Experimental investigation of the influence of refrigerant flow on refrigerator noise

In recent years, the overall noise of refrigerators has decreased, and the flow-induced noise remains as the dominant noise source. Refrigerant flow plays an important role in transmitting compressor induced vibrations, and it generates significant noise due to phase changes. The aim of this study is to develop an experimental setup, and perform measurements to study physical mechanisms behind the flow-induced noise and vibrations. A comprehensive literature survey is conducted on noise generation mechanisms in two-phase flows, especially in capillary tubes. Single-phase and two-phase flow regions are studied separately. The pulsating single-phase flow in the compressor discharge line is regulated by the use of designed mufflers. It is found that regulating the flow in the discharge-line has negligible effect on overall noise. Thereby, an experimental set-up is prepared to study the two-phase refrigerant flow-induced noise. To investigate the variation of refrigerant jet noise at the evaporator inlet region, particular charge levels are supplied to the system under specified thermal loads. It is found that the systems sensitivity to charge increases with increasing charge level. In addition, the location of time-dependent temperature fluctuations is shown to be related to the flow-induced noise for various charge levels and thermal loads.