APU引气压力有没有一个正常范围？ / 四六文摘

可能你也会碰到这样的疑问：

APU引气压力低

APU不开空调引气压力才14PSI，是不是太低了啊？

~（来自飞行员）

AMM手册上并没有给出APU在各种情况下的引气压力范围。这也不能怪波音，因为APU引气压力受外界环境、飞机引气构型、空调负载的影响，确实不好给出一个范围。

比如，正常都是使用APU引气双组件工作时，不同的环境和飞机区别很大：

手册中仅有的一点在FIM 中。

FIM 49-55 TASK 804：

FIM 49-55 TASK 806：

FIM 49-55 TASK 807：

参考之前咨询波音的SR：

问

Please advise CEA the normal range of 737NG APU bleed air pressure corresponding to no bleed air load, single air conditioning pack load, dual air conditioning packs load and engine start situations.

APU bleed air pressure varies with outside air temperature, altitude and cabin temperature setting.

The following are normal APU bleed air pressures at sea level:

-- No load 0-18 psig

-- 1 pack on 26 to 45 psig

-- Both packs on 8 to 40 psig.

-- Main Engine Start approx. 43 - 44 psig

Because of the wide pressure band, do not use duct pressure as the only parameter to evaluate the health of the APU. the parameters provided in the ref AMM 49-11-00/201, Table 203, APU Operating Limits should be used as aguide in determining APU performance.

Please note: For fuel saving, Boeing does not recommend operating a single air conditioning pack while the APU is used as the air source (see the ref /C/ SL for additional information).

（SR 3-2624668790）

答

综合FIM和波音的回复，针对APU引气压给出如下参考范围：

APU引气压力范围