Power Turbines and How They Work
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- เผยแพร่เมื่อ 25 ก.ค. 2024
- Balancing and building up the power turbine used with an LM1500.
Plus a whiteboard talk explaining how power turbines are installed and used with large industrial gas turbine engines. - ยานยนต์และพาหนะ
Seeing those large PT blades and disks rotating out in the open on the balancer is somehow vaguely much more terrifying than watching the actual engine/gas generator tests where everything is mostly out of sight and mind inside the casings, even though it's 1/10th the speed.
It really demonstrates how much rotational mass and kinetic energy is involved. Also: whirling high speed pointy knives.
Im a commercial pilot training now for Airline license , and even though they teach us about basic turbine / jet operations I find that they miss out alot of things because there is also so much more to know in other operations of flight. So I come to your channel as a supplement to my Jet engine knowledge. I know its just the basics but thats all you really need to know as a pilot. Plus I find your videos are fun to watch
Many years ago I toured a natural gas compression station near Caron SK. They had two gas turbines at the installation but only had one running when I was there. I was astounded by how neat and compact the turbine assembly was. The turbine room was a smaller room within a building, there was a view window to watch the thing in operation, and at the front was a large filter that connected to outside. The front end of the turbine protruded from the assembly and drew air from the room which was fed by the filter. It was noisy, even with ear plugs, but there was a rightness about it. It was so powerful yet so compact that it is little wonder why a gas turbine is the preferred way of powering those huge pipeline compressors. I recall reading that one company is looking at power generation using the exhaust heat from their compressor turbines, something on the order of 14MW per station. That's pretty huge, recovering that much otherwise wasted energy.
I saw a clip of a 15,000 horsepower Marine Diesel once. The engine was as big as an apartment block. Meanwhile, the Kutznetov NK-12 makes the same power and is about 30 times smaller. Gas Turbines are the future.
I work for Pengrowth down in Judy Creek Alberta. I'm pretty sure you guys are rebuilding our Turbines now. I have a feeling that exhaust housing is from our plant. Pretty cool stuff, like the vids. Keep up the good work!
Best TH-cam subscription so far.
Awesome presentation as always! Thanks SO VERY much for sharing your knowledge with us! I have a new fascination with jet engines now all because of your videos!
great description !
I have a number of good questions that maybe some of your other video might answer. The rough values of energy in, out and used helps to understand so much more of how these work. Thanks
As always, I'm really amazed by all the detailed explanations.
Thank you very much from the Netherlands!
Great vid and explanation of how this all works, thanks for sharing
Hi, I didn't know about the heat exchanger with water! The exhaust gases from the power turbine goes to make steam! For me at the beginig was like a reduction of power, but it is another function for this system! Thanks for sharing these videos, thera are many things to learn! Phenomenal job!
"all sorts of violence" at 3:04 classic
Love your momentary of technical specs...
That was REALLY interesting!! The words "STAND CLEAR" have real meaning there.
Another super interesting video. 👍
Great informative video there, Jay. Enjoyed it! Thanks again.
DD
AWSOME video mate!
How come you don’t wear gloves when working on these blades and discs? I was also taught to prevent natural oils or contaminants getting on the blades which in turn could create hot spots.....
I have always been very interested in jet engines and how they work. I love your videos. Greeting from Iceland.
ALOT of GREAT info thank you
Thanks. This is a great channel.
I worked at a potato plant for 2 days (didn't keep the job cause of reasons). The guy that was showing me around told me that the power company had a lease agreement with the plant to supply them steam in exchange for having land to put a power plant on, it was a small power plant the guy said there was a 'Jet Engine in there'. So that would be an example of a use for the steam generated by the waste heat. =)
Thank you , I really enjoy the videos you make . I'm from St Marys West Virginia .
Great to see some new hardware! Thanks Jay. What is that tiny turbine out of?
Nice explaining.
sweet rocket car markers! learned about the collector exhaust. used for stuff.Thx also how to quiet these engines down.
So amazed. If an engineer told me what it would take to build a jet engine, the tolerances, the toughness, the speeds, the heat. I’d just tell them, nope. Can’t be done. Let’s stick with pistons. Amazing.
