Why might a fuel preheater be used in a gas turbine installation?

• A. To heat the compressor inlet.
• B. To prevent fuel waxing/icing at low temperatures and to improve fuel atomization and combustor performance.
• C. To increase fuel density.
• D. To reduce engine noise.

Answer: (B)

Fuel preheating is used to keep the fuel at a temperature where its properties support reliable delivery and efficient combustion. In cold conditions, kerosene-type aviation fuels can form wax crystals and become more viscous. Waxing can clog filters and fuel lines and increase the effort required by the fuel pump, leading to flow restrictions or pump cavitation. By heating the fuel, you keep it above those low-temperature limits, preventing waxing and reducing viscosity. The result is better fuel atomization at the injectors, which translates to more uniform air-fuel mixing, smoother combustion, and improved combustor performance and stability. Heating also helps prevent fuel icing in the system by keeping water in solution and avoiding ice formation.

Other options don’t fit because heating the fuel isn’t aimed at increasing fuel density or reducing engine noise, and heating the fuel doesn’t serve to heat the compressor inlet.