Power Recovery Turbine - Pump 1

[Chengin]

Hello,
I have a question regarding Power Recovery Turbine.
It is installed at the high pressure liquid side and produce electricity by letdown to medium pressure.
This Turbine is coupled to the pump and the scheme is as attached capture.

The point is that according to the utility summary, power produced from turbine is much less than the pump's required power. So, does this mean power (electricity) is supplied to the motor simultaneously with power from turbine? I checked other unit having similar configuration, but they have also the same scheme. (less power produced from power recovery turbine while required power for pump is big) How does this work?

https://files.engineering.com/getfi...e-669a-4137-bffe-71233fdf6bbc&file=screen.png

 

[georgeverghese]

In this case, yes, the power recovery turbine is the makeup driver (or supplemental driver) that drives the lean amine pump together with the electric motor. So total power absorbed by lean pump = electric power INPUT + power recovered from HP rich amine stream.

 

[Chengin]

Dear georgeverghese, Thank you for your words. I just would llike to know regarding reliability. If the turbine get failed with some reason, then will the pump operation be maintained by make-up power from motor immediately or there will be some impact?

 

[georgeverghese]

The recovery turbine probably transfers its power to the lean amine pump shaft through some intermediate 2 input shaft hydraulic clutch. So if this PRT drops out, you will only have the electric motor power as max available power for the lean amine stream.