Using an optimized venturi instead of cold orifice in Vortex tube: Thermodynamic and experimental approach

Abstract

A vortex tube (VT) is a separator system (for energy, fluids and particles) that is often used in the industries to provide cooling and heating services. Its exceptional features including; “simplicity of the structure” and “high temperature difference between the outlets” have made it widely used in the thermal applications. The cold outlet structure located in the vortex chamber significantly can change the thermodynamic performance of the VT due to its position at the beginning of the energy separation process. This experimental research focuses on increasing the thermal efficiency of the VT by designing an optimized venturi instead of the cold orifice. The effects of the venturi structural parameters including the middle part diameter (Ø = 12, 13 and 14 mm), the convergence angle (β = 0, 1, 2, 3 and 4°) and the divergence angle (θ = 0, 1, 2, 3 and 4°) are considered on the VT efficiency criteria like; the temperature separations (ΔTc,h,t), the isentropic efficiency (η), the power separations (Q̇c,h,t) and the coefficient of performance (COP). The results show that there are optimum values (Ø = 13 mm, β = 3° and θ = 1°) for obtaining the maximum thermal improvements: ΔTc: 61.68%, ΔTh: 58.74%, ΔTt: 53.39%, η: 61.70%, Q̇c: 47.16%, Q̇h: 61.71%, Q̇t: 55.44%, COPCM: 50% and COPHP: 65%.