排风管对油烟机辐射噪声的影响

对安装排风管后油烟机辐射噪声的A声级及频谱特征进行实验测量和分析，并用阻抗转移和等效阻抗模型对管道及蜗壳系统的声阻抗进行理论研究。理论和实验结果表明，安装排风管后，风机转速明显提高，使油烟机辐射噪声的A声级增大；同时因为声源辐射声阻抗的改变而产生低频的声共振，影响声品质,共振频率取决于管长和油烟机腔体体积。排风管对油烟机噪声的影响研究对用户状态下油烟机的辐射噪声评价和降噪具有实际意义。

Influence of Exhaust Pipe on Noise Radiation of Range Hoods

The A-grade sound level and spectrum characteristics of the range hood＇ s noise with and without exhaust pipes were measured and analyzed respectively, and the acoustic impedance of the pipeline and volute system was studied using the impedance transfer and equivalent impedance model. Theoretical and experimental results showed that the rotation speed of the fan was raised obviously and the A-grade sound level increased as well after installing the exhaust pipe. Meanwhile, sound quality was impaired by the low-frequency sound resonance due to the change of the acoustic radiation impedance of sound source. The resonance frequency depended on the length of the pipe and the volume of the range hood＇s cavity. Study of effects of the exhaust pipe on the range hood＇ s noise radiation is of practical significance for assessment and control of the range hood noise.