内旋流流化床埋管传热研究

The Study of Heat Transfer of Immersed Tube in the Internal Circulating Fluidized Bed

垃圾焚烧系统中 ,内旋流流化床存在不同布风速度的移动区、流动区和换热区 ,处于换热区的埋管的对流换热系数受附近流动区气流参数的影响 ,其变化趋势及数值大小与普通鼓泡型流化床之间有明显不同 :最大的对流换热系数明显高于鼓泡床 ;换热区尚未流化时 ,对流换热系数已经大幅提高 ;整条换热曲线的变化比较平缓 ,易于流化床浓相床内换热。

In the internal circulating fluidized bed,there exist the moving zone,fluidizing zone and heat transferring zone with different fluidized air velocities.The convection heat transfer coefficient of immersed tube in the heat transferring zone is impacted by the velocity of the moving zone nearby and its data and change trend are obviously different with those of the common bubbling bed.The maximum heat transfer coefficient is evidently higher than that of the bubbling bed.As the bed materials have not been fluidized in the heat transfer zone,the coefficient has increased highly.The curve of that changes gently,feasilble to control the combustion intensity in the fluidizing zone.