GT Start --> Starting Motor Start --> 600 RPM approx Purging --> Ignition --> Fuel On (Pilot & Main CV Opening at Ignition Set point --> Flame On --> Speed increasing --> Fuel Control --> 1500RPM Acc ON --> Governor control --> GCB Close --> Load Control --> Load Raise --> BPT Control --> Exhaust Control.

I know this in general but do not know in depth how it transfers from Load control to BPT Control and then exhaust control. I see low selector For CSO - which tells me that when load going up Load CSO and BPT CSO Goes up and at some point BPT CSO is less than load cso which drives BPT Control and subsequently Exhaust CSO (Is this called Outlet temp Control??) Exhaust CSO is determined based on Exhaust Reference which is based on CPR Comb Press Ratio and I see that BPT Bias is applied around 10C (18F) - What is the purpose of it ? Understanding this general information is not satisfactory for me as I want some experts' guidance to understand if someone willing to provide this. My concerns are what is GT Firing? Is it based on Exhaust Temp Set point driving GT? Why BPT Bias? What precaution I need to prevent GT Over Firing?

Any suggestion / help on discussion and my question, greatly appreciated.

Thanks control.com for support & People who have and are replying and sharing their knowledge

 

>GT Start --> Starting Motor Start -->

I think you got brief outline, Here at my site F7E M6e control(before it was M4).Here are the steps.

Auto (master mode selected) "ready to start" permissive acquired.

START/Excute L20TU1X1 = 1. Cranking MTR crank for max torque, ( RPM app 1000) purging for 581 sec (we have HRSG). L20TU1X1 drops and GT costing down, at about 8 % of speed (RPM 288) L20TU1X1 =1. GT ramps up and at 10 % of speed iginitor transformer energizes (FSR = 15%) and you have 60 secs to get two flames. whatever comes first (one min or flame) next step is one minute of warm-up cycle (FSR = 9%). start up FSR is open loop meaning ultimately it will be 100% so MIN FSR select gate can by pass this FSR values for final control.

Next is acceleration, at 60 % of the speed GT is self sustained and cranking MTR drops out. At 95 to 97 % of speed exciter (field) flashes (L14HF=1). FSNL. Syn is selected, Voltage matching is displayed on the screen. At about 11 o'clock on syncscope if frequency and voltage (of line and Generator, SVL and DV) are withing the predefined limit GT goes on grid. If "preselect" selected GT will go to that MW, or if Base selected it will go on temperature control TTRX, which is indirectly linked to Firing temperature. Firing temp is the temp at d/s of first stage turbine nozzle, so that the GT life can be prolonged between T/A

sorry for typo error.

 

Thanks Saardar
I still need to know about BPT Bias and Outlet Temp Control. What determines Change from Load to BPT Control and then Exhaust Control? I see that M/C when reaches close to Baseload, rate goes down and it is not same rate. How OEM Determines Loading rate of GT and Unloading rate of GT when runback occurs ?

 

Susan,

I may be dating myself here, but a reference to a 501F GT means a Westinghouse-design heavy duty gas turbine. Now, Westinghouse doesn't make gas turbines any longer, and I'm not even sure who owns that technology now, but a 501F is not a GE-design heavy duty gas turbine.

Please understand Sardar9 is a "fresher" at GE-design heavy duty gas turbine operation and controls. While many of the underlying concepts of the control and protection of GE-design heavy duty gas turbines and Westinghouse-design heavy duty gas turbines are very similar, the actual implementation is very different. GE-design heavy duty gas turbines, at the present time, don't have a "visible" blade path temperature (BPT) bias.

We don't seem to have a very large, or active, Westinghouse-design heavy duty gas turbine contingent on this site.

I would suggest that you refer to the instruction manuals and documents provided with the 501F GT at your site for more information. You may not find the detail you are seeking, but you may find some very useful information that will form a good foundation for future learning.

 

Maybe I can help you.

What type of DCS you have on your W engine? T3000, WDPF, TXP?

Does your engine has OTC? Dual fuel? Simple or Combined Cycle? Does your engine has Pneumatic or Hydraulic IGV?
DF42 or Dry Low NOx?

So I'll try to explain you how your engine is controlled.

 

Gas Only T3K and one with TXP. Hydraulic IGV and Fuel Valves & DLN

 

> Please understand Sardar9 is a "fresher" at GE-design heavy duty gas
> turbine operation and controls.

Thanks CSA for compliment, I am still learning

 

>Gas Only T3K and one with TXP.
>Hydraulic IGV and Fuel Valves & DLN

After you are above 1500 rpm, close loop speed controller engages, MW controller is tracking it, when you synch speed controller is disable but holds it last values, than value is taken by MW controller, from there the turbine is govern by the lowest controller out put, either MW at partial loads or Temp controller or Base Load. In grid events the engine always self protects and if a load swing is noticed the Jump limiter controller holds the machine to prevent over firing if at base or very high load jumps if not at base (when droops is active and freq transient is too high)each controller is tracking the one is on command. Any engine requires certain BTU or energy from the fuel for a given speed if starting or MW if synch. That energy is translated into CSO also known as Total Fuel Demand. Depending on your engine efficiency you'll see different values in between your both turbines.

Need more info please be free to contact me [email protected]

 

why bpt bias added to exhaust temp control in 501F? how jump limiter works? Please explain if you don't mind.