Shell-and-tube heat exchangers with trefoil-hole baffles are new type heat transfer devices and widely used in nuclear power system due to their special advantages, with the fluid flowing longitudinally on the shell side. However, very few related academic literature are available. In order to obtain an understanding of the underlying mechanism of shell-side thermal augmentation, a CFD model including inlet and outlet nozzles is proposed in the present study. Based on the RNG k-ε model, numerical investigations on shell-side fluid flow and heat transfer are conducted by using commercial CFD software FLUENT14.0. The results show that the fluid is fully developed after the first trefoil-hole baffle. The heat transfer coefficient and pressure drop vary periodically along the axial direction. Fluid velocity increases gradually and the jet flow forms in the region near baffles. The secondary flow is also produced on the two sides of baffles when the fluid flows through trefoil-hole baffle. The jet flow and secondary flow can decrease the thickness of boundary layer and then enhance the heat transfer.
Zhou, G. Y., Xiao, J., Zhu, L., Wang, J., & Tu, S. T. (2015). A Numerical Study on the Shell-Side Turbulent Heat Transfer Enhancement of Shell-and-Tube Heat Exchanger with Trefoil-Hole Baffles. In Energy Procedia (Vol. 75, pp. 3174–3179). Elsevier Ltd. https://doi.org/10.1016/j.egypro.2015.07.656