Cause analysis and elimination of abnormal smoke e

2022-08-12
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Analysis and elimination of abnormal smoke exhaust of diesel engine

when the diesel engine works normally, the color of smoke exhaust of diesel engine should be colorless or light gray, and when the smoke exhaust is black, white and blue, it is considered that the smoke color is abnormal

when the smoke exhaust is black:

the black smoke from the diesel engine is caused by the incomplete combustion of diesel to produce free carbon, which is discharged by the exhaust pipe. The main causes of black smoke are:

1. The diesel engine is overloaded:

if the load is removed, the black smoke disappears, indicating that the load is too heavy, and the load (load) should be appropriately reduced

2. Poor fuel injector operation:

poor atomization, low injection pressure and oil dripping of the fuel injector are common faults of the diesel engine, which can be judged by using the single cylinder oil cut-off method. Under the low and medium speed working state of the diesel engine, loosen the high-pressure oil pipe joints in turn with a wrench, and stop oil supply cylinder by cylinder. For example, the phenomenon of black smoke emitted from a cylinder of the diesel engine is reduced or disappeared due to the uncertainty of the hardness of the standard surface and the back, It can be determined that the fuel injector of this cylinder is faulty

3. Use inferior diesel:

inferior diesel has a lot of impurities, which can't burn or burn incompletely, which will cause black smoke in the exhaust. At this time, it should be replaced with diesel of appropriate brand

4. The oil supply advance angle is wrong

in the process of use, the oil supply advance angle of the diesel engine changes. When the oil supply advance angle is too small, the oil supply time is too late, which makes the diesel engine work rough, the afterburning increases, and the fuel can't burn completely, Form carbon smoke and exhaust, resulting in black smoke from exhaust. Force the sample by clamping the sample (or product) with a fixture

5. Blockage of air filter, exhaust pipe and muffler:

when the air filter, exhaust pipe and muffler are blocked, it will lead to insufficient intake and exhaust of diesel engine. Quality can be said to be the soul of enterprise development. At this time, diesel does not have enough air to mix with it, so that the fuel cannot be completely burned, and it will also cause black smoke

the valve clearance is too large, the valve opening is small, and the valve seal is poor. At this time, the valve clearance should be adjusted; If the valve cone seal is not tight, grind the valve at this time; If the fuel injection timing is incorrect, adjust the fuel injection pump gear to make its mark align

white smoke

the generation mechanism of white smoke in diesel engine is poor diesel combustion, and part of the diesel evaporation is produced by fuel vapor or water entering the combustion chamber, heated and vaporized, and discharged with exhaust gas; In cold seasons, it is normal for the diesel engine to emit white smoke when it is cold, but when the diesel engine is hot, the exhaust pipe still emits white smoke, which indicates that the diesel engine is not working properly

1. When the cylinder head leaks or the cylinder gasket is washed out and connected with the water channel, the cooling water seeps into the cylinder and forms white smoke when exhausting. If there is too much water in the cylinder, the engine must not be started, otherwise major accidents such as connecting rod bending and body destruction will occur, and the engine can be started only after the water is drained

2. When there is more water in diesel, white smoke will be formed after water is discharged after combustion

3. When the injection pressure of the injector is too low, the injector is damaged, or the diesel atomization is poor, and the unburned diesel is discharged to form white smoke, check the injector, adjust the injector pressure, or replace the injector

4. When the intake pipe is blocked, the diesel cannot be atomized and white smoke will also be produced

blue smoke

the mechanism of diesel engine blue smoke is that the lubricating oil enters the combustion chamber and evaporates into blue oil gas, which is discharged with the exhaust gas. The common reasons are:

1. When the diesel engine has too much oil, due to splash lubrication, the oil rushes into the combustion chamber along the cylinder wall and forms blue smoke with the exhaust gas

2. The piston ring is aligned, installed reversely, stuck or worn too much, and the engine oil rushes into the combustion chamber, forming blue smoke with the exhaust gas

3. The clearance between valve stem and guide tube is too large, the valve stem oil seal is damaged, and the lubricating oil in the valve chamber enters the combustion chamber along the valve stem and guide tube according to the statistics of relevant departments, forming blue smoke

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