关于APU的启动

12345机务 · 发表于 2016-1-17 08:09:26

START电门按下后ON灯点亮，the de-oiling solenoid valve used to unload the lube pump opens at low tempreature. 这句话如何理解？

0252119627 · 发表于 2016-1-17 11:27:08

De-oiling Solenoid Valve The de-oiling solenoid valve reduces the oil pressure pump load during the APU start, especially during the cold start condition when oil has a high viscosity. The valve is part of the lube module. A solenoid operates the valve position. The ECB controls the solenoid in relation to the de-oiling solenoid logic. The solenoid valve is open during start up to 60% rpm when · the oil sump temperature is below -6.7 deg.C (19.94 deg.F) or · the aircraft altitude is more than 20,000 ft, or · the fuel temperature is below -12.2 deg.C (10.04 deg.F)

这个活门是在冷启动的时候，特别是温度低的时候，滑油粘性比较大，为了降低进入滑油压力泵的滑油压力由ECB按照一定逻辑打开的（从启动到60%转速）。条件是：滑油温度低于-6.7或者飞机在20000FT以上，或者燃油温度低于-12.2.
按照这个逻辑你那句话翻译就是低温启动APU的时候这个电磁阀控制活门打开，卸载滑油泵前面的压力。
这是我的理解，仅供参考