Howe mixer is walking, what's the matter with smoke and fire from the exhaust pipe?
With the increase of intake air temperature, fuel gasification and intake air temperature are relatively reduced, which makes combustion conditions worse and leads to black smoke from diesel engines.
Detection and diagnosis of common faults;
First, the air intake and exhaust system, poor air intake and exhaust will lead to black smoke in the exhaust, which may lead to diesel engine failure or even serious damage.
1, air intake system is blocked: under high speed and heavy load, diesel engine may emit serious black smoke due to too rich mixture.
There are two main aspects of air filter blockage:
1) The problem of air filter element, which is blocked or dirty, is the main reason why many diesel engines emit black smoke under load.
2) If the air filter element has quality problems, it will also cause the diesel engine to emit black smoke.
The basic method for judging whether the black smoke emitted by diesel engine is caused by air filtration is as follows:
① If the diesel engine does not emit black smoke at ordinary times, there is no other abnormality. Black smoke only appears when the load is reduced, and then disappears. Generally, the problem of air filtration can be judged.
② Remove the air filter element, start the diesel engine, and observe the smoke when the diesel engine is loaded. If the smoke turns pale, it means that the air filter element needs maintenance or replacement.
The intake pipe is blocked. Under special circumstances, the intake pipe may be blocked. If the rubber in the intake pipe is blocked,
The rubber hose is crushed, the inside falls off, the air inlet pipe is blocked by falling debris, which makes its circulation not smooth, or the air inlet of the cylinder is artificially blocked, which may cause the exhaust pipe to emit black smoke seriously.
Second, the blockage of the exhaust system will also lead to serious black smoke from diesel engines. The main reasons are as follows:
1) The exhaust muffler is damaged internally or the exhaust hole is blocked.
2) The oxidation catalyst is blocked or fails; If the diesel engine equipped with exhaust particulate filter is damaged or fails, it may also cause the diesel engine to emit black smoke.
Third, the reasons for the gas distribution system:
The gas distribution system is the breathing tube of diesel engine. If the air distribution is not correct, it will inevitably affect the intake of diesel engine, and insufficient intake will emit black smoke.
The reasons for the black smoke of diesel engine caused by the failure of gas distribution system are as follows:
1) The valve clearance is incorrect. Resulting in insufficient fuel combustion.
2) The valve is not tightly sealed, which directly reduces the compression pressure and temperature of the cylinder and makes the fuel burn.
It's not completely insufficient, which causes the diesel engine to emit black smoke.
Fourthly, the cylinder compression pressure is insufficient, and the pressure and temperature in the cylinder are too low at the end of compression, which seriously affects the combustion efficiency and effect of fuel and will lead to black smoke from diesel engines. The reasons for insufficient cylinder compression pressure are:
1, the piston crown clearance is too large, and the compression ratio decreases when the piston clearance is too large, which directly affects the compression ratio of diesel engine and then affects the compression pressure of cylinder.
2. The valve and valve seat ring are seriously worn and not tightly closed, which correspondingly increases the volume of the combustion chamber and reduces the compression ratio of the diesel engine, thus reducing the compression pressure and temperature of the cylinder, resulting in incomplete and insufficient combustion and serious black smoke from the diesel engine.
3. The piston ring or cylinder liner is seriously worn, which will make the cylinder seal not tight and lead to insufficient compression pressure.
Verb (abbreviation for verb) The cause of the fuel system. The problems existing in the fuel system mainly include:
1, low-pressure oil circuit blocked, air intake, dirty fuel filter,
2. Excessive fuel injection, injector failure, etc. , which may cause serious black smoke from diesel engines.
3. The fuel injector advance angle is incorrect, and the standard fuel injection advance angle can ensure the fuel to fully burn after entering the cylinder.
4. Serious wear of plunger or oil outlet valve will lead to the decrease of pump oil pressure of fuel injection pump, which will lead to black smoke and insufficient power of diesel engine. In severe cases, the diesel engine will easily turn off automatically, making it difficult to start; Fuel consumption has increased.
Six, injector failure:
1. The injector is seriously atomized, stuck or dripped, or is seriously damaged. The fuel injection pressure drops and the atomization quality is poor.
2. The injection pressure is incorrect; Incorrect injection pressure makes the diesel engine emit black smoke when working.
3. The fuel injector is not installed correctly. Some diesel fuel injectors have strict installation directions, but there are no other labels and instructions.
Therefore, the installation angle error is easy to occur. If the matching requirements of the injector and the combustion chamber are inconsistent, the diesel engine will also emit black smoke.
Seven, fuel injection pump governor reason. The main reason is that when the elasticity of the governor's speed regulating spring is insufficient, it will lead to the imbalance between the governor and the throttle control mechanism, and the diesel will emit black smoke seriously when the load changes.
Eight, starting solenoid valve is damaged. Some diesel engine governors are equipped with starting and boosting solenoid valves. Electromagnetic valve failure, diesel engine can not be started or the oil supply is large after starting, resulting in black smoke from diesel engine.