Great job ..keep it up
Interesting stuff.. Thanks
For everyone asking about the damping wire:
_QUICK NOTE_
_Damping, Lacing, and Binding wires are used in steam turbines_
*TURBINE BLADE VIBRATION*
Damping wires, Lacing wires and shrouding are fitted to:
- reduce stress due to vibrations in the blade excited by such as steam flow fluctuations as the blades pass the nozzles. This is referred to as the 'passing frequency'. This particularly occurs with partial admission
- To prevent spreading of the long thin blades found in the final stages of the LP turbine. Shrouding is not fitted to these blades to allow adequate drainage. Due to the high specific volume losses due to spillage is relatively small
- Steam changing direction as it passes over the blade tends to build up in the concave face. There is a tendency to flow to the tip where if unchecked it can spill over leading to considerable loss of efficiency. This is particularly important in parsons turbines expecially as the initial stages of the HP turbine where the steam has a low specific volume.
*LACING, DAMPING, and BINDING WIRES*
There are four sources of vibration damping under normal operating conditions:
- Internal damping of the blade material
- Inherent dry friction damping of the blade assembly at the root and tip
- Fluid damping or viscous damping due to the steam environment
- Mechanical damping through fitting of damping aids such as damping or lacing wires etc
Lacing wires fitted at an antinode provide a very effective form of dampening. However, the antinode may exist at different positions for the different types of vibration so a compromise on the position has to be reached.
A Damping wire which is 'free fitting' is free to move within the holes. Centrifugal force throws the wire to the outside of the hole where frictional effects help dampen the vibration. The disadvantage of damping wires is that heavy fretting can eventually cause the holes to widen to an extent that the rotor has to be re-bladed.
Lacing wires are brazed in and are therefore strengthening and hence are not necessarily placed at an antinode but rather where the blade is thickest.
Binding wire is used to strengthen the trailing edge of the blade. This is a very old fashioned technique and is little used.
Great stuff - thanks for breaking it down for us!
Simply, complex!
Great vid...Would have been good if you showed how the stabilizing cable was inserted and secured ?
Watching the PT rotor disc spinning really helped me visualize how much air this thing is pumping/compressing/igniting out of the exhaust when it's fully assembled and operational.
Turbines of any kind do not pump or compress air. They are like windmills. Their only function is to take energy out of a flowing stream of fluid, and use that energy to turn a shaft. They are the exact opposite in function to a fan.
I am not trying to doubt any of your knowledge but why is there a compressor stage in the engine if they don't compress?
You are getting all confused. A compressor is not a turbine. The two are exactly the opposite.
When you said "this thing" in your first comment, I assumed you meant a power turbine.
It is possible you meant something else: the gas generator that feeds gas to the power turbine. Gas generators are also often called engines. They are turbine engines.
One of the most common mistakes people make is to call a turbine engine a "turbine".
If that's what happened here, well, you can see the confusion it caused.
Because all the parts look similar, and sound similar, and even have similar sounding names, it is very important to use the correct terminology.
The video is about power turbines. If you meant turbine engine, then I misunderstood you.
AgentJayZ I'm sure you have to educate a lot of people in the comments, thank you for taking the time to respond to mine.
In between the cgt and pt you could put a copper ring which is highly conductive and connect that to a sterling engine for even more power efficiency
Your videoss are great, it is awesome that you take the time to educate random people in the world wide web! You shouldve become a proffessor(?) haha.
NO confusion now
Very clear explanation!
45,000 - 30,000 x .87 = 13,050 hp
8000h is a very impressive overhaul interval. I would have guessed much less...
That's just over one year of 24/7 operation.
Actually, it's a little bit over 333 days, which is still impressive, compared to petrol engines.
Dino Alberini
Oh yes, sorry. 1 (non-leap) year is 8760 hous.
Nice choice of music :-)
Brilliant
Sorry if this is already covered in a video I have yet to see, to what tolerance are you balancing the turbine? 0,1g? When balancing the rotor in an ultra-centrifuge (45000 rpm) we kept it around 5-10mg.
