Diesel engines are engines that burn diesel fuel for energy release. It was invented by the German inventor Rudolf Diesel in 1892, and in honor of the inventor, Diesel is denoted by his surname, Diesel, and the Diesel engine is also called the Diesel engine.

Diesel engine advantages and disadvantages

Advantages: large torque, good economic performance. Each working cycle of a diesel engine also goes through four strokes of intake, compression, work and exhaust. However, because the fuel used in diesel engine is diesel, its viscosity is larger than gasoline, it is not easy to evaporate, and the spontaneous combustion temperature is lower than gasoline, so the formation and ignition mode of combustible mixture are different from that of gasoline engine. The main difference is that the mixture in the cylinder of a diesel engine is compression-fired, rather than ignited.

When the diesel engine works, the air enters the cylinder, and the air in the cylinder is compressed to the end point, the temperature can reach 500-700 ° C, and the pressure can reach 40-50 atmospheres. When the piston is close to TDC, the high pressure pump on the engine jets diesel into the cylinder at high pressure, diesel oil forms fine oil particles, mixed with high pressure and high temperature air, the diesel mixture burns itself, violently expands, produces explosive force, and pushes the piston down to do work, at this time the temperature can reach 1900-2000℃, the pressure can reach 60-100 atmospheres. The torque generated is large, so diesel engines are widely used in large diesel vehicles.

Disadvantages: Due to the large working pressure, the relevant parts are required to have higher structural strength and stiffness, so the diesel engine is heavier and larger; Diesel fuel injection pump and nozzle manufacturing precision requirements are high, so the cost is high; In addition, the diesel engine work rough, vibration and noise; Diesel oil is not easy to evaporate, and it is difficult to start when the car is cold in winter.

Diesel engine classification

1. According to the working cycle can be divided into four-stroke and two-stroke diesel engine.

2. According to the cooling method can be divided into water-cooled and air-cooled diesel engines.

3. According to the intake mode can be divided into supercharged and non-supercharged (naturally aspirated) diesel engines.

4. According to the combustion chamber can be divided into direct injection type, vortex chamber type and precombustion chamber type diesel engine.

5. According to the number of cylinders can be divided into single-cylinder diesel engine and multi-cylinder diesel engine.

6. According to the use can be divided into Marine diesel engine, locomotive diesel engine, automobile diesel engine, generator set diesel engine, agricultural diesel engine, construction machinery diesel engine, etc. Automotive diesel engines are mainly arranged in straight line and V shape.

7. According to the layout can be divided into in-line diesel engine V-shaped diesel engine, horizontal diesel engine, star diesel engine, king diesel engine, etc.

8. Diesel engine according to the piston evaluation speed classification can be divided into low-speed diesel engine, cm<6M/ s, medium-speed diesel engine cm=6-9m/s, high-speed diesel engine cm=9-13m/s.

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