Control.com - Nerds in Control

Hello everyone,
I have some trouble on using liquid fuel on gas turbine generator. the type of gas turbine is MS 9001E, with load capacity 100 MW, and using MARK IV as a controller. the unit suddenly got tripped on starting process with the indication excessive liquid fuel alarm. actually the flow is controlled by liquid fuel bypass valve. we have change the solenoid valve and servomotor with a new one and also calibrated it. we also have calibrated the frequency on flow divider.

when unit started, the liquid fuel bypass on 100% open condition. but the result still make such an alarm.

is it possible that the excessive liquid fuel caused by the pressure drop on atomizing air?
because I thought atomizing air pressure and liquid fuel pressure entering the combustion on a manifold, therefore it will forces each other.

or if you have different analysis, please don't hesitate to share with me

frankly, the unit is used to use gas fuel. but in my country, indonesia especially on jakarta city predicted that the fuel gas supply will reduce next year. therefore, be or not to be, we have to use liquid fuel.

I'm looking forward for your reply.

Thanks

You need to have someone who can read and understand schematic piping diagrams (piping & instrumentation diagrams) and who can bleed the air from the liquid fuel piping and piping components. This has been discussed many times before on control.com.

The liquid fuel systems on GE-design heavy duty gas turbine-generators are made up of many components, all of which have to work properly all at the same time, and which have to be free of air to work properly. To troubleshoot liquid fuel operation, one must be familiar with the Liquid Fuel Forwarding System, the Atomizing Air System, the Gas- and Liquid Fuel Purge systems, the Liquid Fuel System, and all of the components of each of the systems.There are solenoids which control purge pressure ratios; there is a Booster Atomizing Air Compressor; there is a Tell-tale Leak-off; there are Liquid Fuel Check Valves; there are Atomizing Air Check valves; there is an Atomizing Air Temperature Regulating Valve; there is a Liquid Fuel Forwarding Pump Pressure Regulator.

We can't help you from afar; you need to get someone to site who can help you understand your systems and help you with your liquid fuel operability issues.

Does the Frame 9 turbine have an MK IV?

Yes it does. The Frame 9 turbine uses MARK IV as a controller. Is it possible that the excessive flow trip caused by malfunction of spring in check valve? Therefore, there isn't something to force the flow of liquid fuel.

Or do you have any suggestion about the instrument trouble?

Thanks.

Guess the last part of the first sentence of the original post wasn't clear:

"I have some trouble on using liquid fuel on gas turbine generator. the type of gas turbine is MS 9001E, with load capacity 100 MW, and using MARK IV as a controller."

Did you notice the liquid fuel flow feedback (fql?) vs. FSR before the trip occurred?

You should observe L60FFLH (Liquid Fues Excessive Flow Trip Value). It should be @9-11%FQL. Secondly, the reason may be a flow divider malfunction. You should replace the flow divider.

To start with, please have a check on the check valves and its operations on a test bunch. Please calibrate the Fuel bypass valve and flow divider. Check the atomising pressure sets. However purge the fuel line (liquid) for some time to free the condensate or air out of the pipeline. And be confident in start again.

Thomas