Spraying water in ram air for fuel cell power systems in aircraft

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.