Exam Question
(a) Describe how fuel injector components deteriorate with time?
(b) What are effects of deterioration of fuel injector components?
(c) What are the signs of a bad injector?
Class 4 (4th Engineer)
MEKM
📅 Sep 2023
Reference Answer
### (a) How Fuel Injector Components Deteriorate with Time
Fuel injectors operate under extremely high pressures (up to 2200 bar) and temperatures, making them susceptible to various forms of deterioration over their service life. The primary modes of deterioration are as follows:
* **Abrasive and Erosive Wear:**
* **Abrasive Wear:** This is caused by hard, microscopic particles in the fuel, primarily catalytic fines (Alumina Al₂O₃ and Silica SiO₂) remaining from the refining process. These particles are harder than the injector's component materials and cause wearing of the nozzle needle and seat, as well as enlarging the nozzle holes. This alters the designed spray pattern and droplet size. (As per retrieved context: *Wear*)
Fuel injectors operate under extremely high pressures (up to 2200 bar) and temperatures, making them susceptible to various forms of deterioration over their service life. The primary modes of deterioration are as follows:
* **Abrasive and Erosive Wear:**
* **Abrasive Wear:** This is caused by hard, microscopic particles in the fuel, primarily catalytic fines (Alumina Al₂O₃ and Silica SiO₂) remaining from the refining process. These particles are harder than the injector's component materials and cause wearing of the nozzle needle and seat, as well as enlarging the nozzle holes. This alters the designed spray pattern and droplet size. (As per retrieved context: *Wear*)
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