Acoustic Analysis And Noise Reduction Technology Research Of Vertical Refrigerated Display Cabinet

Commercial display cabinet is a heat insulation cabinet with functions of refrigeration,preservation and display.The market of commercial display cabinet in China is mainly vertical refrigeration display cabinet.Because of its large display area and intuitive display effect,it is mainly used for storage and sales of various drinks.This paper mainly studies the air-cooled vertical refrigerated display cabinet,which has the disadvantages of high price,large power consumption and high noise.High noise will seriously affect people’s health and quality of life,so the noise problem is more and more concerned by manufacturers and customers.First of all,the structure and working principle of the vertical refrigerated display cabinet are briefly introduced.In the noise test semi anechoic room,the noise and vibration test system of the HANV household appliances is used to test the noise of the main noise sources of the vertical refrigerated display cabinet.Through the noise source test,it is found that the compressor,air-cooled system and condensation system are the main noise sources of the vertical refrigerated display cabinet,among which the air-cooled system and condensation system have a large noise value of 55.08dB(A)and 56.28dB(A)respectively.Therefore,the noise problems of air-cooled system and condensation system are analyzed.Secondly,the structure and working principle of air-cooled system and condensation system are briefly introduced,and the aeroacoustic model and flow field model are determined,and the noise mechanism of axial flow fan and air-cooled system and condensation system are analyzed respectively.Then,according to the aerodynamic noise of air-cooled system and condensation system,combined with the theoretical analysis,Fluent is used to analyze the flow field dynamics and noise simulation of air-cooled system and condensation system respectively,and the characteristics of flow field distribution and sound pressure spectrum are obtained,and compared with the noise experimental data of air-cooled system and condensation system,the experimental data and simulation data are relatively close According to the simulation results,the air-cooled system and condensation system are improved respectively;in the air-cooled system,the rotation speed of the axial fan is changed to 1200 r/min.the installation angle of the axial fan is changed to 12°;in the condensation system,the resistance muffler is designed and installed.Finally,the noise reduction effect of air-cooled system and condensation system is tested by noise experiment.The test results show that the noise value of air-cooled system and condensation system is reduced by 2.38dB(A)and 3.21 dB(A)respectively.When they are operated separately,and the simulation results are consistent with the experimental results.Further,the noise test of the whole vertical refrigerated display cabinet is carried out,and the results show that the noise of the whole machine is greatly improved and the noise value is reduced 2.18 dB(A).