3 replies to this topic

[Said Salim]

Dears
We are having a steam turbine that is driving a centrifugal compressor with a configuration shown in the attached sketch case:1.

We are intending to reduce the extracted steam flow from HP case by almost 18 T/H due to non requirement of original amount in downstream processes. However, this reduction in extraction steam should not affect the power delivered to the compressor and hence the LP case inlet steam flow shall be increased by amount derived from turbine steam diagram.
Actually I am bit confused with second configuration of flow whether turbine shaft rpm in case: 2 will remain the same as case:1 if we know that the shaft power will remain the same?
Another confusion will isentropic efficincies of both LP and HP case remain the same in both cases?

Attached Files

•  Steam Turbine Sketch.jpg   50.07KB   1 downloads

Edited by Said Salim, 09 March 2022 - 11:21 PM.

[Said Salim]

I am sorry I could not attach the sketch because I am posting with my mobile. I shall attach it very soon

[Pilesar]

Steam flow to the HP case provides power. Steam flow to the LP case provides power. If you intend the total turbine power to be the same while supplying more steam to the LP case, then the steam flow to the HP case will be reduced. 

[Bobby Strain]

Normally there is lots of flexibility for extraction in such a case. You can determine exactly the effect on throttle flow by looking at the turbine diagram. And, normally the speed is determined by the compressor power demand. Speed is typically controlled via a compressor inlet pressure controller.

 

Bobby