Hi Guys,

We have 4 units of Frame 6B more than 20 years old. At this stage due to high demand we are aiming to use Peak Load mode instead of Base Load. I got pressure to find EOH or Maintenance Factor. I have read GE document it does not give me any good details apart from one equation. As per the equation it requires firing temperature. We do not have any arrangement in speedotronic for firing temperature and I need to calculate firing temperature. Is that any equation or formula which can give me firing temperature of frame 6b? I have gone through no. of threads but not getting clear details. Your response would be appreciated?

Note: I have all the details for PCD, Exhaust temperature, Gas (Fuel) flow. I have found one equation which is TF/TX = F(PCD+PA)/(PA+dPX)

Where TF=Firing temperature, Tx = Exhaust temperature, PA = Atmospheric pressure, dPX = Exhaust pressure drop. But do not know what is F?

 

Hi there,

Have you got a copy of GER3620L? It can be obtained from the web.

GE does not agree to the notion of using EOH to plan for your inspection. Instead it will be calculated from starts or running hours. Both start and running hours methods have their own formula.

Of course, different kind of starts will contribute to different factors. So as different firing modes. It will consider trips as well.

Hope this helps.

 

What was the earlier M&I interval that you used to adopt while running the machine at BASE load? Operation at peak load basically increases the maintenance factor by 6, i.e. there is six times faster deterioration of the hot gas path. You will find the exact equation for maintenance factor in the "INSPECTION & MAINTENANCE" manual for your turbine. It is more or less same for all frames and is as follows:

Maintenance Factor

= ( Factored Hours/ Actual Hours )

where,

Factored Hours = (K+Mxl) x (G+1.5D+AfH+6P)
Actual Hours = (G+D+H+P)
G = Annual Base Load Operating Hours on Gas Fuel D = Annual Base Load Operating Hours on Distillate Fuel
H = Annual Base Load Operating Hours on Heavy Fuel
P = Annual Peak Load Operating Hours
Af = Heavy Fuel severity factor
I = Percent Water/ Steam Injection referenced to inlet air flow
M & K = Water I Steam Injection constants