Gas Burning Gas Turbines
Milt
Most of your questions have been answered by previous posters and in general they are correct.
As has been pointed out our (Solar) units are industrial gas turbines but built along aviation lines as opposed to the heavy industrial units built by the likes of GE, Westinghouse and many others.
I have never heard of a gas turbine of useable power output running at 3000rpm, as has been pointed out they tend to run at very high (relative to recip engines) rpms which is reduced to the correct speed for the frequency required. This is one of the drawbacks with turbines when applied to say an automotive use, they tend to be happier at high rpm and they have a fairly narrow throttle control band.
Our units as used for power generation tend to be of the duel fuel type which is gas (natural) or diesel. They are usually set up to run primarily on gas but in the event of a loss of gas fuel pressure due to a process fault for example they will transfer automatically to liquid to ensure uninterupted power supply.
The duel fuel injectors are designed to accept both fuels.
Solar
Most of your questions have been answered by previous posters and in general they are correct.
As has been pointed out our (Solar) units are industrial gas turbines but built along aviation lines as opposed to the heavy industrial units built by the likes of GE, Westinghouse and many others.
I have never heard of a gas turbine of useable power output running at 3000rpm, as has been pointed out they tend to run at very high (relative to recip engines) rpms which is reduced to the correct speed for the frequency required. This is one of the drawbacks with turbines when applied to say an automotive use, they tend to be happier at high rpm and they have a fairly narrow throttle control band.
Our units as used for power generation tend to be of the duel fuel type which is gas (natural) or diesel. They are usually set up to run primarily on gas but in the event of a loss of gas fuel pressure due to a process fault for example they will transfer automatically to liquid to ensure uninterupted power supply.
The duel fuel injectors are designed to accept both fuels.
Solar
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Solar:
Many of the industrial aeroderivatives operate at either 3000 rpm output shaft speed (for 50hz) or 3600 rpm (for 60hz). They do this through the use of Low Pressure (power) Turbines which are aerodynamically coupled to the High Pressure Turbine.
In many cases, these LPT (power) turbines alleviate the need for large, heavy reduction gearboxes. The GE LM2500's offshore Norway, for example, do not need reduction gearboxes. However, many other aeroderivatives still need a reduction gearbox to get to the generator's required 3000 or 3600 rpm.
I have never heard of a gas turbine of useable power output running at 3000rpm,
In many cases, these LPT (power) turbines alleviate the need for large, heavy reduction gearboxes. The GE LM2500's offshore Norway, for example, do not need reduction gearboxes. However, many other aeroderivatives still need a reduction gearbox to get to the generator's required 3000 or 3600 rpm.
Matari
I suppose thats the same princible as turboprops operate under.
In our units we generally use single shaft units for power generation through gearboxes and split shaft trubines (aerodynamic coupling) for other applications like gas compression or water injection pumps.
With the advance of electronic control technology we now also use the split shaft configuration for the larger turbines 10MW plus but even on these units the generator is driven through a gearbox as the power turbine rpm is well in excess of the normal frequencys.
I suppose thats the same princible as turboprops operate under.
In our units we generally use single shaft units for power generation through gearboxes and split shaft trubines (aerodynamic coupling) for other applications like gas compression or water injection pumps.
With the advance of electronic control technology we now also use the split shaft configuration for the larger turbines 10MW plus but even on these units the generator is driven through a gearbox as the power turbine rpm is well in excess of the normal frequencys.
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Whatever solution is used, it's certainly man-sized engineering, and proper noisy, just like it should be
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These are very common offshore and burn fuel gas (85% methane,10%ethane, 5% propane/butane mix) or marine diesel when the gas is not available. The diesel is pumped in through separate burners and some of the better machines can run on both fuels at once, and change from one fuel to the other without losing load.The fuel gas delivery pressure is 15.0 barg and is in the gaseous phase. I am unaware of any liquid gas driven turbines, and those who have accidently done this usually end up with a turbine write off. The burners are pepper pots. Once you get them started they run 24/7. Some of these engines, including 24 month overhauls, have been running for 30 years. Avons, RB 211, Olympus, and GE engines are commonly used. Highest power outputs I have seen are of the order of 24 MW. Power is delivered at 3.3KV and transformed down to 440, 240 and 110V.Turbine speed is as mentioned earlier controlled to give 50 or 60Hz. Most Platforms have up to 3 main generators. As well as driving alternators turbines are used offshore to drive centrifugal compressors, high pressure water injection pumps and crude oil pipeline dispatch pumps. Just like the APU on an aircraft we also have 1-2MW turbines for startup, though diesel driven alternators are also used for this purpose.
