Numerical simulation study on heat transfer enhancement by longitudinal fins attached to the outer surface of horizontal tubes in seawater distiller

Abstract

Tubular distillation desalination is one of the most promising thermal desalination methods. The addition of fins outside the tube can improve the heat transfer performance of the desalination units. This paper focuses on optimizing the design of structural parameters of the fin outside the tube of tubular desalination is optimized by numerical simulation. The results indicate that: The overall heat transfer coefficient is most significantly influenced by fin quantity, followed by fin height, with input temperature having the least impact. The overall heat transfer coefficient initially increases and then decreases with rising fin quantity, peaking at 5–7 fins for optimal performance. Enhancing fin height improves heat transfer, but excessive height induces air vortices between fins, which diminish the enhancement effect. The optimal fin height is determined as 15 mm when paired with 5–7 fins. This study elucidates the heat transfer mechanisms of fin structures under multi-parameter coupling effects, providing theoretical foundations and parameter optimization strategies for the efficient design of desalination units.