Diesel oil is a complex hydrocarbon. The unburned diesel oil injected into the combustion chamber is decomposed at high temperature and forms black carbon. When vented, it is discharged with the exhaust gas to form black smoke. Black smoke is an incomplete combustion of fuel in the combustion chamber. The main influencing factors are as follows:
1, piston ring, cylinder liner wear
Piston ring, cylinder liner wear, resulting in insufficient compression pressure, so that the cylinder at the end of the compression stroke, the normal proportion of mixture mixing change, so that the fuel combustion under anaerobic conditions, carbon accumulation.
2, the fuel injector is not working well
The injector does not atomize or drop oil, so that the fuel can not be fully mixed with the air in the cylinder, nor can it be fully burned. The black smoke emission caused by the poor operation of the fuel injector is more obvious when the diesel engine is running at low speed. Because the intake swirl in the cylinder is weak at low speed, the possibility of oil droplets or oil beams being dispersed by the airflow is reduced and the stay time is longer, which is more likely to form carbon black discharge.
3. The shape of the combustion chamber changes
The manufacturing quality of the combustion chamber shape does not meet the technical requirements, so that the compression residual seam is too large and too small and the piston position is installed wrong, will make the combustion chamber shape change, thus affecting the quality of fuel and air mixing, so that the fuel combustion conditions become worse.
4. Improper adjustment of oil supply advance Angle
1) If the oil supply advance Angle is too large, the fuel will be injected into the combustion chamber too early. Because the pressure and temperature in the cylinder are low at this time, the fuel cannot be ignited and burned. When the piston goes up, the pressure and temperature in the cylinder will reach a certain level, and the combustible mixture will be burned.
2) The oil supply advance Angle is too small, the fuel injected into the cylinder is too late, part of the fuel is separated or discharged too late to form the combustible mixture, and the fuel discharged with the exhaust gas is decomposed by high temperature, forming black smoke.
5. Excessive oil supply
The oil supply is too large, so that the amount of oil into the cylinder increases, resulting in more oil less gas fuel combustion incomplete. In addition, the working load is too heavy, the fuel quality is poor, the working temperature is too low will also cause the exhaust black smoke.
Post time: Mar-21-2023