Water injection is also great for reduced EGTs and more power. That much water has a LOT of mass and the acceleration of it through the turbine generates substantially more force. Would love to see a steam heat recovery generator installation. Another great way to make the most of your gas turbine.
OK, caught-up, for now! Interesting to see 'water injection' making a come-back! As you know, the P & W J57s sometimes used water injection for increased thrust on take-off of B-52 & KC-135 aircraft. I remember the water tank trucks that had "NON-POTABLE WATER" stenciled on the sides & back, used to carry the de-ionized water to the parked planes. I have been in a cockpit of a B-52 during an engine test, with water injection, & my observation was that the fuel flow increased by good bit during the water injection period, to increase the thrust up to the temperature limits of the engine. The combination of more fuel burned & the expanding water vapor (vapour, right Graham?) adds a nice kick for the heavy aircraft (of the day) lumbering-off the runway, loaded with fuel & weapons. Thanks for the continuing education course! Cheers. DD
knowing nothing about jet engines, I just love your videos and the way you "teach/inform us!! Always looking forward to your videos and letting people/friends know about them!! Good work!
Great Video on Water Injection. The application in thrust engines is unbelievable... I was hoping you could have covered that little piece of information as well. I hope we get to see a CF6 sometime in the future... especially in the test cell. BTW, I see the Chin warmer is in full effect now.. awesome!...
I love this dude. I wish you would do a PT-6 rebuild sometime, little small for you though. I always thought there would be a fair market for boats running on non flyable PT's.
I red in this really old book with black and white images of water injection in the Boeing 707 to increase thrust in hot climates (it was said the tale tell of it was the black smoke trails left behind it). Only recently in modern times i learned it was made mainly for power in piston engines and that a side effect was cleaner emissions and engine internals (steam cleaning). I guess piston or turbine doesn't matter as it seems to give the same results.👍
Interesting clip man! But all I can think about is the great gobs of soot that early turbojets and turboprops used to kick out on a water injection take off. Would that then be a case of lower NOX and higher particulate emissions? Maybe time has meant better delivery and less soot.
So you went back in time using just 25,000 HP? I always thought it needs 1.21 gigawatts.. ;-) Just kidding... What really surprised me is that there's snow already. Here in Germany we can be lucky if we get any snow before Christmas. Anyway, thanks again for all your great videos!
SNOW!! I went over and gave a read on the dual feed and NOx reduction for the GE LM2500. Pretty good apples them (though I do recall one of your videos you were changing the fuel nozzles out because of the fuel a customer was using unless I misremember), interesting how water improves combustion efficiency. Is the reduction a set and forget flow rate of the water or is it something that needs monitoring and changing during operation?
great video jay,looks really cold,is the water pumped from the water pump cold or is it heated?,and if conditions are minus could the water pump be able to run with the engine,if that make sence lol😀
Black smoke is not Nox. It indicates more fuel and lower combustion temp, which leads to lower NOx emissions. The black soot is made up of solid particles of carbon... which is actually inert in terms of pollution...
Curious about your buliding/storage setup - if that's a fabric "tent", essentially, with no insulation, how do you deal with condensation on any cold metal parts inside when it warms up? Or do you have AC running?
I always thought water injection INCREASED emissions. The first thing that comes to my mind with water injection is smoky takeoffs of first generation jets using it to increase power.
Important point: The black smoke is caused by soot, which is tiny solid particles of carbon... which is inert in the environment (unless you burn it and release CO2). So although they are unsightly, and they are emitted from the engine, they are not the emissions referred to when talking about turbine engine emissions. Modern combustors are more efficient, and make far less smoke. That does not matter. When Emissions are talked about, it's usually oxides of nitrogen, often called NOx, because there are various types. Water injection reduces combustion temperature, so reduces NOx production. This is a summary. If you are interested in the subject, there are many great sources at your fingertips.
I'm wondering how far this concept could go, I was thinking something like a ceramic manifold that could support external combustion with water mist injection to create a superheated steam external to the turbine. . . Seems like it could be a route to a simplified turbine since the majority of the heat would be applied to an external manifold rather than within the confines of the turbine itself. . . I would think that it could be made to operate at any temperature above the lower limit of wet steam at a given pressure. Would elimiate the need for a lot of fancy pipework vs a normal steam turbine system.
@@petrh.4198 No, he has some crazy ideas about what the word "simplified" might mean. That's what I meant. You got your combustion gas turbines, and your steam turbines... they work well when used as intended.
30% reduction in NOx seems low, I had a quick look in some brochures and depending of power setting and the amount of water, water injection is claimed to lower NOx 5-10 fold. Maybe that is fuel dependent and propane produces cleaner combustion to begin with?
I would imagine being on CNG would provide a pretty clean burn from the get go, but switching over diesel would drive up NOx emissions a long way. The motor industry has had that issue for god knows how long with diesel engines, only until the introduction of AdBlue has it kept NOx emissions in check. I wonder if spraying AdBlue directly after the final turbine stage would make a difference? Probably too expensive to use to make a significant difference over water injection
I don't think anybody is aware of the cost of the pieces in your shop. I installed and overhauled GE industrial gas turbines and occasionally saw the prices on repair parts. It was easy for me to say ''Oh, you need a new first stage nozzle'' only to find out it cost more than my house, cars, and everything inside it.
+kimmer6 Allowing the price of parts affect the decision of whether or not to replace them in engines powering airliners has been shown over and over again to kill passengers. A bit more leeway with industrial engines, of course.
You are 100% correct. Where life matters it is never a good idea to be cheap. I always performed overhauls and hot gas path inspections on industrial turbines as if the machine was my very own in my yard. Most customers were in awe that I could have so many pieces lying about on cribbing then have the unit up and running correctly 3 weeks later. I actually had a GE Frame 3 5 bearing 7500 hp compressor drive gas turbine come apart as I was taking temps and pressures. One bearing oil drain temp was way too high and I heard a strange whine and felt some vibration. Within 10 seconds I felt the need to bail out over the railing and dive the 8 feet to the pavement. I saw the trip switch on the way down and banged it. I hid behind a concrete column thinking I was about to die. The machine spun down from 7000 rpm to zero in 15 seconds and made a squeal like a Tripod in The War of the Worlds. After that, I developed a new found respect for heavy things weighing many tons rotating at considerable speeds. It didn't help to see a flatbed rail car with 2 halves of a Frame 5 gas turbine chained down behind the Schenectady GE factory. A compressor wheel exploded and cut it in half. Aero engines are safer! Keep up the awesome videos!
I´m a shift supervisor at a big powerplant (>900MW). Years back i had a steam turbine runaway when i was standing right next to it. It just came out of inspection and had electronic speed monitoring fitted during the inspection and the mechanical overspeed trip disabled. There was a faulty connection in the speed monitoring and during start up the control valves opened to 100%. The turbine spun up from about 50 rpm to over 3700 rpm in less than half a minute. I hit the emergency stop immediatley and the emergency shut off valves closed in time. We were very lucky that the turbine stayed intact and nobody was injured. I had to change my trousers after this.
