EGT指示问题

ryn_82 · 发表于 2012-11-3 19:49:06

如图，EEC用来显示的EGT值既不是S1、S2、S3、S4的平均值也不是S2、S3、S4的平均值，有些时候SET T495的值还比下面任何一个传感器的值要大。有谁知道SEL T495的值是怎么计算的吗？我说的这些情况下发动机和N1都是稳定了很长时间的，所以不会是显示延迟的问题.

hanfeng · 发表于 2012-11-3 20:18:12

什么型号的发动机

hphcafuc · 发表于 2012-11-3 20:33:08

手册中有讲：The temperature that shows is an average from the eight thermocouples on the engine。这个显示没见到过。

shanxiren · 发表于 2012-11-4 00:18:18

不懂，等待高手解答

月黄昏 · 发表于 2012-11-4 01:00:00

不懂,求解答

波音 · 发表于 2012-11-4 04:06:18

NG型号的？

ryn_82 · 发表于 2012-11-4 10:04:57

737NG,CFM56-7B22

jasonpengxb · 发表于 2012-11-4 14:51:52

查了下资料，EGT逻辑与EEC软件版本有关。下面的说明也许对你有帮助。
EGT Selection Logic
– Background
• The -7B engine fleet has experienced nuisance EGT system faults
• EGT Faults have been cleared through replacing or cleaning connections
• The current EGT logic takes an average of the 4 sector inputs
– When any one sector disagrees by more than 200 °C from the average that sector value will be left out of the average
– When one sector drifts high, the average EGT can increase 62.5 °C before that sector is declared invalid.
» This has caused numerous false EGT exceedances, high EGT readings
– When an EGT sector is declared invalid, it is left out of the EGT calculation for the remainder of the flight
» Many of the faults are the result of cold connectors

– 7.B.V2 Functional Change (Reduces the occurrence of high EGT indication caused by a drifting EGT sector)
• The EGT selection logic is being improved to reduce nuisance EGT faults
• The EGT logic in 7.B.V2 software compares each individual sector with the other valid sectors, and creates a correlation factor between 0.0
and 1.0
• The effects of a drifting sector are reduced to no more than 25.6 °C before a sector is invalidated
• Noise detection logic is added so that sector value is excluded from the average.
• The EGT selection logic in software version 7.B.V2 allows for an invalid sector to become valid
– If the sector becomes valid again, the correlation factor is ramped back towards valid (1.0) over a period of 60 seconds

• EGT Dispatch Logic
– Background
• The Time Limited Dispatch (TLD) logic prior to 7.B.V2 is as follows
– LONG TIME for the first EGT sector to fault
– LONG TIME for the second EGT sector to fault
– NO DISPATCH for the third and fourth EGT sector to fault

– 7.B.V2 Functional Change(This change reduces the maintenance burden of a single EGT sector fault)
• The Time Limited Dispatch logic for 7.B.V2 is as follows
– ECONOMIC for the first EGT sector to fault
– LONG TIME for the second EGT sector to fault
– NO DISPATCH for the third and fourth EGT sector to fault

knavewalp · 发表于 2012-11-4 16:48:44

9楼看了半天，还是不太懂...能说的清楚点么

ryn_82 · 发表于 2012-11-4 17:07:23

你说的这个我知道， EEC对超出平均值太多的传感器数据不用来进行平均值计算。这解决不了我说的问题，看看那几个数就知道了

jasonpengxb · 发表于 2012-11-4 18:12:53

猜测S1仍然有效，虽然它比S3低，然后不知道采用了什么纠正因子吧，0到1.0，得问问EEC软件内部啦。软件好像是BAE的

ryn_82 · 发表于 2012-11-5 09:09:27

kamuichen · 发表于 2012-11-8 22:52:17

太棒了

cjl850106 · 发表于 2012-11-9 11:09:00

好复杂啊

ryn_82 · 发表于 2012-12-4 21:55:57

我估计是目前的EGT指示和N1有关。

ryn_82 · 发表于 2012-12-5 12:53:43

应该就是它了。虽说只说了7BE发动机随转速变化，估计其他发动机也一样。

白龙 · 发表于 2012-12-22 11:10:14

EGT漂移自检故障代码多少怎么根据故障代码查找相应的FIM呢？

大海洋 · 发表于 2012-12-23 15:11:46

好东西你是从哪里找的啊

lanjun · 发表于 2013-2-4 01:19:31

指示漂移，我们检查的时候，也发现过插头里面不干净，还有插图有点松动的迹象等。

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[70-80发动机CFM56-7] EGT指示问题

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这是7BV2软件对EGT选择逻辑的改进。

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