Exam Question

### (a) Describe what is nozzle burning of Fuel Injectors and causes of nozzle burning on marine Diesel engine.
Nozzle burning, also known as "trumpet formation" or "carbon trumpets," refers to the localized overheating, erosion, and physical damage occurring at the tip of a fuel injector nozzle, particularly around the spray holes and the nozzle face. This phenomenon is characterized by the formation of hard, brittle carbon deposits that often extend outwards from the spray holes, sometimes resembling a trumpet shape. The intense heat from combustion gases, combined with poor fuel atomization and other factors, causes the metal of the nozzle tip to exceed its temperature limits, leading to oxidation, erosion, and eventual degradation of the material. This damage severely impairs the injector's ability to atomize and distribute fuel effectively.
**Causes of Nozzle Burning:**
1. **Overheating of the Nozzle Tip:**