Analysis Of The Causes Of Diesel Engine Underpowered Failure I

After a long time of operation, due to wear and tear of parts or improper operation and adjustment, maintenance is not timely and so on, often there will be a lack of power. The causes of diesel engine power shortage are complex, but its main reasons are 2 aspects: one is due to poor sealing of the combustion chamber, insufficient fuel supply, poor atomisation of the injector, insufficient gas supply, improper adjustment of fuel supply timing, etc., caused by incomplete combustion of the fuel, resulting in insufficient power of the diesel engine; the second is due to the wear and tear of the machine parts is too large, poor lubrication, poor cooling, improper installation, etc., caused by the diesel engine itself Friction loss of power is too large, so that the output power is reduced, resulting in insufficient diesel engine power. Therefore, when analysing and troubleshooting the diesel engine power failure, should seize the combustion and friction loss size of these 2 key issues, combined with the operation of the user on the wear and tear of diesel engine parts and components and technical state of understanding and mastery, so as to find out the possibility of causing the diesel engine power shortage of the largest several reasons, and then check and eliminate. The main reasons for the lack of diesel engine power are as follows:

   First, the intake and exhaust system is not smooth

    Diesel engine air filter and intake tract due to excessive dust and not smooth or blocked, will make the amount of air into the cylinder is not enough, not only lead to insufficient compression pressure, and fuel can not get enough air and can not be completely combusted, resulting in insufficient diesel engine power. In other normal conditions, if the exhaust pipe or muffler large amount of carbon deposits, exhaust is not smooth, so that the cylinder exhaust gas exclusion is not clean, will also cause the amount of fresh air into the cylinder is reduced. At this time, although the compression pressure is not low, but due to the lack of air into the cylinder, will also make the fuel can not be completely burned, resulting in diesel engine power and black smoke. Therefore, the user should regularly remove the air filter and intake tract in the dust, regularly remove the exhaust pipe and muffler in the carbon and dirt, to ensure that the intake and exhaust system is unobstructed.

    Second, the intake and exhaust system is not sealed

    Turbocharged diesel engines rely on exhaust pressure to blow the turbine to drive the pump wheel rotating at high speed to the intake pipeline delivery of compressed air to ensure that the diesel engine output greater power. Therefore, supercharged diesel engine intake and exhaust systems must be completely sealed. Exhaust piping or joints if the leakage, the exhaust pressure will be reduced, the supercharger speed drop, the intake pressure decreases, which leads to a decline in diesel engine power. Intake system (including the intake tract, intercooler and the joints) if the air leakage, then although the supercharger to provide intake pressure in line with the standard, but the real amount of air into the cylinder will be significantly less than the amount of power to make the diesel engine power drop. This kind of failure also tends to occur after the repair and maintenance, especially after reassembling the intake and exhaust system, due to a variety of reasons caused by the seal is not tight.

    Third, the cylinder compression pressure is insufficient

    Diesel injector mounting holes leakage or copper gasket damage, cylinder gasket leakage, valve, valve seat, cylinder liner, piston, piston ring wear is too large, valve clearance is too small, the decompression mechanism gap is too small, etc., will cause poor sealing of the combustion chamber, so that the fresh air into the cylinder leaks out from these parts, resulting in insufficient air inside the cylinder, so that the fuel does not get enough air in the combustion chamber can not be completely Combustion, the power of the diesel engine is naturally reduced, resulting in a lack of power. At the same time, due to insufficient air in the cylinder, the pressure and temperature of the compression endpoint will inevitably be reduced, so that the fuel combustion process is delayed backward, resulting in the occurrence of afterburning phenomenon, so that part of the fuel is too late to burn completely with the exhaust gas discharge. In addition, the high temperature and high pressure gas will also leak out from the above parts, so that the ability of gas to do work is reduced, resulting in diesel engine power shortage. Diesel engine power is not enough to show another feature is black smoke. Therefore, the cylinder compression pressure is insufficient to lead to one of the main reasons for the lack of diesel engine power, once it occurs should be excluded in a timely manner.

    Fourth, the turbocharger is not working well

    Turbocharger is a key component that affects the power of the diesel engine. If the supercharger burns will cause its speed drop, intake boost pressure drop, resulting in lower diesel engine power. Pre-damage signs of supercharger is "oil", that is, to the exhaust pipe and intake pipe oil discharge, when the oil discharge is serious that the supercharger has tended to damage. Supercharger rotor axial and radial clearance must be ensured in the specified range. Equipped with a supercharger diesel engine in use should pay attention to, after starting to idle for a few minutes, to be oil has circulated and then accelerate and load, especially the first start every day should pay more attention. Diesel engine should also be idling for a few minutes after the engine is off, to be diesel engine and supercharger speed drop before switching off. Blast the throttle before the flameout of the customary operation, is a fatal blow to the life of the supercharger, because the flameout before the blast two feet of throttle, the supercharger speed immediately increased, when the diesel engine suddenly shut down, the oil pump stops running and stop supplying oil, the supercharger is in the lubrication of poor conditions continue to rotate at high speeds resulting in dry grinding, so that the rotor shaft and bearings to accelerate the wear and tear of sealing ring strained and discharged oil, the seriousness of the turbine will be burnt, the rotor axis In serious cases, the turbine will be burnt and the rotor shaft will be twisted off.