Thermo-hydrodynamic and exergy optimization of a photovoltaic thermal (PV/T) air collector using NSGA-II

This study investigates the hydrodynamic, thermal, and exergy performances of a photovoltaic-thermal (PV/T) air collector by examining four geometric and hydrodynamic variables. The Non-Dominated Sorting Genetic Algorithm (NSGA-II) optimization method, combined with the finite volume method, is employed to identify and analyze the optimal configuration in comparison to the initial design. Unlike prior studies that optimize isolated design parameters, this work presents a comprehensive multi-objective optimization strategy, concurrently minimizing pumping power while maximizing first- and second-law efficiencies. Three distinct single-objective optimizations were also conducted to minimize pumping power, maximize first-law (thermal) efficiency, and enhance second-law (exergy) efficiency, exploring various geometric and operational parameters. Analysis of variance (ANOVA) results reveal that airflow rate and air channel height significantly influence pumping power, while the number of fins and airflow rate have the most substantial impact on thermal and exergy efficiencies. The single-objective optimization results indicate a 28 % enhancement in thermal efficiency and an 18 % improvement in exergy efficiency, while hydrodynamic performance sees a significant 98 % reduction. In comparison, the multi-objective optimized configuration—featuring a channel height of 0.088 m, a width of 0.159 m, six fin rows, and an airflow rate of 0.006 kg/s—demonstrates a 30 % decrease in pumping power. Additionally, it improves first- and second-law efficiencies by 25 % and 11 %, respectively. Furthermore, the average panel surface temperature decreases by 7 °C in this optimized scenario. By systematically optimizing air channel parameters and integrating exergy-based analysis, this study establishes a novel performance enhancement framework for PV/T systems, providing valuable insights for next-generation solar energy applications.