GUO Weiguo^1,2, DONG Pengfei², ZHU Zhiping^2,3, SUN Guogang¹, WEI Chenming^2,4

(1.College of Mechanical and Transportation Engineering, China University of Petroleum(Beijing), Beijing 102249, China;2.Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190,China;3.School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China;4.School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China)

Abstract: In view of the problems that decrease in the gas-solid separation efficiency and poor reture of the material in the return loop of the circulating fluidized bed coal gasification unit caused by the fluctuation of furnace pressure, cold state test was carried out on the two-stage separation and return material circulating fluidized bed device.The effects of different bed material particle size distribution, solid-gas ratio at the inlet of the first stage separator，and gas velocity at the inlet of the first stage separator on the separation efficiency of primary separator and the pressure fluctuation of the secondary loop seals were studied.The results show that as the inlet solid-gas ratio increases from 3.5 to 6.2, and the separation efficiency of the primary separator increases from 90.78% to 94.12%.The secondary loop seals is less affected by the furnace pressure fluctuation, and the standard deviation of the pressure drop is maintained at about 0.044 kPa.As the inlet gas velocity increases from 8 m/s to 15 m/s, the separation efficiency of the first-stage separator increases from 92.06% to 95.20%.As the operation the median particle size of the bed material decreases from 499.9 μm to 78.1 μm, and the separation efficiency of the system is maintained at greater than 99.98%, the separation efficiency of the primary separator is reduced from 97.02% by 87.06%.The median particle size of the bed material is less than 107.3 μm, and the volume fraction of Geldart C particles in the secondary loop selas is greater than 35.56 %, the fluidization of the material in the secondary riser is poor, carrying more fine bed material, which affects the stable operation of the system.

Keywords: separator；separation efficiency；pressure fluctuation；circulating flow rate

中图分类号：TQ545                              文献标志码：A

文章编号：1008-5548(2022)03-0033-11

DOI:10.13732/j.issn.1008-5548.2022.03.005

收稿日期： 2021-11-08， 修回日期：2022-03-04，在线出版时间:2022-04-25。

基金项目：中国科学院科技成果转移转化重点专项项目，编号：KFJ-HGZX-003。

第一作者简介：郭卫国(1997—)，男，硕士研究生，研究方向为循环流化床气固两相流动。E-mail：guoweiguo@iet.com。

通信作者简介：董鹏飞(1983—)，男，助理研究员，博士，研究方向为煤气化及流态化。E-mail：dongpengfei@iet.com。