Study Of Performance On Heat Transfer And Flow Field In Heat Exchanger With Helical Baffles And Corrugated Tubes

In this paper, a research of heat transfer and flow field characteristics for composite enhanced heat exchanger with helical baffle and corrugated tubes is carried out by numerical simulation and experiment. The results show that, for single helical baffle configuration, with the increase of overlapped size, convective heat transfer coefficient in shell side increases at first and then decreases. Heat transfer performance is improved by4.2%to6.5%while the overlap size is0.2compared to the continuous one. The widen configuration can reduce the triangle leakage flow and enhance heat transfer performance, but the resistance increase obviously. The smaller helical angle is, the better of the heat transfer performance, but the shell side friction increases.40°helical angle,180°phase difference,0.5axial spacing for double helical baffle structure shows the optimal comprehensive performance. The smaller center tube size is, the better of the comprehensive performance. Bypass dampers and loops can effectively enhance the near wall turbulence. The overlap structure for double helix can improve convective heat transfer coefficient, and the flow field is better distributed. The heat transfer mechanism of a corrugated tube is studied based on the field synergy theory. The structure improvement of a raw oil-circulating oil heat exchanger for coking fractionating column based on research results shows better performance.