摘要
为探究套管式流化床在不同操作参数下的传热特性,对自搭建的套管式流化床进行了基于欧拉-欧拉法的三维数值模拟,并进行准确性验证,考察了不同的环形区烟气流速、表观气速和床料颗粒粒径对流化床内传热特性的影响。实验结果表明,提高环形区域内的热烟气流速可以有效地提高热烟气与内管壁面间的对流传热系数,但对外壁面温度的影响较小;颗粒相与内管壁面和载气间的对流传热系数随颗粒直径的增大而减小,颗粒相平均温度随粒径的增大而下降;随表观气速的增大,管内流体与壁面间的对流传热系数会先上升,并在表观气速为1.1 m/s时达到峰值,后随表观气速的进一步增大而逐渐下降。
Based on a self made double pipe fluidized bed built,a three-dimensional Euler-Euler simulation of heat transfer characteristics of double pipe fluidized bed was carried out under different operating conditions,and the accuracy was verified.The effects of annular area gas velocity,superficial gas velocity and solid particle diameter on heat transfer characteristics in fluidized bed were investigated.The results showed that increasing the annular area gas velocity could effectively improve the convective heat transfer coefficient between the hot flue gas and the inner tube,but the influence to the external wall temperature was small.The convective heat transfer coefficient between the particle phase and the inner tube wall surface and the carrier gas decreased as the particle diameter increased,the average temperature of the particle phase decreased as the particle diameter increased.As the superficial gas velocity increased,the convective heat transfer coefficient between inner fluid and wall surface increased first and reached a maximum when the superficial gas velocity reached 1.1 m/s.As the further increasing of velocity,the coefficient decreased.
作者
赵思元
司慧
Zhao Siyuan;Si Hui(Engineering College,Beijing Forestry University,Beijing 100083,China)
出处
《石油化工》
CAS
CSCD
北大核心
2020年第3期250-255,共6页
Petrochemical Technology
基金
北京市科技计划项目(Z161100001316004)。
关键词
套管式流化床
传热特性
气固两相流
数值模拟
double pipe fluidized bed
heat transfer
gas-solid flow
numerical simulation
