Pressure Pulsation of Discharge Flow in Refrigerating Rotary Compressor

Abstract

In this study pressure pulsation in a discharge flow system of a rotary compressor for air conditioning use is analyzed theoretically by transfer matrix method by using a model of piping system which consists of three volumes (a valve chamber, lower and upper chambers in a hermetic casing) and three pipes (a cylinder path, a motor path and a discharge pipe). Theoretical calculation indicates that intermittent discharge flow from a cylinder causes certain pulsations in both lower and upper chambers in the casing, and the calculated results are in good correlation with measured ones in phase and amplitude of the pulsation. It is also confirmed theoretically and experimentally that a pressure differential force acting on a motor rotor due to the pulsations in the lower and upper chambers induces a longitudinal vibration of the rotor.