Just when I thought the 44mm turbo on my Buick grand national was big n crazy !
Love the sunnies, what make and model are they? The tint is very cool.
Hey Jay! So question about the blade wire. It was hard to see but it looks like where the two ends meet between the blades is open? I take it that it needs to be for expansion? Also, the turbine set being balanced in the video was without wire, I'd guess they balance the blade/disk and then install the wire and rebalance? Looks like a pain in the ass to install! Kinda performs the same function as snubbers on some fan blades. Snubber Wire? lol
Cheers!
I missed a day of shooting during this build. The blades are swapped for balancing, then the wire is installed, and then the little balance weights are moved for final balance.
The wire is for damping of vibration, so you could call it snubber wire if you really want...
Great video as always. Have you ever worked on any marine gas turbines? I'm assuming they will be rather much exactly the same.
FrontSideBus There is more protection from corrosion by salt spray, etc... but you are right.
The LM in the name of the LM500, LM1500, LM1600, LM2500, LM600 stands for Land and Marine...
So the answer is yes.
Within how many grams do you balance the rotor? Do you balance again after pinning the blades in? I would think that there would be weight variances on each locking pin.
Good stuff as always. Keep it up.
I bet osha loooves that rig
Fascinating...Very cool... I love the turbine balancing device... Do you have any clips on putting the damper wire thru the blades and how it's all secured ?
Norway, being a small country, hasn't invented very much but the Agidius Elling is considered as the father of the gas turbine as he in 1903 was the first to invent a turbine that produced more power than it required to run its own components. The development of the turbine engine involves many inventors and it was far from a one man achievement, but Elling introduced compression stages as well and his contribution was substantial.
en.wikipedia.org/wiki/Gas_turbine#Timeline_of_development
en.wikipedia.org/wiki/%C3%86gidius_Elling
Who made the other balancing machine (the blue one)?
Does the discoloration on the end of the un-mushroomed end, belong to the machining proces or a de-hardening heating step so it can be deformed more easily?
The wire was cut with a grinding wheel, and this caused a great deal of heat. Metals used in turbines get their strength from basic properties. The parts work in service at temperatures which would destroy any heat treatment changes in properties.
Interesting inside look Jay. Just out of curiosity , what type of oil is used in gas turbine / jet engines? Silicone /Synthetic base? I know full well that it can't be conventional because of the high rpms and heat. What viscosity ? Multivis. Or single vis. And it has to be refined / purified for obvious reasons. As I've mentioned before thanks for giving us viewers an inside look at things and you and Robin are more generous than those stuck up " big guys."
If space within the housing permitted, you could install a sealed pipe ring on the disk. Within the ring you would drop in 3 or 4 ball bearings that would be free to roll in the tube. At any/all speeds, centrifugal force would throw the ball bearings out, continuously balancing the disk with extreme precision.
Exactly the opposite. If there was any displacement in the bearings due the extra force of a heavy spot, the balls in this supposedly perfect circular tube would be attracted there, adding to the imbalance, increasing the displacement, increasing the attraction of the balls... oops, it just blew up.
@@AgentJayZ Good point. I'll fab up a little jig and give it a try.
I'm surprised the dampening wire does'nt ware wear larger holes in the turbine blades and cause problems.
my guess is it's made of a softer metal than the blades, and therefore takes all the wear.
The name of the manufacturer of the 100 KW Power Turbine/generator you have shown later in the amazing presentation, Please? Thank You.
Have you thought about “Sputtering” the coatings on the turbine blades?
I really admire your channel, Not been critical of your expertise, but is it safe to stand next to than spinning, where it's not in a casing, a blade flying off
+Teddy Bass
Blades don't fly off.
It's safe so long as you don't bump into it, so we don't do that.
in researching the diagrams you have recommended, I have noticed there is a gap between the Low Pressure turbine and the High Pressure turbine sections. Also, there seems to be a gap between where the exhaust exits and where the Power turbine section begins. Is this just the way the diagrams were drawn and there is no gap? If it is a gap, is it there as a convergent /divergent process to increase exhaust velocity? Or, is there a diffuser in that gap but just not represented in the diagrams?
can u use this to temper glass in a factory,when i was at a glass factory it had a high pitched sound and loud u could hear the high rpms?
