I want to know more about the 26BT working on the unit, the function of it during the run up of the unit.

 

@Deprince,

How many years has the Frame 6B you are referring to been in operation? 2 years? 6 years? 16 years? 26 years?

There are MANY different arrangements of Accessory Compartments and Turbine Compartments--some which have negative pressure in the Accessory Compartment and some which have positive pressure in the Turbine Compartment.

Where are the gas valves (presuming the machine can burn natural gas) located? In a small compartment in the Accessory Compartment? In an off-base compartment?

While a GE-design Frame 6B heavy duty gas turbine is pretty much the same machine, the packages and auxiliaries where the machines are located (installed inside) can vary by a lot. So, without a lot more information we can't really say anything with any certainty.

Usually--for most GE-design heavy duty Frame 6B gas turbines--if the machine is started from a "cold" condition (after a cooldown period of at least 24 hours) 26BT doesn't start until flame is detected in the turbine, which means fuel is flowing into the turbine for combustion. If there are leaks in the fuel system(s) then fuel can get out of the systems and into the compartments, which is one of the primary reasons for ventilating the compartments. Yes; cooling is another reason for ventilating the compartments and an important one--but providing sufficient air flow to prevent the build-up of combustible gases from fuel leaks in the compartments is very, very important. So, air flow isn't really required unless fuel is flowing, or unless the compartments are warm from operation (the Accessory Compartment gets warm primarily from the heat radiated from the L.O. tank, and the Turbine Compartment from heat from the turbine combustors, combustion wrapper & turbine shell).

The Belfort, France, division of GE Vernova now has operational influence and control over the Frame 6B machine product, and they can and do change operational philosophies often and without much consideration for knock-on effects. If your machine is an older machine, they were pretty similar in many respects over decades, but not any longer.

If you have a particular issue or problem you can describe it here as best as you can and we can try to help with understanding operational philosophy and troubleshooting. But, without knowing a lot about the machine in question AND without being able to review the control sequencing/application code running in the turbine control system there's not too much we can add to what's already been written above.