2 CT'S AT IDENTICAL LOADS BUT ONE HAS HIGHER CO2

[bigdog50]

PONDERING AS TO WHY I, HAVE TO UNITS THAT ARE AT IDENTICAL LOADS MW WISE, BUT THE OTHER HAS HIGHER CO2 AT MINIUM LOADS AT ABOUT 60% OR 107 MW. THE CO2 IS ABOUT 5 TIMES AS HIGH AS THE OTHER. ALL GAS VALVES ON THESE TWO MACHINES (DLN) ARE PRETTY IDENTICAL, IGV'S THE SAME! CAN ANY ONE SUGGEST SOMETHING? CAN THESE BE A BAD SWIRLER ISSUE AT LOW LOADS WHEN PILOT FLAME BEGINS MAKE AN ENTRENCE BACK INTO THE SCEM OF THINGS? SOMEWHERE FUEL IS NOT BEING BURNED!

FLORIDA,
BIGDOG50

 

[rmw]

What causes you to believe your instrumentation?

rmw

 

[ccfowler]

Are all the gas nozzles identical? Could a gas nozzle have worked loose or be working loose? How does the fuel consumption vs. load compare between the two units?

Many years ago, I had experience with a GT that eventually suffered massive damage (melt-down) due to a lost gas nozzle, but the unit operated "normally" until the nozzle completely fell off. Even after the nozzle fell off, performance deteriorated gradually over a period of hours. Back then, no one measured CO2. The exhaust temperature measurement locations were not sufficiently dispersed to detect the failure in the early stages.

 

[ScottyUK]

Are the bladepath temperatures uniformly distributed around the blade ring, and are they comparable between units?

Picking up on rmw's question, are all other emissions measurements comparable? CO, SOx, etc?

How does EGT map versus fuel flow and IGV position? Do the units have different characteristics?



----------------------------------

If we learn from our mistakes,
I'm getting a great education!

 

[CMfgE1]

Iwould calibrate the CO2 instrument first. Then go from there. Verify the data thats being given to you will help
save you some steps. It could be your CO2 monitor is not functioning properly and that you have a bad sensor




Good Luck!!

Quote: "Its not what you know, its who you know" - anybody trying to find a decent job

 

[Romefu12]

Bigdog50
All of the above replies seem logical and important to verify however you make no mention of the type of units in question. The reasons for high CO readings, aside from the obvious issues listed in the above replies, can vary greatly with each specific OEM, engine type, and combustion system used.

High CO is a result of many potential causes including incomplete combustion, too much air and not enough fuel, too much fuel and not enough air, too much cooling air flow, missing seals etc.

If after verification of you instrumentation and callibrations prove correct there are some warning signs you can look for depending on the monitoring equipment installed and the type of engine in question.

I am assuming by the language used here (ie swirler, blade path spread, pilot flame etc) that some of these replies are originating from Siemens Westinghouse experience.

Regards
Romefu12

 

[gtsim]

Why can’t we calculate the CO2? All you need is the fuel flow and fuel composition. It should also be a lot cheaper. You could calculate it for both engines and see if there is this difference. 5 times more CO2 almost means the measurement is wrong because what you are also saying is that one unit is 5 times more thermally efficiency because CO2 emissions is proportional to the fuel burnt. This is very unlikely.