To me 150lbs of air makes sense but, give it a volume, say 10,000 cubic meters, and people can get a feel for it. ( 6 large barn fulls of air per second )
How do you insert wire trough blades? I presume you insert wire before you insert blades on disk.
Does the 5250 RPM figure occur due to the relation to that being the top of the torque curve?
Well, correction, where the torque curve always meets with the HP curve on a graph.
Question Jay you do a dynamic balance without the blades locked in? Is there a chance of a blade coming loose when the assembly is spinning without the locking rivets? You walked right passed the blades so I doubt there would be much in the way of this but was just wondering. Another great video and you don't give yourself enough credit with your art ability, makes it easy to follow.
The answer is simple, but with important details, so I'm going to put that one in Q37. Be a couple weeks, because there is a quite a line up of good questions like yours...
Does the turning turbine produce a lot of wind on it's backside while the balancing?
Depends what you call a lot.
A turbine turning in the direction it is normally going when driven by wind, is a very inefficient fan.
Swell breakdown!! BUT...let me ask you a question: Would lets say 12-1000 hp piston engines use more or less fuel than this power turbine jet engine? Thanks For all you do Jay! Ron
+69tinatforme. Or one 12,000 horsepower piston engine.
I think a 12 hp engine would use less fuel per unit time, not sure about 1000
Was curious what the gears look like that change the shaft rpm from 5250 to 7200 rpm? Also the gears are in a high temperature environment, so how are they lubricated? Or, is one turbine running at 5250 and another one at 7200?
What is "high"? The gearbox is lubricated with oil. A PT is often connected to a gearbox, but not always. I don't know what you are asking with those specific numbers. Many PT's designed to turn electrical generators do not have gearboxes.
Thanks for replying. The whiteboard discussion showed 7200 rpm at the compressor and 5250 at the turbine output shaft. I was trying to find out if the 7200 rpm was from one turbine wheel and the 5250 was from a separate turbine wheel, or if instead, there was some kind of speed-changing gear to get the two different rpms. Regarding oil cooling, I see the point.
Thanks. If my line of questions is a distraction from what you are trying to get across in your awesome videos, I can understand that and maybe I should just sit back and enjoy. Thanks again.
@@AgentJayZ
Hey, first of all - than you for your great vids!
I've got one remark regarding amount of energy in output gases of LM1500 gas generator:
I guess it is more correct to say that it includes 15k of kinetic energy (which can be extracted by power turbine by mechanic impulse exchange) and 30k of internal energy of gas (pure thermal, does not include mechanic impulse) .
Otherwice it is not clear, where other 30k of energy go from the initial 45k energy of burning fuel (if they remain in engine it would melt quickly =-) )
Regards,
offlaner
Hmmmm...when the engine is not running, it is a hunk of metal, no?
Get it turning, and feed it 45, 000 Hp worth of chemical energy in the form of fuel.
Hit it with a spark or two, and this 45 leaves the combustors as a hot, pressurized stream of combustion byproducts.
Of that 45, 30 is immediately extracted by the turbine and used to power the compressor.
In the gases exiting the engine,15,000 Hp is left over, and can be used by a separate power turbine to drive a load.
AgentJayZ According to my considerations, 30k consumed by compressor are stored in gases (inside the gg) in a form of thermal energy, gas pressure and its kinetic energy. Heating the gas in combustion chamber increases its termal energy and velocity by 45k = at this point total energy of 30k+45k remains in gg; 30k of energy gets recycled by gg's turbine, total of 45k exits the gg. Am I right?
Well, that's how much fuel it burns, and that's how much Hp comes out the back. There is a tremendous amount of waste heat, both in the exhaust, and radiating from the engine itself.
True! I've just ment that out of the gases that come out of gg, roughly 1/3 are recovered by the powerturbine and other 2/3 are lost with hot, but rather slow and thin gases. Howerer, some of this 2/3 energy can be still extracted in a form of heat (exactly what the water steam generator you mentioned is doing). Many thanks for your quick replies! =-)
What is that 75Kw power turbine from ? . . . That could be useful.
