Abstract: Research focuses on the noise of light commercial refrigeration compressors. By comparing the noise spectrum and frequency modes of the shell, the direction for improving noise level of a certain frequency is identified. By Testing and comparing the noise spectrum, shell mode and the frequency results of the A-23cc compressor, the frequency of 2500 Hz was selected as the noise optimization target. In response to the characteristic of the highest excitation amplitude of 2600 Hz in the shell mode, which directly affects the overall noise of 2500 Hz, the shell will be changed as the improvement target. By moving the position of the shell welding strip downwards, the modal excitation peak of the shell was shifted from 2600 Hz to 2800 Hz, thereby reducing the impact on the noise spectrum of 2500 Hz. Compared with the results of the overall noise test before and after the improvement of the shell mode, the noise at 2500 Hz decreased by 6.1 dB(A), and the compressor overall noise decreased by 3.0 dB(A).

Key words: Light commercial refrigeration compressor, Noise optimization, Frequency and vibration mode