300MW CFB锅炉屏式中温过热器管壁温度计算分析

针对循环流化床(CFB)锅炉炉内屏式过热器管子超温爆管问题,建立了某300 MW CFB锅炉屏式中温过热器管壁温度的有限元计算模型,采用四节点四边形单元对温度场剖分并进行了计算分析,不同负荷不同蒸汽流程布置方式(U型布置和Z型布置)的管壁温度分布计算结果表明:不同工况下管壁最高温度出现在鳍片的中心位置处,管内壁温度较低,接近于工质温度;在相同的边界条件下,300 MW CFB锅炉屏式中温过热器蒸汽流程Z型布置优于U型布置。计算结果与实际工程的运行情况吻合良好。

Calculation and Analysis of Temperature Field of Platen Superheater Wall in 300MW CFB Boiler

In order to discuss the tube of superheater wall overheating and rupturing in a circulating fluidized bed,a finite-element calculation model was established for temperature field about a tube of platen superheater wall of a 300MW CFB boiler.Bilinear quadrilateral was used in meshing the temperature field of the platen superheater wall and the analysis and computation was carried on,including temperature field distribution of pipe in the different load and the different arrangement of superheater steam flow(U type arrangement and Z type arrangement).The results show: In different load,the highest temperature of tube wall is the center position of rectangular fin,next is the root of rectangular fin,and then middle point of tube wall,the wall temperature inside tube is lowest which approaches the working medium temperature.In the same boundary conditions,Z type arrangement is better than that of U type arrangement in 300MW CFB boiler.Computed result tallies good with the practical engineering.