Flow Divider for Dual Fuel Gas Turbine - Liquid Fuel Systems

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Thread Starter

Rotimi88

Hello sirs,

Please I will like to know the function of flow divider and how it works including selector on liquid fuel system for GT.

Thanks
 
Rotimi88,

There are multiple combustion cans and fuel nozzles on a GE-design heavy duty gas turbine. And, the same amount of liquid fuel must flow to each combustor's fuel nozzle. The liquid fuel flow divider does that--it separates the single stream of liquid fuel exiting the liquid fuel control valve assembly into equal, individual streams to each combustor's fuel nozzle. There's one inlet to the liquid fuel flow divider (from the output of the liquid fuel control valve) and, if, for example, the unit has 10 combustion cans/fuel nozzles, there would be 10 output lines--one to each fuel nozzle on the combustion can cover.

The function of the selector valve--and it's gauge--is to allow an operator to check/monitor the liquid fuel system pressures. For example, if the unit has 10 combustion cans/fuel nozzles, positions 1 through 10 will correspond to the liquid fuel pressure being applied to combustion cans/fuel nozzles 1 through 10. I believe position 11 would display the incoming fuel pressure to the liquid fuel flow divider, and position 12 would display the incoming liquid fuel supply pressure to the high-pressure liquid fuel pump.

The gas fuel system uses a common manifold around the axial compressor casing and the fuel nozzle orifices to split the output from the gas fuel control valve(s) into equal flows to each combustor. That wouldn't work for the liquid fuel system.

Refer to the Liquid Fuel System P&ID, and the Operation & Service Manuals System Description tabs for some brief explanations of systems and components. The P&IDs are <b><i>CRITICAL</i></b> to any understanding of GE-design heavy duty gas turbine operation and control and protection. They are not difficult to understand, though they may take some time to sort through. And, as part of your research into each system, you should to go out the machine and locate each component that you can. Some components of some systems (such as the L.O.- and Hydraulic Systems are located in the L.O. Reservoir and are more difficult to get to--but you can certainly get access when the unit is shut down while in an outage. The System Descriptions in the Manuals also have good information about how systems operate, and how individual components operate.

Hope this helps!!!
 
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