Investigation on the Effect of Number and Diameter of Nozzles and Inlet Pressure on Performance of a Dual-Circuit Vortex Tube System

This study examines the effect of nozzle count, nozzle diameter, and inlet pressure on the cooling and heating efficiency of double-circuit vortex tubes (DCVTs). Vortex tubes, simple devices without moving parts, are widely used but face challenges in optimizing cooling and heating efficiency. To address this issue, 15 different configurations with nozzle counts ranging from 2 to 5 and diameters of 1.5, 2, and 2.5 mm were tested under inlet pressures of 8, 9, and 10 bar, while maintaining the secondary circuit pressure at 1.5 bar. Additionally, three-dimensional numerical simulations using the k-ε turbulence model were performed to validate the experimental results. The findings revealed that increasing the nozzle count and diameter leads to a reduction in cooling and heating efficiency due to greater energy dissipation. The optimal performance was achieved with two nozzles of 1.5 mm diameter at an inlet pressure of 9 bar, resulting in a 2.41% improvement in cooling efficiency and an 3.10% increase in heating efficiency and a 18.39% improvement in cooling performance coefficient compared to other configurations. Conversely, increasing the inlet pressure to 10 bar caused a 1.38% decrease in cooling efficiency and a 2.58% reduction in heating efficiency and a 8.17% reduction in cooling performance coefficient. This study shows that optimal design enhances energy efficiency and reduces consumption in precise temperature control applications.