不同温控模式下直升机惰化系统性能对比

以某直升机机载中空纤维膜惰化系统为研究对象，设计了电控阀控温和变频风扇控温2种系统。基于AMESim平台以分离膜数学模型计算数据为基础，搭建机载惰化系统，在飞行包线下，研究了2种温控模式的控温效果、不同飞行阶段的惰化系统性能变化及关键参数对其影响。计算结果表明:电控阀控温系统在整个飞行过程均能将引气温度维持在目标温度90℃，在起飞之后富氮气体（NEA）氮体积分数全程维持在91.5%~96.4%之间，所需引气流量为40~243 kg/h，空载燃油箱气相空间氧体积分数可在180 s内降至9%，且保持全程低于9%；变频风扇控温系统在满足爬升、加速、俯冲高温阶段控温惰化要求的选型前提下，在低速、高速巡航阶段，引气被过度冷却至0℃左右，虽然所需引气流量低至26 kg/h，但NEA氮体积分数大幅下降至81%，燃油箱气相空间氧体积分数高达18%，在巡航阶段，飞行速度越大，引气温降越大，且巡航高度越低，为满足控温效果所需的最低巡航速度越低。 

Performance comparison of helicopter inerting system under different temperature control modes

The airborne hollow fiber membrane inerting system of a helicopter is taken as the research subject.in this paper. Two temperature control systems using an electric valve and a frequency conversion fan have been designed. Based on the AMESim platform and the calculated data of the separation membrane mathematical model, an airborne inerting system was built. Under the flight mission, the temperature control effect of the two systems, the variation of the performance of the inerting system at different flight stages, and the influence of key parameters were all studied. The results show that: the system with an electronic valve can maintain the bleed air temperature at the desired level of 90℃ throughout the flight. After take-off, the nitrogen concentration of nitrogen enriched air (NEA) is maintained between 91.5%-96.4%, the required bleed air flow rate is maintained between 40 kg/h-243 kg/h, and the oxygen volume fraction on ullage can be reduced to 9% within 180 s and kept below 9% throughout the flight. Under the premise of the heat exchanger selection that meets the temperature control and inerting requirements during the high temperature stages such as climb, acceleration, and descent, the bleed air is overcooled to about 0℃ during the cruise stage of the system with the variable frequency fan, although the required bleed air flow rate dropped to 26 kg/h, the concentration of NEA is greatly reduced to 81%, and the oxygen volume fraction on ullage rose to 18%. The larger the flying speed, the greater the temperature drop of bleed air and the lower the cruising altitude, the lower the minimum cruising speed required to meet the temperature control effect are all valid during the cruise phase of the system with the variable frequency fan.