Optimized tube bank configurations: A multi-objective approach to entropy and volume minimization

The optimization of tube bank configurations is crucial for enhancing the thermal performance and compactness of heat exchanger designs, especially in applications where volume and energy efficiency are critical. Unlike previous studies that typically focused on either thermal performance or geometric compactness alone, this study introduces a multi-objective optimization framework that simultaneously minimizes entropy generation and volume. The optimization is conducted for tube banks with circular, elliptical, and cam/wing/flat-shaped crosssections, in both in-line and staggered arrangements. The optimization process involves varying the dimensionless transversal and longitudinal pitches, as well as shape-specific geometric parameters for non-circular tubes. All configurations are evaluated under uniform conditions, including constant average inlet velocity, identical heat transfer surface area. Design constraints include a minimum heat transfer rate of 200 W and maximum allowable pitches of 50 mm in both directions. The results demonstrate that tube shape and arrangement significantly influence thermohydraulic performance. The staggered wing-shaped tube bank yields the lowest entropy generation, achieving a 15.2% reduction relative to the circular baseline. Conversely, the inline flat tube bank provides the highest compactness, with an 18.7% reduction in total volume compared to its circular counterpart under identical thermal and flow conditions. This study offers a comprehensive multiobjective optimization framework, guiding the design of high-performance, volume-constrained heat exchangers by simultaneously addressing entropy minimization and geometric compactness.