生物质多孔燃料层辐射加热热解过程的影响因素分析

ANALYSIS OF INFLUENCING FACTORS ON THE PYROLYSIS PROCESS OF THE BIOMASS FUEL POROUS BED UNDER RADIANT HEATING

在分析辐射加热条件下生物质多孔燃料层热解过程特点的基础上,建立了该过程的传热传质模型,采取隐式和半隐式相结合的有限差分方法进行离散求解。在热解过程中,生物质燃料层未热解区、热解区和炭化区共存。热解过程为传热所控制。数值模拟结果表明,生物质物料层和焦炭层的有效导热系数、物料层初始堆积密度、加热温度和加热时间等因素对燃料层热解过程均有影响。辐射加热温度、有效导热系数的增加有助于生物质燃料层的热解过程。

A mathematical model was developed. There are three coexisting zones in the biomass fuel bed during pyrolysis of biomass which are non-pyrolyzed zone, pyrolyzing zone and coked zone. By numerical simulation, the temperature distribution, density and gas yield of the biomass fuel bed were given. It states that the whole pyrolysis process is controlled by the heat transfer. The original density of biomass bed, heating temperature by radiation and effective thermal conduction coeffeient influence the pyrolysis process of biomass fuel bed. Pyrolysis speed of biomass fuel bed increases with in- creasing heating temperature and effective thermal conduction coefficient.