换热器管子-管板液压胀接的有限元模拟

Finite element simulation of the hydraulic expansion of tube-to-tubesheet joints of heat exchangers

采用ANSYS/CAE软件 ,对锅炉、换热器管子 管板的液压胀接过程进行了模拟。管子与管板孔之间采用面 面接触元以模拟相互之间的间隙及管子产生塑性变形并贴紧管板孔后对管板的作用。通过本文的模拟分析 ,可获得胀接时接头处的弹 塑性应力状态及卸除胀接压力后管子与管板之间的残余接触压力。值得注意的是此接触压力沿管板厚度方向分布是不均匀的 ;在管孔槽处会出现较高的数值 ;在管板内侧处 。

The hydraulic expansion process of the tube to tubesheet joints of the boilers and heat exchangers was simulated by ANSYS/CAE software. The plate plate contact element was used to simulate the gap between the tube and tubesheet hole, the process of the tube is yielded plastic deformation and kept close to the tubesheet hole and act on it. The elastic plastic stress state of the joints during the hydraulic expansion process and the residual contact stress between the tube and tubesheet after the expansion pressure is unloaded can be obtained by the simulation analysis. It was found that this contact stress is not well distributed along the thickness of the tubesheet, high stress value is occurred in the tubesheet hole groove. High residual tensile stress is occurred in the transitional region of the tube in the inner side of the tubesheet.