The effect of changing internal tube diameter on the performance of uniflow vortex tube

Abstract

In this present work, the optimum design and performance of the uniflowvortex tube used as a cooling and heating device of high efficiency is investigated experimentally. Great attempts to reach minimizing the uniflow vortex tube size with high separation energy are investigated.The experimental investigation was carried out on a vortex tube rig especiallydesigned for the present study covering all tests. Experiments were carried out onthe vortex tube by fixing (L/D) at (20) for five tubes ,four of them are straight withdiameters (30,20,15and 10) and the last is diverge tube with angle(θ=1.72°) andlength(350mm),the cone angle is (θ= 30°),consequently the study of the energyseparation performance of five uniflow vortex tubes wer carried out.The experimental results shows that the pronounced influence of the uniflowvortex tube (D=20mm, L=400mm) on the energy separation performance at conevalve diameter (dc=12mm), i.e the highest temperature of the hot air stream andthe lowest temperature. The cold air stream reaches (47.5Co) at (Y=0.812) &(2.4Co) at (Y=0.313) respectively at the inlet air temperature (Ti=33Co).The results of the uniflow vortex tube shows that increasing the isentropicefficiency & coefficient of performance with increasing inlet air pressure withinthe range (Piabs = 2-6 bar) which reaches ηise= 24% at Y=0.753 & COP=0.14 atthe same Y. Also the result shows that refrigeration capacity & efficiency of theenergy separation increasing with increase inlet air pressure & reaches Qr=1385watt at Y=0.704 & ηe =34% at Y=0.323.