Yes, Gus, 900 MW ain't no toy. I was a GE Field Engineer and was at the Crown Z paper mill where some young kid was installing his company's newfangled electronic controls on a 10 MW unit. It went from zero to 3700+ in 10 seconds. Sounded like a Wolf Whistle. The o/s trip worked fine, thank you. We were overhauling a GE 6MW unit next to it. The kid did it twice so after screaming in his face I sent the crew to the lunch room before anybody got killed. I saw the aftermath of a single stage feed pump steam turbine failure on an old ship. They installed the trip valve upside down, something went wrong and it came apart at 6000 rpm plus. The turbine wheel was about 30'' diameter and its debris went through cables, panels, and shredded a leather jacket hanging on a valve stem. I got respect for rotating stuff that very day. They said everybody scattered like roaches under a spot light when it made screaming noises before the bang. Nobody hurt. After an exciting career going to every armpit of the world I retired and now spend my days feeding pigeons and doing crossword puzzles. Stay safe!
Yes, it must be demineralized water, scrubbed by chemical process to remove as much minerals and solids from the water. Something similar to distilled water except it uses chemicals instead of condensing steam to produce. Power plants will have an on site water treatment plant to produce this water in huge quantities as it is also used all around the power plant in various equipment like the boiler, cooling system.
Just Google it, I'm speaking from experience as electrical commissioning engineer , part of the job was commissioning all the electrics for the water treatment plants . This is probably one of the smaller consumers in a power plant . average speaking , a 400 mw combined cycle plant will consume 16 to 25 MW of power generated for all the in house loads. There's huge boiler feed pumps , main cooling seawater pumps , lube oil pumps etc etc. Anyways water is only used when running on diesel and is almost always only as back up fuel. Diesel or any other liquid fuel is very harsh on the turbine and eats away operating hours faster than a gas only engine.
Nice, theres actually no water vapor at all, i thought i would see a white myst coming out from the back like the fuel cloud coming out before an afterburner is turned on.
From what I have heard Harrier jets use water injection to cool the engines when the aircraft is in hover. Did you notice a temperature drop in this case? Wouldn't water injection lead to a less complete combustion of the fuel?
Water injection was certainly used in the hover during early development of the Pegasus engine and in the early Pegasus 5 it was used to maintain thrust up to an ambient temperature of 40degC. However, in the later marks of Pegasus, It was/is used for a so-called 'Short Lift Wet ' rating, to perform a short take-off with a maximum fuel and weapons load. The water tank only holds enough water for (from memory) about 90 seconds of use. So, any time you have seen, say, a Harrier II doing a display in the hover, it would not have been using water injection.
Have you ever thought of putting together a forum for people who watch your videos? You could have people's questions by other viewers. It would be a great place to have discussions and share photos. Its not that hard to set up, you could do it through a free website or something.
I don't think many airliner engines used water injection, but the RR Sppey did. A mixup contributed to the loss of a Spey engined BAC1-11. aviation-safety.net/database/record.php?id=19710906-0
Temperature. At higher temps, the oxygen begins to react with the nitrogen in the air, seeing as most of air is actually nitrogen. Lower the temps, and it stops happening (as much).
It's all combined into the fuel nozzle, water, fuel gas, fuel oil. Water injection is nothing more than exhaust gas recirculation on a piston engine except that water substitutes exhaust gases. Same principle, reduce combustion Temps, reduce nox emissions
I don't buy the analogy with EGR in an automotive engine. The fundamental difference is that, with water injection, there is a massive evaporative cooling effect, which reduces turbine entry temperature when used on take-off for aero engines. This allows for an increase in fuel flow and hence thrust for a short period. Continuous water injection for NOx reduction is altogether more sophisticated and I'd moved on from industrial to aero engines by the time they started developing it at R-R IMD.
Are you using De-Min water? Whats the fuel type, liquid or gas? our CHP plant at Heathrow has an LM1600, Alstom turbine, Brush generator as well as the exhaust heat recovery boiler, (heated most of the South of Heathrow with district heating). Our De-min water plant for the Nox injection was huge and we had two Bellis & Morcom gas compressors raising natural gas fuel px from 3.5 to 38bar. That CHP plant is mothballed now though. Are you not bothered by FOD?
Water reduces combustion temperatures. So you can use a lot more fuel to make more power, or you can use the same amount of fuel an make less NOx. Pressure is not affected, and what is efficiency?
Months or years at a time if supplying base load. Engines used to boost power during peak loads may run intermittently, so it would be many years between overhauls for them.
The output of NOx was reduced dramatically, and EGT went down. As for any power increase caused by the water injection ( without any extra fuel being introduced ), I don't think it was significant.
does the water lower egts and maintain the same amount of power though out the system? would this increase or decrease heat cycles on the turbine? i've also been told that on a radial compressor(turbocharger) water flow though it will increase the maximum flow rate, but i can't see it flowing any more air than without water.
Maybe the water is added to prevent predetonation. Check out intercoolers though, they perform the same cooling function without adding water into the fuel air mixture.
I was on a BAC 1 =11 years ago and in the cockpit during a flight to Spain, and the RR Speys used water injection to increase mass acceleration, but the pilots said that it wore out the engines faster by using this system. Is this right?
Interesting video! How do find the optimum amount of water to inject? Does it have a kind of ceiling effect where an increase in water injection does not result in any more decrease in NOx? Or is the limiting factor a loss in engine power by to much water?
The aim is to get it down to the point where your Nox is lowest without CO starting to increase. There is a 'sweet spot' of combustion temp where the two curves intersect. Alternatively there will also be a wet flameout limit where you can't inject any more water past that.
@7:39 what conclusions can you draw from observing the EGT, besides that the engine is working? Does your diagnostics computer check for a EGT to RPM ratio etc... Do engines at the end of their service period show sub optimal EGT and RPM ?
EGT = Exit Gas Temperature. Every engine has a EGT-limit. if you go higher than it you might burn your first stage turbine blades. You measure EGT instead of the Temperature at turbine intake because your thermocouples live longer at the rear of the engine.
Almost everything about a gas turbines operation is based on EGT temps. The controller monitors individually and may also use a variation of all the TC readings, based on how it is programmed. Also monitoring intake and exhaust temperatures, along with fuel pressure and flow to maximize GT operation.
Hi there. absolutely love your vids. small question for you. I have noticed that the start cart valve stays closed until it reaches max power . any reason it can't stay open from the beginning? thanks
Turbine engines work best at their design speed, which is nominally 100% rpm. At any speed below that, they are struggling or running sub-optimally. See my video about starting a jet engine. The start carts engine needs to be running at its design speed before it can afford to have a significant portion of its compressor output diverted away from its own needs in order to power something else. Also see my video called Bleed Air. The start cart is a rare case where the compressor bleed valve is closed during starting and only opens after full rpm is reached.
Sorry to hear about the flood! The beard looks great on you, though :) You seem to have a constant supply of engines to maintain! Are your customers local, all over Canada, or even further? How much competition do you have?
Our customers are located in every corner of the globe..... (does a globe have any corners at all?) Most larger companies are not interested in the engines we support, so we don't have a lot of competition. Rectangles!
Shipping from somewhere in the world is 1.0X to Vancouver, a major west coast port in North America. To FSJ, it is an extra two days by truck, so make that 1.2X. The cost is insignificant in the grand scheme.
I saw you show how they engines are packed, carefully fastened inside a container. But from the outside, it's just a box, right? Do the shipping people need to do any special handling? I have a related question: After balancing turbines, how easily do they come out of balance again? I presume you also have to balance compressors. You've shown how the compressor blades can move a little, so I imagine just shaking them around in a truck won't cause trouble. So what does cause them to become unbalanced? Only physical damage to the blades? Thank you for the wonderful content, as always!
