The R744 vapour compression test rig designed for visualisation of two-phase flow inside ejectors

摘要

Use of advanced experimental technique for the R744 two-phase flow observation inside theejector is required to find a possibility of the ejector efficiency improvement. Hence, the CO2refrigeration test facility dedicated to visualise the flow behaviour inside the ejector is presented.The test rig is designed and installed for operation analysis of freezers through air conditioningapplications. The R744 vapour compression rack is equipped with the transparent ejector designedfor the flow visualisation investigation. The ejector section was prepared in order to perform flowvelocity and mixing process analyses using the Particle Image Velocimetry system and high-speedcamera. The designed system let to investigate various shapes of the ejector cross-sections due tomodular construction as well as another expansion devices, e.g., a capillary tube. The performanceand main characteristics of the test rig was analysed on the basis of the coefficient of performanceand the first-law analysis with and without the ejector.