For a 20MW Frame V Gas Turbine, the atomising air temperature high alarm is at 135deg centigrade, but there is no trip associated with it. What will happen if the atomising temperature goes beyond this limit? What are the direct effects and what are the cascading effects?

 

You run the risk of destroying the Atomizing Air Compressor. It spins at approximately 14,400 RPM, and with increased inlet air temperatures come decreased internal clearances.

 

In addition there is risk of coking liquid fuel droplets instead of combusting the fuel and reduced volumetric efficiency of the prime-mover.

Tomy Zacharia

 

On a lot of later machines when 26AA (High AA Temp) comes on, the machine goes into an auto-unload sequence. If you are reaching this temperature it looks like you have a badly set VTR on the cooling system. I wouldn't advise running at 135 deg C for too long as the other respondants have indicated, you could easily damage the AA compressor.