We’re seeing a high exhaust temperature spread on one of our GE 7F.04 turbines. The spread is consistently outside of the acceptable range, even after fuel nozzle cleaning and combustion tuning.
Here’s what we’ve tried so far:
Fuel nozzles have been inspected and cleaned.
Tuning adjustments were made to the control system.
Compressor bleed valves were checked for proper operation.
What could be causing this persistent temperature spread? Are there any advanced diagnostic techniques we should consider?
We had a similar issue, and it turned out to be a problem with the variable guide vanes (VGVs). If they’re not properly aligned or calibrated, they can cause uneven airflow and result in temperature spreads. I’d recommend checking your VGV calibration.
Check for hot gas path leaks. We found that cracked transition pieces were allowing hot gases to bypass the intended flow path, causing uneven temperatures across the exhaust.
Look into your fuel flow meters. We’ve seen faulty flow meters report incorrect fuel distribution, leading to combustion imbalances.