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After several years of use, is your diesel generator set in good condition?
July 11, 2022
Diesel generator sets as emergency backup power in all walks of life in society are used, a diesel generator set cost is not cheap, general diesel generator set life: domestic diesel generator set service life of 10,000 hours or 10 years; imported diesel generator set service life of 12000 hours or 12 years. Diesel generator set after a certain period of time, the user to carry out regular inspection, maintenance, maintenance, in order to ensure that the unit's working condition is stable and normal, some units used for several years, the user will generally be more worried about its working condition, then how to determine whether a diesel generator set working condition as good as the first? Top Bo power from three aspects for you to analyze one by one.
A, look at the diesel generator set exhaust smoke color
From the color of the diesel generator set exhaust of waste smoke to determine the working condition. Normal working condition, the smoke color discharged from the unit should be colorless or light gray, while the abnormal color is generally divided into three, namely black, blue and white. The main reason for black smoke is that the fuel mixture is too thick, the combustible mixture is poorly formed or imperfect combustion, etc.; blue smoke is generally caused by the diesel engine used for a long time and slowly starts to burn oil; white smoke is formed by the low temperature in the cylinder of the diesel engine and the evaporation of oil and gas, which is especially obvious in winter.
Second, listen to the sound of the unit work
1, listen to the valve chamber
Diesel generator set of diesel engine running at low speed, next to the valve cover can clearly hear the "bar, bar," the metal knocking sound. This sound is the impact between the valve and the rocker arm, the main reason is the valve clearance is too large. Valve clearance is one of the main technical indicators of diesel engines. Valve clearance is too large or too small, the diesel engine can not work properly. In the diesel generator set for a long time after the work will appear this sound, so the engine every 13 days or so, should readjust the valve clearance.
2, listen to the cylinder up and down
(1) diesel generator set from high-speed operation suddenly drop to low speed, in the upper part of the cylinder can clearly hear the "when, when, when" the sound of impact. This is one of the common problems of diesel engines, mainly the piston pin in the connecting rod bushings between the gap is too large, sudden changes in machine speed and a lateral dynamic imbalance, resulting in the piston pin in the connecting rod bushings rotate while swinging to the left and right, so that the piston pin hit the connecting rod bushings and the sound. The piston pin and connecting rod bushing should be replaced in time to ensure that the diesel engine works normally and effectively.
(2) engine running in the cylinder can be clearly heard in the upper part of a piston knocking block of crisp knocking sound, is often said to "knock cylinder". The root cause of this failure is the injection advance angle is too small. Oil supply advance angle is one of the main technical data of the diesel generator set, the correct supply advance angle will directly affect whether the diesel generator set can work normally, and directly affect the engine can provide normal power, affecting the working conditions of the whole machine. The injection advance angle is too small, the air injected into the cylinder to form combustible gas combustion, resulting in unstable combustion, the upward phase of the piston produces a lateral offset and cylinder wall contact collision, knocking the cylinder block to produce the sound of knocking cylinder.
(3) diesel generator set of the cylinder up and down in various places are similar to the sound of a small hammer tapping anvil. The main reason for this sound is the gap between the piston ring and the ring groove is too large, so that the piston ring in the up and down operation and the piston knocking and produce a sound similar to the sound of a small hammer tapping anvil. After this situation should immediately stop the engine work, replace the new piston ring.
3, listen to the lower part of the engine body
Diesel generator set running in the lower part of the body can hear a heavy, dull knocking sound, especially when working under high load, this sound becomes more obvious. This sound is due to the crankshaft main shaft tile or crankshaft main shaft bearing and main journal contact between the abnormal friction and generated. After hearing this sound should immediately stop the work of the diesel generator set, because if this sound still makes the diesel generator set continue to work is likely to appear "hold tile" "burn shaft" phenomenon. After stopping to see if the main shaft tile bolts are loose, such as not immediately remove the crankshaft and main shaft bearing or main shaft tile, measured by the technical staff to calculate the clearance value between them, and compare with the specified data, and check the wear of the main shaft and tile shaft, if necessary, should be repaired or replaced.
4, listen to the front cover of the machine
In the front cover of the diesel generator set, you can clearly hear a "howl" sound. This sound comes from the front cover of the internal meshing gears, the gears of the various meshing gears are excessively worn, resulting in excessive gear clearance, so that the gears can not enter the normal state of meshing to produce this sound, the method of elimination is to open the front cover, with lead or paint to check the meshing of the gears, adjust, if the gear gap is too large, then you must replace the new gears.
Third, the hand touch test to determine
1, touch test exhaust stubs
When the diesel generator sets work for a short time, touch the exhaust stubs of each cylinder by hand. If the hand temperature is high, the cylinder fuel supply or supply advance angle is too small, resulting in serious fuel consumption; if the hand temperature is low, the cylinder fuel supply is small, the combustion is not sufficient or does not work.
2, touch test high-pressure oil pipe
Diesel generator set in operation, touch the cylinder high-pressure oil pipe with your hand respectively. If there is a regular pulsating feel, that the cylinder works well; if there is no obvious pulsating feel, that the cylinder does not work well; if there is a pulsating feel but not regular, that the cylinder has the oil break phenomenon.
The above is the top Bo power for you to determine the working state of the diesel generator set, mainly by looking, listening, touching the three major aspects of judgment, and one of the more effective and direct way is to listen to the sound, because the general diesel generator abnormal noise is the precursor of failure, so in time after hearing the sound to carry out inspection work, eliminate small failures, to avoid the occurrence of major failures in the future, so that the unit to restore good Working condition.
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