Respected Friends;

Good day. We have a two shaft gas turbine with 11 stage axial compressor model Centaur 4702. I have question that
1. During acceleration before reach the idle speed if compressor discharge pressure drop suddenly what happen inside the gas turbine?

2. I ask this question because during acceleration or ramp up the CPD is drop from 32 to 9 psig and a explosive occur in the inlet duct. When we dismantle the gas turbine the HOT section means combustor to power turbine components found ok but the 7th to 11th stage of axial compressor found damage severely.

The turbine trip at Vibration high on compressor and Flame out with high fuel. remember that it happens when turbine in acceleration mode and not achieved the idle speed and IGV just starts to open.

Also there is no evidence of FOD at inlet side.

Please help me on this issue what happen inside the turbine.

 

Jhon Knot,

The most likely cause of a sudden drop in axial compressor discharge pressure was an axial compressor stall.

See this link:

https://en.wikipedia.org/wiki/Axial_compressor