Evaporatively cooled fuel cell system and method for operating an evaporatively cooled fuel cell system

An aircraft fuel cell system having one or more components at least partially arranged in a non-pressurized portion of an aircraft in which it is installed, the system comprising:

• a fuel cell;
• an evaporative cooling system, which is in thermal contact with the fuel cell, wherein heat generated by the fuel cell during operation of the fuel cell is absorbed through evaporation of a cooling medium and is removed from the fuel cell;
• a device for sensing the pressure in the evaporative cooling system;
• and
• a control unit adjusting an operating temperature of the fuel cell in dependence on signals that are supplied to the control unit from the device for sensing the pressure in the evaporative cooling system to track a pressure-dependent evaporation curve of the cooling medium, wherein evaporation of the cooling medium during ascent and descent of the aircraft, is effected in a wet-steam region of the cooling medium.

An aircraft fuel cell system having one or more components at least partially arranged in a non-pressurized portion of an aircraft in which it is installed, the system comprising:

• a fuel cell;
• an evaporative cooling system, which is in thermal contact with the fuel cell, wherein heat generated by the fuel cell during operation of the fuel cell is absorbed through evaporation of a cooling medium and is removed from the fuel cell;
• a device for sensing the pressure in the evaporative cooling system;
• and
• a control unit adjusting an operating temperature of the fuel cell in dependence on signals that are supplied to the control unit from the device for sensing the pressure in the evaporative cooling system to track a pressure-dependent evaporation curve of the cooling medium, wherein evaporation of the cooling medium during ascent and descent of the aircraft is effected in a wet-steam region of the cooling medium, wherein the control unit is configured to control the evaporation of the cooling medium in the wet-steam region of the cooling medium during ascent and descent of the aircraft by adjusting an operating temperature of a low-temperature polymer electrolyte membrane (PEM) in dependence on the ambient pressure.

An aircraft fuel cell system having one or more components at least partially arranged in a non-pressurized portion of an aircraft in which it is installed, the system comprising:

• a fuel cell;
• an evaporative cooling system, which is in thermal contact with the fuel cell, wherein heat generated by the fuel cell during operation of the fuel cell is absorbed through evaporation of a cooling medium and is removed from the fuel cell;
• a device for sensing the pressure in the evaporative cooling system;
• and
• a control unit adjusting an operating temperature of the fuel cell in dependence on signals that are supplied to the control unit from the device for sensing the pressure in the evaporative cooling system to track a pressure-dependent evaporation curve of the cooling medium, wherein evaporation of the cooling medium during ascent and descent of the aircraft is effected in a wet-steam region of the cooling medium, wherein the control unit is configured to control the evaporation of the cooling medium in the wet-steam region of the cooling medium during ascent and descent of the aircraft by adjusting an operating temperature of a high-temperature polymer electrolyte membrane (PEM) in dependence on a pressure generated by a pump or by adjusting the pressure generated by the pump in dependence on the operating temperature of the high temperature PEM.