摘要
采用微元方法建立了机载制氮系统中空纤维膜数学模型,并使用龙格-库塔法对其进行了数值计算,与实验数据进行对比后显示,误差不超过10%.然后分析了单位膜面积进料量、膜丝(membrane fiber)内外压比和氧氮渗透比其对产品气氧体积分数和制氮效率的影响.结果表明:增加单位膜面积进料量虽然可提高制氮效率的增加,但是会显著降低产品气中氮的体积分数,因此需要采用合适的流程设计以克服此缺点.压比和氧气渗透系数的增加均会使氧体积分数与制氮效率减小,但是提高渗透比对制氮效率影响不大,因此对于气体分离过程是有利的.通过计算模型及实验数据,分析了中空纤维膜分离理想度随压比和温度的变化关系,结果显示压力对理想度影响较大,随着压力增加,实际分离过程与理论值偏差趋大,而温度对理想度影响较小.
The mathematical model of the hollow fiber membrane of on-board inert gas generation system （OBIGGS） is set up in term of the differential method, and solved by the Runge-Kutta method. The comparison between calculating results and experimental data published in literature reveals that the deviation is within 10%. Furthermore, this theoreti- cal model is employed to analyze the influence of the specific feed flux of membrane area, pressure ratio of membrane fiber, the separation factor and the permeability coefficient to the volume fraction of oxygen in production gas and the production efficiency of nitrogen. The study shows that though the increase of the specific feed flux of membrane area could positively promote the production efficiency of nitrogen, the volume fraction of oxygen re- duces sharply. Hence, an appropriate process of OBIGGS should be designed to overcome the disadvantage mentioned above. The increase of the pressure ratio and the permeability coefficient of oxygen will decrease the production efficiency of nitrogen and the volume fraction of oxygen, but the influence of the permeability coefficient is slight. Therefore, the increase of the permeability coefficient of oxygen is beneficial to the separation performance. Based on the experimental data and the model, the change of the separation ideal level relat- ed to the temperature and pressure is analyzed, the result shows that the pressure ratio will make greater effect on the separation ideal level. When the pressure ratio increases, the actual separation process will deviate from the theoretical one gradually.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2012年第6期1332-1339,共8页
Journal of Aerospace Power
基金
国家自然科学基金(50906066)
南京航空航天大学引进人才科研基金(S1030-014)
关键词
机载制氮
中空纤维膜
富氮气体
油箱惰化
分离系数
OBIGGS （on-board inert gas generation system）
hollow fiber membrane
nitrogen enriched air
fuel tank inerting
separation factor
