3D numerical study on shell side heat transfer and flow characteristics of rod-baffle heat exchangers with spirally corrugated tubes

摘要

This article presents a numerical simulation of the shell side flow in rod-baffle heat exchangers with spirally corrugated tubes (RBHXsSCT). Results are compared with those in rod-baffle heat exchanger with plain tubes (RBHX). Simulation is conducted to improve the thermo-hydraulic performance in longitudinal flow heat exchangers and to obtain an understanding of the physical behavior of thermal and fluid flow in the RBHXsSCT with Reynolds number ranging from 6000 to 18,000. Simulation results show that the Nusselt number in RBHXSCT with one-start spirally corrugated tubes can be 1.2 times that in RBHX when the Reynolds number is 18,000. The heat transfer quantities in the RBHXsSCT with one-start, two-start, three-start, and four-start spirally corrugated tubes are 104.6%, 105.4%, 106.7%, and 109.6%, respectively, higher than that in RBHX. The pressure drop in RBHX is 1.21, 1.16, 1.12, and 1.08 times that in RBHXsSCT with one-start, two-start, three-start, and four-start spirally corrugated tubes, respectively. The RBHXSCT with one-start spirally corrugated tubes can achieve an efficiency evaluate coefficient of 1.35. Physical quantity synergy analysis is performed to investigate heat transfer and flow resistance performance. Results verify the synergy regulation among the physical quantities of fluid particle in the flow field of the convective. (C) 2014 Elsevier Masson SAS. All rights reserved.