Gas Turbine Trip


Thread Starter


Season's Greetings!

Pls. be informed that we are facing the Gas turbine (Solar) Trip on "High Start Gas Fuel Flow", during start-up of the machine with in approx..8- 10 Sec. after the Purge time step is completed.

Alarm Grp. name: FSNL ,
Tag name: FN_High_Start_Fuel_Flow,

Following are the observations:

Main Fuel Gas Pressure: 24.1 Bar (350 Psig)
Primary Shutoff Valve opens
Secondary Shutoff Valve opens
Gas Torch valve opens
Igniter becomes - ON

ECT Avg. reading visually noticed reached to 240 deg. C for a very short time. The trend plotted it at 45 deg C only.

Fuel Gas flow remains at Zero at this stage. This reading reaches to 250 momentarily during Gas Fuel Control Pressure check step.
Main Fuel Gas Valve command reaches till 6%
Main Fuel gas Valve position feed back achieved 6%

Action taken :
Torch Gas Pri. regulator out put was checked and found at 35 psig,
Torch Gas Sec. regulator output checked and found at 24 psig.

Kindly advise the way forward.
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please note that for your problem for any gas turbine startup fuel - minimum fuel required for firing, increase fuel v/v opening to 10% because of increase in fuel may be increase temp more than 240c. therefore temp holds the trip circuit.

if the temp> 240 degreeC trip circuit holds and turbine start-up sequence will go to next step


There hasn't been much discussion around Solar gas turbines here on, so that's probably why you haven't had a response. I'm hesitant to hazard a guess without knowing more about the logic/sequencing/programming in the control system.

Wish I could have been more help!