Analysis method for noise sources of diesel generator sets

The noise of diesel generator sets is a complex sound source composed of multiple sound sources. According to the mode of noise radiation, it can be divided into aerodynamic noise, surface radiation noise, and electromagnetic noise. According to the causes, the surface radiation noise of diesel engines can be divided into combustion noise and mechanical noise. Among them, aerodynamic noise is the main source of noise.

1. Aerodynamic noise is caused by the unstable process of gases, namely the disturbance of gases and the interaction between gases and objects. The aerodynamic noise directly radiating into the atmosphere includes intake noise, exhaust noise, and cooling fan noise.

2. It is difficult to strictly distinguish between combustion noise and mechanical noise. Generally, the pressure fluctuations caused by combustion in the cylinder are referred to as combustion noise, which radiates outward through the cylinder head, piston, connecting rod, crankshaft, and engine body. The noise generated by the impact of the piston on the cylinder liner and the mechanical impact vibration of moving parts is called mechanical noise. Generally, the combustion noise of direct injection diesel engines is higher than mechanical noise, while the mechanical noise of non direct injection diesel engines is higher than combustion noise. However, during low-speed operation, the combustion noise is higher than the mechanical noise.

3. Electromagnetic noise is generated by the high-speed rotation of the generator rotor in the electromagnetic field.

Noise control measures: The noise of diesel generator sets is mainly exhaust noise, with obvious low-frequency characteristics. In cases where the noise source cannot be reduced, comprehensive measures such as sound insulation, absorption, and noise reduction can be taken for the diesel generator set as needed.