# US 12,113,251 B2 · Fuel cell system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,251 B2 - Document ID: US12113251B2 - Status: Granted - Kind: B2 - Application number: 17/476,710 - Filed: 2021-09-16 - Published: 2022-03-31 - Granted: 2024-10-08 - Earliest claimed: 2020-09-28 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Hans Guenter Grosch; Rainer Kiehn; Krystian Dylong - Web page: https://patentgrep.com/patent/US12113251B2 ## CPC - H01M 8/04111: using a compressor turbine assembly - H01M 8/04014: Heat exchange using gaseous fluids; Heat exchange by combustion of reactants - H01M 8/04067: {Heat exchange or temperature measuring elements, thermal insulation, e.g. heat pipes, heat pumps, fins} - H01M 8/04119: with simultaneous supply or evacuation of electrolyte; Humidifying or dehumidifying - H01M 8/04126: {Humidifying} - H01M 8/04701: Temperature - H01M 8/04716: {of fuel cell exhausts} - H01M 8/0488: {of fuel cell stacks} - H01M 8/2475: Enclosures, casings or containers of fuel cell stacks - H01M 2250/20: Fuel cells in motive systems, e.g. vehicle, ship, plane - Y02E 60/50: 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 ## Abstract A fuel cell system having a fuel cell stack in a housing includes a compressor that provides compressed ambient air to the fuel cell stack and a ventilation system coupled to a suction side of the compressor to provide ventilation of the housing and cool an associated voltage monitoring unit that may be located within the housing or upstream of the housing. The ventilation system may control a valve to supply air from the compressor outlet to the housing to warm the housing and stack when either or both have a temperature below an associated threshold. The ventilation system may include a second valve to control exhaust from the housing based on the temperature of the housing or stack. Stack exhaust may drive a turbine coupled to the compressor. A heat exchanger may be positioned to cool compressed air from the compressor before flowing to the stack. ## Claims ### Claim 1 A fuel cell system comprising: a fuel cell stack having a plurality of fuel cells, the fuel cell stack contained within a housing; a compressor having an inlet coupled to ambient and an outlet coupled to the fuel cell stack; a voltage monitor configured to monitor voltage of the plurality of fuel cells; a ventilation system including a first duct coupling the inlet of the compressor to an inlet of the housing, the first duct having a first electronically controllable valve; and a controller programmed to control the first electronically controllable valve in response to temperature of at least one of the fuel cell stack and the housing. ### Claim 2 (depends on 1) The system of claim 1 wherein the voltage monitor is disposed within the housing. ### Claim 3 (depends on 1) The system of claim 1 further comprising a turbine mounted on a common axis with the compressor, and an exhaust duct coupling the fuel cell stack to the turbine. ### Claim 4 (depends on 1) The system of claim 1 further comprising an exhaust duct coupled to the housing and the inlet of the compressor. ### Claim 5 (depends on 4) The system of claim 4 further comprising an electronically controlled valve positioned within the exhaust duct. ### Claim 6 (depends on 4) The system of claim 4 further comprising a hydrogen sensor coupled to the exhaust duct. ### Claim 7 (depends on 6) The system of claim 6 further comprising: a humidifier coupled to the outlet of the compressor and an inlet of the fuel cell stack; and a fuel cell stack exhaust duct coupled to the fuel cell stack and the humidifier. ### Claim 8 (depends on 7) The system of claim 7 further comprising a heat exchanger having an inlet coupled to the outlet of the compressor and an outlet coupled to the humidifier. ### Claim 9 (depends on 8) The system of claim 8 further comprising: a bypass duct coupled to the outlet of the compressor and an inlet of the housing; and an electronically controlled valve disposed within the bypass duct. ### Claim 10 A method for controlling a fuel cell system, comprising, by a controller: controlling a first valve within a duct coupling a compressor inlet to a first inlet of a housing containing a fuel cell stack and a fuel cell voltage monitor, a second valve within an exhaust duct between an outlet of the housing and the compressor inlet, and a third valve within a bypass duct coupling a compressor outlet to a second inlet of the housing in response to temperature of at least one of the fuel cell stack and the housing. ### Claim 11 (depends on 10) The method of claim 10 wherein controlling the first, second, and third valves comprises at least partially closing the second valve and at least partially opening the third valve in response to the temperature being below an associated threshold. ### Claim 12 (depends on 11) The method of claim 11 wherein controlling the first, second, and third valves further comprises at least partially closing the first valve in response to the temperature being below the associated threshold. ### Claim 13 (depends on 12) The method of claim 12 further comprising monitoring a signal from a hydrogen sensor disposed in the exhaust duct and generating an alert signal in response to the signal from the hydrogen sensor detecting hydrogen exceeding a corresponding threshold. ### Claim 14 A vehicle system comprising: a fuel cell stack having a plurality of fuel cells contained within a housing; a fuel cell voltage monitor contained within the housing; a compressor having an ambient air inlet and an outlet; and a ventilation system comprising: a first duct coupling the ambient air inlet of the compressor to a first inlet of the housing; a second duct coupling the outlet of the compressor to a second inlet of the housing; a third duct coupling an outlet of the housing to the ambient air inlet of the compressor; and an electronically controllable valve in each of the first, second, and third ducts. ### Claim 15 (depends on 14) The vehicle system of claim 14 further comprising a humidifier having a first inlet coupled to the outlet of the compressor, a first output coupled to an input of the fuel cell stack, a second input coupled to an outlet of the fuel cell stack, and a second outlet coupled to ambient, the humidifier configured to transfer moisture from air exhausted from the fuel cell stack to compressed air from the outlet of the compressor. ### Claim 16 (depends on 15) The vehicle system of claim 15 further comprising a heat exchanger coupled to the outlet of the compressor upstream of the humidifier. ### Claim 17 (depends on 16) The vehicle system of claim 16 further comprising a hydrogen sensor coupled to the third duct. ### Claim 18 (depends on 16) The vehicle system of claim 16 further comprising a check valve disposed between the outlet of the fuel cell stack and the second input of the humidifier. ### Claim 19 (depends on 15) The vehicle system of claim 15 further comprising a controller programmed to control the electronically controllable valves in response to temperature of at least one of the housing and the fuel cell stack.