Based on the gas molar flow rate at fuel tank outlet

the molar flow relationship between the gas components flowing through the catalytic reactor and the cooler was deduced

and a mathematical model of the oxygen-consuming inerting system was established. The effect of ambient temperature on “water” performance in the system was studied. Results showed: as the inerting developed

the proportion of water vapor on fuel tank ullage gradually increased

while the amount of cooling air

the relative humidity at the reactor outlet and the amount of removed water decreased. The impact of liquid water precipitation on cooling air amount was huge and cannot be ignored. In addition

the generation and precipitation of water in the system were related to the ambient temperature. The lower ambient temperature indicated the slower rise of water vapor volume on fuel tank ullage

but more cooling air required by the system and the greater amount of precipitating liquid water. For example

when the ambient temperature was 0 ℃

the amount of cooling gas required in the cooler was about 111 times and 126 times of that at 20 ℃ and 40 ℃

respectively.Therefore

when designing an oxygen-consuming inerting system

the effect of temperature changes on the generation and precipitation of water should be fully considered.