周向重叠三分螺旋折流板换热器性能比较  

Performance comparison of circumferential overlap trisection helical baffle heat exchanger

作　　者：董聪[1,2] 陈亚平[1,2] 吴嘉峰[1,2] 操瑞兵[1,2] 

机构地区：[1]东南大学能源与环境学院,南京210096 [2]东南大学能源热转换及其过程测控教育部重点实验室,南京210096

出　　处：《东南大学学报（自然科学版）》2013年第4期793-797,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(50976022;51276035);江苏省科技创新与成果转化专项引导资金资助项目(BY2011155)

摘　　要：对采用正三角形布管且螺距相同的4种螺旋折流板换热器方案,即倾斜角为20°三分周向重叠(20°TCO)、倾斜角为18°四分周向重叠(18°QCO)、倾斜角为18°首尾相连(18°QEE)以及螺旋角为18.4°的连续(18.4°CH)螺旋折流板换热器的流动和传热性能进行数值模拟.给出了子午切面、同心正六边形切面上速度矢量叠加压力或速度云图分布以及60°扇区的9根换热管和4层同心换热管层的局部热流密度分布.结果表明:每个螺旋周期中均存在二次流,非连续螺旋折流板V形缺口处存在"逆向泄漏",但4种方案中20°TCO方案泄漏量最少;20°TCO方案具有最大壳侧传热因子jo、摩擦系数fo和平均综合性能指标(jo/fo);18°QCO方案中的传热因子jo和摩擦系数fo其次;虽然18.4°CH方案摩擦系数fo最低,但其壳侧传热因子jo和平均综合性能指标(jo/fo)均最差.Numerical simulation of flow and heat transfer performances were conducted in respect for four helical baffle heat exchangers w ith identical equilateral triangle tube layout and approximate spiral pitch but different baffle shapes and assembly configurations,i.e.,a trisection circumferential overlap baffle scheme w ith the baffle incline angle of 20°（20°TCO）,a quadrant circumferential overlap baffle scheme w ith the baffle incline angle of 18°（18°QCO）,a quadrant end-to-end baffle scheme w ith the baffle incline angle of 18°（18°QEE）,and a continuous helical baffle scheme w ith the baffle helix angle of 18.4°（18.4°CH）.The velocity-vector superimposed pressure or velocity nephograms meridian slices and the unfolded concentric hexagonal slices and the curves of local average heat fluxes on nine heat transfer tubes w ithin a 60° sector region and on the four concentric heat transfer tube layers w ere presented.The results show that each baffle chamber contains secondary flow and there exists reverse leakage at the V-notch region,but the leakage of 20°TCO scheme is the least of the four schemes.Among the four schemes,the 20°TCO scheme has the highest shell-side heat transfer factor jo,friction coefficient fo and average comprehensive index（jo/ fo）;the 18°QCO scheme has the second highest values of both shell-side heat transfer factor joand friction coefficient fo;although,the 18.4°CH scheme has the lowest shell-side friction coefficient fo,its shell-side heat transfer factor jo and average comprehensive index（jo/ fo） are the lowest.

关 键 词：螺旋折流板换热器 三分折流板 四分折流板 连续折流板 相邻折流板周向重叠 

分 类 号：TK124[动力工程及工程热物理—工程热物理]