Experimental Study On Performance Of Vortex Tube Based On Energy Separation Effect

The energy separation effect means that the flowing working fluid spontaneously separates into two parts of airflow with different total temperature under special working conditions without external work and heat transfer.This phenomenon exists in many kinds of fluid motion,such as: boundary layer separation,cylindrical turbulence,etc.The vortex tube is a new type of energy separation equipment for cooling and heating based on this energy separation effect.The vortex tube,also known as the Ranque-Hilsch tube,is an easy-to-maintain and portable device that can separate high-temperature and low-temperature low-pressure airflows with only high-pressure gas.Because of the advantages of simple structure,convenient operation and low maintenance cost,the vortex tube is used in many industrial fields.The factors that affect the performance of the vortex tube can be divided into operating parameters and geometric structure parameters.The operating parameters mainly include factors such as the inlet pressure,inlet temperature and type of working medium in the vortex tube.The structural parameters are mainly the influence of geometric parameters,that is,the changes of the various structural dimensions of the vortex tube.The different combinations of these structural parameters together determine the quality of the energy separation effect of the vortex tube.Up to now,many scholars have explored the geometric parameters of some vortex tubes with larger diameters,and also explored the effects of different operating parameters on the performance of vortex tubes.However,the working efficiency of the vortex tube is still not very good,and the energy consumed is relatively large,so it greatly limits its promotion and application.Therefore,this paper designs a small-diameter vortex tube with compact structure,light weight and small volume to meet market demand.In this paper,a small-diameter vortex tube experimental prototype is designed by ourselves,and a vortex tube performance test bench is built to conduct experimentalresearch on the factors affecting the vortex tube performance.The performance influencing factors mainly include the following two aspects,operating parameters(inlet pressure,working medium)and structural parameters(hot end tube length,nozzle flow channel number,cold orifice plate aperture).The effect of energy separation effect of vortex tube is analyzed,and the optimal structure of vortex tube is sought.And the temperature of the wall surface of the hot end tube of the vortex tube is measured,and the air flow in the tube is analyzed.Research on the operating parameters: The experimental results show that within the experimental range,when carbon dioxide is used as the working medium,as the inlet pressure increases,the energy separation effect of the vortex tube appears to increase first and then decrease.And when the inlet pressure is 0.4MPa,the best energy separation effect occurs.Research on the geometric structure parameters: The experimental results show that within the experimental range,when the length of the hot end tube is 125 mm,the vortex tube obtains the best energy separation effect.The shape of the nozzle flow channel is a circular tapered nozzle,and when the number of nozzle flow channels is 6,the vortex tube obtains the best energy separation effect.As the diameter of the cold orifice plate increases,the energy separation effect of the vortex tube tends to increase first and then decrease.And when the diameter of the cold orifice plate is 2.5mm,the vortex tube obtains the best energy separation effect,and the best cooling and heating effects are 29.3℃ and 35.9℃,respectively.