文献类型：期刊文献

英文题名：Analysis of stream flow and its impact on thermal performance in shell-side of heat exchangers based on flow dead zone

作者：Wang, Yongqing[1,2];Liu, Keli[1,2];Chen, Weijie[2,3];Chen, Jiangshuai[1,2];Wang, Ke[2,3];Zhou, Guoyan[4]

机构：[1]Zhengzhou Univ, Sch Mech & Power Engn, Zhengzhou 450001, Peoples R China;[2]Zhengzhou Univ, Key Lab Proc Heat Transfer & Energy Saving Henan P, Zhengzhou 450002, Peoples R China;[3]Zhengzhou Univ, Sch Mech & Safety Engn, Zhengzhou 450001, Peoples R China;[4]East China Univ Sci & Technol, Key Lab Pressure Syst & Safety MOE, Shanghai 200237, Peoples R China

年份：2024

卷号：249

外文期刊名：APPLIED THERMAL ENGINEERING

收录：;EI(收录号：20242116117232);WOS:【SCI-EXPANDED(收录号:WOS:001290885300001)】；

基金：This work was financially supported by the National Natural Science Foundation of China (Grant No.52075173) .

语种：英文

外文关键词：Shell-and-tube heat exchanger; Stream flow; Bypass leakage; Flow dead zone

摘要：The performance of shell-and-tube heat exchanger (STHE) is primarily determined by different flow paths on the shell-side. The flow path and its impact on the shell-side flow in segmental baffle shell-and-tube heat exchanger with clearance (SC-STHE) is investigated qualitatively and quantitatively, by adopting stream classification and dead zone analysis method. By utilizing Residence Time Distribution (RTD) curves, the influence of different streams on fluid flow and heat transfer is discussed to reveal the intricate interconnections within the shell-side of SC-STHE. Then the cases with baffle-tube clearance (0.2-1.0 mm) and baffle-shell clearance (1.0-5.0 mm) ranges are studied. The study identifies that optimal comprehensive performance is achieved with a baffle-tube clearance of 0.6 mm, resulting in a 3.5 % improvement compared to a clearance of 0.2 mm. An increase of baffle- shell clearance results in a reduction in comprehensive performance by 8.23-19.54 %. The interactions among stream flows and potential mechanisms are discussed by analyzing the influence of each flow path on the flow dead zone volume. It is revealed that the presence of baffle-tube and baffle-shell clearances reduces the volume fraction of flow dead zones compared to structures without clearances. A-stream and E-stream are identified as pivotal, mutually influencing B-stream and C-stream while maintaining relative independence. The result indicates that an increase in baffle-tube clearance results in a 7.60 % expansion of the volume of the dead zone within the B-stream, while in the C-stream, it decreases by 2.58 %. Conversely, an increase in baffle-shell clearance reduces the volume of the dead zone in the B-stream by 5.04 % but increases it in the C-stream by 31.95 %. The flow dead zones are mainly distributed in the B-stream and C-stream regions, and the diversion effect of leakage flows improves the fluid stagnation but also leads to a decrease in turbulence intensity and flow velocity. This study reveals the complex interaction mechanisms among the stream flows, facilitating further analysis and optimization in STHE design.