The impact of the use factors is multifaceted, such as the quality of fuels and lubricants, the speed and load of the diesel engine, environmental conditions and operating conditions. Discussing the impact of these factors is also the most relevant to our actual work.
The quality of the fuel and lubricants should be compatible with the structure of the diesel engine. If diesel contains sulfur or other impurities, acid and other corrosive substances will be generated during the combustion process to accelerate the wear of the cylinder; too much heavy fraction in the diesel fuel will easily form carbon deposits after combustion, so that the piston ring and the piston ring The cylinder produces abrasive wear; the viscosity of the diesel has an effect on the formation of the mixture and the reliability of the oil supply equipment. For lubricating oil, the most influential is viscosity and oxidation resistance. It should be reasonably selected according to the working conditions of the diesel engine, and must not be used indiscriminately.
Tests have shown that the friction of the diesel engine increases with increasing speed and load. As the load increases, the unit pressure on the friction surface increases and the thermal condition is poor. When the rotational speed increases, the number of frictions per unit time is increased by half, and at the same power, the rotational speed increases more than the load increases. However, too low a speed can not guarantee good liquid lubrication conditions, and also increases wear, so for a certain diesel engine, there is a most suitable working speed range. In addition, when diesel engines are often unstable, such as acceleration, deceleration, parking, and starting, the diesel engine has poor lubrication conditions due to frequent changes in speed and load, and the thermal state is unstable and wear is increased. Especially at the start, the crankshaft speed is low, the oil pump is not supplied in time, the oil temperature is low, the oil viscosity is large, and the friction surface is difficult to establish liquid lubrication, and the wear is very serious.
The temperature of the use environment also has an impact on the wear and tear of the diesel engine. When the temperature is high, the engine tends to overheat, the viscosity of the lubricating oil is low, and the wear of the parts increases. When the temperature is low, the viscosity of the lubricating oil becomes large, and the diesel engine is difficult to start. The cooling water cannot maintain the normal temperature during operation, which increases the wear and corrosion of the parts. When the diesel engine is started at low temperature, the wear is more serious.
The operating temperature of a diesel engine is one of the important factors affecting wear. During the use process, due to the limitation of the structure of the cooling system, the change of the working load and the rotational speed, the change of the ambient temperature and the like, the operating temperature of the diesel engine varies widely. Practice has shown that the cooling water temperature is controlled at 75-85 ° C, and the lubricating oil temperature is most favorable at 75-95 ° C.
In summary, to use the diesel engine reasonably and reduce the wear and tear of the parts, we must start from the following aspects:
1. Reasonably choose the operating conditions of the diesel engine.
2. Improve the running-in quality of diesel engines.
3. Choose the fuel and lubricants that are suitable for the engine's working needs.
4. Improve the level of operation technology and timely maintenance.