力学与实践 ›› 2022, Vol. 44 ›› Issue (4): 844-851.DOI: 10.6052/1000-0879-22-197

• 生物质流化床热化学转化模拟研究专题 • 上一篇    下一篇

流化床生物质燃烧过程中传热特性的CFD–DEM数值模拟

谢俊*,(), 牛淼淼**   

  1. *. 南京师范大学能源与机械工程学院,南京 210046
    †. 东南大学能源与环境学院,南京 210096
    **. 南京工程学院能源与动力工程学院,南京 211167
  • 收稿日期:2022-03-31 接受日期:2022-07-05 出版日期:2022-08-08 发布日期:2022-08-17
  • 作者简介:谢俊,副研究员,研究方向为多相流动及数值模拟。E-mail: xiejun0218@126.com
  • 基金资助:
    南京师范大学科研启动基金资助项目(184080H202B368)。

CFD–DEM SIMULATION OF HEAT TRANSFER DURING THE BIOMASS COMBUSTION PROCESS IN FLUIDIZED BEDS

XIE Jun*,(), NIU Miaomiao**   

  1. *. School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing 210046, China
    †. School of Energy and Environment, Southeast University, Nanjing 210096, China
    **. School of Energy and Power Engineering, Nanjing Institute of Technology, Nanjing 211167, China
  • Received:2022-03-31 Accepted:2022-07-05 Online:2022-08-08 Published:2022-08-17

摘要:

本文基于CFD–DEM方法,将多种传热模型与稠密气固流动与化学反应耦合,对鼓泡流化床内生物质燃烧过程中的传热特性进行了数值模拟研究。结果表明,对于燃料颗粒,反应热占据主导地位,辐射和对流传热同样起到重要作用,导热的影响相对较小。随着燃料挥发分含量的增加,对流传热和颗粒–颗粒导热作用增强,颗粒–壁面导热减弱。床内热点温度由燃料挥发分燃烧引起,从床层表面产生并上升到自由空域。生物质颗粒的温度则随局部颗粒浓度的减小而逐渐增加。

关键词: 生物质燃烧, 传热模式, 流化床

Abstract:

In this paper, based on CFD–DEM, several heat transfer models were coupled with dense gas-solid flow and chemical reaction to simulate the heat transfer characteristics of biomass combustion in bubbling fluidized bed. The results show that for fuel particles, heat of reaction is dominated, and radiation and convection also play an important role, but heat conduction has little effect. With the increase of volatile content of fuel, the contributions of convection and particle-particle conduction increase, but the contribution of particle-wall conduction decreases. The local hot spot in the bed is mainly caused by the volatiles combustion, which is generated from the bed surface and rises to the freeboard. The biomass particle temperature generally increases with the decrease of local particle concentration.

Key words: biomass combustion, heat transfer mode, fluidized bed

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