Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
165 words
A fuel cell system comprising: a fuel cell stack including an anode and a cathode; means for supplying a hydrogen-containing fuel to said anode; means for supplying an oxygen-containing oxidant to said cathode in an amount in excess of the stoichiometric amount relative to said fuel; means for conducting reaction products including excess oxidant and water vapor from said cathode; means for cooling and flowing said products through a flow constriction, said cooling and flow means including a liquid coolant injector; means disposed downstream of said flow constriction for separating said coolant, oxidant and water into a vaporous portion having a large oxidant and small coolant and water content and a liquid portion having a large coolant and water content and a small oxidant content, said separating means including an outlet for said vapor portion; and a conduit interconnecting said outlet and said cathode; said cooling and flow means providing sufficient pressure head to flow said vaporous portion through said interconnecting conduit to said cathode.
Claim 2
Dependent Claim
165 words
A fuel cell system comprising: a fuel cell stack including an anode and a cathode; means for supplying a hydrogen-containing fuel to said anode; means for supplying an oxygen-containing oxidant to said cathode in an amount in excess of the stoichiometric amount relative to said fuel; means for conducting reaction products including excess oxidant and water vapor from said cathode; means for cooling and flowing said products through a flow constriction, said cooling and flow means including a liquid coolant injector; means disposed downstream of said flow constriction for separating said coolant, oxidant and water into a vaporous portion having a large oxidant and small coolant and water content and a liquid portion having a large coolant and water content and a small oxidant content, said separating means including an outlet for said vapor portion; and a conduit interconnecting said outlet and said cathode; said cooling and flow means providing sufficient pressure head to flow said vaporous portion through said interconnecting conduit to said cathode.
Claim 3
Dependent Claim
13 words
The system of claim 1 wherein said oxidant supply means comprises a compressor.
Claim 4
Dependent Claim
33 words
The system of claim 2 further comprising means for controlling pressure within said system, said means including a vent disposed downstream of said cathode space and upstream of said cooling and flow means.
Claim 5
Dependent Claim
164 words
A fuel cell system comprising: a fuel cell stack including an anode and a cathode; means for supplying a hydrogen-containing fuel adjacent said anode; means for supplying an oxygen-containing oxidant adjacent said cathode in an amount in excess of the stoichiometric amount relative to said fuel; means for conducting reaction products including excess oxidant and water vapor from said cathode; means for cooling and flowing said products through a flow constriction, said cooling and flow means including a liquid coolant injector; means disposed downstream of said flow constriction for separating said coolant, oxidant and water into a vaporous portion and a liquid portion, said separating means including an outlet for said vapor portion; and a conduit interconnecting said outlet and said cathode; said cooling and flow means providing sufficient pressure head to flow said vaporous portion through said interconnecting conduit, adjacent said cathode, and back to said flow constriction; and means for conducting said liquid portion through a heat exchanger and to said injector.
Claim 6
Dependent Claim
164 words
A fuel cell system comprising: a fuel cell stack including an anode and a cathode; means for supplying a hydrogen-containing fuel adjacent said anode; means for supplying an oxygen-containing oxidant adjacent said cathode in an amount in excess of the stoichiometric amount relative to said fuel; means for conducting reaction products including excess oxidant and water vapor from said cathode; means for cooling and flowing said products through a flow constriction, said cooling and flow means including a liquid coolant injector; means disposed downstream of said flow constriction for separating said coolant, oxidant and water into a vaporous portion and a liquid portion, said separating means including an outlet for said vapor portion; and a conduit interconnecting said outlet and said cathode; said cooling and flow means providing sufficient pressure head to flow said vaporous portion through said interconnecting conduit, adjacent said cathode, and back to said flow constriction; and means for conducting said liquid portion through a heat exchanger and to said injector.
Claim 7
Independent Claim
137 words
A method of operating a fuel cell system including a fuel cell stack having an anode and a cathode, comprising: supplying a hydrogen-containing fuel to said anode; supplying an oxygen-containing oxidant to said cathode in an amount in excess of the stoichiometric amount relative to said fuel; conducting reaction products including excess oxidant and water from said cathode; injecting a liquid coolant through a flow constriction in fluid communication with said reaction products whereby said coolant and reaction products are mixed, flow through said constriction, and said reaction products are cooled; separating said mixed reaction products and coolant into a vaporous portion and a liquid portion; and conducting said vaporous portion to said cathode; said step of flowing said products through a flow constriction including providing sufficient pressure head to flow said vaporous portion to said cathode.
Claim 8
Independent Claim
137 words
A method of operating a fuel cell system including a fuel cell stack having an anode and a cathode, comprising: supplying a hydrogen-containing fuel to said anode; supplying an oxygen-containing oxidant to said cathode in an amount in excess of the stoichiometric amount relative to said fuel; conducting reaction products including excess oxidant and water from said cathode; injecting a liquid coolant through a flow constriction in fluid communication with said reaction products whereby said coolant and reaction products are mixed, flow through said constriction, and said reaction products are cooled; separating said mixed reaction products and coolant into a vaporous portion and a liquid portion; and conducting said vaporous portion to said cathode; said step of flowing said products through a flow constriction including providing sufficient pressure head to flow said vaporous portion to said cathode.
Claim 9
Dependent Claim
21 words
The method of claim 5 further comprising cooling said liquid portion and injecting said cooled liquid portion through said flow constriction.
Claim 10
Dependent Claim
22 words
The method of claim 5 wherein said injecting step comprises injecting a liquid coolant as a fine spray through said flow constriction.
Claim 11
Dependent Claim
43 words
The method of claim 7 further comprising flowing fresh oxidant into said system in an amount such that the ratio of the mass flow of reaction products recirculating through said system to the mass flow of fresh oxidant is approximately thirty to one.
Claim 12
Dependent Claim
22 words
The method of claim 5 further comprising venting a portion of said reaction products from said system prior to said injecting step.