Analysis of insufficient power of marine diesel engine

1. Failure phenomenon The so-called insufficient power is the "weakness" and "weakness" of the marine diesel engine. Under normal circumstances, the power of marine diesel engines generally has a certain reserve, which can drive the normal operation of working machinery. When the power is insufficient, it is manifested that the marine diesel engine cannot move the supporting working machinery, and the following phenomena are accompanied:

⑴ Black smoke from the marine diesel engine. At this time, a large amount of black smoke was emitted from the exhaust pipe of the marine diesel engine.

⑵The exhaust temperature of marine diesel engine is high. At this time, the exhaust pipe and the turbocharger turbine are dark red.

⑶ The speed of the marine diesel engine drops or the speed is unstable, and the sound of weak work is shown.

2. Reason analysis:

⑴ Insufficient fuel supply: the fuel filter is fouled; the fuel line is too thin and too long to leak; there is air in the fuel system; the fuel quality is not good, and the fuel contains water; the fuel injection pump or regulator limit seal is damaged. Oiling; the governor tie rod screw is screwed in too much, and the rack rod extension length is not enough; the plunger of the fuel injection pump is seriously worn, and the fuel supply of individual cylinders is too small.

⑵ Poor atomization or mismatch with the combustion chamber: poor atomization of the oil head; incorrect fuel supply advance angle; incorrect oil head protruding out of the cylinder head plane; serious carbon formation on the cylinder head piston; too large compression clearance; poor oil valve sealing strict.

⑶ Insufficient air intake: dirty air filter; dirty intercooler; dirty compressor impeller; dirty cylinder head intake; air leakage in intake and exhaust pipes; inaccurate air distribution timing; turbocharger failure, air intake The pressure is low.

⑷ Poor exhaust: the exhaust pipe is too long or too long, or there are many turns; the exhaust muffler is dirty; the cylinder head exhaust duct is dirty; the exhaust timing is wrong.

⑸External factors: the temperature of the inlet water of the intercooler is too high; the ambient temperature is high and the humidity is high; the altitude is high and the air pressure is low; the marine diesel engine is overheated; abnormal wear and tear, the marine diesel engine pulls cylinders, burns tiles, holds axles, etc.