Numerical Enhancement Analyses of Refrigerator Vortex Tubes Cooling Performance

摘要

The vortex tube is a special industrial and refrigerator device that uses pressurized air as a working medium. The pressurized air is injected tangentially to the tube forming a swirling motion so that two regions can be exists; one is warm and the other is cold. This process of air separating called energy separation that based on the Ranque-Hilsch effect. Over years many hypotheses were proposed to demonstrate how this energy separation happens. However, the available hypotheses explained a part of the energy separation phenomena, but the nature of energy separation is still not clear completely. Vortex tubes have become needed in cooling applications in welding and cutting machines, natural gas liquefaction and cooling vests, where essential features like compactness, safety, and low equipment cost are required. To study and hence improve the vortex tube cooling performance, a three dimensional simulation of counter-flow vortex tube was computer-generated using Ansys CFD package. To obtain a flow solution in the refrigerator vortex tube, the k-t Turbulence Model is selected. Selection of k-t- turbulence model refers to that it is the greatest well-matched turbulence model with the experimental results. Assessment of validation was attained using a standard vortex tube product simulation and compared to published experimental results. This paper aims to study the impact of some important parameters variation on refrigerating performance. These parameters are injection jets profile, inlet nozzles number, inlet pressure, cold mass fraction (CMF) and divergence angle of the refrigerator vortex tube was studied and modified to give better cooling performance. This study results to enhance the cooling performance of the refrigerator vortical tube by altering the geometry and operating conditions what enhance the resulted temperature separation effect and coefficient of performance.