Research On Range Hood Noise Control Technology Based On The Channel Sound Absorption

Noise has become one of the three major pollution.As a commonly used household appliance,the problem of noise of range hood has been paid more and more attention.The research and development of low noise range hood has become the main research direction of major manufactories.In this work,a large air volume range hood is taken as the research object,and method of intake channel sound absorption is adopted to reduce the noise.Main contents are as follows:1)By using COMSOL numerical simulation software,sound absorption properties of micro-perforated panel,porous sound absorbing material and their composite structures under different parameters are calculated,and the influences of each parameter on the properties of sound-absorbing structures are obtained.The sound absorption characteristics of a micro-perforated panel are tested using impedance tube,and the results are in good agreement with those of the simulation,which indicates that the simulation is reliable.2)According to the characteristics of the flow field,the internal structure of the range hood is adjusted,the location and direction of the fan are changed,so that a longer intake channel is constructed.After acquiring and analyzing noise signals of the range hood of which structure being rebuilt,conical guide sound absorption linings in the intake channel are constructed.Based on the noise control theory and simulation results,three kind of linings are designed,including sound absorption structures of single and double micro-perforated plates,low impedance microperforated plates and high impedance micro-perforated plates.3)Noise of the range hood with noise reduction restruction were tested.All the cases show good noise reduction effect,which verifies the effectiveness of the noise reduction schemes.The noise reduction effect of the single micro-perforated plate composite structure with high acoustic impedance is the best with the mean noise reduction value of 4.2d BA,and the noise reduction value is 3.1d BA for the double micro-perforated plate composite structure is 3.1d BA.At the same time,the results of air performance test show that flowrate and static pressure of each scheme have little change of no more than 5% comparing with the original structure.