生物质掺混煤粉富氧燃烧中O2/CO2气氛和生物质对着火与燃烧稳定性的影响机制的实验与理论研究

Coal-biomass co-oxyfuel combustion is regarded as a promising large-scale CO2 “negative emissions” technology. In present study, experiment, theoretical analysis and numerical simulation will be used to study the effect mechanism of O2/CO2 atmosphere and biomass on the ignition and combustion stability under coal-biomass co-oxyfuel combustion. TG/DTG, drop tube furnace and entrained flow reactor will be used to study the effects of O2/CO2 atmosphere and biomass on the devolatilization process, char formation and combustion, and macro reaction kinetic equations of these sub-processes. Detail reaction mechanism of the volatile of the coal-biomass mixture for oxyfuel combustion will be study according to the reaction kinetic theory and experimental results, and the ignition and extinguish of the volatile under the condition of oxyfuel combustion will be study using this mechanism. A two-stages heating quartz fixed bed reactor will be used to study the synergistic effect between coal and biomass based on the composition of products. Some optical measurement methods will be used to record the ignition process during coal-biomass co-oxyfuel combustion, and the effect mechanism on the ignition will be researched using ignition model. Large-eddy simulation for coal-biomass co-oxyfuel combustion will be study in order to study the combustion stability combined with the experimental results from the vertical furnace.

生物质掺混煤粉富氧燃烧被认为是一种很有前景的大规模CO2“负排放”技术。本研究采用实验、理论分析和数值模拟相结合的方法，研究O2/CO2气氛和生物质对生物质掺混煤粉富氧燃烧的着火和燃烧稳定性的影响机制。采用TG/DTG、 滴管炉和层流曳带流反应器等台架，研究O2/CO2气氛、生物质对混合燃料在富氧条件下的脱挥发分过程、成焦特性以及燃烧的影响特性及子过程的宏观反应动力学机理。根据反应动力学理论和实验测量，研究适合混合燃料挥发分的详细反应动力学机理，并研究其富氧燃烧中的着火与熄灭机制。采用两段加热石英固定床反应器，基于产物组分研究富氧燃烧条件下生物质与煤粉的协同作用机制。采用光学测量手段捕捉生物质掺混煤粉富氧燃烧的着火过程，结合建立的着火模型，分析生物质掺混煤粉富氧燃烧的着火机理及影响机制。构建并利用生物质掺混煤粉富氧燃烧的大涡模拟程序，结合垂直燃烧炉的实验结果，研究燃烧稳定性的影响机制.

本研究采用实验、理论分析和数值模拟相结合的方法，研究生物质掺混煤粉富氧燃烧过程中O2/CO2气氛和生物质对混合物的着火和燃烧稳定性的影响机制。首先采用热重分析法和滴管炉研究O2/CO2气氛和生物质对混合燃料在富氧条件下的脱挥发分过程、成焦特性以及燃烧的影响特性及子过程的宏观反应动力学机理。采用自主搭建的激波管台架测量了挥发分在O2/CO2气氛下的着火延迟时间，并根据反应动力学理论提出了挥发分的详细燃烧反应动力学机理Oxymech 2.0 Plus。采用Hencken平焰燃烧器和光学测量技术对富氧燃烧条件下生物质与煤粉的协同作用机制进行了研究，发现生物质中的纤维素和煤粉的在脱挥发分过程中的协同作用导致了生物质与煤粉的在均相着火和焦着火上的协同作用。采用滴管炉结合光学测量手段捕捉单颗粒生物质掺混煤粉富氧燃烧的着火过程，结合建立的着火模型，分析生物质掺混煤粉富氧燃烧的着火机理及影响机制。