For heating surface of bubbling bed, the factors  influencing the heat transfer of bed layer and  heating surface mainly are materials fluidization velocity, materials particle size distribution, the original physical characteristics of material itself, bed temperature, the surface temperature of the heating surface, the arrangement mode and geometry size of heating surface. For circulating fluidized bed, the control factors of heat transfer of materials to the vertical heating surface are: Bed temperature, local spatial concentration of particle size, particle size distribution and surface temperature of heating surface.