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What factors can cause wear and tear on diesel generator set parts?

June 28, 2022
Parts wear and tear is an inevitable phenomenon of all operating machinery, diesel generator sets in the use of different types of wear and tear phenomenon, to understand the factors that lead to diesel generator set parts wear and tear, can facilitate the user "the right remedy" to reduce unnecessary wear and tear, thereby extending the service life of the unit.
 
1, the quality of fuel and lubricant
 
Ø diesel fuel contains sulfur or other impurities, in the combustion process will produce acids and other corrosive substances, accelerating the cylinder wear.
 
Ø Too much heavy fraction in diesel fuel will easily form carbon after combustion, which will cause abrasive wear to the piston ring and cylinder.
 
Ø The size of diesel viscosity has influence on the mixture formation and reliability of oil supply equipment.
 
Ø For the lubricating oil, the biggest influence is the viscosity and oxidation resistance, should be selected according to the working conditions of the diesel engine reasonable use, must not be used indiscriminately.
 
2、The speed and load of generator
 
The test shows that the friction of diesel engine increases with the increase of speed and load. Because when the load increases, the unit pressure on the friction surface increases and the thermal condition is bad.
 
Ø When the speed increases, the number of friction per unit of time increases, and at the same power, the speed increases than the load increases when the wear is greater.
 
Ø But too low speed can not ensure good liquid lubrication conditions, also make the wear increase, so the diesel generator set should be in the appropriate speed range when running.
 
Ø In addition, the diesel engine often accelerates, decelerates, stops and starts and other unstable work, due to the frequent changes in speed and load, the diesel engine lubrication conditions are poor, the thermal state is unstable, the wear will increase. Especially when starting, the crankshaft speed is low, the oil pump oil supply is not timely, and then refueling temperature is low, the oil viscosity is large, the friction surface is difficult to establish liquid lubrication, wear is very serious.
 
3、Use environment temperature of the unit
 
Ø When the temperature is high, the engine is easy to overheat, the lubricant viscosity is low, and the wear of the parts will increase.
 
Ø When the temperature is low, the viscosity of lubricating oil becomes large, and it is difficult to start the diesel engine, and the cooling water cannot keep the normal temperature when working, which increases the wear and corrosion of the parts.
 
Ø When the diesel engine starts in low temperature, the wear is more serious.
 
4, the working temperature of the unit
 
The working temperature of the diesel generator set is one of the important factors affecting the wear and tear. In the process of use, due to the limitations of the cooling system structure, work load and speed changes, changes in ambient temperature and other factors, so that the diesel engine working temperature changes in a wide range. Practice shows that the cooling water temperature is controlled at 75~85°C and the lubricating oil temperature is most favorable at 75~95°C.
 
5、Adhesion and melt wear
 
Mutual friction surface metal, from the weaker surface transfer adhesion or fusion in the strength of the larger surface. This causes adhesion wear and melt wear.
 
(1) Adhesive wear is mainly caused by the solid plastic deformation of the friction surface. At the actual contact area of the friction surface, the pressure exceeds the yield limit of the metal, resulting in plastic deformation of the contact area. Under the action of molecular forces between the surfaces (due to their small contact distance), with the relative movement between the friction surfaces, the metal surface with less strength is gouged by the metal surface with higher strength, or the metal surface reinforced by plastic deformation is scuffed.
 
(2) melt wear is mainly due to the friction surface of the molten metal fusion and caused. When the relative speed of movement of the friction surface and contact pressure is large, the friction surface due to plastic flow, the temperature rises sharply (especially in poor lubrication conditions), thus causing.
 
Surface metal local softening or melting, so that the heat resistance of the weak surface melting in the heat-resistant metal surface, adhesion and melt wear often appear in the crankshaft journals, camshaft cams, cylinders and gears and other parts of the friction surface, especially in diesel engines
 
Especially in the diesel engine in high speed, high temperature and poor lubrication conditions, it is easy to appear this kind of wear. Such as the emergence of "bite", "holding" and other failures.
 
Diesel generator set wear failure is a problem that can not be ignored, the user knows the factors that lead to the wear of the unit, you can try to avoid the wrong operation from the daily use of the intensification of wear, which is conducive to maintaining stable performance and extend the service life of the unit.