Noise Research Of The Air-cooling Systerm In Refrigerator

The air-cooling system of refrigerator includes:axial fan、air path、openings. The mainly noise of the whole system are the noise of fan operation and the vortex noise radiation from the air path and the cabinet. The noise sources of the whole machine were located by testing and numerical computation, then find out the influence of the noise of air-cooling system to the whole machine. After this, the structure of the cover and the axial fan were optimized for reduction the noise radiation from the whole air-cooling system. The main achievements and works of this paper as follows:1. In order to understand the characteristics of air-cooled refrigerator noise, the sound intensity testing and the spectrum testing were respectively conducted. The above tests obtained the noise sources of the refrigerator and their frequency distribution;2. In order to acquire sound quality characteristics of air-cooled refrigerator, the sound quality testing and analysis were conducted, then the values of the sound quality parameters of the air-cooled refrigerator and their frequency properties were obtained. Find out that the air-cooled system noise has a big influence to the loudness;3. For reduce the vortex noise of the flow field under the fan cover, the influence of the size of openings and the location of fan to the flow distribution and noise level were analyzed. Then the reasonable opening size and fan location were obtained, result displays that the noise level of the whole machine reduced 2.2dB after optimize;4. For reduce the rotation noise of the fan, on the basis of the original fan structure, design a new low-noise fan by optimize the airfoil profile、number of blades and the blade angle. The numerical calculation of the wind tunnel displays that the new low-noise fan has a noise reduction about 1.5dB in the monitoring;5. For verify the noise reduction effect of the new structure of the cover and the fan, replace the original fan by the new one, the numerical calculation result of the combined optimizations shows that the noise level of the whole machine has declined about 2.5dB.