连续螺旋折流板蒸发器壳侧流动换热数值模拟研究

NUMERICAL STUDIES ON SHELL-SIDE PERFORMANCE OF SHELL-AND-TUBE EVAPORATORS WITH CONTINUOUS HELICAL BAFFLES

本文对相同几何尺寸的连续螺旋折流板蒸发器与传统弓形折流板蒸发器进行对比性的数值模拟研究,结果表明:在相同壳侧体积流量和折流板数条件下,连续螺旋折流板蒸发器的传热因子和摩擦因子约是弓形折流板的1/3和1/4;当以换热因子和摩擦因子比值评价蒸发器综合性能时,连续螺旋折流板蒸发器比弓形折流板蒸发器提高57%;当最小流通截面流速比大于2.4,螺旋折流板蒸发器比弓形折流板蒸发器有更好的壳侧换热性能。

In the present study,the shell-side flow and heat transfer characteristics of shell-and-tube dry expansion evaporator with continuous helical baffles were studied by Computation Fluid Dynamic （CFD） method.The results indicated that,for the same volume flow rate,the j factors and f factors of evaporator with continuous helical baffles were only 1/3 and 1/4 of the evaporator with segmental baffles.However,the comprehensive performance j/f factor had 57%increases.If the maximal velocity ratio was higher than 2.4,the continuous helical baffled evaporator can have higher shell-side heat transfer coefficient than the segmental baffled evaporator.