Optimizing cooling efficiency and cost of transformer radiators through CFD-driven design

This study presents a techno-economic optimization methodology for enhancing power transformer radiator performance through Computational Fluid Dynamics (CFD) analysis and experimental validation. A multi-parameter optimization framework is developed, integrating radiator placement, height (H), fin spacing (S), and fin count (N) to achieve maximum thermal efficiency at minimal cost. Unlike previous CFD-based studies focusing solely on thermal behavior, this work introduces a Cooling Efficiency Index (CEI) to quantitatively assess cost-effectiveness by coupling performance and economic metrics. CFD simulations were validated experimentally using a 20/28 MVA ONAN transformer, demonstrating <5 % deviation between numerical and measured data. Among seven configurations evaluated, the optimized radiator (1450 mm height, 28 fins, 50 mm fin spacing) achieved a 27.5 % improvement in cooling efficiency, 1.1 °C reduction in outlet oil temperature, and 34 % decrease in cost per kW of cooling compared with the baseline design. Results indicate that shorter radiators with higher fin density yield superior heat dissipation and economic performance. The proposed optimization framework establishes a novel CFD-driven cost-performance integration, enabling transformer designers to systematically balance thermal efficiency and manufacturing cost for industrial-scale applications.