椭圆管内层流结冰的数值研究  

NUMERICAL STUDY ON SOLIDIFICATION OF LAMINAR FLOW IN AN ELLIPTICAL PIPE

作　　者：李岚[1] 马欢[1] 司风琪[1] 祝康平 

机构地区：[1]东南大学能源热转换及过程测控教育部重点实验室能源与环境学院,南京210096 [2]中电神头发电有限责任公司,朔州036800

出　　处：《低温物理学报》2015年第3期200-206,共7页Low Temperature Physical Letters

摘　　要：为预防椭圆管换热器等设备内部结冰甚至堵塞,本文采用流体计算软件fluent建立了三维椭圆管内流动换热模型,研究了一定热边界条件下椭圆管内层流流体的结冰规律.通过对不同工况的模拟分析,得到了流体在管内不同位置的结冰规律以及进口温度、进口Re数、长短轴之比对冰层厚度以及管内换热产生的影响,结果表明:椭圆管截面内,不同径向位置的冰层厚度不同;沿轴向管内冰层厚度逐渐增加,压力损失增大,局部Nu逐渐减小;Re数减小,进口水温降低,都会使管内各处冰层厚度增大,从而增加了管道堵塞的危险.而长短轴比例增大时,长短轴方向冰层变化趋势相反.The aim of this investigation is to study the characteristics of solidification of laminar flow through an elliptical pipe and to avoid the solidification and blockage in the pipe. A three-dimentional model has been completed using the commecial fluid dynamics code, Fluent. The solidification and heat transfer of laminar flow in elliptical en- closure is analysed under different conditions, which shows not only the characteristics of ice layer thickness and heat transfer in different axial location but effects of the inlet Reynolds number, temperature,and the ellipse aspect ratio on them. It turns out that the ice layer thickness varies in different radial directions within a cross-section,and that the ice layer thickness and loss of pressure both grow increasingly along the axis while the local Nusselt number de- creasing. The lower the inlet Reynolds number or temperature is, the thicker the ice layer becomes, which will in- crease the risk of blockage. The thickness at the long axis direction will grow with the increase of ellipse aspect ratio while it turns out contrary at short axis direction.

关 键 词：椭圆 层流 结冰 冰层厚度 努赛尔数 

分 类 号：TK172[动力工程及工程热物理—热能工程]