Abstract
Diesel engines do not have spark plugs. But how do diesel engines ignite without spark plugs? Why don't they use spark plugs for ignition like gasoline engines? This article will do a detailed discussion.
First, diesel engines use diesel fuel with low ignition points.
First of all, the diesel engine compression ratio is very high, so the cylinder pressure is also very high, which causes the diesel molecules and air between the molecular activities to be very active plus the ignition point of diesel is low, you can not use spark ignition and combustion on their own, because combustion before the molecules in the cylinder is very close to the activities of the very close, so diesel combustion thermal efficiency is very high.
Second, diesel engines do not need a clear ignition time.
Diesel engines do not need a spark plug partly because it does not need a clear ignition time, it is in the piston upward compression before the injection and in the combustion process will continue to inject oil, so that the mixture in the cylinder completes the isobaric combustion and thus promote the piston downstream so that the diesel engine due to the continuous combustion of the work in the stroke so that the torque output is particularly pleasing.
Third, the diesel engine torque is greater.
It is precisely because of this, that the speed can not be too high, it is like an old cow, with continuous and stable power, characterized by the torque relative to gasoline engines to be much larger, the disadvantage is that the work is relatively rough, the strength of the cylinder block and the strength of the piston, connecting rods and other strength requirements are high, but also caused by the diesel engine must have a relatively large combustion chamber volume, which is also a lot of diesel engines using concave piston top design, due to its high fuel efficiency, and fuel consumption performance is good, torque is particularly pleasing to the eye.
Also fuel consumption performance is very good, and torque abundant, resulting in Europe being very like to use diesel, because Europe's ramp is in too much, at the same time, the exhaust temperature is lower, resulting in nitrogen oxides, carbon soot is also relatively easy to deal with the use of urea injection in the exhaust pipe to catalyze the conversion of exhaust gases, to be able to achieve a high quality of emissions, that is to say as long as the money is spent on the right place, the diesel engine is very clean, diesel engines due to the characteristics of the diesel engine can not be done .
The diesel engine due to its characteristics can not be made very small 4 cylinder displacement is generally around 2300, is the very efficient, clean, economical engine, while the technology is also very high.
Conclusion
Diesel vehicles use compression ignition. Because the diesel engine to diesel fuel, diesel and gasoline, compared to the spontaneous combustion temperature of diesel fuel is low, and more viscous is not easy to evaporate, in addition, the diesel engine compression ratio is greater than the gasoline engine, so the diesel engine can rely on compression of the mixture can be compressed and ignited, so the diesel engine ignition is not required spark plugs. If you still have any questions about this, you can contact us, we can provide you with professional answers and provide you with the products you need.
FAQ:
Why do some people say that diesel cars have a shorter lifespan than gasoline cars?
Compared with a gasoline engine, the diesel engine has a longer history, while the gasoline engine has a shorter history of research and development, so its performance may not be as good as that of a diesel engine. Compared to gasoline engines, diesel engines do not need to pass through the high-pressure ignition system, the structure is simpler, and the technology is mature and more reliable.
Because of this, the maintenance and repair costs of diesel vehicles are also lower, allowing owners to save more money. At the same time, because the volatility of diesel fuel is relatively poor, and the diesel fuel flash point is relatively high, the spontaneous combustion point is relatively low, so the safety of diesel vehicles than gasoline vehicles is higher.
In addition, the rotational speed of the diesel engine is relatively low, spare parts are not easy to age and wear and tear is slower than the gasoline engine, so in terms of the original, the service life of the diesel engine will be longer. In general, diesel engines can reach 1 million kilometers without overhaul, while gasoline engines open 400,000 kilometers to not overhaul is difficult.
What is the reason for diesel engines shaking?
The main reason is that the injection pump idling fuel supply is uneven, or a cylinder injector nozzle stagnation, poor atomization caused by.
What is the reason for black smoke from diesel engines?
Under normal circumstances, the basic reason for black smoke from diesel engines is insufficient and incomplete fuel combustion. In summary, most of the reasons for this incomplete combustion are uneven fuel supply to all cylinders, poor atomization of diesel fuel combustion, too much fuel supply to all cylinders, insufficient intake air intake system air volume or too early injection time, and so on. Prolonged black smoke means that there is something wrong with some part of the diesel vehicle.