Instrument Air


Thread Starter

Tom Murphy

Is it feasible to use the CPD from the Gas Turbine Compressor after being processed through the APU for all Instrument Air on the turbine?

I remember a couple plants I worked at did this, but I cant remember if there was any related problems with this design. The project I'm currently at can use this air for pulsing the inlet filters but not piped for other instruments.

I have been to and work at a site that uses CPD for instrument air purposes.

It works well as long as you have a dryer capable of processing the air needed. If you are just trying to supply air to the turbine, that should be no problem. Obviously you will need to evaluate the quantity needed for the rest of the barges.

I would suggest using the supply from the turbines as the primary feed, and keeping the compressors in standby if needed. At lower loads your CPD may not be enough to provide the pressure you need.
I think the idea is a good one. Some will suggest a loss in turbine output. But operating at part load the way you do I don't think you'll see a large drop in efficiency.