Sources NOX reduction en.wikipedia.org/wiki/Selective_catalytic_reduction. >>Thought corp. was doing burn water for thrust output augmentation.Exampled increased thrust or power output, P-51 water injection, increase manifold pressure and output horse power. Hydrogen from water diffraction under cyclic load heat plus pressure. Two modulus piston vrs. jet, increase of volume of density flows output.*reference compressible and in-compressible gas exit flows and or inlet, mid compression via ignition and exit flows.Course on aerodynamic flows._Thanks very much, like the beard, looks as if your'e about to dig a hole and hibernate. Best to you and yours come this holidays.
Can you explain a water injection system and how it works, if you haven't already. Because a part of me feels it just water misted into the exhaust, thus adding more mass and there for more thrust.
Water must be injected before the highest tempurature that occurs in the engine, so before the flame in the combustion chaimber to lower the peak temp. Since it is retrofitted to this engine it might be in the fuel injection (He won't tell us since it's a secret).
I think for Power output increase water has to be injected in the Compressor so that it increases mass flow rate by increasing density. Injecting in combustor would not have effect on mass flow rate, but the reduction in temperature would reduce NOx. But I have question, where exactly in the combustor area you are injecting water? And do you see increase in CO at the same time NOx are reduced??
CO2 production is a function of the burning of fuel.NOX is a function of the combustion temperature.As they are not increasing fuel burn CO2 remains the same.Only the combustion temperature is lowered by the water.
Once the water was turned on, Robin did increase the power level. Water injection reduces NOx, and allows the use of more fuel, but it does not increase efficiency.
No. The water reduces combustor temp, and at max power, the limiting factor is combustion gas temp. So more fuel can be introduced before the temp limit is reached.
+prancstaman No. The oxygen in water is bonded to hydrogen. Both of those elements are residing happily at a low energy state, and are unavailable for combustion when they are components of a water molecule
Compressor blades do not explode. You don't really understand what you are asking. The answer to your confused question is included in the playlist; Your Questions Answered. Find it in the index, or don't.
Interesting. Would the water injection function in a similar way to a piston engine using water injection, by increasing cylinder (in this case combustor) pressures as the water flashes to steam?
Pressure does not rise in the combustors. The volume of gas expands hugely due to heat, but the rear end is wide open for the expansion to escape through the turbine. Water injection lowers combustion temp, and adds a bit of mass flow to the expansion. It can increase power, but is mainly used to lower NOx emissions.
@@AgentJayZ It can increase power because the vaporized water creates more volume of exhaust gas with no additional compressor work. And, the work to pump liquid water is relatively small. However, the actual increase in exhaust volume is tricky to figure because some of [most of (?)] the water vapor -- steam -- dissolves in the hot compressor flame gas so you don't get the full effect of the additional "steam" volume. Fun stuff.
At 1:46, interesting to see the RPM rise on the control panel as the start start cart air entered the engine. Would have liked to see the numbers on the screen (RPM, oil pressure, EGT, etc.) as the engine reached idle. Question I've increasingly pondered. When you test run an industrial engine, how do you know what size nozzle (cross section area of exhaust) to attach to the gas generator to simulate the "load"? Does each engine have an engine manual that provides the specific nozzle size information for test purposes, including the nozzle information for an aircraft engine that has been converted into an industrial engine (e.g. J-79/LM1500)? Or is this the kind of information you *know* only through your experience?
Not critical. We are not trying to maximize exhaust acceleration ( thrust), we are just putting a measured restriction in the exhaust to measure pressure rise upstream.
Only if you are high enough (the air from the engine is hot) Also it must be cold enough at the Zero-level of Terrain, so that it stays as snow. The most importent is that it was nearly only used at take off. And the time before touching the ground is at take off to short to cool down...
It was just that i have seen water vapour used tho cut thru high strength steel and ceramics and was wondering if it reduces the life span of internal components, although i suppose that as long as it is in gassious form wear could be minimal
If anything, lower temps are probably a benefit for lifetime. Creep would be reduced for one thing. Steam quality should be very high, so no erosion issues there.
Am I wrong that there is a ton of potential energy being wasted in this situation? My instincts would tell me that any exhaust gas movement not being used to rotate a rotar inside a stator lost? Or in the power generation application, is there not really any real thrust in the exhaust when the turbine is under load? Sorry if I am using words wrong, or just plane stupid. I wouldn't have graduated high school if it were not for a lovely woman named Mrs. Ziff, that saw that I was out of my element in school and broke all the rules to help me graduate. (Gave all answers to tests and homework) she knew I was not stupid, just not willing to comply with the extortion of the youth, not interested in what they wanted me to be. I love that woman like my mother. Again sorry if this is a dumb question.
As simply as I can explain it: The energy in the combustion gases can be turned into rotating mechanical power by a (power)turbine, or they can be accelerated to quirt out the back by a jet nozzle. One or the other.
@@AgentJayZ ok, thank you for your time, and your willingness to put up with people like me. This is the most valuable channel on RUclips. In more than one way.
Hey, Glitch, There is some potential energy lost, like you said. AgentJayZ may correct me on this, but the I think the main lost energy is the thermal (heat) energy that's still in the exhaust gas. That's where combined cycle plants come in. Basically they have a gas turbine hooked up to a generator like you were talking about, but then that exhaust gas that would normally go out the stack and be wasted is then used to heat water in tubes to make steam to turn a steam turbine. I think that puts the cycle efficiency up in the 50-60% range, instead of the mid-30's, which is quite the improvement. Your question wasn't dumb, at all, in my opinion.
It can be used to improve power output, or to reduce emissions, or maybe a little of both. The customers of ours who use it are more interested in reducing emissions of NOx
Water injection alone does not increase power in a piston engine. It's used to prevent detonation in forced induction and high compression applications.
Nope, emissions only and only when running fuel oil like diesel, fuel gas is clean tsjt it doesn't require water injection and nox can be managed on fuel gas using very intricate and clever mixing of gas and air before combustion. Water being used to increase performance is always upstream of the compressor in the filter house simply used to cool the air to make it denser. This of course only exists in hot climate countries
Sure, some cargo planes used water injection because it allowed for higher expansion of intake air simply because it was cooler but Darryl Greenemeyer used it to cool inlet temperature on his red baron F104 for both that and the fact that the j79 get's some pretty high inlet temperatures at high altitude much less mach 1.33 at sea level.
@AgentJayZ Right right. Yeah, someone said that the black exhaust the original b52's were spewing was because water injection on takeoff was expelling soot
why does nobody use ethanol and water mixture as jet fuel? ive read they did it in ww2 as rocket fuel. should burn cooler and produce more thrust since more mass is moved and cost cheaper to make parts since no high heat would be involved, and put all the emissions and sustainability talk to rest.
Ethanol has much lower combustion energy available per unit of weight than kerosene-based jet fuel, and water has none. You can't burn water. Jet engines are air cooled, and are designed to burn high energy fuel. They could burn methanol, but they would need more of it to make the same power. The water would just be in the way, and extra weight on an aircraft. The main thing to avoid with aircraft is weight.
Only made by the older engines. This is a modern gas generator, that makes no smoke when running on jet fuel. Here it's running even cleaner on gaseous propane. The smoky test runs are of the older J79 engines. You can find them if you look around my channel.
Do low pressures on the intake every make vorticies, observable or not (how would you know!), on the test stand? OOO OOOO OOOO, and where is the downrange snow from the water injection and combustion water exhaust from such a gas turbine engine? do contrails not exist at ground level in cold, pre-winter, Canada? What happens in the deep-freeze winter downstream from the test stand? "jet engine snow"?
