Experimental investigations into the influences of inlet pressure and cold air fraction on the refrigerating performance of a vortex tube

Systematic experiments were conducted to investigate the influences of the tangential inlet pressure and the cold air fraction on the refrigerating performance parameters, such as the cooling effect, the specific refrigerating output and the adiabatic efficiency of a vortex tube. Empirical equations are presented based on the experimental data. The results show that, the cooling output and the specific refrigerating output both increase with the increase of the inlet pressure under the conditions of constant cold air fraction, whereas the adiabatic efficiency is almost unaffected. When the inlet pressure is constant, the cooling effect, the specific refrigerating effect and the adiabatic efficiency all gradually increase with the increase of the cold air fraction at an initial stage, reaching their maximum values corresponding to different cold air fractions, and then decrease gradually. For the vortex tube used in these experiments, the given empirical equations provide excellent correlativity with the experimental data.