流化床启动过程中底料磨损行为研究

Study on Attrition Behavior of CFB Bed Material During Start-up Process

以国内首台自主研发的65t/h低倍率油页岩循环流化床锅炉底料灰为研究对象,在小型流化床试验台上考察了流化风速、流化时间和床层温度等因素对底料磨损程度的影响,据此建立了二阶磨损模型.结果表明:流化状态下页岩灰的磨损先后经历快速衰减和稳定磨损2个阶段,页岩灰在流化床内的质量保持率呈指数衰减趋势;随着流化风速增大,床层温度升高,磨损相对加剧;二阶磨损模型能够很好地描述流化床内页岩灰质量的变化规律.

Taking the shale ash of the first domestic 65 t/h low rate CFB boiler as an object of study,experimental tests were carried out in a bench-scale fluidized bed so as to analyze how the fluidizing velocity,fluidizing time and bed temperature influence the attrition behavior of the bed material,based on which a second-order attrition model was established.Results show that the shale ash experiences in total rapid decay and stable attrition two stages in fluidized state;its mass reduces exponentially with rising fluidizing time;the degree of ash attrition increases with the rise of bed temperature and fluidizing velocity;the second-order attrition model can well predict the mass changing of shale ash in the fluidized bed.