gas turbine mix fuel


Thread Starter

rakesh bhavsar

We have mark vi frame v gas turbine running on LCO fuel. we want to run it on mix fuel but how we don't know. please help.
LCO fuel.

Does the turbine have the capability to operate on any other fuel(s) besides LCO, whatever that is?

Does the Main Display on the HMI have a button in the Fuel Select section of the display which says MIX?

If the unit is capable of operation on some other fuel *and* there is a MIX button in the Fuel Select section of the Main Display, then while the unit is running (at FSNL (Full Speed-No Load) or on line (while generating power) an operator needs to select the other fuel (for example, Natural Gas) and the Speedtronic will begin the process of transferring from LCO (whatever that is) to Natural Gas. At any point while the unit is operating on a mix of fuels while transferring fuels, the operator then clicks on MIX and the transfer will stop at that point.

Many times there is another button which will allow an operator to set the portion of the primary fuel (depends on what is the primary fuel at your site), such as 40% ( for example, 40%, for LCO if that were the primary fuel, whatever that is,).

Operation on mixed fuel does not mean that one can operate at *any* fuel split. One has to choose a split that allows sufficient fuel to flow to maintain desired pressure drops and/or atomization for proper operation. These limits are usually defined in the Control Specification, Section 5, which is provided with the unit.

NOTE: A GE-design heavy duty gas turbine cannot generally be operated on mixed fuel during starting or during stopping. The Speedtronic will generally automatically switch to one fuel or the other (usually whatever is deemed the primary fuel) if one is operating on mixed fuel and selects STOP or an automatic shutdown is initiated.

Starting a turbine has to be done on one fuel, and transfer or mixed operation can begin once the unit reaches FSNL or load.

If the unit is not capable of operating on any other fuel(s) besides LCO, whatever that is, then you will need to talk to a company about modifying the unit to run on whatever fuel(s) or mixed fuel that you want to run the unit on. Fuel delivery systems and fuel nozzles have to be capable of flowing sufficient fuel quantity to be compatible with other fuels and with the turbine components.

But, you have given us very little information, such as what is LCO and if your turbine has the capability to run on more than one fuel. Hopefully you obtained some useful information.

Finally, in the Instruction Manuals provided with the unit, you should have been able to find a section about operation which describes how to change fuels and how to operate on mixed fuel, if the unit has the capability, including limits of fuel splits. Without being able to see the application code in the Mark VI or the Control Specification for the turbine at your site, that's about all the information that we can provide on this subject. If you have other questions, you should ask the packager of the unit.
Dear CSA,

one thing to add that I learned on our MKVI Frame 5 cimplicity controlled units was there are the buttons to select gas/mix/liquid fuel types. There is an area to enter a mixed fuel setpoint in percent as you stated. We had originally thought to enter a number in percent for the setpoint, like 40%. But actually the number needs to be entered as .40, or basically a number less than 1. Probably does not matter in this case, but maybe down the road it might help someone.