首台600 MW超临界W火焰锅炉水动力特性计算及分析

为校核锅炉水冷壁的安全与可靠性,采用锅炉水动力特性程序,将现场运行参数作为初始值,对世界首台设计并在某电厂投运的600 MW超临界W火焰锅炉的水冷壁流量分配和出口工质温度进行了计算,并将结焦工况与无结焦工况的水动力特性进行了对比。水冷壁出口工质温度的计算结果与实炉数据在总体数值和分布趋势上比较符合,表明所采用的程序可适用于实际工程。计算结果表明：采用了低质量流速优化内螺纹管垂直管屏技术的下炉膛回路流量分配呈现良好的正响应特性,而采用光管的上炉膛回路流量分配呈现负响应特性。与无结焦工况相比,结焦工况下下炉膛侧墙与翼墙回路的质量流速有所降低,所有回路出口工质温度均降低。

Calculation and Analysis of Hydrodynamic Characteristics for First 600-MW Supercritical Down-Fired Boiler

In order to check the security and reliability of the water-wall, the hydrodynamic characteristic computation program is adopted with the operating parameters taken as initial values to calculate the flow rate and outlet temperature of the working substance in a 600-MW boiler of one thermal power plant which is the first supercritical down-fired boiler designed and put into operation in the world. The hydrodynamic characteristics in normal and coking conditions are compared. The overall calculation values of the outlet working substance temperature match well with the operation data, which illustrates that the program is suitable for practical application. The results show that the lower-furnace water-walls with low mass-flux optimized rifled tubes exhibit a strong positive flow response while the upper-furnace water-walls with vertical smooth tubes exhibit an evident negative mass flux response. Compared to the normal condition, in the coking conditions the mass velocities of the coking circuits in the lower furnace decrease with the outlet fluid temperatures of all circuits being decreased.