Refrigeration Characteristics of Vortex Tubes Under Various Operating Conditions: Experimental Study

The refrigeration characteristics in a vortex tube are experimentally investigated to promote their application in aerospace engineering. The experiments focus on the effects of the inlet pressure ([Formula: see text] to 0.7 MPa), inlet temperature ([Formula: see text] to 70°C), cold outlet pressure ([Formula: see text] to 0.7 MPa), and the cold mass fraction ([Formula: see text] to 0.9). The experimental results reveal that, maintaining the same cold mass fraction, elevating the inlet pressure below 0.4 MPa leads to a substantial increase in temperature reduction and cooling effectiveness. This enhancement becomes less pronounced when the inlet pressure surpasses 0.4 MPa. Raising the inlet temperature can enhance temperature reduction and cooling effectiveness. Increasing the cold outlet pressure tends to decrease the actual temperature drop. Although its influence on temperature efficiency is minimal, significant improvements in adiabatic efficiency and coefficient of performance are observed for cold mass fractions exceeding 0.6. Across all test conditions, there exists a critical cold mass fraction point that optimizes the refrigeration process. An empirical correlation formula was derived from experimental data, and its accuracy was validated through a comparative analysis between the experimental results and the predicted values.