Characteristics of flow and heat transfer of shell-and-tube heat exchangers with overlapped helical baffles  

作　　者：Tingting DU Wenjing DU 

机构地区：[1]School of Energy and Power Engineering, Shandong University, Jinan 250061, China

出　　处：《Frontiers of Engineering Management》2019年第1期70-77,共8页工程管理前沿（英文版）

摘　　要：The characteristics of flow and heat transfer of shell-and-tube heat exchangers with overlapped helical baffles (STHXsHB) were illustrated through a theoretical analysis and numerical simulation. The ideal helical flow model was constructed to demonstrate parts of the flow characteristics of the STHXsHB, providing theoretical evidence of short-circuit and back flows in a triangular zone. The numerical simulation was adopted to describe the characteristics of helical, leakage, and bypass streams. In a fully developed section, the distribution of velocity and wall heat transfer coefficient has a similar trend, which presents the effect of leakage and bypass streams. The short-circuit flow accelerates the axial velocity of the flow through the triangular zone. Moreover, the back flow enhances the local heat transfer and causes the ascent of flow resistance. This study shows the detailed features of helical flow in STHXsHB, which can inspire a reasonable optimization on the shell-side structure.

关 键 词：HEAT EXCHANGER overlapped HELICAL BAFFLE TRIANGULAR ZONE HELICAL flow 

分 类 号：N[自然科学总论]