Reduction of the refrigerant-induced noise from the evaporator-inlet pipe in a refrigerator

The flow pattern of the refrigerant in an evaporator-inlet pipe is a very important factor for determining the type of refrigerant-induced noise because the shape and size of the bubble are different according to the flow pattern in the pipe. In this study, the relations between refrigerant-induced noise and flow patterns are discussed. The flow patterns of the fluid in horizontal and vertical pipes were also estimated using Hewitt, Taitel–Dukler and Oshinowo–Charles maps. The refrigerant-supplying equipment was used to monitor the characteristics of the flow in the experiments. The shape and layout of evaporator-inlet pipe were suggested not to be the intermittent flow pattern. The noise level radiated from the refrigerator could be reduced by about 2–5 dB in the frequency range from 315 Hz to 3.15 kHz.