微重力下煤粉燃烧的成灰及污染物生成机理的研究

Our dependence on coal will not be changed in the short term due to the "deficient oil, lean gas, rich coal" energy structure in China. Coal consumption is the first in the world, more than 70% are burned directly, resulting in a large amount of emissions of pollutants such as SO2, NOx, CO2 and inhalable particles. The understanding of physical and chemical essence and reaction mechanism in the process of coal combustion are the basis for further improving combustion efficiency and reducing pollutant emission. The bottleneck problem for observing the intrinsic combustion phenomenon is that the conventional reactor can’t eliminate the influence of gravity and buoyancy during coal combustion. This project intends to carry out the research on the ejection of volatile matter, ignition, combustion and burnout characteristics for some typical power coals at air and oxygen enriched atmosphere. The critical conditions for chemical kinetic control to diffusion control are determined by means of studies on diffusion, mass transport, heat transfer process during heterogeneous combustion. The characteristics of ash formation will be investigated for establishment of ash model in combustion. The formation mechanism for pollutants will be studied under the assistance of on-line measurement under microgravity. Further optimization of microgravity combustion reactor will provide a theoretical and technical support for future space experiments.

我国富煤、贫油、少气的能源格局短时间内不会改变。煤的消耗量世界第一，超过70%被直接燃烧，导致SO2、NOx、CO2、可吸入颗粒物等污染物的大量排放。对煤粉燃烧过程的物理化学实质及机理的研究是进一步提高燃烧效率，降低污染物排放的基础。基于常规燃烧反应器无法观测无浮力作用的本征燃烧现象的瓶颈问题，本项目拟针对我国典型动力用煤及脱挥发分煤焦，研究在微重力条件下，空气气氛和富氧气氛对煤粉挥发份的析出、着火、焦碳燃烧及燃尽特性的影响机制；通过对非均相燃烧过程中物质扩散、传输、传热过程及相关研究确定化学动力学控制向扩散控制转化的临界条件；通过对灰成分的分析研究成灰过程及模型，结合污染物在线测量研究微重力条件下污染物质的生成机理和规律；进一步优化微重力燃烧反应器，为将来的空间实验提供理论和技术支撑。

本项目拟针对我国典型动力用煤及脱挥发分煤焦，研究在微重力条件下，空气气氛和富氧气氛对煤粉挥发份的析出、着火、焦碳燃烧及燃尽特性的影响机制；通过对非均相燃烧过程中物质扩散、传输、传热过程及相关研究确定化学动力学控制向扩散控制转化的临界条件；通过对灰成分的分析研究成灰过程及模型，结合污染物在线测量研究污染物质的生成机理和规律。.此外，项目还系统分析了实践十号返回式试验卫星上煤粉微重力燃烧试验的数据结果，针对已暴露的问题我们提出了具体的优化策略，并对控制系统进行优化设计，进一步优化微重力燃烧反应器，为将来的空间实验提供理论和技术支撑。