# US 8,771,884 B1 · Reactant conditioning scheme for fuel cell systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,884 B1 - Document ID: US8771884B1 - Status: Granted - Kind: B1 - Application number: 13/724,146 - Filed: 2012-12-21 - Granted: 2014-07-08 - Earliest claimed: 2011-12-21 - Assignees: Plug Power Inc. - Applicants: Plug Power Inc. - Inventors: Michael Cacioppo; Ranjieve A. Williams; Charles R. Elder - Web page: https://patentgrep.com/patent/US8771884B1 ## CPC - H01M 8/04007: related to heat exchange - H01M 8/04097: {with recycling of the reactants (H01M8/04119, H01M8/04104 take precedence)} - H01M 8/04134: {by coolants} - H01M 2250/20: Fuel cells in motive systems, e.g. vehicle, ship, plane - Y02E 60/50: Fuel cells - Y02T 90/40: Application of hydrogen technology to transportation, e.g. using fuel cells - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A fuel cell system includes a fuel cell stack and a reactant temperature conditioner. The conditioner includes a fuel inlet for receiving fuel from a fuel source and an oxidant inlet for receiving oxidant from an oxidant source. The conditioner is configured to transfer heat energy from the oxidant to the fuel to arrive at a conditioned oxidant and a conditioned fuel. The conditioner has a fuel outlet coupled to the fuel cell stack to allow flow of the conditioned fuel to the fuel cell stack and an oxidant outlet to allow flow of the conditioned oxidant to the fuel cell stack. ## Claims ### Claim 1 A fuel cell system comprising: a fuel cell stack; a reactant temperature conditioner coupled to a fuel source and an oxidant source, said conditioner having a fuel inlet for receiving fuel from the fuel source and an oxidant inlet for receiving oxidant from the oxidant source, said conditioner configured to transfer heat energy from the oxidant to the fuel to arrive at a conditioned oxidant and a conditioned fuel; said conditioner having a fuel outlet coupled to said fuel cell stack to allow flow of the conditioned fuel to said fuel cell stack and an oxidant outlet to allow flow of the conditioned oxidant to said fuel cell stack. ### Claim 2 (depends on 1) The system of claim 1 wherein said conditioner comprises a heat exchanger to transfer the heat energy from the oxidant to the fuel to arrive at the conditioned oxidant and the conditioned fuel. ### Claim 3 (depends on 2) The system of claim 2 further comprising a coolant source coupled to said fuel cell stack, said fuel cell stack comprising a coolant outlet coupled to said conditioner to allow flow of exhaust coolant from said fuel cell stack to said conditioner to allow a transfer of heat energy to the fuel from the coolant. ### Claim 4 (depends on 1) The system of claim 1 further comprising an oxidant humidifier connected to said conditioner and said fuel cell stack to control a humidity of the conditioned oxidant prior to the conditioned oxidant flowing to said fuel cell stack. ### Claim 5 (depends on 4) The system of claim 4 further comprising a coolant source coupled to said fuel cell stack, said fuel cell stack comprising a coolant outlet coupled to said humidifier to allow flow of exhaust coolant from said fuel cell stack to said humidifier. ### Claim 6 (depends on 5) The system of claim 5 wherein said conditioner is coupled to said humidifier to allow flow of the exhaust coolant to said conditioner. ### Claim 7 (depends on 1) The system of claim 1 wherein said fuel cell stack is electrically coupled to a load device to provide electrical energy to said load device. ### Claim 8 (depends on 7) The system of claim 7 wherein said load device comprises an industrial electric vehicle. ### Claim 9 (depends on 1) The system of claim 1 wherein said fuel cell stack comprises a fuel inlet, a fuel outlet, an oxidant inlet and an oxidant outlet. ### Claim 10 (depends on 9) The system of claim 9 further comprising a mixer coupled to said fuel outlet to allow a fuel exhaust of said stack to flow to said mixer, and said mixer configured to mix the fuel exhaust with the fuel to result in a mixed fuel provided to said conditioner. ### Claim 11 (depends on 1) The system of claim 1 wherein said conditioner is coupled to said fuel outlet to allow a fuel exhaust of said stack to flow to said conditioner, the conditioner comprising a mixing portion to mix the fuel exhaust with the fuel prior to the conditioner transferring heat energy from the oxidant to the fuel to arrive at the conditioned oxidant and the conditioned fuel. ### Claim 12 A fuel cell system comprising: a fuel cell stack; a reactant temperature conditioner coupled to a fuel source and an oxidant source, said conditioner having a fuel inlet for receiving fuel from the fuel source and an oxidant inlet for receiving oxidant from the oxidant source, said conditioner configured to transfer heat energy from the oxidant to the fuel to arrive at conditioned oxidant and conditioned fuel; said conditioner having a fuel outlet coupled to said fuel cell stack to allow flow of the conditioned fuel to said fuel cell stack and an oxidant outlet to allow flow of the conditioned oxidant to said fuel cell stack; and a coolant source coupled to said fuel cell stack, said fuel cell stack comprising a coolant outlet coupled to said conditioner to allow flow of exhaust coolant from said fuel cell stack to said conditioner to allow a transfer of heat energy from the oxidant to the coolant. ### Claim 13 (depends on 12) The system of claim 12 wherein said conditioner comprises at least one heat exchanger to transfer the heat energy from the oxidant to the coolant and to transfer the heat energy from the coolant to the fuel. ### Claim 14 A method for operating a fuel cell comprising: flowing a fuel from a fuel source and an oxidant from an oxidant source to a reactant temperature conditioner; transferring heat energy from the oxidant to the fuel in the conditioner to form a conditioned oxidant and a conditioned fuel; and flowing the conditioned oxidant and the conditioned fuel to a fuel cell stack. ### Claim 15 (depends on 14) The method of claim 14 further comprising flowing the conditioned oxidant to an oxidant humidifier and controlling the humidity of the conditioned oxidant prior to the conditioned oxidant flowing to the fuel cell stack. ### Claim 16 (depends on 15) The method of claim 15 further comprising flowing a coolant to the fuel cell stack and flowing a cooling exhaust from the fuel cell stack to the humidifier. ### Claim 17 (depends on 16) The method of claim 16 further comprising coupling the conditioner to the humidifier and flowing the exhaust coolant to the conditioner. ### Claim 18 (depends on 17) The method of claim 17 further comprising flowing a coolant exhaust from the fuel cell stack to the conditioner to transfer heat from the coolant to the fuel. ### Claim 19 (depends on 14) The method of claim 14 further comprising electrically coupling the fuel cell stack to a load device. ### Claim 20 (depends on 19) The method of claim 19 wherein the load device comprises an industrial electric vehicle. ### Claim 21 (depends on 14) The method of claim 14 further comprising flowing a fuel exhaust from the fuel cell stack to a mixer and mixing the fuel exhaust with the fuel from the fuel source to result in mixed fuel providing to the conditioner. ### Claim 22 (depends on 14) The method of claim 14 further comprising flowing a fuel exhaust from the fuel cell stack to the conditioner and mixing the fuel exhaust with the fuel from the fuel source in a mixing portion of the conditioner.