标题：Performance of continuous helical baffled heat exchanger with varying elliptical tube layouts
作者：Du, Tingting; Chen, Qi; Du, Wenjing; Cheng, Lin
作者机构：[Du, Tingting; Du, Wenjing] Shandong Univ, Sch Energy & Power Engn, Jinan 250061, Shandong, Peoples R China.; [Chen, Qi; Cheng, Lin] Shandong Univ, 更多
通讯作者：Cheng, Lin;Cheng, L
通讯作者地址：[Cheng, L]Shandong Univ, Inst Thermal Sci & Technol, Jinan 250061, Shandong, Peoples R China.
来源：INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
关键词：Helical flow; Heat exchanger; Elliptical tube layout; Heat transfer;; Comprehensive performance
摘要：Helical flow is an optimal flow pattern in shell-and-tube heat exchangers, but the poor heat transfer performance has been always the bottleneck. Aiming to improve heat transfer without tremendous increase of pressure drop, the optimized continuous helical baffled heat exchangers with varying elliptical tube layouts are proposed and investigated by numerical simulation. It concludes that the tube-array angle influences the characteristics of flow and heat transfer significantly. The optimized tube layout can improve heat transfer in fully-developed section and decrease vortices at the back of tubes to some extent. The mean convective heat transfer coefficient and the pressure drop are respectively 2.10-2.33 times and 1.82-4.46 times higher than that of the original heat exchanger with concentric annular layout, and the comprehensive performance proves to be improved by about 50%. The results show that the optimized elliptical tube layouts with varying tube-array angles can realize the initial objective, especially when the Re number of flow is relatively small. This research is beneficial for further optimization on helical baffled heat exchangers to improve heat transfer as well as comprehensive performance. (C) 2018 Published by Elsevier Ltd.