Abstract: The suction muffler of reciprocating compressor has a great influence on the noise and performance of the compressor. Therefore, a three-dimensional sound field model and internal flow field model of the suction muffler are established. The acoustic finite element model and FW-H aeroacoustics model are used to calculate its acoustic characteristics respectively. At the same time, the outlet flow of the muffler is monitored based on fluid mechanics transient calculation. The optimal scheme of the suction muffler of a reciprocating compressor is established by using the multi-physical field numerical analysis method and the simulation results are verified by experimental tests finally. The results show that the measured noise of the optimized scheme is better in the 400 Hz~1250 Hz and 2500 Hz~6300 Hz frequency bands, the maximum optimized amplitude is 4 dB(A) and the total noise is reduced by 2 dB(A). The performance test results are also greatly improved compared with the original scheme, the cooling capacity is increased by 7.8 W (about 5%) and the COP is increased by 0.021, which effectively verifies the accuracy of the sound power level, aerodynamic noise and CFD numerical analysis model of the suction muffler. Therefore, the comprehensive analysis method can better guide the forward design and optimization of the suction muffler.

Key words: Reciprocating compressor, Suction muffler, Aerodynamic noise, Sound power level