Contrails aren't just the exhausts. It's the small particles in the exhaust giving moisture from the surrounding air a nucleus to condense and freeze on. Also the temperature up there is around -50 to -70°C. Hard to match that on the ground.
Yes, quite a few of my videos show inlet vortices forming at high power. I think it's an interaction with the surface of the ground, and doesn't happen in flight. Not enough water in the exhaust to condense out, even with water injection.
@@AgentJayZ Were you able to get any temperature readings inside of the turbine? Equal power at lower temperature could be a plus as long as steam corrosion wasn't a problem.
Boiling 20 gallons of water per minute = 7.2 MJ per minute = 2 kWh/minute = 120kW output power lost to heat the water or roughly 200ml extra fuel per minute. Is it really worth it to reduce emissions. it is decreasing efficiency?
@@AgentJayZ It was not an asshole comment I pulled on you there. You explain it in your video, that this is to reduce NOx emissions. I was just thinking that there should be better ways, like EGR valves in cars, i.e. routing some exhaust back into the mouth of the compressor to reduce the amount of Oxygen, also reducing combustion temperatures, without needing to waste energy on boiling water?
Rule #1: These are not piston engines. Your "I was thinking..." is somehow going to surpass the efforts of thousands of professional engineers? Get busy and show the world how.
@@Tore_Lund Turbine combustion systems need to operate at a very specific flame primary zone temperature to achieve the desired power and emissions targets. That is what determines the flow rate of water. Also, efficiency and emissions don't always correlate in these types of engines. It depends on their application. also industrial gas turbines don't require the water to be boiled; their water is injected downstream of the fuel injectors in the combustor. The water serves to increase mass flow rate through the turbines stage. The water will vaporize as it's injected, before reaching the turbine stage.
Water + Methanol is for cars. You add water so the air is cooler and can compressed further. As you have a higher compression ratio you also need a higher octane number or you get early ignition. Methanol is increasing the octane number.
IIRC, there are some turbine systems that use ethanol injection. Soviet Mig-25 used it and the folk at the air bases would drink it instead of vodka (source "Mig Pilot", Viktor Belenko). In that application, pollutants are not the issue. Also, I thought some (all?) Boeing 747 used water injection.
The engine was running on gaseous propane, and we don't measure fuel consumption. We also did not measure rate of water use. We were running at medium power based on the max reading I saw on the tachometer. The 2500 runs at around 9200, and we were at 8500. As a guess, we were burning the liquid fuel equivalent of about 10 gallons per minute when we were injecting water. These are all rough estimates.
Just Curious, How many Hundreds or Thousands of gallons of JetFuel do you guys go through on an average dyno run? and how long do you run an engine before you consider it "good to go" ? Miniutes? Hours?
If everything is nominal and no adjustments need to be made, a liquid fueled aircraft engine will run for less than an hour, and be tested at all power levels, from ground idle to full afterburner. Such a test is rare, because minor adjustments are often made, with repeat runs then required. A J79 test will use most of our thousand gallon fuel tank. The aircraft can only fly for half an hour or less before landing or hitting a tanker, because the engine is not idling when the aircraft is flying.
That is the mechanism that moves the variable stators. Compression ratio is not a term applicable to turbine engines. Have a look at my video about compressor stall for more info about variable stators.
I can't speak for anyone else but after watching that I can honestly say I wouldn't want one of those things...I'd want TWO! Jets are AWESOME!
Water injection is also great for reduced EGTs and more power. That much water has a LOT of mass and the acceleration of it through the turbine generates substantially more force. Would love to see a steam heat recovery generator installation. Another great way to make the most of your gas turbine.
OK, caught-up, for now! Interesting to see 'water injection' making a come-back! As you know, the P & W J57s sometimes used water injection for increased thrust on take-off of B-52 & KC-135 aircraft. I remember the water tank trucks that had "NON-POTABLE WATER" stenciled on the sides & back, used to carry the de-ionized water to the parked planes. I have been in a cockpit of a B-52 during an engine test, with water injection, & my observation was that the fuel flow increased by good bit during the water injection period, to increase the thrust up to the temperature limits of the engine. The combination of more fuel burned & the expanding water vapor (vapour, right Graham?) adds a nice kick for the heavy aircraft (of the day) lumbering-off the runway, loaded with fuel & weapons. Thanks for the continuing education course! Cheers.
DD
Vapour? OK, you're learning to spell Brit!
Jay's neighbor came by to show off his new top of the line backpack leaf blower. Jay said, "That's cute. Hold my beer." Cue turbine startup sounds...🤣
"If you look and listen carefully ... you can't tell."
lol. I love this channel.
knowing nothing about jet engines, I just love your videos and the way you "teach/inform us!! Always looking forward to your videos and letting people/friends know about them!! Good work!
Thank you for your excellent videos!
You've educated me quite a bit on turbine engines.
The hybernating frogs from the ponds were dreaming of St Maarten airport/beach.
You're welcome, fuzzy face! I need to start mine because the cold is getting here. Good one as usual.
Thats one hell of a turbo heater!!
It's been a while since I've been around the Agent Jay Z site. It's good to come back to these videos.
Great Video on Water Injection. The application in thrust engines is unbelievable... I was hoping you could have covered that little piece of information as well. I hope we get to see a CF6 sometime in the future... especially in the test cell.
BTW, I see the Chin warmer is in full effect now.. awesome!...
I love this dude. I wish you would do a PT-6 rebuild sometime, little small for you though. I always thought there would be a fair market for boats running on non flyable PT's.
yes...PT6A has an SB 1366....water/methanol injection. .....not to be used for augmented power.....just imagine if it was
Sure is a lot cleaner burning than when water was dumped into the P&W J-57's on take off.
Great videos!!
That heat distortion is something else, I bet some people in the movie FX field would pay arms and legs for that.
We ran large TF30P-109's in a block house with water injection in the exhaust to muzzle all that raw noise
I wish they had a PW J75 water injection used in the F105 ThunderCheif they had the most awesome sound when the AB kicked in like no other.
Did you mean ThunderChief?
Brilliant as always! 👍
You're like the Les Stroud of jet engines. Love it.
best job ever
I red in this really old book with black and white images of water injection in the Boeing 707 to increase thrust in hot climates (it was said the tale tell of it was the black smoke trails left behind it).
Only recently in modern times i learned it was made mainly for power in piston engines and that a side effect was cleaner emissions and engine internals (steam cleaning).
I guess piston or turbine doesn't matter as it seems to give the same results.👍
Water injection is great for Diesel engines too, and eventually makes more sense than DEF.
DEF is water
@@RandomShit169 it's not just water, and it's not injected at the intake
@@RandomShit169 Where did you get that from
Interesting clip man! But all I can think about is the great gobs of soot that early turbojets and turboprops used to kick out on a water injection take off. Would that then be a case of lower NOX and higher particulate emissions? Maybe time has meant better delivery and less soot.
You hit the nail on the head.More water,lower combustion temperature,lower NOX,but more soot.(unburnt carbon).
I'd love to do what you guys do for a living!
Kevin Ham it's such a cool set-up
Thank you for the video. Just wondering if there was any noticible reduction in EGT as most NOx is due to high temperatures?
Water injection is used by some operators to reduce NOx emissions.
So you went back in time using just 25,000 HP? I always thought it needs 1.21 gigawatts.. ;-) Just kidding... What really surprised me is that there's snow already. Here in Germany we can be lucky if we get any snow before Christmas.
Anyway, thanks again for all your great videos!
