管壳式换热器传热效率影响因素及数值模拟分析  

The Numerical Simulation Analysis on Heat Transfer Efficiency Influence Factors of Shell and Tube Heat Exchanger

作　　者：王庆锋[1] 庞鑫[1] 赵双[1] 

机构地区：[1]北京化工大学机电工程学院

出　　处：《石油机械》2015年第10期102-107,共6页China Petroleum Machinery

基　　金：国家973计划项目"高端压缩机组高效可靠及智能化基础研究"(2012CB026000)

摘　　要：多数管壳式换热器基于传统的经验设计方法,换热器质量大且能耗高。鉴于此,采用Fluent仿真模拟的方法,研究了换热管类型、折流板间距、折流板切率变化与换热器对流传热系数的关系,并用HTFS工程软件进行了模型验证。研究结果表明,采用特型管(如波节管和波纹管等)代替光管,可以增强管内流体扰动,提高湍流程度,增大管程对流传热系数,但同时也增大了压降;折流板间距越大,壳程对流传热系数越小,压降也越小,当折流板间距为330 mm时,换热器最高效,此时换热器在较小的压降下可以获得较大的对流传热系数;折流板切率越大,压降越小,当管束错流流速与折流窗口流速相等时,壳程对流传热系数最大,折流板切率35%为最优值,换热器效率最高。最后提出了管壳式换热器优化设计方法,将优化设计的换热器用于某化肥厂氮氢气压缩机级间冷却,同等热负荷条件下换热面积减小了21.37%。研究结果为换热器的结构参数优化提供了依据。Most of shell and tube heat exchanger design based on traditional experiences have the issues of high weight and high energy consumption?The effects of heat transfer tube types, baffle spacing, and baffle plate cut rate on the heat exchanger convective heat transfer coefficient have been studied by suing fluent simulation method?The model is validated by HTFS engineering software?The results showed that the alternative special?shaped tube for the smooth tube, like the corrugated tube and bellows, could enhance fluid disturbances and the turbu?lence level, increase the tube convective heat transfer coefficient, but also increases the pressure drop?Increase the baffle plate spacing will decrease the shell side convective heat transfer coefficient and the pressure drop?The heat exchanger is the most efficient when the baffle plate spacing is 330 mm?Meanwhile, the heat exchanger could get a larger convective heat transfer coefficient with smaller pressure drop under this condition?Increased baffle plate cut rate would lead to decreased pressure drop?When the tube cluster cross?flow velocity is equal to the flow rate at the baffle window, the maximum shell side convective heat transfer coefficient is obtained?The maximum heat effi?ciency would be obtained with optimal baffle plate cut rate of 35%?Shell and tube heat exchanger design optimiza?tion method has been proposed?The application of optimized heat exchanger on hydrogen compressor stage cooling in a nitrogen fertilizer plant shows that the heat transfer area is reduced 21?37% under the same thermal load.

关 键 词：管壳式换热器 特型管 折流板间距 折流板切率 对流传热系数 数值模拟 

分 类 号：TE965[石油与天然气工程—石油机械设备]