Entropy Generation and Performance Assessment of Finned Tubes in Double-Pipe Heat Exchangers

Double-pipe heat exchangers are widely used in thermal systems, and enhancing their performance is critical for energy efficiency. This study examines the impact of fin installation on heat transfer and entropy generation in a counterflow double-pipe heat exchanger using CFD simulation. The inner pipe is made of copper with an inner diameter of , outer diameter of  and 1000 mm in length. The outer pipe is made of PVC with an inner diameter of  and an outer diameter of  sharing the same length as the inner pipe. Numerical simulations were conducted to compare smooth and finned tubes under identical thermal and flow conditions. Entropy generation due to heat transfer and fluid friction was analyzed. The results showed that finned tubes improved heat transfer (Q) watts by up to 22%, particularly at higher hot water temperatures of 70 oC and 0.1 kg/s flow rate. However, this enhancement was accompanied by increased entropy generation up to 40%, indicating higher thermodynamic irreversibility. The study highlights the trade-off between thermal performance and entropy generation, providing valuable insight for optimizing heat exchanger design. The finned tube also showed good enhancement of Nusselt number by 46% and effectiveness by 20% compared to the smooth tube.