Hello friends,

We are having 6 no's of Gas Turbine (GE supplied Frame 9E m/c, model no -PG9171E) controlling through Mark VI technology. All the m/c normally running on Natural Gas

I want to know what will be the effect on Gas turbine in following different aspects if I run GT on peak load. Different aspects that I want to know is

Effect on GT components. Effect on logic point of view & Effect on reliability point of view if I run GT on peak load.

It is desirable to run GT on peak load? If yes then how long I can run GT on peak load?

 

Please obtain a copy of GE document GER-3620.

A previous thread had this link to a document on the World Wide Web:

http://www.gepower.com/prod_serv/products/tech_docs/en/downloads/ger3620k.pdf

(Remove any spaces inserted by the control.com software.)

But I was unable to make it work.

You should be able to obtain the most recent copy from your GE contact. (I have seen a Revision "R" of this document, but there may be a newer revision even.)

It will answer all your questions except the one about effect on logic. Operating the unit(s) at Peak Load will have no effect on the application code ("logic") running in the Speedtronic.

 

Dear,

I want to know how it will affect the machine as per the logic 1 hour peak load operation is equal to 6 hour base load operation.Peak load selection command is going in some FSR & temperature curve also but i am not able to conclude how it will affect the m/c..

Basically i am interested to know following things in details..

1. How much FSR,TTXM,Allowable Spread,MW will rise in case of peak load operation with comparing to base load operation.

2.As per the GE it is safe to run m/c for N nos of hour on peak load, but what's your experience is saying for the same. (as it is considering 6 times of base load operations hour), so basic query is How long i can run my m/c on peak load ?

3. What are the other parameters which need to be observed when m/c running on peak load.

4. How fast m/c will reach up to peak load (Rate of rise)?

 

Dear Kiran,

the basic change to logic for base load vs peak load is a change of allowable exhaust temperature. Peak load settings allow for a slightly higher allowable exhaust temperature, usually around 30 degf. which translates to a higher firing temperature, which finally allows for a few more megawatts of output. The actual megawatt increase depends on the machine efficiency, ambient conditions, etc. Usually around 3-5MW.

The idea typically for running a machine in peak mode is that it is used for emergencies only. The logic will protect the machine but the downside is increased maintenance. Since you are firing at a higher temperature the hot gas path parts will degrade faster. Assuming you adhere to the spec's of GER3620 you should be protected, if you were to exceed the recommended fired hours for hardware replacement then you could suffer a failure of a liner, transition piece, or 1st stage nozzle.

As far as time I don't think I have seen anything that says you cannot run in peak for as long as you want, as long as you understand the implications on the needed maintenance.

As far as watching values I do not think you would monitor anything different than in normal mode. Exhaust temperatures, exhaust temp. spreads, oil temperatures. All of the normal critical values should be monitored.

The time for the machine to reach peak load should not be any different than your normal ramp time to any selected load. Again the only change in operation between base load and peak load is a higher allowable exhaust temperature.

I hope this answers your questions.

 

Thanks MIKEVI