Abstract: The low-frequency noise problem is a very common type of complaint in the refrigerator market. The main cause of this problem is the resonance between the compressor and the refrigerator base. The excitation source of this resonance is mostly the unbalanced inertia force generated during the operation of the compressor. By optimizing the dynamic balance of reciprocating compressors, the unbalanced inertia force during operation can be significantly reduced, thereby improving the low-frequency noise of the refrigerator system. Based on a certain fixed-frequency reciprocating compressor, simplifies its crank-connecting rod-piston system into a crank-connecting rod mechanism, conducts dynamic analysis of the mechanism, derives the theoretical formula of unbalanced inertia force, and explains the inertia force characteristics in the reciprocating direction and the nameplate direction. Based on the theoretical formula of unbalanced inertia force, a dedicated reciprocating compressor dynamic balance design software is developed. The software can calculate the reciprocating inertia force curve of different balancing schemes and calculate the optimal balancing mass. For this software, propose a dimensionless factor method to benchmark the calculated values with experimental values, and the results show that the error level between the two meets the requirements of engineering applications.

Key words: Refrigerator system low frequency noise, Reciprocating compressor, Dynamic balance, Dimensionless factor, Test benchmark