在CFB锅炉中煤粉不同喷入位置对炉内固相运动特性的影响

针对循环流化床结合煤粉燃烧技术,建立了炉内气固运动特性的三维数学模型,研究分析了煤粉不同喷入位置及不同二次风速度对炉内气固运动特性的影响.结果表明:在不同二次风速下,煤粉燃烧器布置位置距布风板2600 mm和2000 mm时,颗粒速度波动大,流动不稳定,不能在悬浮段形成局部颗粒流浓度;布置位置为距布风板2300 mm时,流动状态较稳定,而且能够在悬浮段形成高浓度颗粒流.因此在采用联合燃烧技术的循环流化床中,保持流化风速为2 m/s时,煤粉燃烧器布置位置在距布风板2300 mm时,能使煤颗粒在炉膛整个上升过程中处于高温燃烧氛围.

Effects of Different Pulverized Coal Spouting Position on the Solid-phase Flow Characteristics of CFB Boilers with Complex Combustion

A three-dimensional mathematical model describing the gas-solid flow characteristics in furnaces has been stablished,for the purpose of studying and analyzing the effect of different pulverized coal feeding positions and different secondary air vilocities on gas-solid flow characteristics.Results show that,at different secondary air velocities,particle velocities start to oscillaten,flow gets unstable and particles can't get concentrated anymore in the suspension section,in case the dust spouting burners are in a position 2600 and 2000 mm away from the air distribution baffle;but if this distance is made 2300 mm,flow gets relatively stable and high particle concentration can be obtatained in the suspension section.Theerefore,in circulating fluidized beds with complex combustion technology,a particle flow of high concentration can emerge in the upper part of the dese phase zone,wherewith the coal particles are made to stay in a high temperature combustion atmosphere all the way during up-rising,by keeping air velocity at 2m/s and positioning the dust spouting burners 2300 mm away from the air distribution baffles.