What Parts Difference between Conventional and DLN-1 Nozzle in GE-6B?

Hello Friends,

Can anybody help me to know which parts would change in converting Conventional 6B Nozzle to DLN 1?
Are these just Cap&Liner, Fuel Nozzle, Spark Plug and Flow Detector? or there is more?
Also in Auxiliary what changes need?

Thanks already
It's significantly more than that.

I'm not sure what you mean by "Flow Detector." If you meant 'flame detector'--no; it's not entirely necessary to use a different style of flame detector than you might currently be using--though no matter what style you use you will require more than two (2) flame detectors (usually four per combustion zone, and there are two combustion zones in a DLN-I combustion system, which is the type of combustion system used on Frame 6B GE-design heavy duty gas turbines.

What fuel(s) are you wanting to burn?

If it's gas fuel, you are going to need some kind of gas fuel splitter valve, or a valve arrangement that can perform that function.

If you have to burn liquid fuel, there really isn't a DLN combustion system for that. It can be a part of a dual fuel (gas/distillate) system, but in order to achieve NOx reduction while operating on liquid fuel you will require water- or steam injection for NOx emissions reduction--and the NOx reduction won't be anywhere near as low as burning gas fuel.

If you want to operate at loads lower than about 80% of rated (Base Load) you are going to need an Inlet Bleed Heat system.

If you have to operate the unit in islanded mode (a "captive" power plant; Isochronous Speed Control; or under the load control of some external system that attempts to maintain frequency as load changes), DLN-I is NOT a really good combustion system for this application.

And, if you need to meet some kind of emissions monitoring requirements, you will need some kind of emissions monitoring system (not usually provided by a turbine parts provider/OEM).

I suggest you search the World Wide Web for GE publications about DLN combustion systems for documents they have produced for more information.

There are other turbine parts suppliers that also sell and install DLN combustion systems in addition to the OEM. You would do well to check references on any supplier you might be considering using.

Best of luck in your endeavour.
We don`t want to do this by our own, we had some connection with a couple of contractors, but they didn`t give us part no, I want to have some research on parts by part no so can understand the difference, and have something in my hand to deal with them.

Converting from conventional combustors to DLN-I combustors is a very large undertaking. And, for dual fuel applications, it will be even larger. There will need to be at least two, if not three, gas fuel manifolds in the turbine compartment (one for primary fuel gas, one for secondary fuel gas, and one for transfer fuel gas (if the application will use a transfer gas fuel valve). There will need to be an atomizing air manifold (for liquid fuel), and a purge manifold (for liquid fuel), and a water injection manifold for liquid fuel. There will need to liquid fuel lines for each combustor, and there will even be a liquid fuel "distributor" (a mini liquid fuel flow divider) on the end cap of every combustor (to split the liquid fuel flow-rate evenly to each of the liquid fuel nozzles).

And, there are new fuel nozzles (primary AND secondary); new combustion liners; new transition pieces; new flow sleeves (probably); new ignitors (spark plugs); added flame detectors; new and different check valves; new solenoids; new fuel control valve(s); new servo-valve(s); new LVDTs. New piping supports; compartment enclosure modifications to allow new piping penetrations. The work involved in adding all the new piping and tubing is huge.

Yes; we can hear you now. "We already have an atomizing air manifold, and a purge air manifold, and a gas fuel manifold,"--BUT, they will all have to be replaced because of the additional manifolds which all have to be squeezed (and I do mean SQUEEZED) into the turbine compartment.

And that's just the turbine compartment. There have been some 6B sites which added a gas fuel splitter valve to the existing gas fuel compartment--but it, too, has to be SQUEEZED in to the compartment. (In this design, there is no gas transfer valve).

AND, as mentioned above--if you EVER want to operate at loads lower than approximately 80% of base load you are going to need to add an Inlet Bleed Heat System to the inlet duct--and add compressor discharge extraction piping to the turbine compartment!!!

There are LOTS of modifications which have to be made to the turbine control system, and calculations have to be made. It will be necessary to get a fuel analysis to do these calculations.

This is a BIG undertaking--and a parts list of the items required is only one part of the complete project. It's NOT going to give you a real idea of the cost, and it's not going to get you any bargaining power or leverage when trying to purchase or negotiate the purchase of a DLN-I conversion for the unit at your site.

Let's say you had a parts list, and let's even say you had an ESTIMATE of the cost of the parts. Would you be able to install and commission the parts without the assistance of a knowledgeable person or persons? I've done conventional combustor to DLN-I conversions for several 6B units--and no two were alike. ALL required on-site modifications and adjustments to the piping arrangements--which were developed with CAD systems--to be able to fit into the turbine compartment and gas fuel compartment. There has to be new conduit and wiring added to the unit (no easy task in itself). If you use hydraulically-operated gas control valve(s), there has to be hydraulic tubing added to the hydraulic system--outside of the L.O. tank. And wiring for servo valve(s) and LVDTs.

