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超临界、超超临界锅炉水冷壁尤其是燃烧器区水冷壁温度场计算对锅炉的安全运行具有重要意义。该文建立了燃烧器区螺旋管圈水冷壁及鳍片截面的二维稳态导热方程,推导了基于矩量法的有限元数值计算公式,采用双线性四边形单元对截面进行剖分。用分区段热力计算方法确定水冷壁各区段热负荷。依据机组实测的水冷壁入口和出口工质温度和压力,通过计算热负荷引起的焓增确定各校核截面的工质温度和压力。从而确定管内的对流换热系数。计算了不同启动方式下水冷壁管壁内侧温度及其变化率,为指导锅炉的安全稳定运行和锅炉管壁选材提供了依据。
Supercritical and ultra-supercritical boiler water wall, especially the burner area water wall temperature field calculation of the safe operation of the boiler is of great significance. In this paper, a two-dimensional steady-state heat conduction equation is established for the spiral wall of the spiral coil in the burner zone and the fin section. The formula of the finite element method based on the moment method is deduced. The bilinear quadrilateral element is used to segment the section. The heat load of each section of water wall is determined by the method of section heat calculation. Based on the measured temperature and pressure of inlet and outlet working fluid of water wall measured by the unit, the temperature and pressure of working fluid in each calibration section are determined by calculating the enthalpy increase caused by thermal load. In order to determine the tube convection heat transfer coefficient. The temperature inside the wall of water wall and its rate of change under different start modes were calculated, which provided the basis for guiding the safe and stable operation of the boiler and the material selection of boiler wall.