我国北方农村地区推广生物质成型燃料替代散烧煤清洁取暖需求巨大。生物质成型燃料通常在户用采暖炉具内呈堆积体布放，形成物质与无序孔道网络耦合的特殊结构，加之自然引风条件下烟气流场属介于层流和湍流间的过渡态，无法直接套用传统的生物质热解机理解释该过程。.基于燃料在过渡态流动气氛下热解过程呈现出的分层特征，本项目将结合模型模拟与实验研究，探明燃料单颗粒、薄层在过渡态流动氛围下热解的物质迁移、转化路径与能量传递机理；构建基于分形理论的孔道网络堆积体动态热解模型，揭示多因素协同扰动下堆积体内能流网络这一“黑箱过程”的变化机制。运用仪器分析手段，追踪、定位、解析热解产物经随机路径与相邻薄层（不同热解阶段）物质共反应生成的次级产物，逆向解构过渡态气氛下气-固、气-气跨层反应机理，阐明无序孔道网络下热解条件与产物的内在关联机制。预期将推动生物质成型燃料清洁取暖装置技术进步，提高能量利用效率，减少污染物排放。

The demand of biomass pellet fuels using as an alternative for clean space heating instead of raw coal is booming in rural areas of Northern China. Biomass pellets are often placed inside chamber of a stove as multiple-deck stacked bulk state, resulting in a coupling structure of both fuels and disordered porous network. Moreover, the flow field under natural airflow draft is a transition state between laminar flow and turbulent flow, which could not be directly described by traditional mechanism for biomass pyrolysis..Since the pellets showed significant layers during pyrolysis, this project combines modeling, simulation and experimental analysis to determine the migration and transformation paths of pyrolyzed products and energy transfer mechanism of single kernel and thin layer of biomass pellets under the transition flow atmosphere. A dynamic pyrolysis model based on fractal theory will be established to tackle the black box process for energy and flow network of biomass pellet multiple-deck stacked bulk under multiple-factor synergistic disturbance. It is proposed that secondary products generated from co-reaction between pyrolysis products and adjacent layer at different pyrolysis stages will be tracked, determined and analyzed by hi-resolution instruments. Reverse deconstructions of gaseous-solid and gaseous-gaseous reaction mechanisms under transition atmosphere will be performed to convince the internal co-mechanism of pyrolysis conditions and product based on disordered porous network. It is expected that the results of the investigation will promote the development of clean space heating technology using biomass pellet fuels, improve the energy utilization efficiency and reduce the emissions.