3 replies to this topic

[gedditoffme]

Hello all,

 

I'm trying to diagnose a problem with high liquid levels in the discharge scrubber of a natural gas recip compressor package. I have a composition, and out of curiosity am trying to work out how much liquid should drop out due to the compression. This may point to whether the valves are not working, or if there really is just a large amount of liquid in there (so valves need to be resized).

 

How can I work this out?

 

I've tried putting the system into Hysys, but cannot seem to get it to predict liquid production in a compressor - cooler - separator system (having specified all temps, pressures, and input composition). I've also had a go at generating a phase envelope in PVTSim, and can generate a big picture phase envelope 100% vapour - 100% liquid region, but can't get it to break things down more eg the 50% liquid curve.

 

It is possible I'm not using these programs correctly - both feel like I should have gotten an answer from them. What can I do to get an answer?

 

 

[Bobby Strain]

If you complete all the input as required you will get a solution.

 

Bobby

[serra]

for natural gas mixtures std. EOS models such as Peng Robinson or Soave Redlich Kwong

are reasonably accurate (i.e. 1-2 K errors on dew points),

if your software doesn't predict liquid fraction consider some different cause...

you can presume there is no liquid at compressor's discharge conditions,

after that  we can say nothing without detailed information...

[shan]

The middle point between 100% liquid (Bubble Point) and 100% vapor (Dew Point ) is 50% liquid point and 50% vapor point(two phase).