Analysis of L28/32 Diesel Engine Parts

1.Failure phenomenon

Under the control of the governor, the speed of the marine diesel engine is stable when operating under certain operating conditions. Even when the working machinery suddenly unloads the full load, the speed of the marine diesel engine accessory ship diesel engine will not be too high, generally only less than 8% of the speed before unloading. 

When "speeding" occurs, it means that the ship's diesel engine loses control and the speed increases rapidly, greatly exceeding the calibrated speed. The sound is abnormal. Due to the sudden increase in speed, the combustion noise, air noise and mechanical noise of marine diesel engines have increased rapidly, and even become unbearable.

⑵ Abnormal vibration. Due to the sudden increase in speed, the imbalance of the inertial force of the marine diesel engine greatly increases, and therefore, the vibration of the marine diesel engine increases sharply.

⑶ At this time, it is often accompanied by damage to the mechanical parts.

2. Reason analysis

The speeding is caused by the failure of the fuel system, which makes the governor control system unable to control it; and the second is the failure of the governor control system.

In summary, the reasons for the DK28 diesel engine parts marine diesel engine speeding are as follows:

⑴ Fuel system: the plunger of the fuel injection pump is stuck at the position of large fuel volume; the rack of the fuel injection pump is stuck at the position of large fuel volume; the rack rod of the fuel injection pump is loose or jammed; the spring of the fuel injection pump is broken and the gear ring is stuck; The plunger of the fuel injection pump with the opposite direction of rotation was mistakenly installed; the rack limit screw lead seal was opened.

⑵ Speed control system: the moving parts of the governor are stuck; the speed control spring is broken; the fly iron is loose; the lubricating oil temperature is too low, the viscosity is too large, and the fly iron cannot be separated.

⑶ Other factors: the oil return hole of the cylinder head is not smooth, and the oil enters the combustion chamber; the overspeed automatic parking device fails; the parking block on the rack and the parking fork position with low oil pressure are installed incorrectly, and the rack is in the refueling position.