Numerical Analysis Of Heat Transfer In Smooth Spiral Channel Flow

As an energy utilization and recovery device widely used in various industries in the new era,spiral plate heat exchangers have received continuous attention and attention from many experts and scholars at home and abroad,but the research on spiral plate heat exchangers mainly focuses on the optimization of structural parameters of spiral plate heat exchangers and the study of the shape of distance columns,and less attention is paid to smooth spiral channels.In this paper,the smooth spiral channel,a typical channel of spiral plate heat exchanger,is simulated by programming in Fortran language,focusing on the influence of Gorlter vortex on the flow heat transfer in the smooth spiral channel caused by its structural particularity.By studying the Reynolds number Re between 200 and 1600,Influence of three different structural parameters of smooth spiral channel width W,channel height H and channel curvature radius R on velocity field,temperature field,average Nussel number Nu_m,local Nussel number Nu_local,resistance coefficient f,absolute eddy flux J_ABS,dimensionless average secondary flow intensity Se_mnumber and comprehensive evaluation factor JF of smooth spiral channel The influence of structural parameters of smooth spiral channel on its flow characteristics and heat transfer characteristics was investigated.Through numerical simulation,the following conclusions are drawn:For a given width,height and radius of curvature,with the increase of Reynolds number Re,the average Nussel number Nu_mwill increase correspondingly,while the resistance coefficient f will show a downward trend.In addition,the average secondary flow strength Se will also increase.The changes of width and height have little influence on the mean Nussel number Nu_m,drag coefficient f and the mean secondary flow intensity Se_mnumber,while the curvature radius has a greater influence on the mean secondary flow intensity Se_mnumber.The channel width,height and curvature radius have influence on the comprehensive evaluation factor JF.When the width of the channel increases from 12 mm to 35 mm,the average secondary flow intensity increases.The average secondary flow intensity reaches the maximum when the width of the channel is 35 mm,and then the average secondary flow intensity decreases when the width of the channel continues to increase to 40 mm.When the channel height increases from 40 mm to 80 mm,the increase of the channel height will increase the average secondary flow intensity,which reaches the maximum at 80 mm.When the channel height continues to increase to 120 mm,the average secondary flow intensity decreases.Therefore,when the channel height H=80 mm,the average secondary flow intensity reaches the maximum.When the curvature radius R of the channel increases from 20 mm to 120 mm,the average secondary flow intensity in the channel decreases gradually.The overall trend of changes of the absolute eddy flux J_ABSalong the flow direction of the fluid in the channel is roughly the same,which increases first and then decreases.The difference is that the peak value of the absolute eddy flux varies with different channel widths.With the increase of the channel width,the peak value of the absolute eddy flux also decreases.The increase of the passage height will cause the decrease of the peak value of the absolute vortex flux.For the plane spiral passage with different curvature radius of the passage,the G（?）rlter vortex appears in different positions.The smaller the curvature radius of the passage,the earlier the G（?）rlter vortex appears.