Precautions for overhaul of MTU diesel generator set

First, see smoke check wear.

When the engine is working, open the mouth cover of the oil. If there is smoke coming out from the mouth cover, it indicates that the gap of the cylinder wall piston ring is too large or beyond the limit. If the gap does not meet the requirements, it should be repaired in time. Open the valve chamber cover, if there is a trace of green, white smoke from the valve root (that is, valve working face), that valve or valve seat wear is too large or ablative, or valve clearance is too small or even no clearance, at this time can be directly seen which valve, which cylinder leakage, should be repaired in time.

Two, look at the carbon check condition.

After the diesel engine flameout, unload the exhaust pipe, check the carbon accumulation in the exhaust port, can judge the working condition of the diesel engine. The carbon is black gray, the surface like covered with a layer of frost, the carbon layer is very thin, indicating that the diesel engine working condition is good; The carbon is black and bright in color, but not wet, indicating that the diesel engine burns oil slightly, which should be eliminated in time; If the carbon accumulation thickness of the exhaust port is obviously higher than that of other cylinder exhaust ports, it indicates that the cylinder fuel injector is not working well or the cylinder tightness is poor, and should be repaired or replaced; If the individual exhaust outlet is wet or has oil, it means that the cylinder has a large amount of oil and should be repaired; The carbon accumulation layer of the exhaust port of each cylinder is thicker and the color is darker, mostly due to the low working temperature or the late injection of oil, which should be used correctly and adjusted in time.

Three, look at the water temperature check cooling.

When the engine is working, the temperature of the cooling system is too high (more than 100℃), which causes the engine to overheat, resulting in insufficient intake, and the friction loss between the piston group and the cylinder wall rises sharply, and the mechanical efficiency is significantly reduced. Therefore, the cooling system should be maintained in time. After the engine works for 1000h, the scale in the cooling system should be removed, and the thermostat and pump fan should be kept in good technical condition. If there is a fault, it should be eliminated in time.

Four, look at the valve valve.

In the long-term operation of the engine, the crankshaft and camshaft are distorted and deformed by the abnormal impact force, and the timing gear, CAM surface, servo column and tasht will be worn, so that the opening and closing time of the inlet and exhaust valve is delayed and deviated from the optimal valve phase, so that the inflation efficiency is reduced and the engine power is decreased. Therefore, to check the engine valve phase regularly, if not meet the requirements should be adjusted in time.

Five, look at the cylinder pressure to check the leakage.

Cylinder compression force is the key factor affecting the power shortage. The way to judge the compression force is simple. Now take the S195 diesel engine as an example: it is in the case of no decompression shake the crankshaft, when the shaking to the compression force is large, and then upward hard shake, relax the crank, but the hand does not leave the crank, at this time, if there is a great rebound force, that the compression force is very good, whereas the compression force is poor. Let's find out what caused the air leak. The main cause of air leakage is that the cylinder is not sealed. In order to narrow the search scope, when the engine is working, you can first listen to the air filter, whether there is a "hiss" sound, if there is, it indicates that the leakage is related to the valve; Open the oil nozzle cover again, if there is a puff of smoke, that the cylinder and piston, piston ring leakage.

Jiangsu Meao Power Technology Co., Ltd. is an important manufacturer of diesel generators. The company mainly manufactures and sells diesel generator sets with power of 3-3000kW, mobile power station of 24-600kW, Marine emergency diesel generator set of 24-800kW, gas generator set, heavy oil generator set and all kinds of imported series, special series (trailer, static speaker, mobile lighthouse, container, etc.) diesel generator At the same time, we are engaged in generator set maintenance and after-sale service of generator set accessories.