【作者】 张学凯；

【导师】 徐鸿；

【作者基本信息】 华北电力大学（北京） ， 动力机械及工程， 2008， 硕士

【摘要】 为了研究汽缸热膨胀,本文在二维圆筒壁非稳态导热微分方程的基础上,得到了内部蒸汽沿轴向线性分布、随时间非线性变化、外壁绝热和外壁对流换热的温度场迭代计算公式。通过与有限元计算结果进行对比,表明所得模型计算精度高、速度快。在此基础上,针对不同结构的汽缸,经过一些合理假设,将汽缸复杂的结构分解成简单的子结构,就能得到汽缸轴向膨胀的计算模型。该模型还可用于汽缸轴向膨胀的实时监测,所采用的推导方法和得到的膨胀计算公式亦可用于其它具有类似边界条件的厚壁圆筒部件的相关分析。更多还原

【Abstract】 In order to studying the thermal expansion of turbine casing ,the analytics of the cylinder temperature field has been obtained from deduction, which starting from unstable differential equation of heat conduction for a two-dimentional(2-D) cylindrical wall, in which the internal steam is linearly distributing along the axial direction, and varying along with the time, and external wall is adiabatic and convective,and a comparison with the result from finite-element calculation being carried out. It shows that the obtained model has high precision and rapid calculation. Directing against steam cylinders with different structure, and through some reasonable assumptions, a complicated cylinder structure can be decomposed into simple sub-structures, and a cylinder model of axial expansion has been obtained. The said model can also be used for real-time monitoring of axial expansion for the steam cylinder. The deducting method applied and the expansion calculating formula obtained can also be used for other correlative analysis of cylindrical components with thick wall having similar boundary conditions.更多还原