A parts list isn't going to do anything for you--that I can foresee. Do you think any supplier is going to give you a list of the equipment/parts they will be providing so you can compare it to the list of equipment they will be providing? And, if you did get their list of equipment/parts are you going to compare item by item (because the two lists are NOT going to be in line-by-line order). What will you use this list of parts/part numbers you are asking for to do?

And, since this IS a controls forum (and we're really NOT talking about controls in this thread), I will remind you that there is a LOT to do with the control system. The OEM will probably NOT agree to make the control system modifications in any control system other than a Mark* VIe--they just won't. Sure; they made the Mark V, and the Mark VI, but they don't support them any longer--not with hardware and not with software (not for such a large modification). Other suppliers may agree to make modifications to older Mark* turbine control systems, but they may not. They may have a PLC-based control system they want to sell with their DLN-I package--it makes it easier for them to commission and troubleshoot the equipment. And, you won't have any parts list for that equipment, either. Or, software list.

Please stop and think about what you're asking for and how you will use the information to get what you want. You are probably a mechanical department person (maybe not--but you understand there will have to be "some" mechanical changes). But, this is MUCH MORE than changing some mechanical parts. On a change of this scope and magnitude you are going to have to accept that the suppliers you are dealing with are knowledgeable and--if they have done this before (hopefully, more than a few times!) that they understand what's required--for every aspect of the job. Buying the parts is just ONE PART of a project like this; not a small part, but still--just one part. It would seem you are overlooking the other parts. A good salesperson would recognize this and shift some costs to the other areas you have demonstrated little knowledge of or concern about in the negotiations....

I wish you the best of luck. You would do well to visit some of the GE Users Groups (there is one for 6Bs!) and ask there about the cost of DLN-I conversions/upgrades. You may even get someone to give you the parts list you so highly covet.
Thank you CSA for your Time and a comprehend view.
YES I`m from Mechanical Dep. and I tried to have some aspect of work. :)Understand it`s a big job but We don`t have access to OEM for Upgrade, So I try to get some better knowledge on this, so can Moderate well for my company.
At all thanks for Information and help.

As I wrote, there is a Frame 6B Users Group you can probably join and there you can likely find what you are looking for--at least as far as the experiences others have had using various suppliers for DLN-I conversions.

And, there you can also probably ask about any potential suppliers you might be considering--ask others about their experiences with them.

That's a very difficult thing to do for many people: check references of potential suppliers. BUT, on a Users Group site you should be able to do so much easier as people are usually very willing to share their experiences with various suppliers. The site is usually not a public site, so people are more willing to be open and blunt (in cases where bluntness is warranted).

But, the thing you really want to do is ask potential suppliers how many of these conversions they have done, where they have done them. And, ask them to be candid and about how they did meeting the project schedules and guarantees.

It's well known that in some parts of the world there is inherent distrust of any salesperson and most companies. But, remember this: If a company has been in business for several years or more it's pretty likely they couldn't remain in business if they were dishonest and deceitful. In many parts of the world it's very difficult to earn a project without having some kind of personal relationship between the two companies--the one buying the project and the one supplying the project. A supplier may have the best price and/or the best equipment--but if there's no mutual trust between individuals of the companies then the supplier isn't going to get the contract.

My first international job was an eye-opener for me. The Customer was completely distrustful of the Company I worked for--even insuating MANY TIMES that we were trying to cheat them. We had observers who reported back to supervisors every day--observers who had NO IDEA what we were doing and how it should be done. And they continually reported that we weren't doing things properly. It lead to some very difficult times. We offered to explain what we were doing to the observers--if they would ask--and in the beginning, they wouldn't. But, as time went on they began to ask and we actually developed a very good relationship with some of them and the job finished well with everyone happy with the results (well, ..., almost everyone--there's always one or two malcontents in every bunch). I asked one of the observers why they had this attitude that we were trying to cheat or deceive them--and his response was that in their country there was just no trust between suppliers and purchasers, that that was the way everyone business relationship was handled by both parties. I reminded him that the company I worked for had been in business for more than 100 years, and if they had cheated and lied over that period no one would buy anything from them. It took him a good couple of weeks thinking about this idea, but he finally came to accept that we were there to do a good job and make a good impression so that we would continue to stay in business and sell equipment and services around the world. The site went from being entirely adverserial to a place where we joked and laughed with just about everyone and would even sit at the same tables for lunch on the beach some days (whereas before that no one would even enter the restaurant if someone from "the other side" had reached the restaurant first).

Anyway, I understand your anxiety. I ask you to, again, stop and consider that there are other ways of approaching business relationships--they may be hard to accept in the beginning, but working together with a supplier is much easier than working against them.

ge6b(dot)users-groups(dot)com While I hesitate to send people to another forum, I think this one is the one best suited for your needs. You will need to apply (register) for membership, I think, by supplying the serial number of your turbine and a name and probably a site location/name/address.

Best of luck! I hope this helps!