|
曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
Heat Shield
The exhaust gas heat shield is installed on the aft side of the fuselage, below the right engine pylon. The heat shield is used to minimize the exhaust gas impact on the aircraft skin.
EGT Indications
APU exhaust gas temperature is represented on the EICAS page, using a grey legend (EGT) and a digital readout that is displayed in degrees Celsius. The APU’s operating limits are represented by color change of the EGT readout by showing green, yellow and red when the APU temperature increases.
AUXILIARY POWER UNIT Description Vol. 2 05.10.7
Oct 05/06
Air Intake, Exhaust and Indication
Figure 05.10.4
AUXILIARY POWER UNIT Description Vol. 2 05.10.8
Oct 05/06
Description
The APU fuel system provides fuel for APU start, acceleration, and governed speed control. During start, the fuel system provides the correct amount of fuel to support combustion, and ensures smooth acceleration of the engine to full power. Once full power is reached, fuel flow is modulated, as necessary, to meet the demands of varying pneumatic and electrical loads, while maintaining a constant speed.
The normal fuel supply to the APU is from the right main tank. A backup fuel supply from the left engine motive flow system is provided in case negative-G conditions are encountered.
Components and Operation
APU Fuel Pump
The DC battery bus powers the APU fuel pump, which draws fuel from the right main tank. The pump provides fuel to the fuel control unit through the APU’s feed line and the fuel shutoff valve. A portion of the fuel from the APU fuel pump is directed to the APU fuel control unit for combustion, while the remainder is routed through the fuel/oil heat exchanger to provide cooling of the APU generator adapter oil. Fuel that has passed through the fuel/oil heat exchanger is returned to the right main tank.
Selection of the APU PWR FUEL switch/light activates the APU fuel pump. This selection also opens the APU’s fuel shutoff valve and negative-G shutoff valve. Insufficient APU fuel pump output pressure is indicated by an APU PUMP caution EICAS message, and illumination of the PUMP FAIL switch/light legend on the APU panel.
APU Fuel Shutoff Valve
The APU fuel shutoff valve (SOV) opens when the PWR FUEL switch/light is pressed in, and closes when it is pressed out. If the valve does not match the switch position within 5 seconds, an APU SOV caution EICAS message is displayed.
When the APU FIRE PUSH switch/light is pressed in, the APU fuel shutoff valve and the APU negative-G shutoff valve close. Successful closing of the valves is indicated by an APU SOV CLSD advisory message, and illumination of the green SOV CLOSED switch/light legend on the APU panel. If the APU SOV fails to close after APU FIRE PUSH switch/light selection, an APU SOV caution message is displayed.
中国公务机网 www.gongwuji.com
公务机翻译 www.aviation.cn
本文链接地址：庞巴迪挑战者605公务机机组操作手册 CL605-辅助动力装置 AUXILIARY_POWER_UNIT(4)
| 
