Thermal-hydraulic performance of fin-and-oval tube compact heat exchangers with innovative design of corrugated fin patterns

摘要

The flow field inside the heat exchangers is associated with maximum heat transfer, minimum pressure drop and smallest pumping power. During the recent decades, the developments in the application of longitudinal vortex generators as an effective technique and important research topic have increased the heat transfer enhancement in the design of compact heat exchangers. The main motivation of this research is to study thermal-hydraulic performance characteristics in a tube bank compact heat exchanger with introducing new design of fins and tube by using computational fluid dynamics approach. One-corrugated and three-corrugated fins with oval tubes are innovative design of the FTCHE (fin-and-tube compact heat exchanger) that promises a large leap in the development of minimized FTCHEs with increased thermal efficiency. The major advantage of such design is its ability to produce substantially increased thermal efficiency and performance criteria of FTCHE. The investigation of thermal-hydraulic performance criteria is conducted for Reynolds number in the range of 200-900. This study shows that the flow distinction between plain and corrugated fins has a profound influence on the thermal-hydrodynamic performance. The results reveal that the corrugated fins can considerably advance the thermal efficiency of the FTCHE with a moderate pressure loss penalty. The computational results indicate that the average Nusselt number for the FTCHE with corrugated fin can be increased up to 20.0% over the baseline case and the corresponding pressure difference decreased up to 19.0%. In addition, the results show that the average value of performance in one-corrugated and three-corrugated fins and oval tube compact heat exchangers up to 5% and 15% over the baseline case, respectively. The newly designed fin with oval tube shows potential improvement of heat transfer performance and moderate pressure loss in the FTCHE compared with the baseline case.