滚筒内灰渣停留时间的数值模拟实验

Numerical Simulation Experiment on Residence Time of Ash in Drum

冷渣机是燃煤循环流化床锅炉(circulating fluidizedbed boiler,CFB)的重要辅机。为了进一步分析颗粒物料运动物质平衡和热交换平衡之间的关系,研究一种具有六棱柱结构冷渣管滚筒冷渣机中颗粒物料在滚筒内的停留时间及其分布,引入颗粒轨道模型,通过分析单个颗粒的轴向位移来建立物料的平均停留时间(mean residence time,MRT)数学模型,并与实验数据进行对比验证;同时,对实验结果进行分析,得到物料的停留时间分布函数。结果表明,MRT总体上与转速和安装倾角呈反比;降低转速使停留时间概率峰值减小,但会使方差成倍增长并扩大其分布范围,使冷渣机出料更加分散。

The cold slag machine is an important auxiliary machine of coal-fired circulating fluidizedbed boiler(CFB).In order to further analyze the relationship between mass balance and heat exchange balance of granular material movement,the residence time and distribution of granular material in the drum of a slag cooler with hexagonal prism structure were studied,and the particle trajectory model was introduced.The mathematical model of mean residence time(MRT)was established by analyzing the axial displacement of a single particle,and compared with the experimental data.At the same time,the experimental results were analyzed to obtain the residence time distribution function of the material.The results show that the MRT is inversely proportional to the rotational speed and installation inclination.Reducing the rotating speed will reduce the peak value of residence time probability,but will double the variance and expand its distribution range,making the discharge of slag cooler more dispersed.