SNOW!! I went over and gave a read on the dual feed and NOx reduction for the GE LM2500. Pretty good apples them (though I do recall one of your videos you were changing the fuel nozzles out because of the fuel a customer was using unless I misremember), interesting how water improves combustion efficiency. Is the reduction a set and forget flow rate of the water or is it something that needs monitoring and changing during operation?
Why isn't the fan spinning? YES I'M JOKING
ishootstuff sweet, sweet inefficiency.
great video jay,looks really cold,is the water pumped from the water pump cold or is it heated?,and if conditions are minus could the water pump be able to run with the engine,if that make sence lol😀
Funny and interesting as always !
I would love a snow shovel like that one!🤣
Water injection to reduce NOx emissions?
I think a J57 would have something to say about that!!
Black smoke is not Nox. It indicates more fuel and lower combustion temp, which leads to lower NOx emissions. The black soot is made up of solid particles of carbon... which is actually inert in terms of pollution...
Try explaining that to the hippies. If it looks like pollution, pollution it is!
Curious about your buliding/storage setup - if that's a fabric "tent", essentially, with no insulation, how do you deal with condensation on any cold metal parts inside when it warms up? Or do you have AC running?
You add a fan, some stators and the case and you pretty much have a CF6 there
I always thought water injection INCREASED emissions. The first thing that comes to my mind with water injection is smoky takeoffs of first generation jets using it to increase power.
Important point: The black smoke is caused by soot, which is tiny solid particles of carbon... which is inert in the environment (unless you burn it and release CO2).
So although they are unsightly, and they are emitted from the engine, they are not the emissions referred to when talking about turbine engine emissions.
Modern combustors are more efficient, and make far less smoke. That does not matter. When Emissions are talked about, it's usually oxides of nitrogen, often called NOx, because there are various types.
Water injection reduces combustion temperature, so reduces NOx production.
This is a summary. If you are interested in the subject, there are many great sources at your fingertips.
... and those were second generation jets... .. ... Ohhhh.
You were meaning to say jet airliners... got it now.
Who would want to be home when you can play there?
I'm wondering how far this concept could go, I was thinking something like a ceramic manifold that could support external combustion with water mist injection to create a superheated steam external to the turbine. . . Seems like it could be a route to a simplified turbine since the majority of the heat would be applied to an external manifold rather than within the confines of the turbine itself. . . I would think that it could be made to operate at any temperature above the lower limit of wet steam at a given pressure. Would elimiate the need for a lot of fancy pipework vs a normal steam turbine system.
I have no idea what you are talking about, but I wish you luck in your progress.
@@AgentJayZ He was talking about to operate the gas combustion turbine as a steam turbine when you put more water inside the combustion chamber :-).
Sounds like you mean operating the steam superheated!,good idea man,gas turbines with recuperators basically work with that concept
@@petrh.4198 No, he has some crazy ideas about what the word "simplified" might mean. That's what I meant.
You got your combustion gas turbines, and your steam turbines... they work well when used as intended.
30% reduction in NOx seems low, I had a quick look in some brochures and depending of power setting and the amount of water, water injection is claimed to lower NOx 5-10 fold. Maybe that is fuel dependent and propane produces cleaner combustion to begin with?
I would imagine being on CNG would provide a pretty clean burn from the get go, but switching over diesel would drive up NOx emissions a long way. The motor industry has had that issue for god knows how long with diesel engines, only until the introduction of AdBlue has it kept NOx emissions in check. I wonder if spraying AdBlue directly after the final turbine stage would make a difference? Probably too expensive to use to make a significant difference over water injection
I don't think anybody is aware of the cost of the pieces in your shop. I installed and overhauled GE industrial gas turbines and occasionally saw the prices on repair parts. It was easy for me to say ''Oh, you need a new first stage nozzle'' only to find out it cost more than my house, cars, and everything inside it.
+kimmer6
Allowing the price of parts affect the decision of whether or not to replace them in engines powering airliners has been shown over and over again to kill passengers.
A bit more leeway with industrial engines, of course.
You are 100% correct. Where life matters it is never a good idea to be cheap.
I always performed overhauls and hot gas path inspections on industrial turbines as if the machine was my very own in my yard. Most customers were in awe that I could have so many pieces lying about on cribbing then have the unit up and running correctly 3 weeks later.
I actually had a GE Frame 3 5 bearing 7500 hp compressor drive gas turbine come apart as I was taking temps and pressures. One bearing oil drain temp was way too high and I heard a strange whine and felt some vibration. Within 10 seconds I felt the need to bail out over the railing and dive the 8 feet to the pavement. I saw the trip switch on the way down and banged it.
I hid behind a concrete column thinking I was about to die. The machine spun down from 7000 rpm to zero in 15 seconds and made a squeal like a Tripod in The War of the Worlds. After that, I developed a new found respect for heavy things weighing many tons rotating at considerable speeds. It didn't help to see a flatbed rail car with 2 halves of a Frame 5 gas turbine chained down behind the Schenectady GE factory. A compressor wheel exploded and cut it in half. Aero engines are safer! Keep up the awesome videos!
I´m a shift supervisor at a big powerplant (>900MW). Years back i had a steam turbine runaway when i was standing right next to it. It just came out of inspection and had electronic speed monitoring fitted during the inspection and the mechanical overspeed trip disabled. There was a faulty connection in the speed monitoring and during start up the control valves opened to 100%. The turbine spun up from about 50 rpm to over 3700 rpm in less than half a minute. I hit the emergency stop immediatley and the emergency shut off valves closed in time. We were very lucky that the turbine stayed intact and nobody was injured.
I had to change my trousers after this.
Yes, Gus, 900 MW ain't no toy. I was a GE Field Engineer and was at the Crown Z paper mill where some young kid was installing his company's newfangled electronic controls on a 10 MW unit. It went from zero to 3700+ in 10 seconds. Sounded like a Wolf Whistle. The o/s trip worked fine, thank you. We were overhauling a GE 6MW unit next to it. The kid did it twice so after screaming in his face I sent the crew to the lunch room before anybody got killed.
I saw the aftermath of a single stage feed pump steam turbine failure on an old ship. They installed the trip valve upside down, something went wrong and it came apart at 6000 rpm plus. The turbine wheel was about 30'' diameter and its debris went through cables, panels, and shredded a leather jacket hanging on a valve stem. I got respect for rotating stuff that very day. They said everybody scattered like roaches under a spot light when it made screaming noises before the bang. Nobody hurt.
After an exciting career going to every armpit of the world I retired and now spend my days feeding pigeons and doing crossword puzzles. Stay safe!
Hi Jay. Does the water need to meet any special specification that would require testing and treatment before use ?
Yes, it must be demineralized water, scrubbed by chemical process to remove as much minerals and solids from the water. Something similar to distilled water except it uses chemicals instead of condensing steam to produce. Power plants will have an on site water treatment plant to produce this water in huge quantities as it is also used all around the power plant in various equipment like the boiler, cooling system.
Just Google it, I'm speaking from experience as electrical commissioning engineer , part of the job was commissioning all the electrics for the water treatment plants . This is probably one of the smaller consumers in a power plant . average speaking , a 400 mw combined cycle plant will consume 16 to 25 MW of power generated for all the in house loads. There's huge boiler feed pumps , main cooling seawater pumps , lube oil pumps etc etc. Anyways water is only used when running on diesel and is almost always only as back up fuel. Diesel or any other liquid fuel is very harsh on the turbine and eats away operating hours faster than a gas only engine.
3:16 lolololol you should do hurricane testing on model houses with that
It's David Evans (The Edge)!
