百叶窗式水平浓淡燃烧器叶片结构改进的试验和数值模拟研究

EXPERIMENTAL AND NUMERICAL STUDY ON THE IMPROVEMENT OF THE VANES OF THE HORIZONTAL BIAS BURNER

通过冷态模化试验和数值模拟的方法,发现在采用传统叶片结构的百叶窗式水平浓淡燃烧器中存在有浓淡侧流量比偏大和叶片后有较大面积回流区的现象,这些现象是导致该型燃烧器在实际运行中发生烧损、堵粉和磨损的主要原因。在此基础上,通过将第1级叶片改为丘体型结构,第2、3级叶片中间开竖槽并适当调整叶片结构参数,可获得较理想的浓淡侧流量比和煤粉浓缩效果,并基本消除了浓缩器中的回流区结构。

The horizontal bias burner was a high efficiency and low NOx emission pulverized coal burner, but the burnout of the nozzle and the jam and abrasion in the basing channel prevented its applying widely. In the paper, both cold model test and numerical simulation were carried out on the horizontal bias burner for the causes and the improvement measures. It was found that there was a high flow ratio between the rich and lean sides and visible circumfluence zones existed at the downstream of all vanes, which were explained to be the causes of the troubles. Base on this, replacing the first vane by an edgy and cutting notch on other vanes with some optimization of the dimensions as the improved measures were presented. The results of the test and simulation on the improved horizontal bias burner showed that the proper flow ratio between the rich and lean sides and coal-air ratio of the rich side be acquired and the circumfluence zone be eliminated on the whole.