正交网格下配风对四角切圆锅炉燃烧效率影响的数值模拟

在正交网格下考察了不同燃烧器布置方式对DG420／13．7-Ⅱ2型四角切圆锅炉空气动力场模拟的差异，对比试验结果表明，将燃烧器分为两半布置在四角处的两面壁面上是较为合适的布置方式．还开展了配风对该型锅炉和SG420／13．7-M419型锅炉燃烧效率影响的数值模拟和试验研究，计算的煤粉燃尽率与试验值比较符合，配风对两种型号锅炉燃烧效率的影响规律是一致的．研究结果表明，正宝塔配风可增加煤粉燃尽率，有利于提高锅炉燃烧效率；倒宝塔配风会显著降低煤粉燃尽率，降低锅炉燃烧效率；而均匀配风和缩腰配风则处于两者之间．

Effects of secondary air distribution modes on combustion efficiencies of tangentially firing boilers using orthogonal grid

The effects of burner arrangement modes on predicting the aerodynamic field of a DG420/13.7-Ⅱ 2-type tangentially-firing boiler were studied by using orthogonal grid. The test results show that it is appropriate that each burner nozzle was split into two same noz- zles, and each half was arranged on the furnace wall of the corner. Then, the numerical and experimental investigations of the effects of secondary air distribution modes on combustion efficiendes of DG420/13.7-11 2-type and SG420/13.7-M419-type tangentially-firing boilers were carried out. The predicted burnouts of pulverized coal agree well with the measured data. The effects of secondary air distribution modes on the combustion efficiencies of two boilers were same. Under pagoda type secondary air distribution mode, the burnouts of pul- verized coal are increased, and the combustion efficiencies of two boilers are therefore in- creased. Under waist drum type secondary air distribution mode, the burnouts of pulverized coal are obviously decreased, and the combustion efficiencies of two boilers are also de- creased. Under uniform and shrinked-middle type secondary air distribution modes, the burnouts of pulverized coal and the combustion efficiencies of two boilers are between those of pagoda and waist drum type secondary air distribution.