煤炭超临界水流化床制氢反应器内颗粒流动及传热特性的数值分析

Numerical Analysis of Particle Flow and Heat Transfer Characteristics in a Coal-Supercritical Water Fluidized Bed Reactor for Hydrogen Production

煤炭超临界水气化是极具发展前景的高效洁净煤转化利用技术,深入研究反应器内流动和传热过程对反应器的设计及优化具有重要意义.本文基于欧拉-拉格朗日方法,耦合化学反应动力学模型,建立了煤炭超临界水流化床制氢反应器的三维瞬态CFD模型,研究了反应器内流动和传热特性、颗粒及产物组分的分布转化规律,得到了煤炭颗粒表面的对流和辐射换热系数,并从传热学的角度,揭示了颗粒粒径对煤炭转化速率的影响机理。

Supercritical water gasification of coal is a clean and efficient coal conversion technology with great development prospect.In-depth study of flow and heat transfer characteristics in the reactor is of great significance to the design and optimization of the reactor.Based on Euler-Lagrange method and coupled with chemical reaction kinetic model,a three-dimensional transient CFD model of coal-supercritical water fluidized bed reactor for hydrogen production was established in this paper.The characteristics of flow and heat transfer in the reactor,the distribution of particles and the transformation rule of product components were studied.The numerical results provide the convective and radiative heat transfer coefficients of coal particles respectively,and reveal the influence mechanism of particle size on the coal conversion rate from the prospect of heat transfer.