Analyzing The Influence of Diameter and Winding on Heat Transfer Efficiency in Spiral Tube Heat Exchangers: A CAD-Integrated CFD Study Using Solidworks Flow Simulation

Abstract

Spiral tube heat exchangers (STHE) are coiled metal devices with two fluid channels around a central core, enabling counterflow or parallel flow of gases, liquids, or both. Compared to traditional straight-tube heat exchangers, STHEs offer a larger heat transfer surface area. This study used Computational Fluid Dynamics (CFD) simulation integrated with Computer Aided Design (CAD) to investigate STHE’s heat transfer performance. The STHE dimensions, a 12-mm copper tube, and a 10-inch PVC shell were adopted from a previous study. Cold and hot water at 20°C and 70°C flowed in parallel at specific flow rates. The objective was to explore the impact of STHE dimensions on heat transfer efficiency and performance. The parameters varied were the internal diameter of the copper tube and the number of spiral coil windings. Results revealed that changing the spiral heat exchanger’s diameter affected the heat transfer rate and coefficient. Larger diameters reduced efficiency due to lower flow velocities and convective heat transfer coefficients. The number of windings significantly affected heat transfer performance, with winding 5 demonstrating the highest rate and winding 7 showing the highest coefficient. CFD analysis reliability was validated by convergence with analytical solutions for heat transfer simulations with varying diameters and windings.