循环流化床锅炉炉膛内气体浓度的分布

循环流化床锅炉炉膛中气体组分反映了燃烧过程，影响了燃烧效率和脱硫效率．采用自行研制开发的水冷探针，对循环流化床锅炉炉膛中气体浓度分布进行了热态测试．测试结果表明，不同操作条件下沿炉膛轴向和径向气体浓度存在差异，高循环流率循环流化床锅炉存在严重的混合问题，在循环流化床锅炉燃烧室中心区存在三角形的贫氧区．二次风的穿透力直接影响到燃烧效率．增加二次风速可以使混合问题得到改善，飞灰含碳量下降．

Gas Concentration Profiles in the Furnace of CFB Boilers

The gas concentration profiles, which influence not only the combustion efficiency but also the sulfur retention, can be used to understand the combustion process in a Circulating Fluidized Bed (CFB) furnace. Hot test measurements of gas concentration profiles in the furnace of a circulating fluidized bed boiler under several operation conditions were carried out. The water cooled probe used in the tests was developed by Tsinghua University. The experimental results showed that the axial and radial profiles of gas concentration were different for different operation conditions. The uneven radial distribution of O 2 concentration in the furnace indicated that there is a poor gas mixing core in freeboard of the high circulation rate CFB boiler. The authors believe that this is caused partially by deficient penetration depth of secondary air. With the improvement of secondary air duck, the difference of the gas concentration along the depth of the furnace was improved, and the carbon content in fly ash decreased.