1 reply to this topic

[Olaniyi]

Hi all
I have a turbo expander/recompressor arrangement for an NGL extraction process (feeding a demethanizer - typical line up as shownin attachment). I wish to increased the feed to the plant (and thus to my turbo expander) by 10%. I have the expander curves (flow vs efficeincy and flow vs shaft power) and the compressor curves (flow vs head and flow vs efficiency) from the manufacturer. I am trying to model the unit in unisim/hysis, and I have inputed the compressor and expander curves. However, I see that the expander gives me a speed higher than its quoted design speed from the manufacturers curves. I have inputed feed conditions and discharge pressure as stated on the manufacturers curves to try to align my data as much as possible but my calculated speed is still some 10- 15% higher than the "design" speed.

Any experience on such simulations? Does anyone know if there is something I am missing out? How would forum members approach this type of problem?

Many thanks!

Ogeds

Attached Files

•  turboexpander.doc   73KB   73 downloads

[ankur2061]

ogeds,

Check the values of the adiabatic and / or polytopic efficiencies provided by the vendor and input these instead of the default values in the model. Manufacturer's provide the efficiency data also. Maybe this is the problem.

Regards,
Ankur.