燃尽风率对新型W火焰锅炉主燃区气固流动特性的影响  

Influence of Overfire Air Ratio on Gas/Solid Two-Phase Flow Characteristics in Primary Combustion Zone for an Improved Down-Fired Boiler

作　　者：王青祥 陈智超[1] 关硕 曾令艳[1] 李争起[1] WANG Qing-Xiang;CHEN Zhi-Chao;GUAN Shuo;ZENG Ling-Yan;LI Zheng-Qi(School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]哈尔滨工业大学能源科学与工程学院

出　　处：《工程热物理学报》2020年第1期20-28,共9页Journal of Engineering Thermophysics

基　　金：国家重点研发计划(No.2017YFC0212502);吴仲华奖励基金

摘　　要：针对采用偏心旋流二次风燃烧技术的300 MWe旋流燃烧器W火焰炉,借助1/10冷模试验台,通过三维激光颗粒动态分析仪测量研究了不同燃尽风率下其主燃区内气固流动特性。随着燃尽风率减小,拱下回流区内回流速度不断增加,且回流区尺寸不断增大。随着燃尽风率由25%减小到10%,在分级分区域,颗粒的最大竖直速度由2 m/s增大到4 m/s.燃尽风率由20.3%减小到10%,拱下回流区内气固两相竖直脉动速度明显增大,气固两相湍流强度将不断增大.在乏气和分级风区域,燃尽风率15%下最大颗粒体积流率是燃尽风率20.3%的2至2.7倍,拱上气流下冲深度明显增加.随着燃尽风率减小,下冲颗粒开始折转向上的位置被推迟,下炉膛空间利用率将不断增加.The eccentric-swirl-secondary-air combustion technology has been proposed for a 300 MWe down-fired boiler with swirl burners.The gas/solid two-phase flow characteristics in primary combustion zone under different overfire air ratios were investigated within a 1/10-scaled model furnace by a three-dimensional particle dynamic analyzer.With decreasing overfire air ratio,the recirculation velocity and the dimension of recirculation zone under the arch both increase.With decreasing overfire air ratio from 25% to 10%,the maximum vertical velocity of particles increases from 2 to 4 m/s in the staged-air region.With decreasing overfire air ratio from 20.3% to 10%,the vertical fluctuation velocities of gas/solid two-phase flows in recirculation zone under the arch increase obviously,and the turbulence intensity of gas/solid two-phase flows increases continuously.The maximum particle volume flux for overfire air ratio of 15% is 2 to 2.7 times than that for overfire air ratio of 20.3% in vent-air and staged-air regions,and the downward depth of gas/solid flows obviously increases.With decreasing overfire air ratio,the position where the downward particles begin to turn back and flow upward is delayed,and the space utilization ratio of lower furnace increases continuously.

关 键 词：W火焰锅炉 低NOX燃烧技术 燃尽风率 气固两相流 

分 类 号：TK223.23[动力工程及工程热物理—动力机械及工程]