Many users encounter increased fuel consumption during the operation of diesel generator sets. However, no faults can be detected during equipment inspection, and maintenance work fails to identify the root cause. What are the key factors that affect the fuel consumption of diesel generator sets?
Lubricating oil enters the combustion chamber through the clearances between piston rings and ring grooves, as well as the gaps between valves and guides. The direct cause for oil blow-by is that the speed of the top piston ring drops sharply near the top dead center, throwing the attached lubricating oil into the combustion chamber. Therefore, the fit clearance between piston rings and pistons, the oil scraping capacity of piston rings, the pressure inside the combustion chamber and the viscosity of lubricating oil are all closely related to oil consumption. If excessive oil consumption is observed, the following inspections can quickly locate and resolve the issue:
Inspect the integrity of gaskets at joints including the diesel engine block, gear chamber cover, flywheel-side disc, rear cover and housing cover, and check whether connecting bolts are loose. If oil leakage occurs at the frame, examine the front part of the oil sump on the flywheel side. This problem is usually caused by loose base bolts. The flywheel, driven by the V-belt, continuously rubs against the angle iron of the frame protecting the oil sump, forming gaps and resulting in oil leakage.
Wear of the diesel engine valve guides leads to extra oil consumption of the generator set.
Engine wear creates longitudinal scratches on the cylinder liner of the diesel engine. When the clearance between cylinder bore and piston skirt exceeds the specified value, the tension of piston rings will decrease correspondingly, resulting in incomplete oil scraping. Alternatively, the broken internal support spring of the oil ring will also cause poor oil scraping and oil combustion. These faults will lead to difficult engine starting, blue smoke from the exhaust pipe and severe oil spraying from the breather, bringing about additional lubricating oil consumption.
