燃油箱耗氧惰化与中空膜惰化的数值模拟及比较

Numerical simulation and comparison of oxygen consumption inerting and hollow membrane inerting in fuel tank

针对耗氧型惰化系统燃油箱上部空间氧气体积分数随时间变化规律的问题,对耗氧型惰化系统的反应过程建立了数学模型,并通过CFD方法对机载绿色惰化气体产生系统(GOBIGGS)系统和机载惰化气体产生系统(OBIGGS)的惰化过程进行了模拟仿真,并与实验数据进行对比,验证了仿真结果的准确性。研究结果表明,当耗氧型惰化系统抽吸气的体积流量与中空膜惰化产生的富氮气体(NEA)体积流量相同时,耗氧型惰化系统不仅惰化时间短,而且能将燃油箱的O2摩尔分数降至更低。同时耗氧型惰化系统的惰化效果与相同体积流量下NEA0(100%N2)的中空膜惰化效果相近。另外,耗氧型惰化系统使燃油箱气相空间上部O2摩尔分数大于下部O2摩尔分数,中空膜惰化则相反。

To solve the problem of oxygen mole fraction changing with time in the upper space of oil tank of oxygen consuming inerting system. A mathematical model was established for the reaction process of the Green On-Board Inert Gas Generation System(GOBIGGS), and the inerting process of the GOBIGGS and the On-Board Inert Gas Generation System(OBIGGS) was simulated by CFD method. The simulation results were compared with the experimental data, which verifies the accuracy of the simulation results. The research results show that, when the flow rate of the exhaust gas from the fuel tank in the GOBIGGS is identical with that of the Nitrogen Enriched Air(NEA) in the OBIGGS, GOBIGGS not only has shorter inerting time than OBIGGS, but also reduces the oxygen mole fraction of the fuel tank to a lower level. The inerting effect of the GOBIGGS is similar to that of the OBIGGS of NEA0(100%N2) under the same flow rate. GOBIGGS makes the upper oxygen mole fraction greater than the lower oxygen mole fraction in the gas phase space of the fuel tank, while OBIGGS is the opposite.