摘要
为研究固定管板管接头结构对管板支撑作用,并考察对接头结构进行简化数值模拟所带来的误差。采用有限元方法建立了不同管接头结构的数值分析模型,得到了管板的中心挠度及应力,并与将换热管与管板连为一体的简化模型计算结果进行了比较。同时,还分析了胀接连接时换热管的相对胀接长度以及焊接连接时管子与管板孔间隙大小对管板强度和刚度的影响。结果表明,管接头结构对管板中心挠度及应力有明显影响;在胀接接头未松脱的前提下,胀接结构的管板刚度和强度要好于焊接结构的管板;与实际接头模拟结果相比,简化模型模拟结果偏于不保守;胀接长度越大,管子对管板的支撑作用越大,结果越接近于简化模型模拟结果。对于焊接接头,换热管与管板管孔间隙在0.05~0.25 mm范围内变化,对管板强度和刚度的影响可以忽略不计。
In order to explore the support effects of tube joint structure of fixed tube-sheet heat exchangers and investigate the error brought by the simplified numerical simulation of the tube joint structure.Numerical analysis models for different connection joints between tubes and tube-sheet in heat exchangers were established by the finite element method.Deflection and stress at the tube-sheet center were calculated and compared with the calculation results from a simplified model which simply connects the tubes and tubesheet as a whole.Meanwhile,the effects of the relative expansion length of heat exchange tube during expansion connection and clearances between tubes and holes on the tubesheet on the tubesheet strength and stiffness during welding connection were also studied.Results show that the tube joint structures have significant effect on the deflection and stress at the tubesheet center.Under the premise that the expanded joint is not loose,the strength and stiffness of the tubesheet with expanded joints is better than the tubesheet with welded joints.Compared with the simulation results of the actual joint models,those of the simplified model are on non-conservative side.The longer the expansion length is,the stronger the support action of the tubes on the tubesheet is,and the closer to the simulation results of the simplified models the results are.For the welding joints,the clearances between tubes and holes at the tubesheet in the range of 0.05~0.25 mm.The effects on the strength and stiffness of the tubesheet are negligible.
作者
王静姝
钱才富
Wang Jingshu;Qian Caifu(College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China)
出处
《压力容器》
北大核心
2020年第8期24-30,72,共8页
Pressure Vessel Technology
关键词
胀接接头
焊接接头
有限元分析
挠度
应力
expansion joint
welded joint
finite element analysis
deflection
stress
