Switch Off IBH gas turbine 6B

hello everyone,
if i need to switch Off IBH, can i do it with MW (at which MW can i do it)? or without (F.S.N.L)? or just when turbine is stop can i make IBH Off? please if anybody has information and manuals regarding IBH ON or Off?
 
AhmedSnot,

Does your HMI have a button to disable or enable IBH?

Does the unit run on natural gas fuel, and does it have a Gas Fuel Transfer Valve? Or does it have four right angle gas control valves?

IBH isn't used when the IGV angles are greater than 62 DGA. So if you have a button on the HMI to disable it, I would suggest you do it prior to initiating a START. Be aware that when loading the unit will transition to Premix Steady State at a much higher load than when IBH is on. And when unloading it will transfer out of Premix Steady State at a much higher load.

I would not recommend trying to disable IBH when the unit is running because I don't really know what will happen if IBH shuts down and the unit is on Premix Steady State below approximately 80% of rated load. It might just trip as it's trying to transfer back to Lean-Lean at the same time the IBH is being reduced.

If there's no button on the HMI for disabling IBH, then I wouldn't try forcing logic to disable IBH; probably a poor idea for many reasons.

I am curious: Why is it necessary to shut of IBH?
 
thank you for replay,
yes, we have option to switch off IBH. and off course the unit working on gas fuel that why we switch ON IBH, as i knew, there is no advantage from IBH on Diesel fuel except the weather not freezing. also there is no advantage if we are on primary mode, so it is possible to switch OFF on primary mode on gas? like 5MW? or, we can also to switch OFF when we working on diesel fuel, and you know why. i am aware and i have information about the stage of premix steady state, my question is: can i switch OFF IBH with load, without load or just when GT is OFF? that is the reason I did not switch OFF because I did not the logic and behavior of GT after make it OFF.
finally, i am like you, just a curious, and i need to be aware about every situation.
much appreciate from you, thanks for replay again.
 
At 5 MW the IGVs are likely to be less than 62 DGA. I the unit is in Primary mode, there will probably be a little swing in load. Will it trip? I don't know.
 
"i am aware and i have information about the stage of premix steady state, my question is: can i switch OFF IBH with load, without load or just when GT is OFF? that is the reason I did not switch OFF because I did not the logic and behavior of GT after make it OFF. "

The transfer to DLN not only involves IBH, it also involves gas transfer purge valves that isolate purge air to the secondary nozzle and a vent valve that ensures less than 50 psi between the purge valves. The IBH is commanded to 100% at 95% speed and is only allowed 15% deviation from command to position.

You can switch IBH modes in primary mode < 1600 f combustion ref temp. you can also switch modes when the IBH is completely closed i.e. 0% IBH command signal loads > 80% of max load based on inlet temp.

Just from experience.....If you attempt anything else; the IBH simply cannot respond fast enough and the turbine WILL TRIP.

If you have a fuel oil mode, the IBH is probably disabled in logic when Fuel oil is selected.

Hopefully, CSA will/can explain it better than I.
 
"i am aware and i have information about the stage of premix steady state, my question is: can i switch OFF IBH with load, without load or just when GT is OFF? that is the reason I did not switch OFF because I did not the logic and behavior of GT after make it OFF. "

The transfer to DLN not only involves IBH, it also involves gas transfer purge valves that isolate purge air to the secondary nozzle and a vent valve that ensures less than 50 psi between the purge valves. The IBH is commanded to 100% at 95% speed and is only allowed 15% deviation from command to position.

You can switch IBH modes in primary mode < 1600 f combustion ref temp. you can also switch modes when the IBH is completely closed i.e. 0% IBH command signal loads > 80% of max load based on inlet temp.

Just from experience.....If you attempt anything else; the IBH simply cannot respond fast enough and the turbine WILL TRIP.

If you have a fuel oil mode, the IBH is probably disabled in logic when Fuel oil is selected.

Hopefully, CSA will/can explain it better than I.
just one thing, you talked about purging of secondary nozzle of gas fuel! there no purge for secondary nozzle of fuel gas! just for secondary fuel nozzle, i am talking about what we have DLN-1 frame 6B.
 
AhmedSnot,

EVERY FRAME 6B IS NOT LIKE EVERY OTHER FRAME 6B!!!!!!!

As the publication Curous_One shows, there are several types of DLN combustion and fuel delivery systems--you were asked about the configuration of yours early on, but you have not chosen to provide that information.

I do seem to be surprised that at least one of the DLN-I fuel gas system variants does not have purge air on the secondary nozzle--but, as mentioned you have not told what the configuration of the gas fuel system is for YOUR unit--WHICH IS NOT LIKE EVERY OTHER FRAME 6B!!!

When you enquire of strangers for assistance and they ask questions to try to help provide the most concise and helpful information it's a good idea to provide the information they are requesting to get the best possible response. If you wish to pick and choose the questions you believe to be relevant, then you're not likely to get the best information.

