Experimental investigation on the cycle nature of pressure time history in the compression chamber of a domestic refrigeration compressor

The cyclic nature of the pressure time history in the compression chamber of compressor may produce equivalent pressure pulsation effects at the pumping frequency and its higher harmonics. Due to the flow restrictions that appear at the suction and discharge valves, pressure time history can not stay on true sinusoidal shape, and may produce a significant number of higher harmonics. The pressure fluctuations, caused by fluttering discharge valves during discharge process, might provide oscillations in nature. These excitations of higher frequency harmonics when transmitted to the shell on variety of paths exist in the shell, cause further coincidence problems. This study summarizes how time frequency analysis techniques could be an efficient tool for the further analysis of vibration and acoustic based diagnostic signals. The time frequency analysis may provide the information that cannot be available from time or frequency domain analyses alone