How to prevent pitting corrosion in diesel generator sets

The so-called pitting corrosion refers to the surface of the wet cylinder liner of a diesel generator set that is in contact with the coolant, which is damaged into some needle shaped holes. These holes gradually expand and deepen, and finally form deep holes or cracks. It is generally believed to be caused by high-frequency vibration of the cylinder liner. So how can we prevent the occurrence of pitting corrosion in diesel generators? The following text provides several suggestions for preventing generator pitting corrosion:

(1) Usage factors

a. The coolant temperature that is most prone to pitting corrosion is 40 ℃ -60 ℃, so it is important to maintain the coolant at a normal working temperature (80 ℃ -85 ℃) during use.

b. Use the manufacturer's specified coolant instead of hard water or cooling water (liquid) with high impurities. Experiments have shown that hard water containing salts and alkalis corrodes at a rate several tens of times faster than clean soft water.

c. Try to reduce idle, heavy load, and overloaded operation time as much as possible.

d. Add fuel according to regulations to reduce the rough operation of diesel generators caused by combustion.

(2) Maintenance factors

a. Replace the coolant according to regulations and clean the cooling system in a timely manner to keep it in good technical condition.

b. Adjust the fuel supply advance angle and various components of the fuel system according to regulations, maintain the working performance of the fuel system, and reduce the harm caused by abnormal combustion.

c. Maintain good cylinder clearance, crankshaft bearing clearance, and connecting rod bearing clearance to reduce cylinder knocking and vibration.

d. When installing components such as cylinder liners, pistons, and connecting rods, it is necessary to achieve the requirements of verticality and parallelism as much as possible to reduce the abnormal impact of the piston on the cylinder liner.

(3) Manufacturing factors

a. Apply anti cavitation materials and vibration absorbing substances on the side wall of the water jacket of the diesel generator.

b. Improve the hardness of the outer surface of the cylinder liner; Minimize the roughness of the outer surface as much as possible; Select materials with strong resistance to pitting corrosion.

c. Choose an appropriate cylinder liner wall thickness to increase its stiffness and avoid resonance.