Centrifugal vs reciprocating ng compressors
Centrifugal vs reciprocating ng compressors
(OP)
Hello everybody!
I am not a turbine machinery specialist and I would like some advice on the following issue: we need to feed a gas turbine with natural gas (approx. 65.000 Nm3/h) but the pressure of the ng system is relatively low. For this reason we need to install a natural gas compressor, to boost a bit (approx. 5 bars, from 40 barg to 45 barg) and keep the pressure at the inlet of the gt burner at a sufficiently high point. We are currently considering two types, centrifugal vs reciprocating. Since the no1 target is the minimization of the energy consumed in the compressor, what would be the suggested type?
Thanks in advance!
I am not a turbine machinery specialist and I would like some advice on the following issue: we need to feed a gas turbine with natural gas (approx. 65.000 Nm3/h) but the pressure of the ng system is relatively low. For this reason we need to install a natural gas compressor, to boost a bit (approx. 5 bars, from 40 barg to 45 barg) and keep the pressure at the inlet of the gt burner at a sufficiently high point. We are currently considering two types, centrifugal vs reciprocating. Since the no1 target is the minimization of the energy consumed in the compressor, what would be the suggested type?
Thanks in advance!





RE: Centrifugal vs reciprocating ng compressors
This paper should help you. It has been prepared by Centrifugal and Reciprocating experts.
RE: Centrifugal vs reciprocating ng compressors
I have not failed. I've just found 10,000 ways that won't work."-Edison "If Edison had a needle to find in a haystack, he would proceed at once to examine straw after straw until he found the object of his search. I was a sorry witness of such doings, knowing that a little theory and calculation would have saved 90% of his work.- Tesla
RE: Centrifugal vs reciprocating ng compressors
RE: Centrifugal vs reciprocating ng compressors
I have not failed. I've just found 10,000 ways that won't work."-Edison "If Edison had a needle to find in a haystack, he would proceed at once to examine straw after straw until he found the object of his search. I was a sorry witness of such doings, knowing that a little theory and calculation would have saved 90% of his work.- Tesla
RE: Centrifugal vs reciprocating ng compressors
If your goal is lower cost and your gas is reasonably light, then a recip fits that goal far better than a centrifigul almost all of the time. Considerations of pulsation, surge, oil caryover, etc. can all be engineered out of either machine through competent packaging.
In my practice, I say that the only time you want a centrifigul compressor is when energy density is the key design consideration (e.g., on an offshore platform). You can mate a centrifigul to a turbine and move a bunch of gas with very little deck space. Other than that, there are better ways to solve most problems.
I can't emphisise enough that a great package can get rid of most inherent disadvantages while a poor package can get rid of all inherent advantages.
David
RE: Centrifugal vs reciprocating ng compressors
Interstate gas transmission is virtually all done by centrifugals. In fact, I can't think of one recip I know of installed in an interstate transmission system (outside a liquid extraction plant), on a liquid or gas pipeline. I've only used gas recip compressors for gathering systems where relatively low volumes, small diameter pipe and high pressure ratios were the optimal solution, with little liquids and for very low volume and high pressure injection of blown down and interface fluids on crude oil and product lines.
I have not failed. I've just found 10,000 ways that won't work."-Edison "If Edison had a needle to find in a haystack, he would proceed at once to examine straw after straw until he found the object of his search. I was a sorry witness of such doings, knowing that a little theory and calculation would have saved 90% of his work.- Tesla
RE: Centrifugal vs reciprocating ng compressors
I know there are a lot of centrifugals onshore, but I've never seen the economic or technical analysis that put them there. Every time I've done that analysis onshore, the centrifugal comes up way short. I'm probably missing something when I run the numbers.
David
RE: Centrifugal vs reciprocating ng compressors
RE: Centrifugal vs reciprocating ng compressors
A wider range of flowrates, much higher reliability, faster repairs and overall lower maintenance costs are supposedly the greatest advantages of centrifugals for transmission service.
I have not failed. I've just found 10,000 ways that won't work."-Edison "If Edison had a needle to find in a haystack, he would proceed at once to examine straw after straw until he found the object of his search. I was a sorry witness of such doings, knowing that a little theory and calculation would have saved 90% of his work.- Tesla
RE: Centrifugal vs reciprocating ng compressors
Pressures are too high for screws to be an option.
David
RE: Centrifugal vs reciprocating ng compressors
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25,000acm/h at 60 BARG here too.
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The transmission companies got away from turbine centrifugal packages when gas was deregulated. Fuel became the KING and not a "rate base and the whole fuel cost could be passed on to the consumer" based industry imurged.
RE: Centrifugal vs reciprocating ng compressors
Those are interesting machines, last time I got a quote from packagers who carry Kobelco and Howden, the packager was claiming long lead times (on the order of 56 weeks) for 350 psig MAWP machines, I'd hate to think how far out these beasts would be.
David
RE: Centrifugal vs reciprocating ng compressors
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RE: Centrifugal vs reciprocating ng compressors
What are the hours of the deal in Purgatory? I may have to go to Albuquerque on Saturday, but if I don't I'll be there.
David
RE: Centrifugal vs reciprocating ng compressors
Other events are coming up soon. On August 23, United Way supporters in Archuleta County can play in the annual charity golf tournament. Also on August 23, residents of La Plata County can attend the 10th annual San Juan Brew Fest in downtown Durango. This event has been held at Purgatory at Durango Mountain Resort for the last nine years, but this year is moving to downtown Durango from 1:00 pm to 4:00 pm. The 10th annual San Juan Brew Fest will bring 20 brewers from all parts of the Southwest to Durango, and this year proceeds will benefit United Way.
Rats sorry we missed ya, we took first place in the fish cooking catagory for our blacken Talapia.