Diesel generators may experience mechanical failures during operation, ranging from basic component damage to major mechanical accidents. Usually, before a diesel generator malfunctions, it will show some abnormal signs in terms of speed, sound, exhaust, water temperature, engine oil, etc., which are the warning signs of the malfunction. So operators should quickly make correct judgments based on the characteristics of the warning signs, take decisive measures, and avoid accidents.

1. Prewarning features of "speeding" faults: Before "speeding", diesel generators usually emit blue smoke, burn engine oil, or have unstable speed.

Solution: Firstly, turn off the throttle to stop fuel supply and press the brake; The second is to block the intake pipe and cut off the entry of air; Thirdly, quickly release the high-pressure oil pipe to stop supplying oil; Fourthly, during the operation of the vehicle diesel generator, high gear heavy load (braking) can be used to prevent the engine from stalling due to insufficient torque.

2. Precursor characteristics of sticking cylinder failure

Sticking cylinder usually occurs in diesel engines with severe water shortage. Before sticking cylinder, the engine runs weakly and the water temperature gauge indicates over 100 ℃. A few drops of cold water are dropped onto the engine body, making a hissing sound and emitting white smoke. The water droplets quickly evaporate.

Solution: Idle for a period of time or turn the crankshaft to help cool, so that the water temperature drops to around 40 ℃, and then slowly add cooling water. Be careful not to add cooling water immediately, otherwise it may cause the machine to deform or crack due to a sudden rapid drop in local temperature.

3. Prewarning signs of cylinder failure

Tamping the cylinder is a highly destructive mechanical failure. Except for the valve dropping causing the cylinder to be tampered with, it is mostly caused by the loosening of the connecting rod bolts. After the connecting rod bolts are loosened or stretched, the clearance between the connecting rod bearings increases. At this time, a "click" sound can be heard in the crankcase area, which increases from small to large. Finally, the connecting rod bolts completely fall off or break, and the connecting rod and bearing cover are thrown out, breaking the body and related parts.

Solution: Immediately shut down for maintenance and replace with new parts.

4. Premature characteristics of tile burning faults

During diesel engine operation, the speed suddenly decreases, the load increases, the engine emits black smoke, the oil pressure drops, and there is a dry friction sound inside the crankcase.

Solution: Immediately shut down the machine, remove the cover and inspect the connecting rod bearing shells, identify the cause, and repair and replace them.

5. Predictive characteristics of shaft failure

When a hidden crack appears at the shoulder of the crankshaft of a diesel engine due to fatigue, the symptoms of the fault are not yet obvious. As the crack expands and intensifies, a dull knocking sound occurs in the engine crankcase. The speed change causes the knocking sound to intensify, and the engine emits black smoke. Soon, the knocking sound gradually increases, causing the engine to shake, the crankshaft to fracture, and the engine to shut down randomly.

Solution: If any signs are detected, stop the machine immediately for inspection. If cracks are found, replace the crankshaft in a timely manner.

6. The precursor characteristics of cylinder pulling failure

The exhaust pipe emits severe black smoke and suddenly stalls, preventing the crankshaft from rotating. At this time, the diesel engine cannot be restarted for operation, and the cause should be identified and eliminated.

Handling measures:

(1) When early detection of cylinder pulling occurs, the first step should be to increase the amount of oil injected into the cylinder's lubricating oil. If the overheating phenomenon does not change, measures such as stopping the oil in a single cylinder, reducing the speed, and accelerating piston cooling can be taken until the overheating is eliminated.

(2) When a cylinder pull is detected, the engine speed must be quickly reduced and then stopped. Continue to increase piston cooling while turning.

(3) If the situation of piston jamming is severe, kerosene can be injected into the cylinder, and after the piston cools down for a period of time, it can be turned to move.

(4) When the situation of piston jamming is severe, kerosene can be injected into the cylinder, and after the piston cools down, the flywheel or turning gear can be pried.

(5) When inspecting the hanging cylinder, the marks of cylinder pulling on the surface of the piston and cylinder liner should be carefully smoothed with an oil stone. Damaged piston rings must be replaced with new ones. If the piston and cylinder liner are severely damaged, they should be replaced with new ones.

(6) When reassembling the piston, it is necessary to carefully check whether the oil injection holes on the cylinder are functioning properly. If both the piston and cylinder liner are replaced, they should be run in after reassembly. During the run in, the load should be gradually increased from low load and continuous operation should be carried out.

(7) If the cylinder pulling accident cannot be repaired or repair is not allowed, the cylinder sealing method can be used to continue operation.