低压环境下航空电缆材料燃烧特性的研究

在高高原实验室(61 kPa、4 290 m)和广汉实验室(96 kPa、520 m),分别开展常低压条件下FXL型航空电缆的对比燃烧实验。通过热辐射加热箱、烟密度及成分测试仪和氧指数仪等设备,测量点燃时间、烟密度、质量损失速率和CO、CO2及O2等浓度变化。实验结果表明:在96 kPa和61 kPa两种实验环境下,低压下最小点燃时间及温度的数值更大,两者的温度和时间差分别为15℃和4.8 s;烟密度曲线快速升高后趋于平衡,61 kPa条件下的发烟量小于96 kPa;O2体积浓度随着加热时间先下降后升高,而CO2的变化趋势相反。在61 kPa条件下,CO曲线会出现双峰现象且更明显;随着氧浓度增加,质量损失速率加快且呈线性关系;压力因素对燃烧影响减弱且燃烧持续时间差值变小。研究结果揭示了低压环境对航空电缆的燃烧影响,为增强航空安全提供参考。

Experimental Study on Combustion Characteristics of Aviation Cable Materials under Low Pressure Environment

The comparative combustion experiments of FXL aviation cable were carried out at the highaltitude aviation safety laboratory(4 290 m) and the Guanghan aircraft laboratory. The ignition time, smoke density, mass loss rate and concentration of CO, CO2 and O2 were measured by thermal radiation heating box, smoke density and composition tester and oxygen index analyzer. The experimental results show that the minimum ignition time and temperature were larger at 61 kPa, and the temperature and time difference between them are 15℃ and 4.8 s, respectively. The smoke density curve tended to be balanced after rapid increase, and the smoke density of aviation cables at 61 kPa is less than that at 96 kPa. The volume concentration of O2 decreased first and then increased with heating time, while the change trend of CO2 was opposite, in addition, the CO curve had a double-peak phenomenon which was more obvious at 61 kPa. The mass loss rate increased linearly with the increase of oxygen concentration. In addition, the influence of pressure on combustion was weakened and the difference of combustion duration was reduced. The results reveal the influence of low-pressure environment on the combustion of aviation cables, and provide a reference for enhancing aviation safety.