Analyzing the judgment method of insufficient power of diesel generator set
2021-08-21
1. Look at the smoke
When the diesel engine is working, open the oil port cover. If a thick smoke comes out of the oil port cover, weigh the smoke. The serious smoke phenomenon indicates that the piston, cylinder liner, piston ring and other parts are seriously worn.
Open the valve cover. If there is a trace of cyan or white smoke from the valve root, weigh it as smoke. If the smoke is serious, it indicates that the valve or valve seat is seriously worn or ablated, or the valve clearance is too small or even no clearance. By observing the smoke situation on the, you can directly see which valve and cylinder has air leakage, which should be repaired in time.
2. Check the cooling system according to the water temperature
If the water temperature of the cooling system in the diesel engine working room is too high, it can indicate that the scale in the engine cooling water chamber is too thick or the efficiency of relevant components of the cooling system (thermostat, water pump, fan lamp) is low or invalid.
3. Blue valve timing check valve phase
After the diesel engine works during the production period, the timing gear, cam surface, follow-up column and tappet will be worn, which will delay the opening and closing time of inlet valve and exhaust valve and deviate from the optimal valve train phase, so as to reduce the charging efficiency and diesel engine power. Therefore, the valve timing of the diesel engine shall be checked regularly. If it does not meet the requirements, it shall be adjusted in time.
4. Look at the compression force and check for air leakage
The method to check the compression force is: rotate the crankshaft without decompression. When the compression force is large, use an upward force to release the handle, but do not leave the handle. At this time, if there is a large rebound force, it indicates that the compression force is very good, otherwise, it indicates that the compression force is poor.
5. Look at the smoke and check the color of the smoke
When the diesel engine works normally, it generally does not emit smoke or some light gray smoke, which is sometimes difficult to see with the naked eye. If black smoke is emitted, it indicates that there is more gas in the cylinder, less gas and incomplete combustion; If white smoke is emitted, it means that the fuel oil is mixed with water, or the diesel oil is not completely burned and comes out of the exhaust pipe after gasification.
6. Check the working condition of carbon deposit
The carbon deposit at the exhaust port of the diesel engine is black gray, which is covered with a layer of white frost, and the carbon deposit layer is very thin, indicating that the diesel engine works well; The carbon deposit is black and bright, but not wet, indicating that the diesel engine burns engine oil slightly and should be eliminated in time; If the thickness of carbon deposit at the exhaust port of a cylinder is significantly higher than that of the exhaust port of other cylinders, it indicates that the fuel injector of the cylinder works poorly or the sealing performance of the cylinder becomes poor, which should be repaired or replaced; If the individual exhaust port is wet or has oil, it indicates that the cylinder discharges a large amount of oil and should be repaired; If the carbon deposit layer at the exhaust port of each cylinder is thick and dark, it is mostly caused by too low working humidity, too late fuel injection and serious diesel after fuel injection. It should be used correctly and adjusted in time.
7. Watch the fire sooner or later
When checking the ignition, it refers to checking whether the fuel injection is normal, that is, whether the fuel supply advance angle meets the regulations. If the fuel supply is too late (the advance angle is too small), the diesel engine is difficult to start, incomplete combustion, exhaust smoke, high engine temperature and insufficient power; If the oil supply is too early (the advance angle is too large), there is a knocking sound when the diesel engine works, which is easy to damage the parts, and it is easy to reverse when starting, which will also affect the power output of the diesel engine.
8. Check whether the fuel injection is stuck
The fuel injection of the fuel injection pump shall not deflect or drip oil, the oil mist shall be uniform, and the range shall be appropriate. During operation, you can hear the clear "puff, puff" sound, and touch the high-pressure oil pipe with your hand. Good fuel injection does not completely mean that there is no problem with oil circuit parts. Therefore, it is also necessary to check whether the fuel supply pull rod and shift fork are stuck and loose.
When the diesel engine is working, open the oil port cover. If a thick smoke comes out of the oil port cover, weigh the smoke. The serious smoke phenomenon indicates that the piston, cylinder liner, piston ring and other parts are seriously worn.
Open the valve cover. If there is a trace of cyan or white smoke from the valve root, weigh it as smoke. If the smoke is serious, it indicates that the valve or valve seat is seriously worn or ablated, or the valve clearance is too small or even no clearance. By observing the smoke situation on the, you can directly see which valve and cylinder has air leakage, which should be repaired in time.
2. Check the cooling system according to the water temperature
If the water temperature of the cooling system in the diesel engine working room is too high, it can indicate that the scale in the engine cooling water chamber is too thick or the efficiency of relevant components of the cooling system (thermostat, water pump, fan lamp) is low or invalid.
3. Blue valve timing check valve phase
After the diesel engine works during the production period, the timing gear, cam surface, follow-up column and tappet will be worn, which will delay the opening and closing time of inlet valve and exhaust valve and deviate from the optimal valve train phase, so as to reduce the charging efficiency and diesel engine power. Therefore, the valve timing of the diesel engine shall be checked regularly. If it does not meet the requirements, it shall be adjusted in time.
4. Look at the compression force and check for air leakage
The method to check the compression force is: rotate the crankshaft without decompression. When the compression force is large, use an upward force to release the handle, but do not leave the handle. At this time, if there is a large rebound force, it indicates that the compression force is very good, otherwise, it indicates that the compression force is poor.
5. Look at the smoke and check the color of the smoke
When the diesel engine works normally, it generally does not emit smoke or some light gray smoke, which is sometimes difficult to see with the naked eye. If black smoke is emitted, it indicates that there is more gas in the cylinder, less gas and incomplete combustion; If white smoke is emitted, it means that the fuel oil is mixed with water, or the diesel oil is not completely burned and comes out of the exhaust pipe after gasification.
6. Check the working condition of carbon deposit
The carbon deposit at the exhaust port of the diesel engine is black gray, which is covered with a layer of white frost, and the carbon deposit layer is very thin, indicating that the diesel engine works well; The carbon deposit is black and bright, but not wet, indicating that the diesel engine burns engine oil slightly and should be eliminated in time; If the thickness of carbon deposit at the exhaust port of a cylinder is significantly higher than that of the exhaust port of other cylinders, it indicates that the fuel injector of the cylinder works poorly or the sealing performance of the cylinder becomes poor, which should be repaired or replaced; If the individual exhaust port is wet or has oil, it indicates that the cylinder discharges a large amount of oil and should be repaired; If the carbon deposit layer at the exhaust port of each cylinder is thick and dark, it is mostly caused by too low working humidity, too late fuel injection and serious diesel after fuel injection. It should be used correctly and adjusted in time.
7. Watch the fire sooner or later
When checking the ignition, it refers to checking whether the fuel injection is normal, that is, whether the fuel supply advance angle meets the regulations. If the fuel supply is too late (the advance angle is too small), the diesel engine is difficult to start, incomplete combustion, exhaust smoke, high engine temperature and insufficient power; If the oil supply is too early (the advance angle is too large), there is a knocking sound when the diesel engine works, which is easy to damage the parts, and it is easy to reverse when starting, which will also affect the power output of the diesel engine.
8. Check whether the fuel injection is stuck
The fuel injection of the fuel injection pump shall not deflect or drip oil, the oil mist shall be uniform, and the range shall be appropriate. During operation, you can hear the clear "puff, puff" sound, and touch the high-pressure oil pipe with your hand. Good fuel injection does not completely mean that there is no problem with oil circuit parts. Therefore, it is also necessary to check whether the fuel supply pull rod and shift fork are stuck and loose.