化工学报 ›› 2008, Vol. 59 ›› Issue (10): 2455-2459.

• 传递现象 • 上一篇    下一篇

多孔介质反应体系中的耦合扩散效应

李明春;田彦文;翟玉春   

  1. 沈阳工业大学材料科学与工程学院;东北大学冶金物理化学所
  • 出版日期:2008-10-05 发布日期:2008-10-05

ross-diffusion effect in porous medium with endothermic chemical reaction

LI Mingchun;TIAN Yanwen; ZHAI Yuchun   

  • Online:2008-10-05 Published:2008-10-05

摘要: 采用不可逆过程热力学方法研究固有强吸热化学反应的多孔介质物质体系,建立了描述该体系内各不可逆过程交互耦合的数学模型,应用有限容积隐式方法数值求解,并以煅烧石灰石为例,计算分析了热扩散现象和达福尔效应对多孔介质体系内传热、传质和化学反应的影响规律。结果表明,在Peclet准数较小的情况下,不能忽略Soret效应和Dufour效应的影响,Soret效应和Dufour效应会加快反应器内产物气体和热量传出的速度,使得颗粒物料层内产物气体浓度和主气流温度都相应降低,固体转化率减小。

关键词:

多孔介质, 吸热反应, Soret效应, Dufour效应

Abstract:

A porous medium involving endothermic chemical reaction was studied by using the irreversible flow processes thermodynamics methodA mathematical model describing the coupled irreversible processes of heat transfer, mass transfer and chemical reaction in porous medium was established, and the model was solved numerically by applying the finite volume implicit methodBy taking the decomposition of limestone as a case, the effects of the Soret and the Dufour phenomena were analyzedThe results showed that when the Peclet module was lower, the effects of the Soret and the Dufour phenomena could not be ignoredAs a result, the product gas and the quantity of heat of gas in the porous medium would come through the reactor much quicker, and the concentration of the product gas, the temperature of gas flow and the solid conversion degree would be lower.

Key words:

多孔介质, 吸热反应, Soret效应, Dufour效应