Wind turbine noise control mainly adopts sound insulation, sound absorption, noise elimination and other measures, which can completely reduce fan noise to environmental requirements. Fan is a wide range of general machinery and equipment. It is widely used in chemical, petroleum, metallurgical, mining, machinery and other industrial departments, as well as some civil departments, and the fan is in the middle of the operation. The noise of raw materials often affects the health of the workers and disturbs the quiet of the environment. It seriously interferes with the normal work and rest of the people, and becomes a public hazard, and the discrete noise of the fan (rotating noise) is related to the rotation of the impeller. Especially under the condition of high speed and low load, this noise is particularly prominent.

Discrete noise is caused by the uneven and smooth interaction of the asymmetrical structure around the blade and the rotation of the blade design test.            

1.Intake interference noise due to the presence of a guide vane or metal mesh cover before the intake.            

2.Rotation frequency noise generated by blades in unsmoothed or asymmetric shells.  

3.The outlet interference noise caused by the existence of the worm tongue or the presence of the axial flow wind surface in the centrifugal outlet, the discrete noise has the discrete spectrum characteristics, the fundamental frequency (the corresponding frequency of i=1) is the strongest, and the high order harmonics are decreasing.            

Fan vortex noise is generated by various eddy currents when air flows. It is generally considered that there are 4 causes:            

1.Turbulent noise generated by the flow of airflow to the blade with a certain degree of incoming turbulence.        

2.Turbulent boundary layer noise caused by fluctuating turbulent boundary layer through airflow through the blade surface.            

3.The vortex noise generated by the turbulent boundary layer on the blade surface falling off the trailing edge of the blade.            

4.Due to the concave pressure greater than the convex surface, the two flow of the flow from the concave surface to the convex surface at the top of the blade is taken away by the main air flow. 

The control method of fan noise:            

Fan noise includes mechanical noise and airflow noise control. Noise control measures include noise elimination, sound insulation and sound absorption. Because pipeline airflow noise is an important noise source, it is very necessary to build a pipeline muffler.            

After the wind machine room is taken, the cooling and cooling of the fan and its motor must be taken into consideration. At the same time, the timely discharge of the toxic and harmful gases in the indoor air is also considered, such as the CO in the deflux wind machine room, and the C02 and other gases in the decarbonization machine room.            

The fan inlet butterfly valve is installed and the original water pressure control system is changed into a microcomputer integrated oil pressure control system. In this way, it is expected that the valve can be closed in time when the gas boiler is not used, and the fan is truly empty, so that the surge noise is eliminated.            

When the fan noise is treated, the sound of the factory is obviously decreased, and the requirements of the noise standard of the factory are reached. The quality assurance of the engineering is guaranteed.