Nozzle Control Principle

S

Thread Starter

saha

I want to know the principle operation of the second stage Nozzle for a GE two shaft gas turbine frame 5, controlled by mark 5 TMR. When the second stage nozzle starts modulates?
What is the relationship between the nozzle position and other turbine parameters (speed, load etc..)?
 
The general concept with two-shaft GE-design heavy duty gas turbines is: Fuel control is used to control LP shaft speed (torque), and nozzle control is used to control HP shaft speed. Fuel is increased to increase or decrease LP speed (torque) and the second stage nozzles are used to "split" the power between that required to turn the HP shaft, and control its speed, and that required to turn the LP shaft.

It's been more than 20 years since I worked on a two-shaft machine, but that one piece of information was extremely helpful to my understanding of the system.

Armed with that piece of information, you should be able to go into the Speedtronic control logic (I believe you indicated in a previous post that you had a Mark V, so that would be the CSP) and start looking for HP speed control. Work "backwards" from the second stage nozzle servo output and you will see what drives the second stage nozzle output. You should find that HP shaft speed is the control reference (SP, setpoint) and HP shaft speed feedback is the process variable that is compared to the reference and used to drive the second stage nozzle servo.
 
CSA,
Appreciate if you provide a detail on variable Nozzle control, its all control/operating parameters during control in connection with GE speedtronic MK-II control system.

Best wishes,
 
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