Hi,

This is my first post here. I'm hoping someone can help me.

I am a student studying gas turbine engines. I am currently undertaking an assignment where I have to write a paper on "Fuel control systems for industrial gas turbines".

I am having trouble locating quality information on my subject matter. Is there anyone that could recommend any good books/ websites?

Within the paper I have to cover working theories, evolution of the system, performance, configuration, applications and future development.

Please bear in mind I am a student and would only need the basics and fundamentals.

Thanks,
Bob

 

Hello,

You should include the term 'governor' in your searches, because that was the most common term for turbine control systems for decades, beginning with the fly-ball governors of yore.

This is something of a difficult topic, but not an impossible one. I suggest you research texts and handbooks, such as 'Power Generation Handbook', published by McGraw-Hill Handbooks, and other such reference materials.

Another possible source of information is Woodward Governor Co. They publish some pretty decent manuals for their equipment which sometimes contain gems of information about topics such as droop speed control or isochronous speed control.

I frequently use Amazon.com and other on-line booksellers when looking for texts and references. One site I discovered from posts here on control.com, alibris.com, has proven very beneficial as it many used books available for very low prices (sometimes the shipping costs more than the book!). These sites are easy to search, and don't forget to expand your search term(s) as you find more relevant information during your searches.

You may find some of these volumes in the library at your school (depending on the level of technical depth of the library; by the way, where are attending school?).

Turbine control is primarily about speed control, with overspeed protection being very important. Then there are all the protective functions (vibration, L.O. pressure/temperature, and the turbine-specific protective functions depending on the type of turbine (combustion or steam)).

It's really only been in the last 30 years or so that digital control systems have come into widespread acceptance. And most advances are based on improvements in digital technology (more computing horsepower; faster execution/scan rates; etc.).

There is also some good, basic information available on wikipedia.org, and another site, canteach.candu.org, has some really excellent materials of very basic, and even some higher level information.

Many of the major manufacturers of industrial gas turbines are loathe to divulge many of the details of their systems as they are considered proprietary, so it's generally difficult to find information from them (I'm speaking of GE and Siemens, specifically). Some manufacturers, like Solar, use PLCs configured as turbine control systems (which presents another set of issues and concerns), and many after-market companies also use PLCs for turbine control retrofit applications.

Emerson is also using their DCS system, Ovation, as a turbine control these days, but I don't know what kind of documentation they have.

Many times, one can glean little bits and pieces of information from sales brochures, which you might find on the World Wide Web-sites of the major manufacturers.

One of the things you may run across in your research is the concept of redundancy, which is a way of improving availability, and to a certain extent, reliability. There are systems that use just a single microprocessor (generally referred to as SIMPLEX systems), and some with two micro-processors (generally referred to as DUAL redundant) and some with three microprocessors (usually called TMR, for Triple Modular Redundant).

Multiple processors are used to provide a kind of "hot back-up" in the event one processor fails, or two-out-of-three voting for control and protection as is done in the TMR systems. The concept of multiple processors usually means that in the event of a failure of one of the processors while the turbine is running that it can be replaced without shutting the unit down, thereby increasing availability.

Hope this helps! Best of luck in your research!

 

Bob ,
I am uploading a document here . It is a GE manual on Mark V control system. This is one of the very first manuals i was given to read and i am passing on the torch to you.

this document has
a. brief history of gas turbine control evolution

b. basic gas turbine control philosophy

c. detailed explanation about governor control used in gas turbines

d. brief overview of field control and instrumentation.

e. overview of gas turbine protection

f. overview of mark v (it is a ge general purpose turbine governor) hard ware and software configuration.

you probably won't be needing the last part but its extra information.

here is the doc

http://www.2shared.com/document/lJoLt-NK/SPEEDTRONIC_MARK_V_Control_Sys.html

Hope this hooks you on to gas turbine controls as it did to me .

 

ProcessValue, I'd be very curious to know where you obtained this document, because it was pulled from distribution and modified shortly after its release, including correcting the sideways photo of the inside of the cabinet (Fig. 12).

The information is accurate.

 

well , i got it from a senior at work , almost two years ago , this was one of the first GE manual i read about gas turbine controls.

i do not know from where he got it from , probably from BHEL i guess.

 

Thank you for your replies CSA and Process Value. It is much appreciated.

From my research so for I am led to understand that the fuel supplied to the gas turbine is controlled by a fuel metering valve. This is controlled electronically by a PLC control unit which calculates how much fuel is needed by receiving sensor values such as ambient temp etc from the gas turbine?

Am i right so far?

Im not quite sure what a 'governor' actually is? is it another word for the PLC control unit? is it something that i have completely missed out?

Also, what is the difference between a fuel metering valve and a fuel metering unit? are they the same thing?

If anyone could help me out I would greatly appreciate it. Apologies for the basic level of questions. This kind of stuff is all new to me.

Thanks.

 

bob,

well i have slight difficulty in understanding what you are asking. there may be many confusing interrelated terms that the industry uses. well i am making the following assumptions

a.fuel meeting unit - this might me what we call the fuel flow transmitter or a mass flow transmitter , which measured the quantity of fuel input to the turbine

b. fuel metering valve ?? - this might be fuel control valve , this actuator controls how much fuel should be input to a turbine.

so given that the above assumptions are correct , i following is true.

in gas turbine control , the governor's primary function is to regulate the fuel flow to the turbine so that a required output is achieved. in industrial gas turbines it is the power output from the generator , in aero gas turbines used in aircraft it is the required thrust. thus you give more fuel more is the power output and vice versa. to control the fuel input into the turbine you need a fuel control valve and to stop the fuel at the required amount you need the fuel flow meter. so to increase the power output to a particular value , the controller goes on increasing the fuel till the required power is attained.

hope this helps.