It's part of an air turbine starter.
You know what would be cool? One of those things, but to be able to use it as a home fan for warm summers! Of course at low RPM.
A fan and a turbine are like a bat and a catcher's mitt. They have exactly the opposite function.
How far could you hit a ball with a catcher's mitt?
@@AgentJayZ Not very far. Then again, the efficiency can be super bad because in a living room, you don't need much :)
How is the reinforcement damping wire installed and how the ends of the damping wire is secured on the turbine blades?
In order to know all of our secrets, you must become one of us.
@@AgentJayZ Heh, I am partially "one of us"... I am working with ceramic coating machinery (ZrO2 based). Thousand turbine blades finished with ceramic thermal barrier went through plasma coating machinery that I am involved with. I am serving a number of customers across the globe, and of course there is know-how top secret thing. So I understand you...
The power turbine is basically a torque converter, like you find in an automatic transmission. Would that be a good way to understand it?
I would not recommend that. A power turbine is more accurately imagined as a windmill. It takes the energy from a moving flow of gas, and turns it into torque. As a matter of fact, modern windmills are called wind turbines. They are called that because that is exactly what they are.
To start off with imagining a torque converter, you will get lost in the changes and adjustments to your model, and you will end up off-target.
Just my suggestion.
Never seen wire like that on a turbine before. Is it very stiff or is it make more like that soft, white high temp hardware. I'm imagining it's not a pleasurable experience getting it all in place.
Nice music backgrounds
Didn't find the the question/answer in the comments, but what exactly are the average length of the duct connecting the gas turbine to the power turbine? Like you said, it would be best if that length were minimum as to minimize energy losses but in the industry or from your own experience, what has the average length been between the last stage of the gas turbine to the first stage of the power turbine?
+Sophrosyne duct length is basically irrelevant. I've seen the 50cm long, and one that was 50m long, with four 90 degree bends along it's length.
Like the length of the driveshaft of a truck, it has no effect on power, within reasonable but very wide limits.
I don't understand, how are four 90 degree bends not absorbing most of the kinetic energy from the fluid?
What is a recuperator?
Hi AgentJayZ, where i work we have a Rolls Royce Avon MK 1533 GG that runs a gas compressor. Can you create a vid to explain it? Thank you again.
ecordy Yeah, I did. This one. did you watch it?
Since the power turbine is separate from the engine, could a new, modern turbine be installed to extract more shaft horsepower from an old engine?
Yes, modern aerospace turbines are more efficient, but they are more expensive, and optimized for flight, so they are lighter and less durable. These power turbines are built like bridges, and get beat on for a decade or more between service. Plus, to design a new industrial power turbine is an expensive operation, so it doesn't happen very often.
87% percent is already pretty good. A more modern design could squeeze out a few more percent, but it would probably take decades to amortize.
How are those reenforcing rings installed?
The wire? In order to learn our secrets, you must become one of us...
Does the weight of the Sharpie ink create any problems? I'd be afraid to put my finger prints on any of these parts.
Jay so the old question comes up: (and I only think I know the answer, it will likely never be proven by an actual working model). Can a jet fly faster than the speed that its exhaust gases exit the jet engine? I know it's kind of a naive question, but given Thrust = Mass Flow x Velocity I think a huge diameter engine could theoretically do it. Ah, it's a silly point to argue. I don't mind if you call me a knucklehead for asking. Love your videos for no other good reason than great technical dope.
Could I get one of those to make a wind mill from?
Yes. It would be terribly inefficient, because it is designed for wind at 600 mph, but we will sell you one!
When you panned over the door to the shop I thought it said "Old Fart Road". Bwahahaha
How are the ends of the 'damping wire' joined?
They aren't joined together, but they are hammered to slightly flatten them so they could never actually pass through the hole.
Kind of over-doing the safety, because I've never seen a segment of this wire move, even after years of running.
AgentJayZ How is the wire installed? Is it simply bent slightly and slid in place?
That is one of those things you will only know if you become one of us...
"simply" ? Ha !
We'll be re-wiring a set of blades soon. You can be Byron's helper... if you survive the day, your hands will be bleeding, and you will have boot prints on your ass.