We get paid exactly the same amount as you paid to post your question here: Nothing. We do it because we want to help spread knowledge and experience. If you can find a better source of information at the same price, feel free to avail yourself of it. BUT, if they aren't asking similar questions (such as about the gas fuel system configuration) you should be prepared to get incomplete information.

Unless, of course, whomever is providing the answers has exactly the same Frame 6B (including the gas fuel system!) as you are operating at your site.

You know, you were also asked why it was felt that IBH needed to be disabled (turned off). And, again, no real good response. The purpose of IBH, as explained in the publication, is to allow the unit to operate in Premix Steady State for a wider load range, say from approximately 45% to 100%, instead of the typical 80%-100% only possible without IBH. With IBH on during starting and loading, the unit will transition to Premix Steady State at around 45%, instead of the 80% or so without IBH on. During unloading while in Premix Steady State the unit will remain in Premix Steady State down to approximately 45% or sometimes lower, instead of transitioning back to Lean-Lean at around 80% load.

If you are even considering operating the machine for extended periods in Lean-Lean, or Extended Lean-Lean, or even Primary Mode, you should know that GE has factors for the number of fired hours of operation in those modes that can quickly increase the need to perform scheduled maintenance. For example, one hour of operation in Extended Lean-Lean is equivalent to 10 hours of operation in Premix Steady State! Lean-Lean operation is also a pretty high rate compared to Premix Steady State, if I recall correctly. (Though many places in a certain region of the world routinely ignore those recommendations, preferring to operate their Frame 6Bs as if they had conventional combustors, and if they can't get to or stay in Premix Steady State they just don't. And, then they are always surprised to find hot gas parts issues. They scream (yes; that happens a lot in that part of the world, too...), "Why did the Mark* let me continue to operate the turbine in Lean-Lean or Extended Lean-Lean without shutting down or tripping?!?!?!!!?? It's the damn Mark*'s fault!" No, it's not actually; if the Mark* were programmed to shut down or trip for every less than ideal operating condition it would have a reputation as an unreliable turbine control system. It is presumed that operators and operations supervisors understand the units they are operating, and will act accordingly to protect the unit. AND, if the unit just must stay online, then that's an option that should only be exercised with due acknowledgement.)

Anyway, I digress. And I exit this thread with best wishes for obtaining a proper answer.
 
AhmedSnot,

EVERY FRAME 6B IS NOT LIKE EVERY OTHER FRAME 6B!!!!!!!

As the publication Curous_One shows, there are several types of DLN combustion and fuel delivery systems--you were asked about the configuration of yours early on, but you have not chosen to provide that information.

I do seem to be surprised that at least one of the DLN-I fuel gas system variants does not have purge air on the secondary nozzle--but, as mentioned you have not told what the configuration of the gas fuel system is for YOUR unit--WHICH IS NOT LIKE EVERY OTHER FRAME 6B!!!

When you enquire of strangers for assistance and they ask questions to try to help provide the most concise and helpful information it's a good idea to provide the information they are requesting to get the best possible response. If you wish to pick and choose the questions you believe to be relevant, then you're not likely to get the best information.

We get paid exactly the same amount as you paid to post your question here: Nothing. We do it because we want to help spread knowledge and experience. If you can find a better source of information at the same price, feel free to avail yourself of it. BUT, if they aren't asking similar questions (such as about the gas fuel system configuration) you should be prepared to get incomplete information.

Unless, of course, whomever is providing the answers has exactly the same Frame 6B (including the gas fuel system!) as you are operating at your site.

You know, you were also asked why it was felt that IBH needed to be disabled (turned off). And, again, no real good response. The purpose of IBH, as explained in the publication, is to allow the unit to operate in Premix Steady State for a wider load range, say from approximately 45% to 100%, instead of the typical 80%-100% only possible without IBH. With IBH on during starting and loading, the unit will transition to Premix Steady State at around 45%, instead of the 80% or so without IBH on. During unloading while in Premix Steady State the unit will remain in Premix Steady State down to approximately 45% or sometimes lower, instead of transitioning back to Lean-Lean at around 80% load.

If you are even considering operating the machine for extended periods in Lean-Lean, or Extended Lean-Lean, or even Primary Mode, you should know that GE has factors for the number of fired hours of operation in those modes that can quickly increase the need to perform scheduled maintenance. For example, one hour of operation in Extended Lean-Lean is equivalent to 10 hours of operation in Premix Steady State! Lean-Lean operation is also a pretty high rate compared to Premix Steady State, if I recall correctly. (Though many places in a certain region of the world routinely ignore those recommendations, preferring to operate their Frame 6Bs as if they had conventional combustors, and if they can't get to or stay in Premix Steady State they just don't. And, then they are always surprised to find hot gas parts issues. They scream (yes; that happens a lot in that part of the world, too...), "Why did the Mark* let me continue to operate the turbine in Lean-Lean or Extended Lean-Lean without shutting down or tripping?!?!?!!!?? It's the damn Mark*'s fault!" No, it's not actually; if the Mark* were programmed to shut down or trip for every less than ideal operating condition it would have a reputation as an unreliable turbine control system. It is presumed that operators and operations supervisors understand the units they are operating, and will act accordingly to protect the unit. AND, if the unit just must stay online, then that's an option that should only be exercised with due acknowledgement.)

