Experimental investigation on startup process for oil supply system of a variable speed rotary compressor

The aim of this study is to provide further insight into the flow process during startup for oil supply system of a variable speed rotary compressor. The oil climbing process during startup is usually too short to be captured experimentally. With the help of a high speed camera, a novel experimental test rig has been designed and built to perform the measurements of oil climbing time, which is defined as the amount of time needed for an oil particle to travel from the oil sump to the radial oil feeding holes. The proposed flow visualization methodology is capable of acquiring instantaneous state of oil flow inside the oil pump and also provides qualitative information about the flow features at different operating conditions. Significant design parameters associated with the oil climbing time such as oil viscosity, oil level height as well as the rotational speed have been studied. Experimental results indicate that the oil supply system may even fail when the rotational speed is too low and changes of oil viscosity, oil level height and the rotational speed have a pronounced influence on the oil climbing time. The visualization technique in this study could offer valuable insight to enhance the understanding of startup characteristics for oil supply system of a variable speed rotary compressor. (C) 2020 Elsevier Ltd and IIR. All rights reserved.