波纹管膨胀节温度场数值模拟

从传热学基础理论出发,运用对流传热实验关联式,计算了膨胀节导流筒与烟气、膨胀节外表面与周围环境的对流换热系数,同时以等效辐射换热系数来简化辐射换热,并且对波纹管与隔热层之间的烟气夹层及波纹管与保温层之间的空气夹层的传热方式进行了分析,综合考虑了对流和辐射传热,得出了烟气夹层和空气夹层的当量热导率。采用ANSYS实现几何建模、网格化、加载和求解的自动进行,得出了膨胀节在模拟工况下的温度场分布;研究了结构设计参数的变化对波纹管工作温度的影响,为膨胀节的设计提供了参考依据,以保证膨胀节在管网中安全运行。

Numerical Simulation of Temperature Field of Bellows Expansion Joint

This paper is based on the heat transfer theory,using experimental correlations of convection heat transfer to calculate the convection coefficient between the expansion joint sleeves,the smoke and expansion joint external surface on the one hand and ambient medium on there;meanwhile,it also simplifies the radiation heat transfer as equivalent radiation heat transfer coefficient,and by analyzing the heat transfer mode of the smoke layer between the bellows and the heat-insulating layer,the air layer between the bellows and the outer insulating layer,the equivalent thermal conductivity of the smoke layer and air layer is determined.By ANSYS,the automatic calculation of modeling,meshing,loading and solution is realized,and the temperature field of expansion joints in simulated operating conditions can be displayed;the structural design parameters influencing the bellows’ operating temperature are also researched,providing some reference for designing the expansion joints so as to ensure the safe running of the expansion joints in the pipelines.