力学与实践 ›› 2022, Vol. 44 ›› Issue (4): 834-843.DOI: 10.6052/1000-0879-22-078

• 生物质流化床热化学转化模拟研究专题 • 上一篇    下一篇

流化床生物质气化过程的CFD–DEM模拟研究

孔大力(), 王帅(), 罗坤, 樊建人   

  1. 浙江大学能源清洁利用国家重点实验室,杭州 310027
  • 收稿日期:2022-02-14 出版日期:2022-08-08 发布日期:2022-08-17
  • 通讯作者: 王帅
  • 作者简介:王帅,博士后,研究方向为流化床稠密气固反应流的模拟研究。E-mail: wshuai2014@zju.edu.cn
    孔大力,博士研究生,研究方向为流化床多相反应流的模拟研究。E-mail: 21827053@zju.edu.cn
  • 基金资助:
    国家自然科学基金资助项目(51925603)。

CFD–DEM SIMULATION OF BIOMASS GASIFICAITON IN FLUIDIZED BED

KONG Dali(), WANG Shuai(), LUO Kun, FAN Jianren   

  1. State key Laboratory of Clean Energy Utilization of Zhejiang University, Hangzhou 310027, China
  • Received:2022-02-14 Online:2022-08-08 Published:2022-08-17
  • Contact: WANG Shuai

摘要:

本文采用计算流体力学–离散单元法耦合热化学和多分散曳力子模型,对鼓泡流化床反应器内生物质气化过程进行了数值模拟研究。在进行了模型验证后,讨论了关键操作参数对颗粒尺度信息(如颗粒运动、混合、传热)和反应器性能的影响。结果表明,在生物质气化过程中,对流传热起主导作用,其次是辐射传热和反应热,传导传热所占比例最小。提高操作温度和生物质/水蒸气比可以促进传热过程和化学反应的进行。

关键词: 生物质气化, 传热传质, 离散单元方法, 流化床

Abstract:

In this paper, the biomass gasification process in a bubbling fluidized bed (BFB) reactor was numerically simulated by using computational fluid dynamics–discrete element method (CFD–DEM) coupled with thermochemical and poly-dispersed drag model. After model validation, the effects of key operating parameters on particle-scale information (e.g., particle motion, mixing, heat transfer) and reactor performance were discussed. The results show that in the process of biomass gasification, convective heat transfer plays a leading role, followed by radiative heat transfer and reaction heat. The proportion of conductive heat transfer is the smallest and can be ignored. Increasing the operating temperature can enhance heat transfer and reaction, and increase the temperature of biomass particles. Increasing biomass/steam ratio promotes gasification reactions, consumes more heat and reduces biomass particle temperature. The decrease of biomass particle temperature will increase the temperature difference between biomass particles and bed material particles, so as to increase the conductive, convective and radiative heat transfer.

Key words: biomass gasification, heat and mass transfer, discrete element method, fludized bed

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