No kidding... it ain't easy !
AgentJayZ It seems to me that one would have to tip the blades in one direction, push the wire in one little bit, then tip the blades back one at a time, then push the whole mess forward again, the wire sticking in every hole and getting harder and harder to advance, eh? Love this stuff, so glad you share and share so well.
The blades don't tip. They do have a tiny bit of "looseness" to damp out vibration, but they won't twist or move any significant amount.
Best part was knowing that there are Damping wires on the Power Turbine. Not sure if they still use this technology on newer power turbines. This was the Power Turbine of LM 1500?
Power turbines like this one are completely separate from the engine. They are made by different manufacturers. This is an old one, and I would guess that more modern PTs don't have wired blades.
Interestingly, in the Planes of Fame museum in Chino, they have a cutaway of a very early model of the J79. it's a -3, and the turbine has wired blades in the 3rd stage.
Can you feel any air movement from a single fan disk spinning outside the housing?
Yes. Airliner engine fan sections are spun in a partial vacuum, because otherwise they would require thousands of Hp to turn them at any reasonable speed for balancing.
This is a turbine, which is functionally the exact opposite of a fan., but it still moves the air around quite a bit.
@@AgentJayZ man I'd love to see that balancing process!! Interesting. Is the proper terminology "fan section" or "fan disk"? Same with "turbine section" "turbine disk"?
Fan section is a module, including the fan blades, disk, bearings, casings... All ready to be attached to the rest of the modules to make an engine. Fan disk is a part that will be needed along with many other parts and fasteners to make up a fan module, that could also be called a fan section.
where are the pt bearings located, how are they lubricated
+Matts Berggren Two of my videos may help. Twin shaft turbine engine bearings, and Jet engine Lube system.
How long can a landfill methane gas turbine run for without shuting down? How reliable are they? Can I email you some questions?
Whatever it's fuelled by, an industrial engine can run for thousands of hours before major service work is needed. Typically we see a compressor wash and combustor inspection every two thousand hours of running.
Usually ten thousand hours or more before any repairs are needed.
Could the efficiency of a PT be increased by using a jet nozzle before it to accelerate the gas going in? or would that just trade a higher speed for less torque?
each energy conversion reduces overall efficiency somewhat
There is a nozzle (stator) positioned before each turbine stage to do just that. The turbine manufacturer has optimised those nozzles to achieve maximum efficiency
ValExperimenter Yes, and the turbine is also an impulse-reaction type, meaning that some pressure is traded for velocity as the gas is accelerated between the turbine blades.
Better to transmit a high pressure, low speed stream of gas from the engine to the PT, because there are less frictional losses at lower velocities.
Also... to accelerate the exhaust gases would require a smaller diameter duct... which would just have to expand again to meet the inlet diameter of the PT.
All the power turbines we've seen have been connected to their gas generators by a straight duct. Is this because the parts have been designed to work together from the beginning and there is no need to change the exhaust speed or pressure with a nozzle?
That is basically it. Power turbines are designed for a fairly narrow range of mass flow rates and pressures.
There are a few cases I've seen where older steam turbines, which are huge, are powered by more than one gas turbine unit, feeding into a combining duct.
GE has a system that uses ten LM1500 gas generators all supplying their full output into one large PT.
green marker behind you at 7;16
@AgentJayZ Dear Sir, if I understand this correctly the compressor and the turbo fan are connected with one shaft and they spin at the same speed. Are there any engines made that would use a planetary gear system to change the speed of the compressor to spin faster? Isn't that the whole idea to try to force more air into the combustion chamber? So once the engines up and running you could use a planetary gear system to speed the compressor fan faster then the turbofan. Or is there just not enough power to do such a thing?
When you start from scratch, you design the thing that supplies the power ( turbine) to turn at the same speed as the thing that needs the power ( compressor) so as to avoid the need for a gearing system.
There is a type of turbofan where gears are used to allow one turbine to power the compressor at a high speed, and a fan at a lower speed.
The way you've worded you question makes me think that you would enjoy reading the first few chapters in an introductory turbine engine text, like the ones I recommend in my video: Books.
