How to judge the fault based on the exhaust gas discharged from Cummins diesel generator

After the fuel of Cummins diesel generator is burned, the normal exhaust color is generally light gray, and when the load is slightly heavy, it is dark gray. During the operation of Cummins diesel generators, abnormal phenomena such as black smoke, white smoke, and blue smoke occasionally occur. It is a condition for judging the failure of Cummins diesel generators. Haixing Power analyzes it as follows:

(1) Black smoke

diesel is a complex hydrocarbon compound. Unburned diesel sprayed into the combustion chamber is decomposed at high temperature to form carbon black. When exhaust gas is exhausted, black smoke is formed. Black smoke is a manifestation of incomplete combustion of fuel in the combustion chamber. The main influencing factors are as follows:

1.

After the piston ring, cylinder liner, etc. wear, the piston ring and cylinder liner are worn, the compression pressure is insufficient, causing the normal proportion of the mixture to change at the end of the compression stroke, causing the fuel to burn under an oxygen-free conditions and produce carbon deposits.

2. The fuel injector does not work well.

The fuel injector does not atomize or drip oil, so that the fuel cannot fully mix with the air in the cylinder and cannot fully burn. The black smoke discharge phenomenon caused by poor fuel injector operation is more obvious when the diesel engine is running at low speed. Because the intake vortex in the cylinder is weak during low speed operation, the possibility of oil droplets or oil bundles being flushed by the airflow is reduced and the staying time is longer, making carbon black discharge more likely.

3.

The manufacturing quality of the combustion chamber shape changes the shape of the combustion chamber does not meet the technical requirements. The compression joint is too large and too small and the piston position is incorrectly installed, which will change the shape of the combustion chamber, thereby affecting the quality of fuel and air mixing and causing the fuel combustion conditions to become deteriorated.

4. Improper adjustment of the oil supply advance angle

1) The oil supply advance angle is too large and the fuel is injected into the combustion chamber too early. Because the pressure temperature in the cylinder is low at this time, the fuel cannot catch fire and burn. When the piston rises, the corresponding pressure and temperature in the cylinder are reached, and the combustible mixture is burned.

2) The fuel supply advance angle is too small, and the fuel injected into the cylinder is too late. Some of the fuel is separated or discharged before it can form a combustible mixture. The fuel discharged from the exhaust gas is decomposed at high temperature, forming black smoke.

5. The oil supply is

too large. The oil supply is too large. The amount of oil entering the cylinder increases, resulting in incomplete combustion of fuel. In addition, excessive workload, poor fuel quality, and low working temperature will also cause black smoke to emit exhaust gas.

(II) Blue smoke

lubricating oil enters the cylinder and evaporates when heated to become blue oil and gas. The blue smoke is discharged along with the exhaust gas. The main reasons are:

1. The air filter is blocked, the air intake is not smooth, or the oil surface in the oil basin is too high (oil bath air filter).

2. Mix lubricating oil into the fuel.

3. The piston ring corresponds to the mouth.

4. The cylinder gasket near the oil channel leading to the cylinder head of the body is burned.

5. Piston ring, piston, and cylinder liner wear

(III) White smoke

Cummins diesel generator is when it is started or when it is cooled, and white smoke comes out of the exhaust pipe because the temperature in the diesel engine is low and the oil and gas evaporates. It is particularly noticeable in winter. If white smoke still emanates from the exhaust pipe during the heater, it is judged that the diesel engine is faulty. The main reasons are as follows:

1. There are cracks in the cylinder liner or the cylinder gasket is damaged, and cooling water enters the cylinder, and water mist or steam is formed when exhausted.

2. The fuel injector is atomized poorly and there is oil dripping.

3. The premature angle of oil supply is too small.

4. There is moisture and air in the fuel.

5. The pressure of the fuel injection pump is too low or the piston, cylinder liner, etc. is seriously worn, resulting in insufficient compression force.

According to different exhaust gas conditions, everyone can discover problems in a timely manner and solve them to avoid greater damage to generators and generator sets. Haixing hopes that everyone will be more careful in their spare time in operation.