燃烧器布置方式对循环流化床炉内气固流动特性的影响

Effects of Burner Arrangement on the Gas-Solid Flow Characteristics in the Furnace of Circulating Fluidized Bed Boilers

以采用混合燃烧的循环流化床(CFB)锅炉为研究对象,利用Simple算法对其炉内气固流动进行了三维数值模拟,得到了不同工况下炉内颗粒的速度和体积浓度分布.结果表明:双侧布置二次进料口的方式优于单侧布置方式;对冲布置方式下,燃烧器布置位置h/Z为0.145、二次风速为35 m/s时,炉内的气固混合比较强烈,流动状态较稳定,能够形成密相区之外的二次高浓度颗粒流,是较为合理的布置方式.

Three-dimensional numerical simulation was made by use of Simple algorithm to simulate the gas-solid flow in the furnace of a circulating fluidized bed（CFB） boiler which adopted combined firing technology. Velocity distribution and volumetric concentration distribution of the particles in the furnace under different conditions were obtained. Results show that the arrangement of secondary fuel feeder in both sides of CFB is better than that in single side. Under opposed disposition, when the location of the burners are at h/Z=0. 145 and velocity of secondary air is 35 m/s, the mixture intensity of the particle and gas is strengthened and the flow is stable. Meanwhile a secondary particle flow of high concentration can be formed outside the dense phase zone. It is a reasonable arrangement for burners.