带N型管箱换热器中筒体厚度对管板设计厚度的影响

INFLUENCE OF CYLINDER THICKNESS ON TUBE SHEET DESIGN THICKNESS IN HEAT EXCHANGER WITH N-TYPE CHANNEL BOX

对于带N型管箱的固定管板换热器,管板与两侧筒体直接焊接;文章从基本原理入手,考察管板周边区域的受力情况,分析了筒体厚度对旋转刚度参数Kf及管板边缘支撑条件的作用;区分壳程带与不带膨胀节两种情况并结合换热管加强系数K的调整,文章通过八个算例来分析圆筒厚度变化对管板内径向应力分布以及极值的影响。由于壳程筒体的轴向刚度与其自身厚度有关并会直接影响到管板的设计厚度,文章分析了这一影响规律并提出了壳程筒体由不同厚度段组成时的轴向刚度计算。

For the fixed tube sheet heat exchanger with n-type channel box,the tube sheet should be directly welded with the tubes on both sides.This paper studies the force condition of the boundary zone of the tube sheet according to the basic principles.It analyzes the effect generated from cylinder thickness on rotating rigidity factor Kf and boundary supports.Combining with the adjustment of the strength factor K of the heat exchange tube,the paper also distinguishes two conditions with expansion joint or without it.It analyzes the radial stress distribution and maximum value in tube sheet influenced by the change of cylinder thickness through calculation of eight examples.Since the axial rigidity of the shell-side cylinder is related to its thickness and may directly affect the design thickness of the tube sheet,this paper analyzes this influence law and brings forward the calculation of the axial rigidity for shell-side cylinder with segments of different thickness.