Exergy destruction minimization: A principle to convective heat transfer enhancement. (July 2018)

• Record Type: Journal Article
• Authors: Liu, W.; Liu, P.; Wang, J.B.; Zheng, N.B.; Liu, Z.C.
• Is Part Of: International journal of heat and mass transfer. Volume 122(2018)
• Page Start: 11
• Page End: 21
• Publication Date: 2018-07
• Subjects: Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2018.01.048
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: A principle of convective heat transfer enhancement was proposed based on exergy destruction minimization. An optimal field of longitudinal whirling flow with vortexes was obtained by convective heat transfer minimization. An insert of center-connected awl-shaped slices was studied by numerical simulation and a PIV experiment. Abstract: Enhancing convective heat transfer, by strengthening fluid disturbance, is an effective way of raising the utilization efficiency of an energy system. In this study, in order to introduce a principle for convective heat transfer enhancement, a physical quantity called available potential was defined, and an equation of available potential was derived to obtain an expression of local exergy destruction caused by heat transfer and fluid flow. Then, a mathematical model of convective heat transfer optimization was established by adopting adequate objective function and constraint condition based on exergy destruction minimization, and an optimal flow field of longitudinal whirling flow with multi-vortexes was obtained by solving the optimization controlling equations. Finally, through numerical simulation and a PIV experiment, a heat transfer unit consisting of center-connected awl-shaped slices was studied to realize longitudinal whirling flow with multi-vortexes in a tube, which indicated an excellent effect of heat transfer enhancement.