Noise Reduction of Hermetic Reciprocating Compressor

This paper refers to the noise reduction of reciprocating compressors for HFC-134a household refrigerators. The reciprocating compressor's highest noise level on household refrigerators is at around 500Hz(l/3 octave band). There is evidence that the 500Hz is caused by the gas cavity resonance and vibration transmission. The mode of the gas cavity resonance was specified by experimental analysis and theoretical analysis using FEM(finite element method) and BEM(boundary element method). The effects of changing the position of the suction tube opening in the compressor shell, which is the source of the gas cavity resonance, was estimated. Generally, in order to reduce the gas cavity resonance, the compressor shell configuration is changed, however, this paper presents that it is effective to change the position of the suction tube opening to the node of the gas cavity resonance without changing the compressor shell configuration. Regarding the accuracy and the calculation time of the theoretical analysis, it is more effective to analyze the resonanse mode by BEM than by FEM. Furthermore, a noise caused by vibration transmission is reduced by changing the looped discharge tube configulation in the compressor shell. As a result, a substantial noise reduction was accomplished in an HFC-134a refrigerant system.