Views: 73 Author: Site Editor Publish Time: 2020-06-30 Origin: Site
We often say that 6 Cylinder diesel engine generators may have pulling cylinders, vibrating cylinders, cracking cylinders, etc., what do that mean by specific? Today we will discuss the phenomenon and its causes
There are many reasons for the "pulling cylinder" of the diesel generator, such as deformation of the piston-connecting rod group, incomplete combustion or post-combustion of the 1800rpm 4 stroke 6 cylinder diesel engine, overload operation, too high cooling water temperature, too high lubricating oil temperature or too low pressure and so on. These can cause the direct contact between the piston and the inner wall of the cylinder liner due to the lack of a layer of lubricating film between the piston and the cylinder liner during the working of the diesel generator. Small cracks appear in the weaker parts of the cylinder liner, causing the cooling water to leak into the oil pan or causing clogging of the lubricating oil filter.
In addition, because the "pulling cylinder" destroys the original gap between the piston and the cylinder liner, the suction air vortex effect becomes worse, the atomization quality of the injected fuel becomes worse, causing serious afterburn, and the generated heat is not dissipated in time, the temperature in the cylinder rises too high, which causes the piston head to melt and collapse.
Reasons of pulling cylinder
The basic reason of the pulling cylinder is that it is difficult to form an oil film between the inner wall of the cylinder and the piston, thus causing poor lubrication and even dry friction.
1) The piston ring clearance is too small. If the opening clearance, side clearance or back clearance of the piston ring is too small, the piston ring is thermally expanded and stuck when the powerful 6 cylinder diesel engine is working, and it is pressed tightly against the cylinder wall, or the piston ring is broken, and it is easy to cause grooves on the cylinder wall.
2) The piston pin escapes. Because the piston pin retainer is not installed or falls off or breaks, the piston pin escapes during the movement, and it is easy to damage the inner wall of the cylinder, causing the cylinder to blow air to the crankcase.
3) The clearance of the matching cylinder of the piston is too small or too large. If the piston material is poor, the manufacturing size error is too large, or the piston is deformed after the piston pin is assembled, resulting in a too small gap between the piston and the cylinder, the piston is stuck after being heated and expanded, and then the cylinder wall is injured.
4) The piston ring is heavily carbonized. Too much carbon deposits cause the piston rings to stick or bite in the ring grooves. At the same time, the carbon deposits are a kind of hard abrasive, which will grind into longitudinal grooves on the cylinder wall.
5) Piston severely deviate from cylinder. Due to the bending and twisting of the connecting rod, the parallelism and coaxiality deviation of the connecting rod journal, main journal, and piston pin seat are too large, causing the piston to deviate significantly from the cylinder, which will accelerate the wear of the piston and cylinder wall, destroying the oil film formation.
In the engine, due to improper use of the piston and the kit, a violent impact causes the piston and the kit to be damaged and could not work normally. "vibrating cylinder" is a major accident. When it is serious, it will scrap important parts of the 227KW 6 cylinder 4 stroke diesel engine, such as the body and piston being broken, the connecting rod twisted and deformed, the crankshaft broken, the cylinder liner damaged, etc. There will be a strong knocking sound in the cylinder shortly before the diesel engine "crammed",, thick smoke is emitted from the exhaust pipe, and the diesel engine is unable to work. At this time, it should be stopped immediately, otherwise it will cause serious consequences.
Reasons of vibrating cylinder
1) Broken connecting rod bolt or broken connecting rod breaks the cylinder.
2) The valve falls into the cylinder or the cylinder liner turns around, that is, the shoulder on the upper end of the cylinder liner breaks, causing vibrating.
3) The piston pin breaks and the piston comes off the top, and the cylinder body is damaged;
4) If the fuel injection advance angle is too large, the diesel engine knocks on the cylinder, long-term strain on the parts can easily cause vibrating.
5) Improper operation, such as slamming the throttle before starting and before extinguishing, resulting in unstable speed of the diesel engine, deteriorating lubrication conditions, long-term fatigue and damage to parts, causing "vibrating".
To prevent diesel engines from "vibrating cylinder", we should do the followings:
1) Maintain the crank connecting rod mechanism and gas distribution mechanism correctly.
2) Proper operation, it is forbidden to slam the throttle before starting and before turning off the flame.
3) Ensure that the lubrication system works normally and prevent the failure of burning tiles.
4) During the operation of the diesel engine, you should listen carefully for any abnormal noises. If there is, stop the vehicle immediately and check to avoid “vibrating” or reducing the loss of “vibrating” as much as possible.
Special reminder here: please take care of your KPV970 4 stroke diesel engine generator to prevent cracking cylinder when the weather is getting cold.
Reasons of bursting cylinder
1) When the generator set is in operation, the cooling water is little or the temperature of the water tank boiler is too high, if you still till add cooling water. Over-cooling can also cause cracking.
2) Use the decompression machine to stop the generator, so that the high temperature cylinder head suddenly encounters cold air and causes cracking.
3) After shutdown, no cooling water is discharged. The water in the machine freezes into ice, the volume increases, and the cylinder block and cylinder head cracks.
4) The generator set operates for a long time, the temperature inside the machine is high, and the high temperature water is released immediately after parking, which will cause high temperature parts to suddenly crack with cold air.
5) Add cooling water only after starting. After the diesel engine is started, the temperature inside the diesel generator immediately rises. If the cooling water is added at this time, the cylinder block and the cylinder head cool rapidly, and cracks will occur due to cold shrinkage.
To prevent diesel engines from "cracking cylinder", we should do the followings:
1) When the generator is overheated and severely short of water, the diesel engine should be idling at low speed for 10-15 minutes, and then gradually add the cooling water.
2) Before starting the diesel engine, the water tank should be filled with warm and hot water. During the winter season, hot water should be poured 2 to 3 times. It is better to start when the water flowing out of the drain valve is about 30-50°C.
3) When the operating time of the diesel engine is long, you should wait for about half an hour after the shutdown, and then release the cooling water when the temperature of the engine drops to 40~50℃. After draining the water, it is best to poke the drain valve switch with a thin wire to avoid sediment blocking the drain valve.