Particle to Wall Heat Transfer in Circulating Fluidized Beds

由于对循环流化床（CFB）燃烧的基本机理缺乏了解，阻碍了商业规模电厂的发展。这项工作集中在与床壁接触的颗粒的传热上，这是循环流化床传热的一个重要而鲜为人知的组成部分。控制传热过程的参数在现有的20 cm CFB测试设备上进行测量，使用颗粒传感器和电容探头来测量各种不同的颗粒和流化条件，并与床流体动力学相关。传热系数将被预测并与实际的传热测量值进行比较。这项工作将增加对循环流化床传热和流体力学之间联系的理解，并有助于循环流化床燃烧器传热表面的设计。

Development of commercial-scale plants using circulating fluidized bed (CFB) combustion has been hindered by a lack of understanding concerning the basic mechanisms of heat transfer. This work concentrates on the heat transfer from particles in contact with the wall of the bed, an important and poorly understood component of heat transfer in CFB's. The parameters controlling the heat transfer process are being measured in an existing 20 cm CFB test facility using a particle sensor and capacitance probe for various different particles and fluidization conditions and related to the bed hydrodynamics. The heat transfer coefficient will be predicted and compared to actual heat transfer measurements. This work will produce an increased understanding of the link between heat transfer and hydrodynamics in CFB's, and aid the design of heat transfer surfaces in CFB combustors.