What is the cause of the oil dripping of diesel generators?
July 8, 2021
There are many places in the diesel engine that use pressure seals, such as the cylinder liner-piston-piston ring, and the turbocharger-supercharger rotor shaft. This kind of seal is generally fully effective when the diesel engine has about 1/3 of the load. , If the load is empty or the load is small, there may be slight leakage, which is what we often call dripping.
So what exactly caused the dripping phenomenon?
If the unit is operated under a small load, the following failures may occur after a long period of operation:
1. The piston-cylinder liner is not well sealed, the oil strays upwards, enters the combustion chamber and burns, and the exhaust emits blue smoke.
2. For supercharged diesel engines, the pressure is low due to low load or no-load. It is easy to cause the sealing effect of the turbocharger oil seal (non-contact type) to decrease, and the oil rushes into the booster chamber and enters the cylinder along with the air.
3. Part of the oil moving up to the cylinder participates in the combustion, and part of the oil cannot be fully burned, forming carbon deposits on the valve, intake duct, piston crown, piston ring, etc., and part of it is discharged with the exhaust gas. In this way, oil will gradually accumulate in the exhaust duct of the cylinder liner, and carbon deposits will also be formed.
4. Oil accumulates in the pressurizing chamber of the turbocharger to a certain extent, and it will naturally leak out from the joint surface of the turbocharger.
5. Long-term low-load operation may lead to increased wear of moving parts, deterioration of engine combustion environment and other serious consequences, which may lead to the advancement of the overhaul period.
So how to avoid this from happening?
When using diesel generator sets, the operating time of low load or no-load should be minimized, and the minimum load should not be lower than 25%-30% of the rated power of the set, so as to ensure the effective operation of the set.