What should be paid attention to in the operation of diesel generator sets

First, the diesel generator set with no load after cold start

 

Diesel engine cold start, due to the oil viscosity, poor fluidity, the oil pump is not enough oil, the machine friction surface due to poor lubrication, causing rapid wear, and even pull cylinder, burning tile and other failures.

 

Therefore, after the diesel engine starts to cool, it should be idling and warming up. When the standby oil temperature reaches 40°C or more, it should be operated with a load. The machine should start with a low gear and drive a mileage in each gear step by step until the oil temperature is normal and the oil supply is sufficient. After that, you can turn to normal driving.

 

Second, the diesel generator running in the lack of oil

 

At this time, due to insufficient oil supply, the surface of each friction pair is insufficient for oil supply, resulting in abnormal wear or burn. For this reason, before the start of the machine and during the operation of the diesel engine, it is necessary to ensure that the engine oil is sufficient to prevent the cylinder from pulling out due to the lack of oil, and to cause the failure of burning the tiles.

 

Third, the diesel generator set with a load emergency stop or immediately after the load is shut down

 

Because the circulation of the cooling water is stopped after the diesel engine is out of flame, the heat dissipation capacity is drastically reduced, and the heat-receiving part loses the cooling, which can easily lead to overheating of cylinder heads, cylinder liners, cylinder blocks, etc., cracks, or excessive expansion of the piston and jamming in the liner. .

 

On the other hand, when the diesel engine is stopped without idling, the oil on the friction surface will be insufficient. When the diesel engine is started again, it will be aggravated by poor lubrication. Therefore, the diesel engine should be unloaded before the flameout, and gradually reduce the speed, no-load operation for a few minutes before shutting down.

 

Fourth, the diesel engine after the cold start

 

If the throttle is slammed, the speed of the diesel engine will increase sharply, causing some friction surfaces on the machine to wear out due to dry friction. In addition, pistons, connecting rods, and crankshafts have a large change in the handling force when they hit the throttle, causing severe impact and easily damaging the parts.

 

Fifth, the diesel generator set when the cooling water is insufficient or the engine oil temperature is too high

 

The lack of cooling water in the diesel engine will reduce its cooling effect. The diesel engine will overheat due to lack of effective cooling. The engine oil will be overheated due to the high oil temperature of the cooling water and engine oil. At this time, cylinder heads, cylinder liners, piston assemblies and valves are mainly subjected to large heat loads, and their mechanical properties such as strength and toughness are rapidly reduced, which increases the deformation of parts, reduces the fitting clearance between parts, and accelerates the wear of mechanical parts. There will also be cracks and mechanical stuck problems. If the temperature of cooling water and oil is too high, the aging, deterioration and burning of the oil will be accelerated, and the viscosity of the oil will be reduced. The conditional lubrication conditions of the sleeve cylinder and the piston and the main friction pair will be deteriorated and abnormal wear will occur. Diesel overheating will also deteriorate the combustion process of the diesel engine, causing abnormal operation of the injector, poor atomization, and increased carbon deposition.

 

6. When the diesel generator set cooling water and oil oil temperature is too low

 

During the diesel engine working process, the temperature of the cooling water is too low, and the temperature of the cylinder wall decreases. The steam generated by the combustion condenses into water droplets, and contacts with the exhaust gas to generate acidic substances that adhere to the cylinder wall and cause corrosion wear. Practice has proved that when the diesel engine is often used at a cooling water temperature of 40°C~50°C, the wear of the parts is several times larger than the normal working temperature (85°C~95°C). At this time, when the water temperature is too low, the temperature in the cylinder is low, and the ignition delay period of the diesel engine is prolonged. Once on fire, the pressure rapidly rises, and the fuel of the diesel engine is rough, which can easily cause mechanical damage of parts. The diesel engine runs for a long time under the condition that the cooling water is at a relatively low temperature. The clearance between the piston and the cylinder liner is large, a knocking phenomenon has occurred, and a vibration is generated, so that a cavitation corrosion occurs in the cylinder liner. The temperature of the oil is too low, the viscosity of the oil is large, and the fluidity of the oil is poor. The amount of oil in the lubrication part is insufficient, so that the lubrication is deteriorated, the wear of the friction pair is increased, and the service life of the diesel engine is shortened.

 

Seventh, when the diesel generator set oil pressure is too low

 

If the oil pressure is too low, the lubrication system cannot perform normal oil circulation and pressure lubrication, and sufficient oil cannot be obtained at each lubrication location. Therefore, when the machine is running, it is necessary to observe the oil pressure gauge or the oil pressure indicator. If it is found that the oil pressure is lower than the specified pressure, stop immediately and rectify the fault before proceeding.

 

Eight, diesel generator set machine speeding or overload driving

 

When the machine is severely speeding and overloaded, the diesel engine will operate under conditions of excessive load and high speed, which may result in rough work. The thermal and mechanical loads on cylinder liners, pistons, connecting rods, etc., are increased, and are prone to occur. Pull cylinders and burn tiles and other faults. If the diesel engine is constantly overloaded, it will cause long-term rough combustion in the cylinder and it will easily damage the cylinder head gasket.

 

Nine, before the diesel generator sets turn off the throttle

 

If the diesel engine running at a high speed suddenly stops operating, its huge inertia will damage the components of the crank linkage and the valve distribution mechanism, shortening the service life.

 

At the same time, the fierce bombardment throttles the fuel oil to dilute the oil by flowing down the cylinder wall due to the excessive amount of fuel entering the cylinder.

 

In addition, it will increase the carbon deposition of pistons, valves and combustion chambers, resulting in clogged injectors and stuck pistons.

 

Tenthly, sudden increase of cooling water when the temperature of the diesel generating set is too high

 

If the diesel engine is suddenly overheated and the cooling water is suddenly added, the cylinder head, the cylinder liner, and the cylinder block will be cracked due to the rapid changes in the cold and heat. Therefore, when the temperature of the diesel engine is too high, the load should be removed first, and the rotation speed should be slightly increased. After the temperature of the water drops, the diesel engine is turned off, and then the radiator cover is loosened to remove the water vapor. If necessary, slowly inject cooling water into the water radiator.

 

XI. Long-term idle operation of diesel generator sets

 

When the diesel engine is idling, the pressure of the lubricating oil is low, and the effect of cooling the top of the piston is poor, resulting in a sharp increase in wear and tear. It is also easy to pull the cylinder, causing poor atomization and incomplete combustion, resulting in serious carbon deposition, and sometimes even resulting in valve and piston ring cards. Death and cylinder cavitation etc. For this reason, some diesel engine operating instructions clearly stipulate that the idle running time of the diesel engine shall not exceed 15 to 20 minutes to restrict the reduction of the above faults of the diesel engine.