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  • Date : 10 / 04 / 2010
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  • Comments : Comments Off on Diesel engine exhaust and remedy the cause of abnormal
Diesel engine exhaust and remedy the cause of abnormal

Abstract from the perspective of the use and environmentally friendly diesel engine exhaust causes and troubleshooting anomalies, to improve equipment utilization, reduce maintenance costs have practical significance.
Keywords Emission Diesel Combustion System
Diesel engine with good economy and power performance, is widely used in mining machinery, engineering machinery and other industries. Diesel engines in daily use, can change the color of its smoke to determine fault, so do timely maintenance, to reduce economic losses. The following 3 common to the unusual engine exhaust causes for the failure and exclusion method to make an introduction.
1 smoky and remedy the reasons for
This phenomenon is due to incomplete combustion of fuel produced. When black smoke, often accompanied by a decline in engine power, exhaust temperature is too high, the water temperature is too high, leading to the engine’s mechanical wear, reduces engine life. The causes of the phenomenon (leading causes of incomplete combustion of many) and excluded as follows.
(1) high exhaust back pressure or exhaust duct obstruction. This situation may lead to inadequate intake air, thus affecting the air and fuel mixture ratio, resulting in too much oil. This situation occurs: The first exhaust pipe bends (especially the 90 �� bend) too much, should be minimized; the second is * too much soot blocked internally and should be removed.
(2) lack of or into the air intake duct obstruction. To find out the reason, should check the following: First, the air filter is blocked; Second, intake manifold leaks (if this phenomenon, the engine load increases due to the gas associated with more harsh whistling); three is the turbocharger for damage. Should check the exhaust wheel and turbocharger wheel blades for damage, and moves freely flexible; Fourth, in the cold is blocked.
(3) valve clearance adjustment is not correct, the valve sealing line is bad. Should check the valve clearance, valve springs and valve seals situation.
(4) of the cylinder high-pressure oil supply pump uneven or too large. Uneven supply will result in speed instability, intermittent black smoke, should be adjusted to balance or in the specified range.
(5) injection late fuel injection timing should be adjusted.
(6) injector working poor or damaged, remove the cleaning inspection.
(7) injector model selection error. Imports of high-speed engine of the optional injector, there are strict requirements (jet diameter, hole number, injection angle), such as the inappropriate choice of black smoke can also cause the engine, even the same type of engine used in different situations (output power, not the same speed, etc.), requiring the use of the injector is not the same model. Such as the matching error, the correct model should replace the injector.
(8) grades of diesel fuel quality is poor or wrong. Injector equipped with a porous combustion chamber, the import high-speed direct injection diesel engines, fuel injector aperture as small, high precision, quality and grades of diesel fuel has more stringent requirements, otherwise the engine will cause black smoke, and even the the engine will not operate.Therefore, we should use clean diesel qualified, suggested the use of diesel Arranging, the summer with a 0 or +10 No, the winter use -10 or -20 No. No. No. -35 cold regions are selected.
(9) cylinder, piston wear more serious. When this situation occurs, piston rings Mifengbuyan, a serious decline in cylinder pressure, resulting in combustion of diesel can not be fully black smoke, and engine power dropped dramatically, seriously, in the load, the engine will automatically turn off. Worn parts should be replaced.
2 emissions and remedy the causes blue smoke
Blue smoke emissions was due to an excessive amount of oil in the combustion chamber due to combustion. This failure occurs the following reasons:
(1) oil pan add the oil too much. Too much oil will splash as the high-speed operation of the crankshaft to the cylinder wall, and fleeing into the combustion chamber. Exclusion is down about 10 minutes, and then check the oil gauge will drain excess oil.
(2) cylinder, piston assembly badly worn, the gap is too large. As its gap is too large, the oil will be a large number of fleeing into the combustion chamber, accompanied by an increase in the engine crankcase emissions, treatment should be timely replacement of worn parts.
(3) piston rings useless. Insufficient flexibility, such as piston rings were stuck in the ring carbon tank, or the collar in the same line, or the oil return hole plug ring, fleeing into the combustion chamber will cause a lot of burning oil, blue smoke emissions occur. Approach is to remove the ring, remove carbon, heavy cloth of the collar (on the proposal to stagger under the collar 180 ��), if necessary, replace the piston rings.
(4) valve and catheter clearance is too large. Due to wear, resulting in the gap between the two is too large, in the inlet, the rocker was a lot of indoor inhalation of oil combustion chamber, approach is the replacement of worn valves and ducts.
(5) take the blue smoke caused by other reasons. If too thin oil, engine oil pressure is too high, the engine is not running well, will take the blue smoke caused by burning oil.
3, gray smoke emissions cause and remedy
Gray engine exhaust emissions, fuel for machines that are part of the temperature is too low, oil and gas atomization bad, too late to burn the fuel to be discharged from the exhaust pipe. The main reasons for this phenomenon are:
(1) If the injection time of late, when leaking fuel injector fuel injection, injection pressure is too low, poor atomization, when the machine was too late combustion temperature is too low to be discharged to the form of white smoke.Approach, the correction of fuel injection time, check the injector conditions.
(2) lack of pressure within the cylinder. The cylinder liner, piston ring wear components, and the bad valve seals, causing the engine to take gray smoke when first started, and then with the machine temperature rise, into a light smoke or black smoke. Approach is to replace the worn cylinder liner, piston ring or valve repair, valve seat ring.
(3) diesel in the water. If, after the engine started emitting smoke gray, with the machine temperature rise, gray smoke still exists, then it may be too much diesel fuel mixed with water. Solution is to start a day before the fuel tank drain valve is opened, the bottom sediment and water discharge out.
To sum up, the engine exhaust exception is a comprehensive reflection of internal fault. Therefore, the engine exhaust to determine the normal working condition or not is an important indicator of good or bad one, if untreated, can guarantee the ideal engine to use, to avoid unnecessary economic losses.