基于临界低温释放民机发动机舱灭火剂浓度测试

Research on Engine Compartment Fire Extinguishing Agent Concentration Test in Civil Aircraft Based on Method of Discharging Fire Extinguishing Agent at Critical Low Temperature

国际上通常采用模拟低温环境灭火瓶压力方法开展民机发动机舱灭火剂浓度测试,该方法由于未考虑到低温环境对灭火剂扩散影响,目前不被FAA建议使用,因此提出一种基于临界低温释放的测试方法。首先通过计算获取灭火瓶临界低温条件确定灭火瓶释放温度;然后建立以Statham高精度分析仪为核心测试设备,并通过理论计算结果和布置原则确定测试采样管安装位置;最后设计出适用于本试验的测试程序。测试结果表明,灭火瓶环境温度对灭火剂浓度有重要影响,通过所建立的测试流程和方法顺利获取临界低温条件下灭火剂浓度,所测12个测试采样点符合适航条款中浓度要求。

The engine fire extinguishing agent concentration test of civil aircraft was usually performed based on method of simulating fire extinguisher pressure at low temperature in the world. The method was refused by FAA at present as low temperature also have impact on fire extinguishing agent concentration. Therefore, one test method which is discharging fire extinguishing agent at a low temperature was created. The fire extinguisher discharging temperature was deteureined by calculating a low fire extinguisher temperature. The Statham analy- zer was utilized as the core test equipment. The fire extinguishing agent sampling probe location was selected through calsulation analysis results and layout principle. The test procedure was also generated. The test results show that the fire extinguisher temperature has a great influence on fire extinguishing agent concentration. The fire extinguishing agent concentration is obtained successfully based on test procedure and test method created and complied with concentration requirement of air worthiness regulation.