Cool job these guys have. So it's more efficient? Doesn't reduce power, combustion?
Nice, theres actually no water vapor at all, i thought i would see a white myst coming out from the back like the fuel cloud coming out before an afterburner is turned on.
Water vapor is a colourless gas.
From what I have heard Harrier jets use water injection to cool the engines when the aircraft is in hover. Did you notice a temperature drop in this case? Wouldn't water injection lead to a less complete combustion of the fuel?
Water injection was certainly used in the hover during early development of the Pegasus engine and in the early Pegasus 5 it was used to maintain thrust up to an ambient temperature of 40degC. However, in the later marks of Pegasus, It was/is used for a so-called 'Short Lift Wet ' rating, to perform a short take-off with a maximum fuel and weapons load. The water tank only holds enough water for (from memory) about 90 seconds of use. So, any time you have seen, say, a Harrier II doing a display in the hover, it would not have been using water injection.
grahamj9101
Thanks
Winter's coming! :)
Have you ever thought of putting together a forum for people who watch your videos? You could have people's questions by other viewers. It would be a great place to have discussions and share photos. Its not that hard to set up, you could do it through a free website or something.
I have never had a useful experience in a forum. Of any kind. Wasted many hours with no success at all. Ever.
I am not qualified to start one.
I don't think many airliner engines used water injection, but the RR Sppey did. A mixup contributed to the loss of a Spey engined BAC1-11. aviation-safety.net/database/record.php?id=19710906-0
As I was reading the comments I mistook your name for mine and had a moment of "what the fuck do I know about jet engines and when did I watch this?"
Is the reduction in NOx purely a function of the lower temperature in the combustion chamber or does the water also have some chemical effect?
Temperature.
At higher temps, the oxygen begins to react with the nitrogen in the air, seeing as most of air is actually nitrogen.
Lower the temps, and it stops happening (as much).
Where are you injecting the water relative to the fuel injectors and the actual flame of the combustors?
This is a somewhat unconventional system, which I have been asked not to discuss in detail like that.
That's fair. At least we get to look in awe at all that extra piping on the combustors!
It's all combined into the fuel nozzle, water, fuel gas, fuel oil. Water injection is nothing more than exhaust gas recirculation on a piston engine except that water substitutes exhaust gases. Same principle, reduce combustion Temps, reduce nox emissions
I don't buy the analogy with EGR in an automotive engine. The fundamental difference is that, with water injection, there is a massive evaporative cooling effect, which reduces turbine entry temperature when used on take-off for aero engines. This allows for an increase in fuel flow and hence thrust for a short period. Continuous water injection for NOx reduction is altogether more sophisticated and I'd moved on from industrial to aero engines by the time they started developing it at R-R IMD.
Are you using De-Min water? Whats the fuel type, liquid or gas? our CHP plant at Heathrow has an LM1600, Alstom turbine, Brush generator as well as the exhaust heat recovery boiler, (heated most of the South of Heathrow with district heating). Our De-min water plant for the Nox injection was huge and we had two Bellis & Morcom gas compressors raising natural gas fuel px from 3.5 to 38bar. That CHP plant is mothballed now though. Are you not bothered by FOD?
Cogeneration or Combined heat and power rarely proves to be that useful or efficient.
It's alot more efficient than exhausting gases at 800 centigrade directly into the atmosphere.
Woah, haven't watched in a while so the beard was all O_O
Is it any more efficient when injecting water? I would assume the water would vaporize and turn into steam theoretically increasing the pressure?
Water reduces combustion temperatures. So you can use a lot more fuel to make more power, or you can use the same amount of fuel an make less NOx.
Pressure is not affected, and what is efficiency?
@@AgentJayZ so the water makes it "safer" for the engine?
During power generation how long would this engine run between shutdowns?
Months or years at a time if supplying base load.
Engines used to boost power during peak loads may run intermittently, so it would be many years between overhauls for them.
was there any change in power output of the jet engine when the water was injected into it??
i was wondering about exhaust gas temps too.
The output of NOx was reduced dramatically, and EGT went down. As for any power increase caused by the water injection ( without any extra fuel being introduced ), I don't think it was significant.
Good Job
does the water lower egts and maintain the same amount of power though out the system? would this increase or decrease heat cycles on the turbine? i've also been told that on a radial compressor(turbocharger) water flow though it will increase the maximum flow rate, but i can't see it flowing any more air than without water.
Maybe the water is added to prevent predetonation. Check out intercoolers though, they perform the same cooling function without adding water into the fuel air mixture.
I was on a BAC 1 =11 years ago and in the cockpit during a flight to Spain, and the RR Speys used water injection to increase mass acceleration, but the pilots said that it wore out the engines faster by using this system.
Is this right?
Interesting video! How do find the optimum amount of water to inject? Does it have a kind of ceiling effect where an increase in water injection does not result in any more decrease in NOx? Or is the limiting factor a loss in engine power by to much water?
I don't have an answer to this question.
The aim is to get it down to the point where your Nox is lowest without CO starting to increase. There is a 'sweet spot' of combustion temp where the two curves intersect. Alternatively there will also be a wet flameout limit where you can't inject any more water past that.
@7:39 what conclusions can you draw from observing the EGT, besides that the engine is working? Does your diagnostics computer check for a EGT to RPM ratio etc... Do engines at the end of their service period show sub optimal EGT and RPM ?
Kevy Elyod EGT kinda varies. I'm not too sure about this one but I think the thermocouple is near the end of the exhaust tail pipe?
EGT = Exit Gas Temperature. Every engine has a EGT-limit. if you go higher than it you might burn your first stage turbine blades. You measure EGT instead of the Temperature at turbine intake because your thermocouples live longer at the rear of the engine.
Almost everything about a gas turbines operation is based on EGT temps. The controller monitors individually and may also use a variation of all the TC readings, based on how it is programmed. Also monitoring intake and exhaust temperatures, along with fuel pressure and flow to maximize GT operation.
Hi there. absolutely love your vids. small question for you. I have noticed that the start cart valve stays closed until it reaches max power . any reason it can't stay open from the beginning? thanks
Turbine engines work best at their design speed, which is nominally 100% rpm. At any speed below that, they are struggling or running sub-optimally. See my video about starting a jet engine.
The start carts engine needs to be running at its design speed before it can afford to have a significant portion of its compressor output diverted away from its own needs in order to power something else.
Also see my video called Bleed Air.
The start cart is a rare case where the compressor bleed valve is closed during starting and only opens after full rpm is reached.
Sorry to hear about the flood! The beard looks great on you, though :)
You seem to have a constant supply of engines to maintain! Are your customers local, all over Canada, or even further? How much competition do you have?
Our customers are located in every corner of the globe..... (does a globe have any corners at all?)
Most larger companies are not interested in the engines we support, so we don't have a lot of competition.
Rectangles!
I see! Geez, shipping must cost a tonne. But then I suppose everything associated with jet engines does. Thanks!
Shipping from somewhere in the world is 1.0X to Vancouver, a major west coast port in North America.
To FSJ, it is an extra two days by truck, so make that 1.2X. The cost is insignificant in the grand scheme.
I saw you show how they engines are packed, carefully fastened inside a container. But from the outside, it's just a box, right? Do the shipping people need to do any special handling?
I have a related question: After balancing turbines, how easily do they come out of balance again? I presume you also have to balance compressors. You've shown how the compressor blades can move a little, so I imagine just shaking them around in a truck won't cause trouble. So what does cause them to become unbalanced? Only physical damage to the blades?
