超临界和超超临界汽轮机汽缸传热系数的研究

提出了汽轮机汽缸传热系数的计算方法。介绍了超，临界和超超临界压力汽轮机汽缸光滑内表面和安装镶片式汽封表面的对流换热表面传热系数的计算公式，安装整体车制式汽封的汽缸内表面、安装静叶的汽缸内表面和安装隔板的汽缸内表面的传热过程总传热系数的计算方法。采用圆筒壁与肋片传热等简化模型来计算汽封块、静叶和隔板的传热过程总传热系数。给出了某型号超，临界600MW汽轮机高压内缸内表面传热系数的计算结果。该方法考虑了不同运行工况下汽缸不同部位的传热过程，在超临界和超超临界压力汽轮机汽缸的温度场与热应力场的有限元法数值计算和寿命评定中，为确定传热边界条件提供了依据。

Casing's Heat Transfer Coefficients of Supercritical and Ultra-Supercritical Steam Turbines

A method for calculating the heat transfer coefficient of steam turbine casings is being presented.Calculation formulas of convection heat transfer coefficient of smooth inner surfaces of supercritical and ultra-supercritical steam turbine casings,and those of gland surfaces with inserted sealing fins,are referred to;ways of calculating the overall heat transfer coefficient of inner casing surfaces with integrally machined glands,as well as those with inserted stationary blades or diaphragms are described.Simplified heat transfer models like cylindrical surfaces and fins are used for calculating the overall heat transfer coefficients of gland blocks,stationary blades and diaphragms.Calculated heat transfer coefficients of the high pressure inner casing's internal surface of a certain 600 MW supercritical steam turbine is being presented.The mentioned method considers the heat transfer process of different parts of the casing under various modes of operation,providing a basis for determining the boundary conditions of temperature and thermal stress field calculations of supercritical,and of ultra-supercritical steam turbines casings,by the finite element method,as well as for their life assessments.Figs 2,table 1 and refs 3.