管壳式换热器管束有限元模拟合理性研究及失稳分析  

Study of finite element simulation rationality and buckling analysis of tube bundle in shell-and-tube heat exchangers

作　　者：朱志颖 于洪杰[1] 朱国栋 钱才富[1] 吴志伟 ZHU Zhiying;YU Hongjie;ZHU Guodong;QIAN Caifu;WU Zhiwei(College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China;China General Machinery Engineering Co.,Ltd.,Beijing 100050,China;Hefei General Machinery Research Institute Co.,Ltd.,Hefei 230031,China)

机构地区：[1]北京化工大学机电工程学院,北京100029 [2]中国通用机械工程有限公司,北京100050 [3]合肥通用机械研究院有限公司,合肥230031

出　　处：《压力容器》2024年第9期39-47,共9页Pressure Vessel Technology

基　　金：中央高校基本科研业务费专项资金项目(ZY2409);新疆维吾尔自治区市场监督管理局科技计划项目(S2023010107)。

摘　　要：针对某DN300 mm、热管长度3 m的浮头式换热器管束失稳的数值模拟问题,首先,不考虑换热管和折流板之间的间隙,采用直接绑定接触将换热管和折流板连接在一起进行非线性失稳分析,结果是由于管束抗失稳,刚度显著增加,在壳程等效轴向压力达到42.606 MPa时,管束在轴向载荷作用下发生塑性失效,没有出现失稳;然后,针对换热管和折流板之间存在间隙而出现非线性接触分析难题,提出间隙等效法,即在间隙中填充软材料,从而改变接触形式,实现非线性失稳分析。同时,还针对该浮头换热器,采用间隙等效法成功进行了在壳程等效压力作用下的非线性稳定性分析,结果发现,由于换热器没有筒体支撑,管束会发生整体失稳,失稳变形呈整体偏斜,此时的等效轴向压力为18.6 MPa,小于换热管和折流板直接绑定的结果。另外,由GB/T 151—2014确定的基于欧拉公式计算的单根管临界失稳压力为89790 N,远大于本算例中整体失稳平均每根管承受的轴向压力,这意味着基于欧拉公式的换热器常规设计可能无法保证不会发生管束整体失稳的情况。For the numerical simulation of the buckling of floating head heat exchanger tube bundle with DN300 mm and a heat tube length of 3 m,first,direct binding contact was used to connect the heat exchange tubes and the baffles for nonlinear buckling analysis without considering the gap between the heat exchange tubes and the baffles.The result is that due to the significant increase in the anti-buckling stiffness of the tube bundle,when the equivalent axial pressure on the shell side reaches 42.606 MPa,the tube bundle plastic failure occurs under the action of the axial load without buckling.Then,for the difficulty in nonlinear contact analysis due to gap existing between the heat exchange tube and the baffle,a gap equivalence method is proposed,i.e.filling the gap with a soft material so as to change contact type and realize nonlinear buckling analysis.Meanwhile,the gap equivalent method is used for this floating head heat exchanger to successfully analyze the nonlinear stability analysis of the heat exchanger tube bundle under the shell-side equivalent pressure.It is found that due to no support of the cylinder,the tube bundle will experience overall buckling,and the buckling deformation exhibits an overall deflection.At this time,the equivalent axial pressure is 18.6 MPa,which is smaller than the result of direct binding of the heat exchange tube and the baffle.In addition,the critical pressure of a single tube calculated based on the Euler formula determined by GB/T 151—2014 is 89790 N,which is much larger than the average axial pressure of each tube in the overall buckling in this example,implying that traditional buckling design of shell-and-tube heat exchanger based on Euler formula cannot ensure that the overall buckling of the tube bundle won’t occur.

关 键 词：浮头式换热器 壳程压力 临界压力 管束整体失稳 

分 类 号：TH49[机械工程—机械制造及自动化] TQ051.5[化学工程] O344.7[理学—固体力学]