Gas compressors, with different power diver

[wd1980]

Folks;

our engineering companie is proposing 2x 50% compressors configuration.
one is electrically driven and the second is through gas engine working in parallel.

from technical perspective anyone has an experience with this configuration and especially any expected drawbacks, potential issues?

cheers

 

[LittleInch]

So long as the compressors run at the same speed with the same power I can't see a big issue.

The electric one will stay a more constant speed as it will just draw whatever current it needs whereas the gas engine might run out of power.
Gas engines will need more maintenance oil changes etc
Why two different types though?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[georgeverghese]

No problems. But go through the derate calcs on the GE carefully and check with other plants / installations and your mech - rotating machinery engineers if overall derate looks reasonable.
Agreed, you can expect more maintenance for GE than for EM.
Check the materials of construction for the oil cooler on the GE (tubes and especially fins) particularly if this installation is coastal or offshore.

 

[wd1980]

@LittleInch
this is due to electrical availability.

the compressors are reciprocating not centrifugal!

rgds

 

[georgeverghese]

Think you may have more problems with the recip compressors than with the gas engine:
a)Dirt or gunky corrosion inhibitor laden feed gas - install a well sized filter sep to clean up the gas before suction drum
b)Feed gas with high hydrocarbon or water dewpoint coupled with pocketed suction line - feed and insterstage suction lines should be free draining.
c)Problems with piston rod packing, carbon piston rings, scouring of cylinder liner
d)Leaking suction or discharge valves leading to high discharge temp

In many cases, after a few years, gas engine does not develop the required power and speed has to be reduced.

In any case, with this configuration, you can expect mech maintenance staff will be kept busy with these machines after a few years.

 

[catserveng]

Systems with mixed drivers are becoming more common in areas with more stringent air quality regulations. As long as the systems are properly engineered and maintained they work fine together.

Usually in gathering areas, and most transmission areas, available utility power capacity is limited.

Also dual drive technology has evolved and several sites are operating with both gas engine and electric motor drive a single recip compressor.

Other than the issues mentioned above, one big factor I have seen is while the gas patch has a good availability of experienced gas engine technical staff, MV qualified electricians for large motors and drives, at least for now, are harder to come by in a lot of areas.

Your question is very general in nature, easy answer is yes, it can be done, but without more detail, seeing if it will work for your customer and location is up in the air.

MikeL