What's the matter with the semi-trailer often emitting black smoke?
Generally, the reason for the black smoke of diesel vehicles is that the engine is overloaded or the oil quality is not good. The reasons for the black smoke of gasoline vehicles are: ignition time and oil quality problems.
The essence of black smoke is insufficient combustion. There are two possibilities for poor combustion: too little intake air or abnormal fuel supply.
Why not burn enough:
When the vehicle sharply changes the fuel supply in a short period of time (that is, when the bigfoot accelerator reaches the bottom), the gas supply cannot keep up, and a relatively thick oil-gas mixture will be produced in a short period of time, that is, the diesel and air are not fully mixed, and combustion will occur. Insufficient, the directly ignited diesel generates a large amount of carbon particles under high temperature cracking, which is discharged into the atmosphere with the exhaust gas, which is the fundamental reason why a large amount of black smoke is emitted when the diesel vehicle accelerates rapidly. In fact, gasoline engine emissions will increase significantly when accelerating rapidly, but it does not have these carbon particles, and people can't see the increase in these emissions.
It can be seen from the above description that the sharp change in fuel supply is the direct cause of the black smoke phenomenon, including fuel injection at startup and increased fuel supply during rapid acceleration. Therefore, improving the driving habit of stepping on the accelerator with big feet can improve the degree of black smoke phenomenon.