# US 2022/0032818 A1 · Spraying water in ram air for fuel cell power systems in aircraft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0032818 A1 - Document ID: US20220032818A1 - Status: Published application - Kind: A1 - Application number: 17/389,575 - Filed: 2021-07-30 - Published: 2022-02-03 - Earliest claimed: 2020-08-03 - Assignees: Airbus Operations GmbH - Applicants: Airbus Operations GmbH - Inventors: Guido KLEWER; Kurtus HANCOCK - Web page: https://patentgrep.com/patent/US20220032818A1 ## CPC - B64D 33/08: of power plant cooling systems - B60L 58/33: by cooling - B64D 27/33: Hybrid electric aircraft - B64D 27/355: using fuel cells - H01M 8/04029: Heat exchange using liquids - H01M 8/04059: {Evaporative processes for the cooling of a fuel cell} - H01M 8/04074: {Heat exchange unit structures specially adapted for fuel cell} - H01M 8/04291: Arrangements for managing water in solid electrolyte fuel cell systems (H01M8/04119 takes precedence) - H01M 8/04358: {of the coolant} - H01M 8/04619: {of fuel cell stacks} - H01M 8/04723: {of the coolant} - H01M 8/04768: {of the coolant} - B64D 37/30: Fuel systems for specific fuels - B64D 37/32: Safety measures not otherwise provided for, e.g. preventing explosive conditions - B64D 41/00: Power installations for auxiliary purposes - B64D 2041/005: {Fuel cells} - H01M 2250/20: Fuel cells in motive systems, e.g. vehicle, ship, plane - Y02E 60/50: Fuel cells - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - Y02T 90/40: Application of hydrogen technology to transportation, e.g. using fuel cells - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - 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 power system including at least one fuel cell, a ram air system and a cooling circuit in which coolant is intended to circulate for regulating a temperature of the at least one fuel cell. The cooling circuit comprises a ram air heat exchanger in the ram air system and the ram air system comprises a nozzle. The fuel cell power system further comprises a water tank and the fuel cell power system is arranged to flow water from the water tank to the ram air system so as to spray water in ram air via the nozzle. Thus, dimensioning of the ram air system which includes the ram air heat exchanger is reduced. ## Claims ### Claim 1 A fuel cell power system comprising at least one fuel cell, a ram air system, and a cooling circuit configured to receive a circulating coolant to regulate a temperature of the at least one fuel cell, the cooling circuit comprising a ram air heat exchanger in the ram air system, wherein the ram air system comprises a nozzle, and the fuel cell power system further comprises a water tank and the fuel cell power system is arranged to flow water from the water tank to the ram air system so as to spray water in ram air via the nozzle, wherein the fuel cell power system further comprises a controller, referred to as a cooling controller, and a water flow regulating device configured to regulate a temperature of the coolant by adjusting operation of the water flow regulating device to regulate a flow of water from the water tank to the ram air system, wherein the cooling controller is configured to operate in a first operating mode when regulating the temperature of the coolant according to a first target temperature and to operate in a second operating mode when regulating the temperature of the coolant according to a second target temperature, wherein the cooling controller is configured to switch from the first operating mode to the second operating mode when a first event is received, wherein the first event indicates that the fuel cell power system should prepare for highly demanding electrical energy situation or cooling low availability situation, and wherein the cooling controller is configured such that water spray in ram air is inactivated in the first operating mode and is activated in the second operating mode. ### Claim 2 (depends on 1) The fuel cell power system according to claim 1, wherein water resulting from a chemical reaction of dihydrogen with dioxygen in the fuel cell is used to supply the water tank. ### Claim 3 (depends on 1) The fuel cell power system according to claim 1, wherein the water flow regulating device is a water pump. ### Claim 4 (depends on 1) The fuel cell power system according to claim 1, wherein the cooling controller is configured such that the regulation of water flow from the water tank to the ram air system is performed according to an ambient temperature. ### Claim 5 (depends on 1) The fuel cell power system according to claim 1, wherein the cooling circuit comprises a bypass valve mixing hot coolant, as heated up by the fuel cell, and refreshed coolant, as output by the ram air heat exchanger, and wherein the cooling controller is configured to further regulate the temperature of the coolant by adjusting operation of the bypass valve. ### Claim 6 (depends on 1) The fuel cell power system according to claim 1, wherein the cooling controller is configured to switch from the second operating mode to the first operating mode when receiving a second event indicating that the fuel cell power system has authorization to resume nominal operations. ### Claim 7 (depends on 1) An aircraft comprising at least one propulsion system including a fuel cell power system according to claim 1. ### Claim 8 (depends on 7) The aircraft according to claim 7, comprising avionics, wherein the avionics are configured to send the first event to the cooling controller when upcoming highly demanding electrical energy situation or cooling low availability situation is detected by the avionics. ### Claim 9 (depends on 8) The aircraft according to claim 8, wherein the avionics are configured to send the first event in advance of a take-off phase. ### Claim 10 (depends on 8) The aircraft according to claim 8, wherein the avionics are configured to send the first event when a Traffic Collision Avoidance System TCAS pre-alert or Terrain Awareness Warning System TAWS alert is triggered. ### Claim 11 (depends on 8) The aircraft according to claim 8, wherein the avionics are configured to send the first event when an approach of a runway for landing is initiated.