What is the impact of fuel quality and cleanliness on gas turbine operation?

• A. Fuel quality and cleanliness do not affect turbine operation.
• B. Cleaner fuel lowers emissions but has no other effects.
• C. Contaminants can cause deposits, instability, sticking valves, and combustion problems.
• D. Fuel quality only affects the lubrication system.

Answer: (C)

Fuel quality and cleanliness directly affect how the fuel system meters and delivers the mixture and how cleanly the combustor burns it. Contaminants and water in the fuel can form deposits on fuel injectors and filters, changing spray patterns and restricting flow, which leads to unstable or incomplete combustion. They can cause metering valves to stick, resulting in erratic fuel delivery. In the combustor, dirty fuel promotes instability, soot formation, and hot spots, increasing the risk of flameout, surge, and higher emissions. Clean fuel minimizes these risks by keeping the spray predictable, the valves free to move, and the combustion process stable. So contaminants can lead to deposits, instability, sticking valves, and combustion problems. Other statements that claim there’s no effect or that fuel quality only affects emissions or lubrication miss the broad range of issues fuel contaminants can cause.