Diesel engine characteristics

- Jun 11, 2020-

Diesel engine characteristics


 

The characteristics of traditional diesel engines: better thermal efficiency and economy. The diesel engine uses compressed air to increase the air temperature so that the air temperature exceeds the spontaneous ignition point of diesel. At this time, it is injected into diesel, diesel spray and air to mix and ignite and burn. Therefore, the diesel engine does not require an ignition system. At the same time, the fuel supply system of the diesel engine is relatively simple, so the reliability of the diesel engine is better than that of the gasoline engine. Due to the limitation of deflagration and the need for diesel spontaneous combustion, the compression ratio of diesel engines is very high. The thermal efficiency and economy are better than gasoline engines. At the same time, under the same power, the torque of the diesel engine is large, and the speed at the maximum power is low, which is suitable for the use of cargo vehicles.


However, due to the high working pressure of the diesel engine, all relevant parts are required to have high structural strength and rigidity, so the diesel engine is relatively bulky and bulky; the manufacturing accuracy of the fuel injection pump and nozzle of the diesel engine is high, so the cost is high; in addition, the diesel engine works rudely , Vibration and noise are large; diesel is not easy to evaporate, and it is difficult to start when the car is cold in winter.


Due to the above characteristics, diesel engines were generally used in large and medium trucks. New development of small high-speed diesel engines: emissions have reached the Euro III standard. Traditionally, diesel engines are relatively cumbersome, their power-raising indicators are not as good as gasoline engines (lower speed), noise and vibration are higher, and soot and particulate (PM) emissions are relatively serious, so they have rarely been favored by passenger cars. However, with the advancement of diesel engine technology in recent years, especially the new development of small high-speed diesel engines, a number of advanced technologies, such as electronically controlled direct injection, common rail, turbocharging, and intercooling, have been applied to small diesel engines , So that the shortcomings of the original diesel engine have been better solved, and the advantages of diesel engines in terms of energy saving and CO2 emissions are that all thermal engines, including gasoline engines, cannot be replaced. Therefore, advanced small high-speed diesel engines, their Emissions have reached the Euro III standard and become a "green engine". It has become the powerplant of many new cars in Europe and America. It is foreseeable that more and more diesel cars will appear in China