Thank you for the wonderful content, as always!
Sources NOX reduction en.wikipedia.org/wiki/Selective_catalytic_reduction. >>Thought corp. was doing burn water for thrust output augmentation.Exampled increased thrust or power output, P-51 water injection, increase manifold pressure and output horse power. Hydrogen from water diffraction under cyclic load heat plus pressure. Two modulus piston vrs. jet, increase of volume of density flows output.*reference compressible and in-compressible gas exit flows and or inlet, mid compression via ignition and exit flows.Course on aerodynamic flows._Thanks very much, like the beard, looks as if your'e about to dig a hole and hibernate. Best to you and yours come this holidays.
Can you explain a water injection system and how it works, if you haven't already. Because a part of me feels it just water misted into the exhaust, thus adding more mass and there for more thrust.
There's a playlist called your questions answered, and it has a sort of index...
Water must be injected before the highest tempurature that occurs in the engine, so before the flame in the combustion chaimber to lower the peak temp. Since it is retrofitted to this engine it might be in the fuel injection (He won't tell us since it's a secret).
I think for Power output increase water has to be injected in the Compressor so that it increases mass flow rate by increasing density. Injecting in combustor would not have effect on mass flow rate, but the reduction in temperature would reduce NOx. But I have question, where exactly in the combustor area you are injecting water? And do you see increase in CO at the same time NOx are reduced??
Google exhaust gas recirculation, do a word search and replace the word exhaust with water, done. That is all it does.
CO2 production is a function of the burning of fuel.NOX is a function of the combustion temperature.As they are not increasing fuel burn CO2 remains the same.Only the combustion temperature is lowered by the water.
I'm so addicted to your videos.
I don't see any variable control on the water injection. Is the flow rate static or based on fuel consuption? Or just a test?
its static, only used at certain high power levels.
You got snow, WTF? I thought I heard the engine spin just a tad faster when he turned the water on. Will this save fuel too?
Once the water was turned on, Robin did increase the power level. Water injection reduces NOx, and allows the use of more fuel, but it does not increase efficiency.
The oxygen in the water allows for more fuel?
No. The water reduces combustor temp, and at max power, the limiting factor is combustion gas temp. So more fuel can be introduced before the temp limit is reached.
+prancstaman No. The oxygen in water is bonded to hydrogen. Both of those elements are residing happily at a low energy state, and are unavailable for combustion when they are components of a water molecule
Is the room that you have your computers in armored to protect the people from shrapnel in case the compressor blades exploded?
Compressor blades do not explode.
You don't really understand what you are asking.
The answer to your confused question is included in the playlist; Your Questions Answered.
Find it in the index, or don't.
Interesting. Would the water injection function in a similar way to a piston engine using water injection, by increasing cylinder (in this case combustor) pressures as the water flashes to steam?
Pressure does not rise in the combustors. The volume of gas expands hugely due to heat, but the rear end is wide open for the expansion to escape through the turbine. Water injection lowers combustion temp, and adds a bit of mass flow to the expansion. It can increase power, but is mainly used to lower NOx emissions.
@@AgentJayZ It can increase power because the vaporized water creates more volume of exhaust gas with no additional compressor work. And, the work to pump liquid water is relatively small. However, the actual increase in exhaust volume is tricky to figure because some of [most of (?)] the water vapor -- steam -- dissolves in the hot compressor flame gas so you don't get the full effect of the additional "steam" volume. Fun stuff.
Welcome
At 1:46, interesting to see the RPM rise on the control panel as the start start cart air entered the engine. Would have liked to see the numbers on the screen (RPM, oil pressure, EGT, etc.) as the engine reached idle.
Question I've increasingly pondered. When you test run an industrial engine, how do you know what size nozzle (cross section area of exhaust) to attach to the gas generator to simulate the "load"? Does each engine have an engine manual that provides the specific nozzle size information for test purposes, including the nozzle information for an aircraft engine that has been converted into an industrial engine (e.g. J-79/LM1500)? Or is this the kind of information you *know* only through your experience?
Not critical. We are not trying to maximize exhaust acceleration ( thrust), we are just putting a measured restriction in the exhaust to measure pressure rise upstream.
10:42
10:43
With that much water vapour going into the air there has to be snow, lots of it!
Only if you are high enough (the air from the engine is hot)
Also it must be cold enough at the Zero-level of Terrain, so that it stays as snow.
The most importent is that it was nearly only used at take off. And the time before touching the ground is at take off to short to cool down...
is there any special modifications you have to do to the internals to combat wear/erosion due the water injection
None. The water instantly turns to steam and then to vapour. It reduces peak combustion temp and adds to the mass of working fluid.
It was just that i have seen water vapour used tho cut thru high strength steel and ceramics and was wondering if it reduces the life span of internal components, although i suppose that as long as it is in gassious form wear could be minimal
If anything, lower temps are probably a benefit for lifetime. Creep would be reduced for one thing. Steam quality should be very high, so no erosion issues there.
AgentJayZ , Build a Turbine powered Blender with one of the spares and make high speed smoothies & margarita's!~
I said Margarita's... same thing :)
Hello. I have a question. If my injected water has some colloids. Will my blades be prone to deposition with respect to time? Any experience?
Depends what the material is.
Depends where the water is injected.
Am I wrong that there is a ton of potential energy being wasted in this situation? My instincts would tell me that any exhaust gas movement not being used to rotate a rotar inside a stator lost? Or in the power generation application, is there not really any real thrust in the exhaust when the turbine is under load? Sorry if I am using words wrong, or just plane stupid. I wouldn't have graduated high school if it were not for a lovely woman named Mrs. Ziff, that saw that I was out of my element in school and broke all the rules to help me graduate. (Gave all answers to tests and homework) she knew I was not stupid, just not willing to comply with the extortion of the youth, not interested in what they wanted me to be. I love that woman like my mother. Again sorry if this is a dumb question.
As simply as I can explain it: The energy in the combustion gases can be turned into rotating mechanical power by a (power)turbine, or they can be accelerated to quirt out the back by a jet nozzle.
One or the other.
@@AgentJayZ ok, thank you for your time, and your willingness to put up with people like me. This is the most valuable channel on RUclips. In more than one way.
Hey, Glitch,
There is some potential energy lost, like you said. AgentJayZ may correct me on this, but the I think the main lost energy is the thermal (heat) energy that's still in the exhaust gas. That's where combined cycle plants come in.
Basically they have a gas turbine hooked up to a generator like you were talking about, but then that exhaust gas that would normally go out the stack and be wasted is then used to heat water in tubes to make steam to turn a steam turbine. I think that puts the cycle efficiency up in the 50-60% range, instead of the mid-30's, which is quite the improvement.
Your question wasn't dumb, at all, in my opinion.
Hi,
Do you remember what inlet temperature of the injected water?
How do you recirculate it? DO you recirculate it?
Thanks ! :)
Ambient. We don't. No.
It's recycled to the atmosphere.
Doesn't water injection increase power/improve economy like in piston engines? I know jets are not like piston engines, just being curious :-)
It can be used to improve power output, or to reduce emissions, or maybe a little of both. The customers of ours who use it are more interested in reducing emissions of NOx
Water injection alone does not increase power in a piston engine. It's used to prevent detonation in forced induction and high compression applications.
Nope, emissions only and only when running fuel oil like diesel, fuel gas is clean tsjt it doesn't require water injection and nox can be managed on fuel gas using very intricate and clever mixing of gas and air before combustion. Water being used to increase performance is always upstream of the compressor in the filter house simply used to cool the air to make it denser. This of course only exists in hot climate countries
EGT's drop any noticeable amount i know in diesel trucks it does that happen here to?
