Gas Turbine Inlet Pressure Loss and Exhaust Pressure Loss

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Thread Starter

GTguy99

Dear all,

I am aware that two of the parameters that affect the performance of a gas turbine and require measurement during a performance test are Inlet Pressure Loss and the Exhaust Pressure Loss.

I understand that the Inlet Pressure Loss is defined as the difference between ambient pressure and the pressure in the units inlet duct, after the filter house. This inlet pressure loss is measured using a differential pressure transmitter (96CS for GE units) with high side connected to atmosphere and the low side connected to a kiel probe located in the inlet duct above the GT bellmouth.

I also understand that the Exhaust Pressure Loss is defined as the difference between ambient pressure and the turbine outlet pressure. This exhaust pressure loss is also measured using a differential pressure transmitter (96EP for GE units) with high side connected to a pancake probe situated somewhere in the units exhaust flange/stack transition and the low side connected to atmosphere.

The question I have is why "total" pressure loss is used for the Inlet pressure loss (use of kiel probes) but "static" pressure loss is used for the Exhaust pressure loss(use of pancake probes)???

Is this industry standard? would total pressure loss never be used for Exhaust? Why not? does it have anything to with not being able to use kiel probes in that location due to the high temperatures?

I am aware that Inlet Pressure Loss and Exhaust Pressure Loss will be corrected back to reference conditions using OEM correction curves during a performance test. If using static pressure loss for the exhaust pressure loss is industry standard, would it be taken into account for the OEMs correction curves? Would their thermodynamic models be using static pressure for exhaust pressure loss?

Any help would be appreciated. If I can provide any more information or clarification that would help with your understanding of my enquiries please just let me know.

Many Thanks.
 
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