Could anyone explain me when IGV start to move opening from 57 deg.? Which control constant is responsible for opening further from 57 deg. When base load appears: when TTXM and TTRXB are equal or when FSRT become the lowest? Are the combined cycle mode and IGV Temperature control on mode the same? What is modulated IGV?

Anonymous

 

You'll likely find the answer to your first question in http://control.com/thread/1026231443#1026231630. If you're new to control.com, the search feature is one of the best on any forum on the Internet.

You'll need to look at your Mk IV Speedtronic elementary for the exact details of your machine's operation.

Base Load is both--when TTXM equals TTRX and at that point FSRT is equal to or slightly less than FSRN.

For most machines, IGV (Inlet Guide Vane) Temperature Control and "Combined Cycle Mode" are the same. The IGVs are used to maximize exhaust temperature at part load to improve overall thermal efficiency (even though it very slightly reduces the gas turbine's efficiency).

Modulated IGVs are IGVs that are infinitely variable between limits (-mechanical and -control system)--as opposed to the old "bang-bang", or, two-position IGVs which were only open or closed.

markvguy

 

Hi MarkVguy,

I am really impressed by amazing clarity given by your answers.

I request your help to give a brief explanation of blocks like FSR or other control blocks which come in sequence when we start any GE turbine.
This would be useful to help me troubleshoot if we face any problem.

Thanks & rgds,
PC