介质温度对换热器胀接接头的影响分析

Analysis of the Influence of the Medium Temperatures on the Expanded Joints of Heat Exchangers

在换热器不同的工作介质温度下,选取液压胀接后的管板与接头为研究对象,建立了换热管与管板接头三维有限元模型,模拟分析了在10种介质温度下接头胀接后的密封性能和拉脱强度。计算结果表明,在工作状态下,残余接触压力随管程介质温度的升高先增加后减小,然后趋于稳定;拉脱力随温度升高先增大,然后趋于稳定。同常温相比,管程的介质温度升高使它的密封性能和拉脱强度都得到增强。

The tube-sheets and the joints after being expanded by hydraulics were selected as research objects, the 3-D finite element model of the heat exchange tubes and the joints of tubes and sheets was founded, the seal performance and the pull-off force of the expanded joints under ten medium temperatures were simulated and analyzed for the heat exchangers under different temperatures of working mediums. The calculation result shows that under functional mode, the residual contact pressure was firstly increased and later reduced with the rise of the medium temperature in the tube pass, then it became stable; the pull-off force was firstly increased, and then it became stable with the rise of temperature. In comparison with normal temperature, the increase of the temperature of the tube pass makes the seal performance and the pull-off strength of the expanded joints stronger.