机载空分装置富氮气体流量及影响因素

借助实验平台,对某型机载空气分离装置富氮气体流量随高度、压力、温度及富氮气体浓度的变化规律展开了实验研究;基于实验数据采用多项式拟合方法获得了富氮气体流量计算的经验公式,并对该公式的准确性进行了验证;在此基础上,研究了影响空分装置富氮气体流量的诸多因素,并计算获取了在全飞行包线下的富氮气体流量变化规律.研究结果表明,所获取的流量计算方程具有较好的准确性;采用所建的数学模型,可实现对全飞行包线下富氮气体流量变化的计算;在一定压力、温度下,富氮流量与浓度成反向关系,当富氮气体浓度增加时,其流量下降;且温度越高、压力越大时,富氮气体浓度对流量影响越明显;高度、压力、温度与流量成正向关系,且当富氮浓度越低,而高度、温度和压力越高时,对流量的影响越明显.本研究成果对于实际油箱惰化系统的设计计算具有较好的参考价值.

Flow rate of nitrogen-rich air and influence factors for onboard air separation unit

The flow rate of a certain type onboard air separation unit to produce the nitrogen-rich air related with the flight height, inlet pressure, temperature and the nitrogen concentration was experimentally studied on a test apparatus. An empirical correlation to predict the flow rate of the nitrogen-rich air was obtained and verified via the polynomial fitting method and experimental data. In addition, the influence factors affecting the flow rate were investigated and the variation of the flow rate along the entire flight profile was calculated. Results indicate that, the obtained empirical correlation has high prediction accuracy; the flow rate of the nitrogen-rich air along the flight profile could be calculated based on the present mathematical model; under a constant pressure, temperature, flow rate of the nitrogen-rich air is reversely proportional to the nitrogen concentration, so when nitrogen concentration increases, the flow rate decreases; especially, the effect will be larger under the higher inlet temperature and pressure; the flight height, pressure, temperature are proportional to the flow rate, and the lower nitrogen concentration, higher flight height, temperature and pressure will bring larger impact on the flow rate. The research results could be beneficial to the design of fuel tank inert system.