Effect of Connection Resistance between Cyclones and Backpass on Furnace Solids Suspension Density Profile and Circulation Rates in CFB

Energies

Junfeng Wang¹  Xiaoguo Jiang¹  Guanwen Luo²  Liyao Li²  Leming Cheng²  Weiguo Zhang² 

[1] Harbin Boiler Company Limited, Harbin 150046, China;State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China;

关键词: CFB;    connection between cyclones and backpass;    resistance;    theoretical model;    solids suspension density;    solids circulation rate;   

DOI  :  10.3390/en14196162

来源: DOAJ

【 摘 要 】

The connection section between cyclones and backpass is an important configuration in multi-cyclone circulating fluidized bed boilers (CFB). In this work, the resistance coefficient of different connection modes, and connection resistance distribution from each cyclone outlet to backpass (connection branch) in one mode are defined and calculated, in order to investigate their effects on furnace solids suspension density distribution and circulation rates. Three connection modes with different overall resistance coefficients were tested experimentally and analyzed by a 1.5-dimensional model in a four-cyclone scaling CFB apparatus. Both experimental and theoretical results show that, with larger overall resistance of a connection, there are more solids suspended in the furnace bottom and fewer in the top section. The investigation of the C-type connection has revealed that when the branch resistance of the connection decreases from branch No. 1–4, the solids suspension density and circulation rate from corresponding solids recycle loops (No. 1–4) increase. Moreover, the non-uniformity of connection branch resistance distribution will lead to uneven lateral solids suspension density distribution and circulation rates allocation. This effect is enhanced by growing superficial velocity.

【 授权许可】

Unknown