@@AgentJayZ thank you for the reply. I will take a look at that info. I thought maybe that at higher altitudes were there is less oxygen it might be to an advantage to change the speed of one in relationship to another as increasing altitude.
@@AgentJayZ is this the video you related to?
th-cam.com/video/Hp3StrY-_B8/w-d-xo.html
Yes I believe one of the books on how and why they built it that way would be great can you suggest one?
How many electric generators can place in a row at the end of the gear box at 8,000 rpm, theoredically?
They come in different sizes, so you only need one.
Why is the PT shaft not directly coupled to the GT shaft ?
My most recent video is for you.
@@AgentJayZ Thanks for the pointer. Just watched that video and it answers lots of questions. 👍
At 9:11 in the video, was 150 pounds per second of air supposed to be 150 pounds per square inch? I am enjoying these videos.
150 pounds of air per second is the mass airflow of the LM1500 / J79 engine.
Somewhat coincidentally, the compressor discharge pressure is about 155 to 160 psi.
Hi! I have one question about power turbine. You say that, efficiency of this turbine is about 87%. But when I checked (for example) LM2500 power turbine efficiency, it is about only 35%... And compressor is on remaining 65%. I'm not a specialist, and I'm not saying that you are wong. I'm just learning and I want to understand what's this is about :) Also great videos, and really good explanation! Greetings from Poland !
You are making a very common mistake.
A turbine is not the same thing as a turbine engine.
The efficiency of turbines can get as high as to low 90s of percentage, but they are only a component of turbine engines. Compressors also are components of turbine engines.
The efficiency of a turbine engine in conveting fiel to mechanical output power is about 30%... about the same as piston engines.
Interesting that the weight variance in the blades seems like it is allowed to be 5% or perhaps more. I had imagined these to be manufactured with closer weight tolerances.
+crashtech66 They need to have a variance in their weights, so that balance adjustments can be made by switching blade positions.
+AgentJayZ Thanks for the answer. The concept of swapping blades into different positions for balance is not hard to grasp, but 5% between parts which are in theory identical seems large, for instance much larger than seen in piston engine connecting rods and pistons. I see in your video that in one spot shown, there are light blades directly adjacent to much heavier ones. It seemed as if that arrangement might be compensating for the relatively large weight tolerance that is allowed (or built in?) during their manufacture. I'm assuming that the hub itself is internally balanced, of course.
Your assumptions are not useful, and you are forgetting rule #1 : these are not piston engines.
I've got videos on balancing that may help reduce the confusion.
Did they end up selling their trailer, just wondering.
Still available.
Do you work on industrial duty turbines also? I understand that there are aero engines adapted for power generation, and then there are heavy duty stationary turbine engines with much longer service life because they don't have to worry about weight like an aero engine so they're much heavier duty.
Yes. I started out in this town working for S&S Turbine Services, and aeroderivative industrial gas turbine engines is their core business.
@@AgentJayZ I know that you work on aeroderivative engines, was wondering if you ever worked on stationary gas turbines like at a larger power plant
We do not work on the big frame turbines. That's is a whole different world, compared to our little engines.
@@AgentJayZ gotcha. I'd guess all that is on site and specialized work with guys trained by GE or whoever, similar to nuclear or coal turbines.
What's the little power turbine from?
I forgot to mention it's part of an air turbine starter?
AgentJayZ I thought that looked familiar, It's amazing how much power they produce.Thanks. Great video, as always.
my old O/H shop in Richmond (PT6, rr250s, etc.) would never allow an unshielded balance like this. I guess its not a big deal in jet city!
This was at Maddex Turbines, and it is a very big deal. That's why we have never had an incident.
Complacency kills.
Electron Bill is the star of the show
How blade s are shaped
I have a video called Blade Production Techniques, which you might like.
Legitimate question here.
Why don't just connect the output shaft to the gas generator shaft and get rid of the power turbine stages?
it would take more energy to start the engine and if something went wrong with whatever the engine was driving it could destroy the engine
That is exactly what I try to explain in this video.
Makes sense. Thanks!, and sorry for the dumb question