Experimental evaluation of vortex tube and its application in a novel trigenerative compressed air energy storage system

• Research idea of dividing the vortex tube flow field into six regions was proposed. • An expression for the axial velocity profile was developed. • The mathematical model for the flow field based on the axial velocity was established. • The flow fields under four different μ c were computed and analyzed. • The reliability of the calculation model was verified through experimental data. The flow pattern and energy transfer process in the vortex tube are extremely complex, resulting in the difficulty of the direct calculation and prediction of the flow structure and temperature separation performance of a vortex tube. In view of this, research idea of dividing the vortex tube flow field into six regions was proposed, corresponding simplifications were made in different regions according to the flow features, and fluid parameters were coupled at the boundaries. An equation for the axial velocity component in the hot tube region was developed based on the characteristic that the axial velocity profiles under different conditions present similar patterns, the calculation method of reverse flow boundary which separates the working fluid into hot and cold fluids was described, and a set of relatively simple calculation methods for the internal flow field of vortex tubes was established based on the partition model. Three-dimensional velocity distributions inside the vortex tube under different working conditions were computed and analyzed. Further, the model was evaluated and validated through experimental data. The results showed good agreements of calculated data and experimental velocity fields. This work proposed a convenient calculation method for the estimation of the flow behavior inside a vortex tube and provide reliable predictions. 

Simple model for flow field division and flow structure calculation in a vortex tube

A vortex tube is a device, which uses pressurised inlet gas to split into hot and cold separate streams. This phenomenon is referred to as energy separation. The literature behind the energy separa...

Review of vortex tube: a sustainable and energy separation device for multi-purpose applications

CFD simulation and thermodynamic analysis of energy separation in vortex tube using different inert gases at different inlet pressures and cold mass fractions

Present work is intended to discuss the computational analysis of vortex tube (VT) with inlet pressure (3–5.5 bar), the number of inlet nozzles as 3, 4, 5, 6 and 7, different turbulence models, and varying cold exit diameter as 4, 5, 6 and 7 mm of VT taking air as working fluid on the temperature separation performance of VT. The simulation is performed with ANSYS17.1 FLUENT software using different turbulence models and validated with the experimental result. It is concluded that the standard k-ε turbulent model shows a promising result than other turbulent models used for the study. The study has been performed on the VT for the same to obtain the optimum cold exit diameter (dc), i.e. 5 mm, best-suited nozzle for VT, and the optimum inlet pressure is 5.5 bar. The results of optimum cold exit diameter show an increment of 10.65% in cooling performance of VT than the previous experimental study. The cold temperature gradient for dc = 5mm is 42.02 K which is the highest among all the cold exit diameters considered. 

Computational study of temperature separation for a three-dimensional vortex tube with cold exit diameter and nozzle number variation

In order to get the internal parameters of a vortex tube, a large-scale vortex tube was designed and an experimental device was built. A five-hole probe and thermocouples were used to obtain the three-dimensional velocities, the static pressure, static temperature and total temperature distributions inside the vortex tube. Four different cold mass fraction conditions (0.2, 0.4, 0.6 and 0.8) were chosen and the impacts on the internal parameters of the vortex tube were discussed. Different from the traditional view, the tangential velocity was considered to be the steady Burgers vortex form. A reverse flow boundary was found, and the location of which was changed at different operation conditions and axial positions. Further, it was found that the lowest static temperature existed near the nozzle outlet, and a new static temperature difference distribution law was firstly proposed experimentally.

Lichen Fu

Papers

Experimental study of the impacts of cold mass fraction on internal parameters of a vortex tube

Investigation on the influence of AC electric filed and KCl on the structure and gel properties of Konjac glucomannan.

Preparation and Characterization of Water-Insoluble Konjac Glucomannan-Calcium Chloride Electrogel Film