【作者】 田晨； 王勤辉； 张锡梅； 程乐鸣； 骆仲泱； 倪明江； 岑可法；

【Author】 Tian chen,Wang Qin-hui,Zhang Xi-mei,Cheng Le-ming,Luo Zhong-yang,Ni Ming-jiang,Cen Ke-fa (State Key Laboratory of Clean Energy Utilization(Zhejiang University),Hangzhou 310027,Zhejiang,China)

【机构】 浙江大学能源清洁利用国家重点实验室；

【摘要】 在尺寸为1.5×0.864×4.9m~3的循环流化床试验台上,以粒径0.1-0.425mm的玻璃珠为床料,以空气为流化介质,利用高速摄影和粒子图像测速技术,对炉膛结构对床内气固两相流动特性的影响进行了实验研究.获得了流化床内密相区,过渡区防磨板台阶处以及稀相区炉膛边角和挂屏处颗粒流动的速度分布,得出的实验数据表明:在密相区,颗粒的运动过程主要是以气泡尾迹携带上升为主.受炉膛后墙渐扩截面的影响,颗粒更容易对后墙形成较大冲刷.密相区内气泡的运动速度要远大于颗粒的运动速度.过渡区防磨板的布置引起流通截面突变,台阶效应作用下颗粒对防磨板的冲刷作用显著增强.由于分离器的偏置布置,稀相区段出口效应作用明显,整个稀相区截面运动均受其影响,颗粒横向运动显著,环核流动受到破坏.由于挂屏的阻隔,在局部位置一定程度上减弱了出口效应,挂屏与炉壁之间的颗粒流动主要受气流和壁面约束的影响,在挂屏拐角处由于颗粒的聚集易形成局部的高浓度区域,而挂屏与左墙之间颗粒运动依然受出口影响较大.更多还原

【Abstract】 By using a high-speed video camera and particle image velocimetry(PIV) technology,the local flow properties of the solid-gas two phase flow were studied in a plexiglas rectangular CFB cold model with the size of 1.5×0.864×4.9m~3.Measurements were carried out with transparent glass bead between 0.1-0.425mm as bed materials and cold air as flow medium.The experimental results showed that in the dense region,particle movement was dominated by bubble wake and inclined to the back wall on the influence of expanding cross-section of back wall.Projection section in transition region decreased the flow area and increased the particle lateral velocity.Besides,projection section was also a high particle concentration region.In the dilute region,the outlet and the corner effect causes the defluxion of the particles movement and the core-annular distribution was broken.The closer to the outlet,the stronger the lateral velocity is.The obstruct of hanging screen reduced the furnace outlet effects between the hanging screen and the front wall,the particles movement in the area was controlled by the gas flow and the constrain of the wall.High particle concentration areas were formed in the junction between the screen and the front wall and in the corner between the left wall and the front wall.更多还原