Analysis of noise generation mechanism for two-phase flow of refrigerant in evaporator inlet pipe of refrigerator

In this paper, numerical flow and acoustic analysis were conducted on the inlet piping of refrigerator evaporator, taking actual operating conditions to investigate the mechanism of refrigerant induced noise generation. Four operating conditions were selected as boundary conditions, considering the expansion process of the refrigeration cycle. Two-phase flow analysis was performed, considering temperature changes and phase transitions of the R600a refrigerant in the region from the condenser outlet to the evaporator inlet. Acoustic analysis results confirmed that the area near the evaporator inlet has a higher noise contribution compared to the capillary tube. By comparing the instantaneous sound pressure of bubbles and acoustic analysis result, pipe area for reducing refrigerant induced noise was proposed.