Analysis of the causes of diesel generator turbocharger failure

In order to enhance the power of the unit, the diesel generator is equipped with a turbocharger on the engine, which can greatly improve the power of the generator set. Although turbochargers can effectively increase engine power, the occurrence of turbocharger failures cannot be avoided. In order to avoid such failures as little as possible or not, the following is the reason for analyzing the malfunction of the silent generator set turbocharger.

1. Insufficient lubricating oil or oil supply lag

( 1) When the turbocharger speed and the silent generator load increase, the turbocharger oil supply must also increase because the unit is running at high load and the turbocharger speed is high, even if it is only short-lived. Insufficient oil supply to the turbocharger bearings for a few seconds will also cause bearing damage.

( 2) When the unit is working under tilt (partial load or full load operation), if the oil level is too low or the air is sucked in, the oil pressure will decrease, even if the time is short, the supercharger may be lack of lubrication. Damaged by oil.

2. External debris or sediment enters the lubrication system

Engine oils containing dirt or sand have much more wear and damage to turbocharger bearings than engine bearings, because the turbocharger's speed is much higher than the engine's speed. If such damage occurs in the turbocharger, the cause of the oily waste should be identified and eliminated, otherwise damage will occur even if the new supercharger is replaced, and the engine may be damaged if it is developed. When the dirt particles mixed in the oil are large enough to block the oil passage inside the turbocharger, the supercharger will be damaged by the lack of lubricating oil. When changing the oil and oil filter, the oil sample in the diesel engine can be extracted for analysis under conditions, which will help prevent the above damage; the oil should be replaced according to the replacement period specified in the instruction manual. The filter must never be extended at will.

3. External foreign matter enters the intake or exhaust system of the diesel engine

Turbocharger turbines and compressor impellers are rotating at very high speeds. Once the foreign matter enters the engine's intake and exhaust systems, the impeller will be damaged; small objects such as sand will erode the impeller. The airflow angle of the blade changes; large and hard objects cause the blade to rupture; soft objects (such as cotton yarn) roll onto the blade in the direction of rotation of the impeller.

4. Oxidation or deterioration of engine oil

Due to the oxidation and deterioration of the oil of the silent generator set, the engine oil will form sludge deposits, which will affect the performance and life of the turbocharger.

5, the turbocharger operating temperature is too high

In general, the heat source that causes the operating temperature to be too high comes from the gas (exhaust gas) discharged from the silent generator set . If the exhaust gas temperature is too high, the supercharger will be damaged directly or indirectly.

( 1) Direct damage, that is, the superheating of the intermediate casing of the supercharger and the corrosion and deformation of the casing material of the turboshell; the excessive temperature of the exhaust gas may also cause cracking of the turbine casing.

( 2) Indirect damage, that is, when the exhaust gas temperature is too high, the extra heat energy in the exhaust gas will accelerate the turbocharger rotor assembly and operate at a higher than the design speed. If this happens, the compressor The impeller will crack due to one or repeated high stress loads, and the turbine wheel will also crack due to the material's reduced strength at high temperatures and increased turbine speed.