民航燃气涡扇发动机启动原理

Starting principle of civil aviation gas turbofan engine

为了保证航空燃气涡扇发动机能顺利启动,需要有两个相互协调工作的系统:启动系统和点火系统。发动机在地面正常启动时,两个系统必须同时工作;首先由启动系统将发动机转子N带转到一定转速,使适量高温高压空气进入燃烧室并与燃油喷嘴喷出的燃油相混合;其次再由点火系统点燃燃烧室里的油气混合物,释放燃料化学能并转化为热能推动涡轮对外做功。启动过程中两个系统的工作需要相互协调,并在循环开始后,由启动控制电路自动调节两个系统的工作。点火系统还应该能够独立工作,以实现空中再点火以及恶劣天气情况下为防止发动机熄火而进行的常明灯式的持续点火;启动系统也应能单独工作,以实现"干冷转"和"湿冷转",以便于发动机检查及维修后的试车。

To ensure aviation gas turbofan engine can be started smoothly,you need two mutual coordination work system：the starting system and the ignition system.Normal engine starting on the ground,these two systems must work at the same time.First,the starting system drives the N engine rotor to a certain speed,then add amount of high temperature and high pressure air into the combustion chamber and mixed with fuel from the fuel nozzle.In order to drive the worm wheel,the ignition system lights the gas mixture in the combustion chamber to release the fuel chemical energy into heat energy.The two systems require work coordination in the starting process.In the cycle after the start,the two systems must be automatic adjustment by the control circuit.The ignition system should work independently,in order to ignition successfully in the air or prevent the engine flameout in the bad weather conditions.