三叶孔板换热器壳程流体流动和传热特性数值研究.docVIP

三叶孔板换热器壳程 本文档由【中文word文档库】提供，转载分发敬请保留信息； 中文word文档库免费提供海量教育、范文、学习、政策、报告和经济类word文档。 董其伍，杜庆飞，刘敏珊（郑州大学，郑州 450002）摘要对三叶孔板换热器壳程进行了数值模拟研究，对流传热系数三叶孔板换热器内，换热管壁面对流传热系数减小 关键词 三叶孔支撑板流场温度场数值模拟characteristics in shell-side of heat exchanger with trefoil-tube-support plates Qiwu Dong, Qingfei Du, Minshan Liu, Yongqing Wang (Key Laboratory of Process Heat Transfer and Energy Saving of Henan Province, Zhengzhou University, Zhengzhou, 450002, China) Abstract The flow and heat transfer characteristics in the shell-side of the heat exchanger with trefoil-tube-support plates were numerical studied by using FLUENT, The “Periodic Whole Cross-section computation Model” was built and the Strengthening mechanism of heat transfer was studied, the relationship between surface heat transfer coefficients of tubes located in different position and the distance from tubes to the axis of the shell were also analyzed. It turned out that, the heat transfer is strengthened by the jet flow appeared when fluid go through the trefoil holes and the secondary flow emerged behind the support plates; and the surface heat transfer coefficients of tubes in the shell-side of the heat exchanger decrease with the he distance from tubes to the axis of the shell increasing. Key words trefoil-tube-support plates; flow field; temperature field; numerical simulation 收稿日期：2012-01-05 基金项目：作者简介：董其伍（1941），男，浙江鄞县人，教授，博士生导师。是核电，[1]。但是，在折流板管壳式换热器中，壳程流体为横向、不均匀冲刷管束，易导致换热管产生诱导振动[2]，不仅缩短了换热器使用寿命，降低了核级换热设备的安全性[4]，且在一定程度上增加了维护费用。三叶孔板换热器是核电站常用的新型换热设备之一，与传统的弓形折流板换热器相比，将壳程流体由横掠管束改为纵掠管束，能流动死区并管诱导振动[5]减小了换热器失效的概率[6]三叶孔板换热器壳程流体流动和传热的因素很多但是目前关于该结构壳程流体流动和传热的研究却。本文对三叶孔板换热器中进行了数值模拟研究，，为换热器内流体流动和传热况的改善依据 1 物理模型及计算方法 1.1 物理模型 流体流动和传热周期性充分发展段流动传热特性，反映换热器的整体性能[7][8]。三叶孔板换热器属于纵流壳程换热器的一种，因此，对三叶孔板换热器的结构进行一定的简化后，可建立周期性全截面计算模型由三叶孔支撑板管孔排列结构对称性，建模时取，如图2所示。其主要几何尺寸列于表1 图1 支撑板管孔排列示意图Fig.1 Schematic plot of arrangement of trefoil holes in the support plate 图2 三叶孔板换热器周期性全截面计算模型Fig.2 Periodic whole cross-section computation model of heat excha