When the Cummins diesel generator set is running, the turbocharger rotor set rotates at a very high speed (tens of thousands to hundreds of thousands of revolutions per minute). If the pressure and quality of the lubricating oil do not meet the requirements specified in the technical manual, the Faults often occur during use. Common faults of turbochargers include bearing burnout, blade fracture, boost pressure drop, supercharging pressure too high, compressor surge and so on.
1. Bearing burnout is generally caused by too low lubricating oil pressure, too little lubricating oil, or too much impurities in the lubricating oil. If the lubricating oil is not clean during the use of the turbocharger, and metal chips and other impurities are mixed into the engine oil, it is easy to cause the bearing to burn out.
2. Blade breakage or damage is mainly caused by foreign matter. Because the blades of the turbine are exposed to high temperature and rotate at a high speed, if there is a small hard object, it will have a big impact, which will cause the blade to bend or crack.
3. The decrease of boost pressure means that the value of boost pressure becomes relatively small under the condition that the load carried by the unit is connected. The decrease in the speed of the supercharger and the decrease in the boost pressure are mainly due to the failure of the exhaust gas turbine or the mechanical part. This failure may be due to the deformation of the nozzle ring blades due to high temperature, which increases the flow area of the nozzle; or there is air leakage at the exhaust pipe joints, which reduces the exhaust gas energy that can be used in the turbine. The mechanical factor is that the turbocharger has not been maintained for a long time, and there is too much carbon deposit on the impeller inside the turbine shell, which increases the rotation resistance of the rotor group. If the boost pressure is reduced and the speed of the turbocharger does not change significantly, the fault generally lies in the compressor. For example, the air filter element is too dirty, and the airflow channel inside the compressor is contaminated by dust and grease, resulting in the efficiency of the compressor. Drop and so on.
4. Excessive boost pressure is often accompanied by supercharger overspeed. The reasons for this failure include: poor fuel supply system work, resulting in poor combustion of individual cylinders; exhaust valve leakage, which makes the exhaust temperature too high; turbocharger turbine nozzle ring is blocked by dust and carbon deposits, resulting in reduced circulation area If it is small, the gas ejection speed is too fast, which speeds up the rotation speed of the rotor group.
5. When the turbocharger is running at a certain stable speed, the amount of air delivered to the interior of the combustion chamber is insufficient, and the delivered air pressure fluctuates greatly. At the same time, it is accompanied by the sound of panting at the compressor. This phenomenon is called As “surge”. The factors that cause this failure include: blockage of the airflow channel; deformation or looseness of the diffuser of the turbocharger or the blades of the nozzle ring, resulting in a change in the shape of the airflow channel, making the turbocharger and diesel engine unable to match; improper operation Wait.
Post time: Jun-28-2021