In the early days the engines were all American and thus 60 HZ. The British shipyards building the infrastructure were initially unaware of this so we had many clocks in the early days which seemed to make the day pass quickly!!
In the early days the engines were all American and thus 60 HZ. The British shipyards building the infrastructure were initially unaware of this so we had many clocks in the early days which seemed to make the day pass quickly!!
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Now to Co-generation and Overflights.
Fascinating to learn of the ways aircraft gas turbines have been adapted to become reliable quick start electrical power generators and that some apparently run 24/7 non stop for yonks.
Am still intrigued with the methods of injecting high pressure gaseous fuel into the burners and how much the engines have to be derated. Didn't the Avons run at 7600 rpm full chat?
Heartell that some installations get maximum efficiency using co-generation. That is the high temperature exhaust gases are passed through heat exchangers to make steam to drive auxilliary turbines. What a masterpiece of gubbinry that must be. Anyone have a diagram?
Then as a TP I have to be concerned about the effects of the final exhaust plumes on a low flying lighty? Navies must have a problem also overflying funnelled exhaust plumes from a ship's gas turbines.
Fascinating to learn of the ways aircraft gas turbines have been adapted to become reliable quick start electrical power generators and that some apparently run 24/7 non stop for yonks.
Am still intrigued with the methods of injecting high pressure gaseous fuel into the burners and how much the engines have to be derated. Didn't the Avons run at 7600 rpm full chat?
Heartell that some installations get maximum efficiency using co-generation. That is the high temperature exhaust gases are passed through heat exchangers to make steam to drive auxilliary turbines. What a masterpiece of gubbinry that must be. Anyone have a diagram?
Then as a TP I have to be concerned about the effects of the final exhaust plumes on a low flying lighty? Navies must have a problem also overflying funnelled exhaust plumes from a ship's gas turbines.
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To all the participants in this discussion
Fascinating discussion! I stumbled across this forum when I was doing a search for information on the industrial versions of Rolls Royce's Olympus jets..... called an "industrial gas generator" . It's probably well known that they are used for propulsion in some of the British navy ships, and these are installations wherein the hot gas stream from the engine is piped directly into a separate (and big and heavy!) power turbine. The torque from the PT can drive whatever is coupled to it. In my home town, Dresser Rand had a manufacturing plant where they built huge industrial turbines and gas pipeline compressors. They did a lot of work with the Rolls RB211's, which drove a power turbine coupled to a gearbox and thence to a huge gas pipeline compressor. The engine itself was powered from the same natural gas that was in the pipeline. I could hear them running from my house... beautiful noise! I worked with Pratt & Whitney Canada building our little PT6 turbines for fifteen years ..... marvellously simple, rugged and reliable little wonders.... sewing machine motors compared to the big stuff, of course. Some of those were the ST6 version, which were the industrial version, used for (small) applications much like the big units in these discussions.
So here's my question:
I was asked by a friend to take a look at some turbine parts near my home town, which turned out to be leftovers from a stillborn electrical power generation project. A bit of research showed it to be a Rolls Royce Olympus installation, driving a Rolls Royce SK20 power turbine, which was coupled to a 26 MW 50 cycle electrical generator. (origin was out of North America.... we run all 60 HZ here) There is a generous stock of new spare bearings, combustors, fuel nozzles, temperature probes, etc. with it, but the parts manuals and technical drawings, etc. all went astray when the project ground to a halt. I noted posts from a number of individuals in this thread who seemed well experienced with these aeroderivative installations, and am hoping that one of them might be able to refer me to someone working with an Olympus installation who could help me locate the parts breakdowns I need to identify and sort these items. Any leads would be much appreciated.... maybe I can get this stuff to someone who needs it!
As a side note to the turbines, the concept of aeroderivative power sources existed well before the advent of turbines of course...... In the eighties, the town of Foremost, down near our Alberta/Montana border, was a hotbed of tractor-pulling activity, and one group had an Allison V1710 in about a '39 Chev 1 or 2 ton truck chassis for the pulls. (there are truck as well as tractor classes).
I owned an automotive speed shop at the time, and I built several engines for the participants, and wanted to build a pulling tractor myself, so I began hunting for a suitable powerplant. As our area was home to part of the Commonwealth Forces air training program during WWII, there was still a considerable amount of surplus aviation materiel around, and it wasn't long before I found a Rolls Royce Merlin engine, then another.
Then I hit the jackpot!
