Experimental investigation on heat transfer and flow friction characteristics in three types of plate fin-and-tube heat exchangers

Air side heat transfer and friction characteristics in three nine-row and three twelve-row fin-and-tube heat exchanger cores with varied types of fin configurations are experimentally investigated. The test cores consist of three extended surfaces such as plain fins (PF), slit fins (SF) and fins with longitudinal vortex generator (LVG). It is shown that SF offers higher heat transfer and flow friction than the other two fin surfaces. The heat transfer of LVG is slightly lower than that of SF while the corresponding flow friction is slightly larger than that of PF, and LVG in heat exchanger enables to perform better. The effects of number of tube rows on the same kind of fin surface are ignorable. The heat transfer and friction factor correlations for three fin surfaces are obtained in a wide range of Reynolds numbers for the further research and engineering applications.