Anyway, I digress. And I exit this thread with best wishes for obtaining a proper answer.
CSA, why you upset, i will talking about my self, always, when i face a problem i visit control automation and get the best answers from you and the friends, without pay any things, just thanks, i dont have a problem my friend, i am just thinking what if i need in any case to switch-off IBH! even when i asked my question, i did not mention that i have a problem, and when you ask me, also i answered your questions. sorry for friends here because my question is not useful. i will not switch-off IBH ever never.
thank you for your information and replay.
 
Just a little input, Most of the DLN machines that I have been exposed to. Although a IBH ON/OFF button does exist, a LFALSE in the logic prevents it from working.

LFALSE also disables the IGV control buttons. I just wish the GE TA folks that put in the LFALSE would take the time to learn about the "Visibility property" in the HMI and HIDE THOSE BUTTONS.
 
It's so odd that so many of the GE field service personnel commissioning units during the Mark V era (and I'm presuming the units at the OPs site have Mark Vs) were infinitely more interested in changing displays in the way they thought they should be configured instead of making sure that every button on every display actually did something and worked properly (the latter would require a bit of digging and engineering to get to the bottom of). They just ass-u-me-d if the buttons were there, they should be and they worked. (Except for the many people who were always trying to get On- or Off-line Water Wash buttons to work and were continually asking about Peak Load and Peak Reserve (because Customers wanted that for free, of course).) Many of those same field service personnel couldn't find 20TV-1 or 33HR-1 and insisted they didn't need to study and learn P&IDs--because they weren't told they had to during Mark V training and never figured out how valuable they were.

The OP asked in the original post, "If I need to switch OFF IBH, ..." which I have learned almost always means, "I want to switch OFF IBH..." Not always, so maybe I was wrong. The question would have been better phrased as, "Is there ever a situation when IBH needs to be shut down, and if so, when should it be shut down (before starting, or at some load, or ???" See, no possible confusion with that question.

I'll venture the OP doesn't know to look for the IBH ON/OFF rung to see if it has an LFALSE, or what the significance of that is. (Most sites I go to these days people are actually forcing LTRUE and/or LFALSE and the turbine won't start or it trips and they don't understand why. (GE should never have allowed either of those signals to be force--they blocked L25 from being forced, so it is possible to do so.) Curious_One explained it really well: If IBH is enabled and the unit is above approximately 45-50% load, and IBH is disabled (switched OFF) a LOT of things are going to be happening. TTRF/TTRF1 is going to be changing, and the unit is going to have to transfer out of Premix Steady State, the splitter valve is going to have to move, the diffusion flame in the Primary combustion zone is going to have to be reignited--it's just a lot of stuff happening. And the IGVs are probably going to be moving pretty quickly also. NONE of it is good to all be happening at the same time for a DLN-I machine.

It seems like the OP has decided it's not a good idea, so that's a very good thing.
 
many thanks for you curious_one, you replay very useful for me, and smart point you mentioned before. and MR.CSA don't presuming please just ask me and i will told you which type of MARK we have. every one know, that some people think they now every things, and think also no one have right to think and make scenario for problems or issues, its not possible, because they think every think GE or other companies make it its stander and nothing can be discuses. for your information i am not a control engineer or working as a control engineer, i am mechanical engineer working in operation department. and i wont to mention also, if my question is not understood for someone, that is not mean its not understood by every one. by the way i will try to switch-OFF IBH but with some precautions to maintain the trip in case, and if any friend need to share the situation after SWITCH_OFF IBH, i will with my pleasure for advantage and experience.
 
AhmedSnot,

TRIPS from LOAD are FUN and FELT.

Decades ago,

I was asked to troubleshoot the generator RF field fault detection system. After contacting the manufacture, I was given waveform data to compare to data obtained by me from a OScope.

I followed the manufacture instruction to the letter. However; the manufacture did not care/know that if one lifts certain wires that a exciter trip will occur. I learned to check these things out myself utilizing generator protection drawings.

One can REALLY FEEL at full load trip when standing on the generator platform.

In closing, I had a lot of FUN examining historical data of Wheelspace temps, Vibration peaks, and other data to ensure I did not damage the turbine/generator.

Feel free to press that button anytime you wish. Since, you are a mechanical engineer........... You should be able to pick up the pieces and put the thing back together again.

I do not have the ability to be nice like CSA.
 
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