锅炉锅筒的稳态温度场及热应力场分毕业设计.docVIP

锅炉锅筒的稳态温度场及热应力场分析 学生姓名： 学号： 学 院： 专 业： 指导教师： 年 月 摘要 锅筒是锅炉中非常重要的受压元件，锅炉系统中的熙然循环回路的主要组成部分是锅筒、上升管和下降管，它在系统工作时会接收来自省煤器的供水，并向过热器输送饱和蒸汽，锅筒是加热、蒸发和过热三个过程的连接点。锅筒运转工况非常繁杂，不单要承受来自内部较高的压力，还必须承受系统冷、热态启停及变负荷时的循环机械应力和热应力，这些交变应力很容易导致疲劳破坏。所以，对锅筒进行温度分析和热应力分析，得出锅筒在稳态工作时的温度和热应力分布规律，可为增压锅炉的安全运行提供一定的理论支撑。 运用有限元分析软件ANSYS建立给定锅炉锅筒的三维模型，并将给定数据带入，对锅筒内热应力分布和温度场分布进行三维有限元数值模拟分析。按相应的边界条件施加合适的约束，使锅炉锅筒始终在正常范围内工作。用ANSYS软件分析并确定锅筒正常工作时其内部的温度场及热应力分布规律，并根据分析结果和给定材料特性对锅炉锅筒进行相关的强度评定，最终为锅筒的安全评判提供参考。 关键词：锅炉；锅筒；有限元；温度场；热应力；强度评定 Abstract The drum is the most important pressurized component of boiler,and it connects with the riser tubes and downcomers of the natural circulation loop,at the same time drum gets the feed water from economizer and provides saturated steam for superheater.It is the junction of heating,evaporation and overheating.Drum running conditions are very complicated because it not only bear a high internal pressure but also endure cyclic mechanical stress and thermal stress induced easily fatigue wreck during cold,heat starting and stopping and variable conditions.Therefore,variable rules on stress of supercharged boiler drum in steady and startup period can provide theoretical support for optimal starting scheme of supercharged boiler through analysis of the boiler drum stress. The finite element analysis software ANSYS is used to establish the three-dimensional model of the boiler drum, and the given data is brought into the three-dimensional finite element numerical simulation analysis of thermal stress and temperature field in the pot. According to the appropriate boundary conditions to impose appropriate constraints, Make the boiler barrel always work in the normal range. Using ANSYS software to analyze and determine the temperature field and thermal stress distribution of the cylinder during the normal operation,According to the analysis results and the characteristics of the given materi