Yes, for this operator, the main reason for using water injection is the reduction in EGT, which reduces Nox production.
Are the effects of Water Injection and Water Ingestion the same at the tail pipe? Maybe as you mention less NOx and how about lower EGT?
+King Of Drones
Water ingestion is never great enough to have a significant effect, even in heavy rain.
Sure, some cargo planes used water injection because it allowed for higher expansion of intake air simply because it was cooler but Darryl Greenemeyer used it to cool inlet temperature on his red baron F104 for both that and the fact that the j79 get's some pretty high inlet temperatures at high altitude much less mach 1.33 at sea level.
Much more fun way than catalytic converters and DEF fluid. Lol
OK, so what have you got against R-R's helical splines?
I'm guessing there a bitch to remove!
I feel like this is a stupid question. Why aren't the front blades spinning? They aren't stators are they?
Inlet guide vanes, yes like stators but variable
Cobus Laubscher ah, Thanks!
They are variable right @AgentJayZ?
stators can be variable too
So,
I have heard that water injection has been used to boost thrust by adding to the combustive expansion.
Can you confirm or deny?
Has been. Not on any modern engines flying these days.
Industrial engines sometimes use water injection to reduce emissions of NOx.
@AgentJayZ Right right.
Yeah, someone said that the black exhaust the original b52's were spewing was because water injection on takeoff was expelling soot
@@vanpenguin22 I thought the water was used to increase mass being expelled?
(I have no idea what I am talking about).
why does nobody use ethanol and water mixture as jet fuel? ive read they did it in ww2 as rocket fuel. should burn cooler and produce more thrust since more mass is moved and cost cheaper to make parts since no high heat would be involved, and put all the emissions and sustainability talk to rest.
Ethanol has much lower combustion energy available per unit of weight than kerosene-based jet fuel, and water has none.
You can't burn water.
Jet engines are air cooled, and are designed to burn high energy fuel.
They could burn methanol, but they would need more of it to make the same power. The water would just be in the way, and extra weight on an aircraft.
The main thing to avoid with aircraft is weight.
AgentJayZ i think he was meaning methanol
Where is the JET black smoke?
Only made by the older engines. This is a modern gas generator, that makes no smoke when running on jet fuel. Here it's running even cleaner on gaseous propane.
The smoky test runs are of the older J79 engines. You can find them if you look around my channel.
so can the steam being created let you use up less fuel
No, the temp drop due to the evaporation of the water allows the use of more fuel, if you want.
awesome...
Do low pressures on the intake every make vorticies, observable or not (how would you know!), on the test stand? OOO OOOO OOOO, and where is the downrange snow from the water injection and combustion water exhaust from such a gas turbine engine? do contrails not exist at ground level in cold, pre-winter, Canada? What happens in the deep-freeze winter downstream from the test stand? "jet engine snow"?
Contrails aren't just the exhausts. It's the small particles in the exhaust giving moisture from the surrounding air a nucleus to condense and freeze on. Also the temperature up there is around -50 to -70°C. Hard to match that on the ground.
Yes, quite a few of my videos show inlet vortices forming at high power. I think it's an interaction with the surface of the ground, and doesn't happen in flight.
Not enough water in the exhaust to condense out, even with water injection.
huh! i guess ive missed them, ill keep a more sharp eye.
I want to try this on my omc sled rotary motor, im running 50:1 amsoil dominator oil. Does this turbine use a 2 stroke synthetic oil?
It uses synthetic Mobil Jet II engine oil, and depending on how you look at it, it has either no strokes, or infinite strokes.
lol
what was the peroformance difference from no water to water injection?
were temps different, speed, pressures?
Our NOX emissions dropped by over 50%, if I remember correctly. Same power, same fuel flow.
@@AgentJayZ Were you able to get any temperature readings inside of the turbine? Equal power at lower temperature could be a plus as long as steam corrosion wasn't a problem.
Boiling 20 gallons of water per minute = 7.2 MJ per minute = 2 kWh/minute = 120kW output power lost to heat the water or roughly 200ml extra fuel per minute. Is it really worth it to reduce emissions. it is decreasing efficiency?
It's a widespread industrial practice. Perhaps the thousands of professional engineers involved need you to show them the error in their ways?
@@AgentJayZ It was not an asshole comment I pulled on you there. You explain it in your video, that this is to reduce NOx emissions. I was just thinking that there should be better ways, like EGR valves in cars, i.e. routing some exhaust back into the mouth of the compressor to reduce the amount of Oxygen, also reducing combustion temperatures, without needing to waste energy on boiling water?
Rule #1: These are not piston engines. Your "I was thinking..." is somehow going to surpass the efforts of thousands of professional engineers? Get busy and show the world how.
@@AgentJayZ I bow to you, you are 100% no bullshit! Cheers.
@@Tore_Lund Turbine combustion systems need to operate at a very specific flame primary zone temperature to achieve the desired power and emissions targets. That is what determines the flow rate of water. Also, efficiency and emissions don't always correlate in these types of engines. It depends on their application. also industrial gas turbines don't require the water to be boiled; their water is injected downstream of the fuel injectors in the combustor. The water serves to increase mass flow rate through the turbines stage. The water will vaporize as it's injected, before reaching the turbine stage.
Would this work if you use water and methanol together
no.
Water + Methanol is for cars. You add water so the air is cooler and can compressed further. As you have a higher compression ratio you also need a higher octane number or you get early ignition. Methanol is increasing the octane number.
Succinct.
IIRC, there are some turbine systems that use ethanol injection. Soviet Mig-25 used it and the folk at the air bases would drink it instead of vodka (source "Mig Pilot", Viktor Belenko). In that application, pollutants are not the issue. Also, I thought some (all?) Boeing 747 used water injection.
B-52 as well.
My brother has one of these to heat his airplane hangar.
Are there not any concerns of corrosion with this kind of setup?
The nickel alloys of the hot parts don't rust.
We are using de-ionized water. Many operators use distilled water.
How much fuel was used when 10-20 gallons of water were also used?
The engine was running on gaseous propane, and we don't measure fuel consumption. We also did not measure rate of water use.
We were running at medium power based on the max reading I saw on the tachometer. The 2500 runs at around 9200, and we were at 8500. As a guess, we were burning the liquid fuel equivalent of about 10 gallons per minute when we were injecting water.
These are all rough estimates.
Just Curious, How many Hundreds or Thousands of gallons of JetFuel do you guys go through on an average dyno run? and how long do you run an engine before you consider it "good to go" ? Miniutes? Hours?
If everything is nominal and no adjustments need to be made, a liquid fueled aircraft engine will run for less than an hour, and be tested at all power levels, from ground idle to full afterburner.
Such a test is rare, because minor adjustments are often made, with repeat runs then required.
A J79 test will use most of our thousand gallon fuel tank.
The aircraft can only fly for half an hour or less before landing or hitting a tanker, because the engine is not idling when the aircraft is flying.
I have a Agent Jay Z tuk just like that 😎
Hello! Could you explain the servo mechanism? It is changing the compression ratio? (at 9:40 - 9:54)
That is the mechanism that moves the variable stators. Compression ratio is not a term applicable to turbine engines. Have a look at my video about compressor stall for more info about variable stators.
What's that white thing on the ground? -- he asked from California 😎
The left-over-cocaine after a party at Charlie Sheen's house :-)