Experimental Investigation on the Performance and Efficiency Optimization of a Ranque–Hilsch Vortex Tube for Industrial Applications

Abstract

The Ranque–Hilsch vortex tube (RHVT) is a simple, compact, and mechanically elegant device that separates a compressed gas stream into a hot and a cold fraction without any moving parts, refrigerants, or external energy input beyond the compressed air itself. Despite decades of research, the underlying energy separation mechanism is still debated, and the device's relatively low thermodynamic efficiency has limited its widespread industrial adoption. In this study, a counter-flow vortex tube was designed, fabricated from stainless steel and mild steel components, and experimentally tested at five inlet pressures ranging from 6 bar to 9.5 bar. The temperatures at the cold outlet, the hot outlet, and the ambient (normal) condition were recorded with a CIE 305 digital thermometer. Key performance parameters—cold temperature drop (ΔTc), hot temperature rise (ΔTh), coefficient of performance (COP), and isentropic efficiency—were calculated and analyzed. The results show that the maximum temperature difference of 17.1 °C (between hot and cold streams) was achieved at 9 bar, while the greatest cold-side temperature drop of 15.3 °C below ambient was obtained at the same pressure. A comprehensive graphical data analysis is presented, and recommendations for further efficiency improvements are discussed.