基于新型换热评价指标的管壳式换热器折流板结构优化  

Optimization of baffle structure in shell-and-tube heat exchanger based on new heat transfer evaluation index

作　　者：郑平[1] 王嘉迪 陈旭[1] 

机构地区：[1]辽宁石油化工大学石油天然气工程学院,辽宁抚顺113001

出　　处：《江苏大学学报（自然科学版）》2018年第1期64-70,共7页Journal of Jiangsu University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51201009);辽宁省教育厅科学研究一般项目(L2016017);辽宁省自然科学基金资助项目(20170540591)

摘　　要：为了全面准确评价换热器换热效果,并保证换热器的安全稳定运行,采用了新型换热评价指标η,即对流传热系数与压降的三分之一次幂的比值,着重考虑压降影响,对换热器折流板进行CFD结构优化数值模拟.首先确定最佳折流板间距,然后确定最佳折流板缺口高度.计算结果表明,随着折流板间距和缺口高度的增大,流体的流速减小,压降减小,对流传热系数减小,但换热评价指标都是先增大后减小.换热器的换热效果不仅取决于对流传热系数,而且与压降大小密切相关.对于文中长度1 632 mm的管壳式换热器,折流板间距为300 mm,缺口高度为0.375D时,换热效果最佳,这与某炼油厂常减压蒸馏装置实际运行换热器折流板结构相符合.To accurately evaluate the heat transfer effect and ensure the safe and stable operation of heat exchanger,a new heat transfer evaluation index η was proposed,which was equal to the ratio of convection heat transfer coefficient to the one-third power of pressure drop. With special consideration of the effect of pressure drop on heat exchange,the baffle structure was simulated and optimized by CFD software. The optimized baffle spacing was determined,and the optimized baffle cut height was then determined. The results show that with the increasing of baffle spacing and cut height,fluid velocity,pressure drop and convection heat transfer coefficient are decreased,while heat transfer evaluation index is decreased with latter increasing. The heat transfer effect is dependent on convection heat transfer coefficient and pressure drop. For the specific heat exchanger with the length of 1 632 mm,the optimal heat transfer effect was obtained under the conditions with baffle spacing of 350 mm and baffle cut height of 0. 375 D. The simulation results are in good agreement with the results of the baffle structure of heat exchanger in atmospheric-vacuum distillation unit of a refinery.

关 键 词：管壳式换热器 换热评价指标 压降 折流板 CFD模拟 结构优化 

分 类 号：TE965[石油与天然气工程—石油机械设备]