Refrigeration plant performance

[gcetchem]

Hello,

I have just started working in gas plant. Last year we expanded our gas plant capacity. Very often I have heard operators talking about refrigeration capacity slight changed after expanding gas plant. Can you explain me :
what are the parameters should be observed when comparing old capacity vs new capacity of refrigeration gas plant? means, should i compare referigeration speed/referigerant flowrate/process temperature or any other things. Our is propylene refrigeration plant & centrifugal compressor driven by gas turbine.
I need good suggestions from all experienced engineers.
thanks
gcetchem

 

[dcasto]

Pounds per hour of refrigerent would be a start. To get this you'll need to know density at the suction and the compressor curve. What about interstage flows from high level chillers or economzers.

Why not run a simulation of the system before and after the changes.