Numerical study on thermal-hydraulic performance and exergy analysis of laminar oil flow in a circular tube with fluid exchanger inserts

摘要

A novel tube insert, fluid exchanger inserts, is proposed and numerically investigated for enhancing convective heat transfer of laminar oil flow in a circular tube. Effects of parameters including diameter ratio and number of inserts on convective heat transfer performance are also investigated. In the present work, servotherm medium oil is selected as the working fluid. It is found that the heat transfer performance is effectively enhanced as the thermal boundary layer is completely destroyed when the fluid passes through the fluid exchanger inserts. The Nusselt number and friction factor of the tube with fluid exchanger inserts are enhanced to 1.63-2.69 and 1.72-7.01 times that of the plain tube, respectively. Thus, the performance evaluation criterion ranges from 1.24 to 1.62. Moreover, exergy analysis is conducted to appraise the thermodynamic performance of the tube with fluid exchanger inserts. It is found that the exergy efficiency of the enhanced tube is improved by 0.3%-1.9% compared to the plain tube.