1. Correctly maintain and maintain the air filtration system
Failure of the air filtration system will cause wear of the cylinder liner, which will greatly reduce the life of the cylinder liner. Therefore, there are high requirements for air filtration, and multi-stage high-efficiency air filters should be selected. Check and clean the dust of each component regularly to ensure that it is clean inside and outside. Replace damaged components in time to prevent abrasive particles from entering the cylinder liner. Ensure the sealing of the connection between the filter and the suction hose, and ensure that there is no air leakage between the outlet of the supercharger compressor and the cylinder head.
2. Control of engine temperature
The corrosion and wear of the cylinder liner depends to a large extent on the operating temperature of the diesel engine. Tests show that when the coolant temperature drops to 40-50℃, the wear of the cylinder liner will be 5-6 times the normal wear, and it is mainly corrosive wear. Therefore, keeping the operating temperature of the cooling system no more than 90℃ will greatly limit the condensation of sulfur-containing vapor on the cylinder liner wall, thereby achieving the purpose of reducing corrosion.
3. Selection of diesel engine lubricant quality and viscosity
Diesel engines should use CC and CD grade or above engine oil according to the instruction manual, that is, according to the diesel engine's reinforcement strength and working environment temperature.
4. Cavitation and antifreeze coolant on the outer surface of the cylinder liner
The gas in the cylinder burns, and the piston will swing left and right in addition to reciprocating linear motion in the cylinder, causing the cylinder liner to vibrate severely. At this time, the cooling water in contact with the cylinder liner generates bubbles under vibration. Over time, many pits are generated on the outer circle of the cylinder liner, which gradually expand to form holes, resulting in penetration of the cylinder wall. In order to prevent cavitation of the cylinder liner, in addition to taking measures in design and manufacturing, the following work should be done from the perspective of use, maintenance and repair:
1) Reduce the impact of the piston on the cylinder liner. Under the condition of ensuring basic lubrication, the gap between the piston and the cylinder liner should be as small as possible, and the verticality of the center of the cylinder liner should be ensured during assembly.
2) Pay attention to the selection and replacement of antifreeze coolant, and select qualified products with good anti-corrosion and corrosion resistance. Check frequently during use, and the replacement time should not exceed two years.
5. Correct installation and use of cylinder sleeves, piston connecting rods and crankshaft assembly
Should be carried out strictly in accordance with the provisions of the diesel engine manual. First, ensure the cleanliness of parts such as cylinder sleeves and engine bodies and the assembly clearance of each part. The weight of each piston and connecting rod of the same diesel engine should be as consistent as possible and should not exceed the tolerance. At the same time, ensure the tightening torque values of various bolts and nuts.
During the use of the crankshaft assembly, pay attention to whether the torsional vibration damper fails and whether the clearance of each bearing is out of tolerance to avoid abnormal vibration of the crankshaft and accelerate the early wear of the piston connecting rod assembly and cylinder sleeve.
6. Reasonable selection of running-in specifications
Before the new or overhauled diesel engine is officially used, it must be run-in according to the provisions of the manual. Generally, it can be put into full load use after 60 hours of running-in. The purpose of running-in is to improve the working conditions of the moving parts of the diesel engine and improve reliability and service life. During the running-in period, the load should be 50%-80% and the speed should not be greater than 80% of the rated speed. It should also be noted that it should not be operated at idle speed for a long time. After the running-in is completed, the engine oil must be carefully replaced. High idling conditions and overload operation should be avoided during normal use.
