Studies on the flow-induced noise at the evaporator of a refrigerating system

Studies were performed here to investigate the behaviour of flow-induced noise at the evaporator section of a refrigerating system located in an anechoic chamber. An x-ray system was used to visualize the refrigerant flow in the pertinent tubes of the system. The flow-induced noise under transient and steady-state operations of the system was studied using acoustic, pressure and temperature measurements. Calculations on the bubble size-resonant frequency and x-ray results agreed with the dominant frequency range obtained through acoustical measurements. One-third octave band analysis was performed for the 200–500 Hz frequency range as this frequency band was where the refrigerant-induced noise was found to be dominant in the system. Factors that influence the transient noise generated by the refrigerant flow were identified.