Data-driven geometric optimization of helical tube heat exchangers for enhanced heat transfer with acceptable pressure drop

Efficient heat exchangers are essential in modern energy systems, where the demand for compact, reliable, and cost-effective thermal devices continues to grow. Conventional straight-tube exchangers often suffer from fouling, limited heat transfer rates, and high maintenance requirements, highlighting the need for alternative geometries that deliver superior performance without excessive pressure losses. Although helical tube configurations show promise, systematic optimization of their geometric parameters remains underexplored, particularly in balancing enhanced heat transfer with acceptable hydraulic penalties. This study addresses that gap by employing a data-driven approach to optimize helical tube heat exchangers using Response Surface Methodology (RSM). Within the turbulent flow regime (Reynolds numbers 3000–10,000), results reveal that the helical configuration elevates the Nusselt number by 3.7–3.9 times compared to straight tubes. For a working fluid entering at 20 °C and exposed to a 620 °C surface, the outlet temperature increases by over 80% in helical tubes, versus 45% in straight tubes. Geometric parameters—including loop number and helix pitch (26–36 cm)—are shown to be decisive in maximizing performance. RSM analysis demonstrates strong model reliability, with R² values of 0.796 for temperature increase and 0.999 for pressure loss. The optimum configuration is identified as a single-loop helix with a pitch of 30.83 cm and a radius of 60 cm. Beyond technical performance, the findings carry practical implications for energy policy and architectural applications. By enabling higher thermal efficiency with reduced maintenance, helical exchangers can contribute to energy-saving strategies, carbon reduction, and sustainable building services such as HVAC and district heating.