Performance Evaluation of Heat Transfer Enhancement in Plate-fin Heat Exchangers with Offset Strip Fins

Generally, the Offset Strip Fin (OSF) in a plate-fin heat exchanger provides a greater heat transfer coefficient than plain plate-fin, but it also leads to an increase in flow friction. A new parameter, called relative entropy generation distribution factor, Ψ*, is proposed to evaluate the thermodynamic advantages of OSFs. This parameter presents a ratio of relative changes of entropy generation. The relative effects of the geometrical parameters α, γ and δ are discussed. The results show that there exist the optimum values of α and γ at a certain flow condition, which obviously maximize the degree of the heat transfer enhancement of OSFs.