温度对耗氧型惰化系统产水性能影响

Effect of temperature on water production performance of oxygen-consuming inerting system

以油箱出口气体的摩尔流量为基准,推导了流经催化反应器、冷却器前后各气体组分的摩尔流量关系,建立了耗氧型惰化系统的数学模型。研究了环境温度对系统中"水"性能的影响。结果表明:随着惰化的进行,油箱上部水蒸气占比逐渐增加,而冷却气体量、反应器出口相对湿度及中除水量逐渐降低;液态水析出对冷却气体量影响巨大,不能忽略;另外,系统中水的生成与析出与环境温度相关,且环境温度越低,油箱水蒸气体积分数上升越慢,但系统需要的冷却空气量越多且析出的液态水量越大,如环境温度为0℃时,冷却器中所需冷却气体量分别约为20、40℃时的1.11倍、1.26倍。因此在设计耗氧型惰化系统时,应充分考虑温度变化对水的生成与析出的影响。

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.