Enhancing energy efficiency of plate-tube and fin heat exchangers through thermo-hydraulic optimization using advanced nanofluids for low-carbon heating systems

Abstract

This study investigates the thermo-hydraulic optimization of plate-tube and fin heat exchangers using advanced nanofluids to enhance energy efficiency and support low-carbon heating systems. A multi-objective genetic algorithm (MOGA) was employed to optimize the heat exchanger design by minimizing both volume and pumping power while maintaining thermal performance. The results demonstrate significant improvements in energy efficiency and compactness through the use of nanofluids, particularly CuO-based formulations. Compared to the baseline design, Solution A achieved a 21% reduction in heat exchanger volume (from 0.19 to 0.15 m³) and a 15.5% decrease in pumping power (from 116 to 98 W). These enhancements were attributed to optimized geometric parameters, including shorter tube lengths (0.7 m vs 0.8 m), smaller tube diameters (13 mm vs 15 mm), thinner fins (0.25 mm vs 0.3 mm), and the implementation of CuO nanoparticles with a higher volume fraction (2% vs 1.5%). Sensitivity analyses revealed that increasing nanoparticle volume fractions, tube diameters, and fin densities improved thermal efficiency but required careful consideration of trade-offs involving pumping power and heat exchanger size. Additionally, CuO-based nanofluids outperformed Al₂O₃-based counterparts in terms of thermal efficiency (0.83 vs 0.81), pumping power (112 W vs 116 W), and heat exchanger volume (0.18 m³ vs 0.19 m³). Overall, this research highlights the potential of nanofluid-enhanced heat exchangers to significantly augment energy efficiency and reduce the carbon footprint of HVAC&R systems, providing valuable insights for designing environmentally sustainable thermal systems.