet port and an air supply, for forcing air into the cathode electrodes during normal operation. 16. A fuel cell module according to claim 15, wherein the blower is further configured to passively deter, but does not completely stop, the free flow of air into the cathode electrodes during the shutdown process. 17. A fuel cell module according to claim 15, further comprising a cathode input valve, connectable between the blower and the cathode inlet port, for cutting-off a flow of air through the blower into the cathode input port. 18. A fuel cell module according to claim 17, further comprising a check valve, connectable between the cathode inlet port and the air supply, wherein the check valve opens at a predetermined pressure differential between an internal pressure in the cathode electrodes and an air supply pressure, and remains closed when the internal pressure and the air supply pressure are approximately the same. 19. A fuel cell module according to claim 15, further comprising a cathode output valve, connectable to the cathode outlet port, for sealingly closing-off the cathode outlet port during the shutdown process. 20. A fuel cell module according to claim 15, further comprising an exhaust port, connectable to the cathode outlet port, for deterring, but not completely stopping, a free flow of air into the cathode outlet port. 21. A fuel cell module according to claim 9, further comprising a flow control device connectable to the anode electrode for regulating a flow of the first reactant delivered to the anode electrode. 22. A fuel cell module according to claim 9, wherein the reactant reservoir is one of a vessel, a pressurized vessel and a length of tubing. 23. A fuel cell module according to claim 9, wherein the parasitic load includes at least one of internal resistances of the fuel cell module and an external resistance element. 24. A fuel cell module according to claim 11, wherein the first reactant is hydrogen, the second reactant is oxygen carried in the air and the non-reactive agent is nitrogen carried in the air, and wherein the fuel cell module includes: a hydrogen supply port; and, an anode input valve, connectable between the hydrogen supply port and the reactant reservoir, for cutting-off a flow of hydrogen from the hydrogen supply port to the anode inlet port during the shutdown process. 25. A fuel cell module according to claim 24, further comprising an anode output valve, connectable to the anode outlet port, for sealingly closing off the anode outlet port during the shutdown process, and a blower, connectable between the cathode inlet port and an air supply, for forcing air into the cathode electrodes during normal operation. 26. A fuel cell module according to claim 25, wherein the blower is further configured to passively deter, but does not completely stop, the free flow of air into the cathode electrodes during the shutdown process. 27. A fuel cell module according to claim 26, further comprising a cathode input valve, connectable between the blower and the cathode inlet port, for cutting-off a flow of air through the blower into the cathode input port. 28. A fuel cell module according to claim 27, further comprising a check valve, connectable between the cathode inlet port and the air supply, wherein the check valve opens at a predetermined pressure differential between an internal pressure in the cathode electrodes and an air supply pressure, and remains closed when the internal pressure and the air supply pressure are approximately the same. 29. A fuel cell module according to claim 25, further comprising a cathode output valve, connectable to the cathode outlet port, for sealingly closing-off the cathode outlet port during the shutdown process. 30. A fuel cell module according to claim 24, further comprising: a hydrogen supply port; an anode input valve, connectable between the hydrogen supply port and the reactant reservoir, for cutting-off a flow of hydrogen from the hydrogen supply port to the anode inlet port during the shutdown process; and a check valve connectable between the cathode inlet port and the anode inlet port; wherein the check valve opens at a predetermined pressure differential between an internal pressure in the cathode electrodes and an internal pressure in the anode electrodes, and remains closed when the internal pressures are approximately the same. 31. A fuel cell module according to claim 25, further comprising an exhaust port, connectable to the cathode outlet port, for deterring, but not completely stopping, a free flow of air into the cathode outlet port.