It seems that a gentleman who had been a flight engineer with the RAF during WWII had gone to work for Dresser Industries after the war, in the oilfield servicing industry. At the time, the huge triplex pumps used for pumping drilling mud down into the oil bearing rock formations (to fracture the rock and open up passages for the oil flow) required a powerplant the size (and unfortunately the weight! ) of a locomotive engine. Bringing equipment of that weight into some of the oilfields over muskeg areas was a tricky business. The gent I am referring to had a better idea...."why don't we buy up some of these war surplus Merlin engines...... they're up in the 1600 horsepower range like a locomotive diesel...... and use them to run the pumps???" And they did, with resounding success. After that when Dresser was on wellsites with their fracturing rigs, it sounded like Bomber Command was flying over the site! As time went on, they accumulated a lot of used equipment at their storage site south of Edmonton, and I was given a bunch of the Merlin engines... what a find! Alas, my project was not to be....... I ended up selling the engines to one of the unlimited hydroplane teams, where they doubtless provided lots of thrills and noise.
Ahh..... the love of machinery! Anyways, if anyone out there has a clue where I can get my hands on some of the paperwork I need, drop me a reply or a line...... thanks!!
So here's my question:
I was asked by a friend to take a look at some turbine parts near my home town, which turned out to be leftovers from a stillborn electrical power generation project. A bit of research showed it to be a Rolls Royce Olympus installation, driving a Rolls Royce SK20 power turbine, which was coupled to a 26 MW 50 cycle electrical generator. (origin was out of North America.... we run all 60 HZ here) There is a generous stock of new spare bearings, combustors, fuel nozzles, temperature probes, etc. with it, but the parts manuals and technical drawings, etc. all went astray when the project ground to a halt. I noted posts from a number of individuals in this thread who seemed well experienced with these aeroderivative installations, and am hoping that one of them might be able to refer me to someone working with an Olympus installation who could help me locate the parts breakdowns I need to identify and sort these items. Any leads would be much appreciated.... maybe I can get this stuff to someone who needs it!
As a side note to the turbines, the concept of aeroderivative power sources existed well before the advent of turbines of course...... In the eighties, the town of Foremost, down near our Alberta/Montana border, was a hotbed of tractor-pulling activity, and one group had an Allison V1710 in about a '39 Chev 1 or 2 ton truck chassis for the pulls. (there are truck as well as tractor classes).
I owned an automotive speed shop at the time, and I built several engines for the participants, and wanted to build a pulling tractor myself, so I began hunting for a suitable powerplant. As our area was home to part of the Commonwealth Forces air training program during WWII, there was still a considerable amount of surplus aviation materiel around, and it wasn't long before I found a Rolls Royce Merlin engine, then another.
Then I hit the jackpot!
It seems that a gentleman who had been a flight engineer with the RAF during WWII had gone to work for Dresser Industries after the war, in the oilfield servicing industry. At the time, the huge triplex pumps used for pumping drilling mud down into the oil bearing rock formations (to fracture the rock and open up passages for the oil flow) required a powerplant the size (and unfortunately the weight! ) of a locomotive engine. Bringing equipment of that weight into some of the oilfields over muskeg areas was a tricky business. The gent I am referring to had a better idea...."why don't we buy up some of these war surplus Merlin engines...... they're up in the 1600 horsepower range like a locomotive diesel...... and use them to run the pumps???" And they did, with resounding success. After that when Dresser was on wellsites with their fracturing rigs, it sounded like Bomber Command was flying over the site! As time went on, they accumulated a lot of used equipment at their storage site south of Edmonton, and I was given a bunch of the Merlin engines... what a find! Alas, my project was not to be....... I ended up selling the engines to one of the unlimited hydroplane teams, where they doubtless provided lots of thrills and noise.
Ahh..... the love of machinery! Anyways, if anyone out there has a clue where I can get my hands on some of the paperwork I need, drop me a reply or a line...... thanks!!
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One of my early jobs (late 60s) involved an LM1500 aeroderivative of the J79, upwards of 15K shp and light enough to be airlifted (in modules) to a remote natural gas pipeline pumping station. It ran on NG of course. 
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Turbines
Years ago I did some work for Cal-Pine, a small Power generating firm located in Antioch, California. Having seen the powerplants before at MOC UAL in SFO, I recognized them right off. JT8-D's. What a treat working in that sound and smell. I can't recall if they had 4 GU's or cascaded the engines, but I have a possible suggestion for mobile HP.
