Which is Better? Two Stroke Engine or Four Stroke Engine?

There are two stroke engine and four stroke engine, which one is better? Today Diingbo Power company shares with you base on working principle and advantages of them.

What is the working principle of a two-stroke diesel engine?

A diesel engine that completes a working cycle through two strokes of the piston is called a two-stroke diesel engine. The oil engine completes a working cycle and the crankshaft makes only one revolution. Compared with a four-stroke diesel engine, it has improved working power. There are also big differences in terms of specific structure and working principle.

What are the advantages of two-stroke diesel engine?

1. When the structural parameters and operating parameters of the diesel engine are basically the same, compare their power, for non-supercharged diesel engines, the output power of a two-stroke diesel engine is about 60%-80% higher than that of a four-stroke diesel engine. From the perspective of the cycle principle, it seems that a two-stroke diesel engine has twice the power than a four-stroke diesel engine. In fact, because the two-stroke diesel engine has air ports on the cylinder wall, the effective stroke is reduced, the air exchange process is lost, and the power is consumed to drive the scavenging pump. The power can only be increased by 60%-80%.

2. The structure of the two-stroke diesel engine is relatively simple, with few parts and no parts or only part has the valve structure, which is convenient for maintenance.

3. Due to the short interval of the power stroke, the diesel engine runs smoothly. Four-stroke diesel engines and two-stroke diesel engines have their own advantages, and their applications in production are different. Two-stroke diesel engines are mostly used on ships.

What is the working principle of four-stroke diesel engine?

The working principle of a four-stroke diesel engine The work of a diesel engine is completed by the four processes of intake, compression, combustion expansion and exhaust. These four processes constitute a working cycle. A diesel engine in which the piston goes through four processes to complete a working cycle is called a four-stroke diesel engine

What are the advantages of four-stroke diesel engine?

1. Low heat load. Due to the large interval between the power strokes, the thermal load on the piston, cylinder and cylinder head of a four-stroke diesel engine is lower than that of a two-stroke diesel engine, which prevents thermal fatigue (referring to parts that are damaged due to long-term exposure to high temperatures, resulting in reduced mechanical properties) It is more advantageous than two-stroke diesel engines.

2. The air exchange process is more perfect than the two-stroke diesel engine, the exhaust gas is cleanly discharged, and the charging efficiency is higher.

3. Because of the low thermal load, it is easy to use exhaust gas turbocharging to increase the power of the diesel engine.

4. Good economic performance. Due to the perfect ventilation process and full utilization of heat energy, the fuel consumption rate is low. Due to the structural characteristics, the lubricating oil consumption rate of the four-stroke diesel engine is also low.

5. The working conditions of the fuel system are better. Since the crankshaft only has one fuel injection every two revolutions, the service life of the plunger pair of the jet pump is longer than that of a two-stroke diesel engine. The heat load of the jet nozzle during operation is low and there are fewer failures.

In a four-stroke diesel engine, the piston takes four strokes to complete a working cycle, of which two strokes (intake and exhaust), the function of the piston is equivalent to an air pump. In a two-stroke diesel engine, each revolution of the crankshaft, that is, every two strokes of the piston completes a working cycle, and the intake and exhaust processes are completed by part of the compression and working process, so the piston of the two-stroke diesel engine does not The role of the air pump.

Due to the different number of strokes in each working cycle of the two kinds of diesel engines, and the different ways of air exchange, they have their own characteristics when compared with each other. But overall it is definitely a four-stroke engine easy to use. Nowadays most diesel engine of generator set is four stroke. Compared with the two-stroke engine, the four-stroke engine has low fuel consumption, good starting performance and low failure rate.