Abstract: Electrical appliances such as air conditioners and refrigerators were considered to be the main source of noise in the indoor environment, especially noise generated by the flow of refrigerant. Use the aerated supercavitation theory to optimize the structure of the traditional electronic expansion valve. The refrigeration at the inlet of the evaporator was introduced to the outlet of the electronic expansion valve through the installation of a bypass pipe to form supercavitation, increase the local pressure of the refrigerant, and effectively suppress the bursting of bubbles in the two-phase flow. The optimization was compared and analyzed. Improved refrigerant flow state, partial pressure, turbulent kinetic energy and gas phase volume fraction. Based on various factors, it was found that the flow noise of the improved refrigerant was reduced by 3.16 dB. It showed that supercavitation caused by aeration could effectively suppress the flow noise of refrigerant, which was of great significance to engineering design to a certain extent.

Key words: Electronic expansion valve, Aerated supercavitation, Noise reduction optimization