You are of course familiar with the Chev. 454 RAT. There is a new engine available for Street driving based on that architecture. It is all Aluminum, burns pump Fuel, weighs five Hundred Pounds, and develops 2200 HP.
821 CID, 3 HP per CI. Impressive.
AF
You are of course familiar with the Chev. 454 RAT. There is a new engine available for Street driving based on that architecture. It is all Aluminum, burns pump Fuel, weighs five Hundred Pounds, and develops 2200 HP.
821 CID, 3 HP per CI. Impressive.
AF
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Originally Posted by Solar
I have never heard of a gas turbine of useable power output running at 3000rpm...
The GE LM6000 quoted earlier produces over 40MW, which is a lot of useable power in my book. The LP turbine section of that one runs at 3600 rpm, so a 3000 rpm turbine is perfectctly feasible also.
When I tried to read up on the subject some time ago, I got the impression you have:
- twin-spools like the LM6000 with the LP section already running at 3600 rpm, so you can take power directly off the shaft (front or back), without a gearbox,
- nearly-original jet engines such as the Olympus, with a large box with a free turbine bolted on the back, which then drives a generator at 3600 or 3000 rpm directly, or something like a ship's propellor shaft through a gear box,
- smaller single-shaft engines with added turbine stages (cf. turboprop engines) that normally will need a gearbox.
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Airfoilmod:
Did you happen to see the LM2500 at UAL SFO? As I said earlier, that machine is a derivative of the CF-6/TF39 gas turbine that powered the C-5A.
I believe UAL's LM2500 is used in a "cogeneration" application where heat from the exhaust is routed to a heat recovery steam generator, which produces steam for heating or other processes.
It is a remarkably reliable, and thermally-efficienct system.
Having seen the powerplants before at MOC UAL in SFO, I recognized them right off.
I believe UAL's LM2500 is used in a "cogeneration" application where heat from the exhaust is routed to a heat recovery steam generator, which produces steam for heating or other processes.
It is a remarkably reliable, and thermally-efficienct system.
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Originally Posted by Matari
It is a remarkably reliable, and thermally-efficient system.
Run them at the optimum rpm, optimum air flow, optimum fuel flow and EGT, maintain them properly, and gas turbines will last nearly forever.
Just keep them away from bird strikes, TOGA "slams" and all those other things pilots will subject them to....
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ChristiaanJ:
You're right. Typical (modern generation) natural gas fired powerplants run 25,000 hours between hot section inspections, and 50,000 hours between major overhauls. Regular maintenance of air inlet filtration systems keeps the threat of compressor damage low.
The biggest killer of land or marine gas turbines is fuel quality. Industrial gas turbine operators rarely have the strict fuel specifications and handling procedures of airlines...and no oversight from a regulator authority like the JAA/CAA/FAA. Therefore poor fuel often gets downstream into the turbine.
This is true with diesel (DF2) but also with natural gas fuel. Slugs of condensate, traces of vanadium, sodium, etc. can destroy a hot section very quickly. Operators who fail to invest up front in good fuel sourcing, maintenance practices and fuel filtration systems regret it not long after the units are commissioned.
Run them at the optimum rpm, optimum air flow, optimum fuel flow and EGT, maintain them properly, and gas turbines will last nearly forever.
The biggest killer of land or marine gas turbines is fuel quality. Industrial gas turbine operators rarely have the strict fuel specifications and handling procedures of airlines...and no oversight from a regulator authority like the JAA/CAA/FAA. Therefore poor fuel often gets downstream into the turbine.
This is true with diesel (DF2) but also with natural gas fuel. Slugs of condensate, traces of vanadium, sodium, etc. can destroy a hot section very quickly. Operators who fail to invest up front in good fuel sourcing, maintenance practices and fuel filtration systems regret it not long after the units are commissioned.
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I believe UAL's LM2500 is used in a "cogeneration" application where heat from the exhaust is routed to a heat recovery steam generator, which produces steam for heating or other processes.
BTW, the LM2500 burns Jet-A from the test cell ("bench") fuel farm - I once had to plan my engine tests around the fuel burn rate of the LM2500 so we avoided running on fumes!
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"barit1,
Stupid question, really, but in the context I presume Abu DHabi has large bauxite deposits?
CJ"
NO, but it has access to cheap gas and this plus GE Turbines = CHEAP Electricity & thus reasonably priced Aluminium
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Stupid question, really, but in the context I presume Abu DHabi has large bauxite deposits?
CJ"
NO, but it has access to cheap gas and this plus GE Turbines = CHEAP Electricity & thus reasonably priced Aluminium
PZU - Out of Africa (Retired)