对流换热条件下换热器管板的应力分析

Stress Analysis of Tubesheet of Heat Exchangers Subjected to Thermal Convection

给出对流换热条件下换热器管板中应力场的有限元分析方法。分析中将管板布管区折算为受管孔削弱并被管束支承的横观各向同性均质等效板；在计算位移场时采用具有附加内部自由度的ｗｉｌｓｏｎ非协调元，以保证计算应力的精度与温度场精度相匹配。计算结果得到了试验验证。典型算例说明过厚的管板将引起过大的温度应力。对于核工业中各种以温度载荷为主的换热器，应注意合理选择管板厚度。

An analysis method of stress fields in tubsheets of heat exchangers subjected to thermal convectiong is proposed by finite element method.The tubed zone of a tubesheet modelled as equivalent uniform and transversely isotropic solid plate weakened by holes and supported on elastic foundation.Wilson's incompatible elements with additional degree of freedom are employed in analysis of displacement fields for raising the computation accuracy of stress fields.The presented results are verified by experiment.The results for a typical intermediate heat exchanger show that significant thermal stresses exist in thick tubesheet.Therefore,thickness of tubesheets should be chosen in reasonable size for the exchangers in nuclear power stations subjected mainly to thermal loading.