Analysis And Research On Acoustic Performance Of Suction Muffler And Exhaust Coil Of Refrigerator Compressor

The working principle of the refrigerator compressor is to use the rotation of the crank connecting rod to drive the reciprocating motion of the piston.During the working process,it cooperates with the opening or closing of suction and exhaust valves to realize the transformation of internal refrigerant from low temperature and low pressure to high temperature and high pressure,thus providing power for refrigeration cycle.During the working process of compressor,due to the influence of periodic inertial force,pulsating gas pressure,frictional force and electromagnetic force,the compressor will vibrate and noise.With the pursuit of high standards of life,noise has become an important indicator of compressors.Research and manufacture of low noise refrigeration compressors has become the key to the formation of core competitiveness and high market share.At present,domestic and foreign scholars have achieved certain research results for the noise problem of refrigerator compressors,but lack of the overall concept,and less research on aerodynamic noise induced by unsteady flow field.In this paper,the refrigeration compressor is taken as the research object.According to the theoretical analysis,in view of the noise radiation characteristics of the refrigeration compressor,a multi-stage expansion structure muffler is designed to form a relatively wide muffling frequency band to improve the noise reduction.After the analysis muffling theory and redesign of the muffler,the three-dimensional modeling of the suction muffler and the pre-processing before the finite element simulation are completed.Then the transmission loss and resistance loss of the suction muffler are calculated in the acoustic simulation software and the flow field simulation software respectively,and the structural parameters of the suction muffler that affect the transmission loss result are analyzed,which provide a basis for the overall design and improvement of the suction muffler.The gas periodically discharged by the piston is compressed and expanded in the exhaust coil,and the interaction between the fluid and the elastomer causes vibration,and the refrigerant generates aerodynamic noise when flowing through the exhaust coil.Taking the internal exhaust coil of the compressor as the research object,the finite element model of the exhaust coil and the internal fluid is established,and the influence of the fluid on the natural frequency of the exhaust coil is analyzed;Calculate the flow field of the exhaust coil in the CFD software,and analyze the vibration mode of the exhaust coil under fluid-solid coupling;After obtaining the flow field inside the exhaust coil,the noise source data is obtained.The acoustic noise of the exhaust coil at different flow rates is calculated by the combined acoustic software simulation,and the generation,propagation and attenuation of the aerodynamic noise are analyzed.By analyzing the fluid-solid coupling,the natural frequency of the exhaust coil will be reduced,so the effect of the fluid should be considered when actually calculating the natural frequency;Based on the analysis of the vibration and aerodynamic noise of the exhaust coil,an improved scheme of the exhaust coil is proposed,which provides a rationalization idea for the optimization of the subsequent exhaust coil.Finally,the experimental test of the suction muffler with different structural parameters was carried out,and the spectrum analysis of the test results was carried out.The results show that the designed suction muffler can effectively reduce the noise of the compressor and prove the feasibility of the scheme.