Katalin Horváth McClure (asker) Oct 9, 2013:

Még további infó Turndown represents the difference between the minimum amount of gas you can feed into the compressor compared to the ideal amount you wanted to feed in, and still have the compressor not go into surge. The equation: Ideal flow minus minimum flow, then divided by ideal flow all multiplied by 100. Of course, you have to have a control system that can vary the speed of the turbine, and that's our very sophisticated electronics that control that process. What is being turned down is the feed rate (the flow) of gas into the compressor. So, if you have a 15% turndown, that means you can accept 15% less gas than you had planned on before your compressor goes into surge. You can look at it the other way and think of it as turning down the actual feed rate into the compressor to 85% of your ideal feed rate before the compressor goes into surge.

Katalin Horváth McClure (asker) Oct 7, 2013:

További információ Rákérdeztem az ügyfélnél, hogy kaphatnék-e bővebb magyarázatot. Ezt a választ kaptam:
"Here's a definition of turndown:
Turndown: The allowable operating range for the centrifugal compressor between the design point and the surge line at any given speed for a fixed compressor head.
The meaning of the "Turndown %" indicator:
The control system calculates where the compressor operation is in this turndown range (in percentage), and that is what is being displayed on the screen. This calculation is useful for avoiding a surge."
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