What component is equipped on a fuel nozzle to prevent carbon build-up?

The correct answer focuses on the function of the air shroud, which is designed to control temperatures and prevent carbon build-up in the fuel nozzle. The air shroud surrounds the nozzle and helps to cool it by directing a flow of air around the nozzle assembly. This cooling effect is crucial in managing the high temperatures experienced during fuel atomization and combustion.

Carbon build-up typically occurs when fuel is not completely burned, leading to residual deposits that can impede the operation of the nozzle. The air shroud helps maintain optimal temperatures to enhance the combustion process, which in turn minimizes the risk of carbon deposits forming. By ensuring that the fuel operates at the right temperature, the air shroud effectively contributes to the longevity and performance of the fuel nozzle.

While other components like a water cooling jacket or combustion chamber liner play roles in the overall cooling and efficiency of the gas turbine system, they are not specifically responsible for preventing carbon build-up at the nozzle level like the air shroud is. Therefore, the function of the air shroud is critical in addressing the issue mentioned in the question.