Improving the energetical performance of vortex tubes based on a comparison between parallel, Ranque-Hilsch and Double-Circuit vortex tubes using both experimental and CFD approaches

Abstract

The types of vortex tubes (VTs) or separators (professional heating and cooling systems) are usually determined based on the position of cold and hot exit areas. Based on these arrangements, there are three general types of vortex tubes including; Ranque-Hilsch (opposite directions), Parallel (same direction) and Double-Circuit (opposite directions with extra injection). This study tries to present a comprehensive energetical comparison between all the mentioned types of VTs. This research presents an energetical study on the quality of the separation process in all types of VTs based on using a new type of nozzles (as parallel injectors), different diameters (13–17mm) for orifice at the cold place and various main tube lengths in the range of 240–390mm (parallel length for the PVTs and main length for the DCVTs and RHVTs). As the results, there are three different optimum L/D ratios for the three different VT types (L/D=9 for PVT, 10 for RHVT and 11 for DCVT). Also, using the parallel nozzles destroys the separation for RHVT and DCVT, but improves the PVT efficiency. Also, this study presents an accurate CFD model (based on the validation) to analyze the internal flow for all VTs.