When a diesel generator set is running, it usually generates 95-110db(a) noise. When the noise source cannot be reduced, what measures should be taken to control the noise of the diesel generator set?
Analysis of diesel generator noise sources:
Diesel engine noise is a complex sound source composed of multiple sound sources. According to the noise radiation mode, it can be divided into aerodynamic noise, surface radiation noise and electromagnetic noise. According to the cause of generation, the surface radiation noise of diesel generator sets can be divided into combustion noise and mechanical noise. Among them, aerodynamic noise is the main noise source of diesel engine noise.
1. Aerodynamic noise is the diesel generator noise generated by the unstable process of gas, that is, the disturbance of gas and the interaction between gas and objects. Aerodynamic noise radiated directly into the atmosphere includes intake noise, exhaust noise and cooling fan noise.
2. Electromagnetic noise is the diesel engine noise generated by the high-speed rotation of the generator rotor in the electromagnetic field.
3. It is difficult to strictly distinguish between combustion noise and mechanical noise. The diesel engine noise radiated outward through the cylinder head, piston, cylinder head, crankshaft and engine body due to the pressure fluctuations formed by the combustion in the diesel generator cylinder is usually called combustion noise. The diesel engine noise generated by the impact of the piston on the cylinder liner and the mechanical impact vibration of the moving parts is called mechanical noise. Generally, the combustion noise of direct injection diesel engines is higher than the mechanical noise, while the mechanical noise of non-direct injection diesel engines is higher than the combustion noise. However, the combustion noise is higher than the mechanical noise when running at low speed.
Control measures for diesel generator noise:
1. Soundproof room.
Install a soundproof room at the location of the diesel generator set, with a size of 8.0m×3.0m×3.5m, and the outer wall of the soundproof board is 1.2mm galvanized plate. The inner wall is a 0.8mm perforated plate, the middle filler is 32kg/m³ ultra-fine glass wool, and the concave surface of the channel steel is filled with glass wool.
2. Exhaust silencer.
The diesel generator set relies on its own fan to exhaust air. An AES-type rectangular silencer is installed in the front of the exhaust room. The size of the silencer is 1.2m×1.1m×0.9m. The silencer is installed with a 200mm thick silencer and a spacing of 100mm. The silencer is made of galvanized perforated plates on both sides with ultra-fine glass wool. 9 silencers of the same size are assembled into 1. A large silencer of 1.2m×3.3m×2.7m. 300mm in front of the silencer is an exhaust shutter of the same size.
3. Inlet silencer.
A natural air intake silencer is installed on the top of the soundproof room. The silencer is made in the same way as the exhaust silencer, with a net silencer length of 1.0m, a cross-sectional size of 3.4m×2.0m, a 200mm thick silencer, a 200mm spacing, and an unlined 90° silencer elbow connected to the silencer. The silencer elbow is 1.2m long.
4. Smoke exhaust silencer.
The smoke is silenced by two residential silencers provided by the diesel generator set. The silenced smoke is combined into a Φ450mm smoke pipe and discharged upward from the exhaust louver.
