ABSTRACT

An improved experimental methodology is presented that provides combustion data of single pulverized coal and biomass particles with a high level of detail. This is the first part of a two-article series. A stereoscopic imaging system based on four intensified CCD-cameras is calibrated for in-situ measurements of temperature, size, shape, and velocity of solid fuel particles in the diameter range of 30–300 µm. An elaborate approach for 3D shape reconstruction from orthogonal projections of single particles shows significantly improved accuracy, which is validated against particle samples being collected with a suction probe. The close-meshed combination of imaging pyrometry and shadowgraphy is a further novelty. The parallel application of both techniques provides results for both self-luminous “hot” (imaging pyrometry) and “cold” (shadowgraphy) particles. This enhances information on particle ignition (particles switch from cold to hot) and duration of char burn-out (particles switch from hot to cold). Selected experimental results are presented which demonstrate the informative power of data sets formed by this approach. Torrefied miscanthus is burned in a laminar flow reactor. The particle size and aspect ratio are evaluated for the in-situ measuring method as well as for the collected samples. The results show a good correlation between both analysis routines, indicating the progress in solid fuel characterization by the improved optical technique in combination with particle sampling.

摘要

提出了一种改进的实验方法，它提供了单个粉煤和生物质颗粒的高度详细的燃烧数据。这是两篇文章系列的第一部分。校准基于四个增强型 CCD 相机的立体成像系统，用于对直径范围为 30-300 µm 的固体燃料颗粒的温度、尺寸、形状和速度进行原位测量。从单个粒子的正交投影进行 3D 形状重建的精细方法显示出显着提高的准确性，这已针对使用抽吸探头收集的粒子样本进行了验证。成像高温测量和阴影成像的紧密结合是进一步的创新。这两种技术的并行应用提供了自发光“热”（成像高温测量）和“冷”（阴影成像）粒子的结果。这增强了有关粒子点火（粒子从冷切换到热）和烧焦持续时间（粒子从热切换到冷）的信息。选定的实验结果展示了这种方法形成的数据集的信息能力。焙干的芒草在层流反应器中燃烧。对原位测量方法以及收集的样品的粒度和纵横比进行评估。结果表明两种分析程序之间具有良好的相关性，表明改进的光学技术与粒子采样相结合在固体燃料表征方面取得了进展。这增强了有关粒子点火（粒子从冷切换到热）和烧焦持续时间（粒子从热切换到冷）的信息。选定的实验结果展示了这种方法形成的数据集的信息能力。焙干的芒草在层流反应器中燃烧。对原位测量方法以及收集的样品的粒度和纵横比进行评估。结果表明两种分析程序之间具有良好的相关性，表明改进的光学技术与粒子采样相结合在固体燃料表征方面取得了进展。这增强了有关粒子点火（粒子从冷切换到热）和烧焦持续时间（粒子从热切换到冷）的信息。选定的实验结果展示了这种方法形成的数据集的信息能力。焙干的芒草在层流反应器中燃烧。对原位测量方法以及收集的样品的粒度和纵横比进行评估。结果表明两种分析程序之间具有良好的相关性，表明改进的光学技术与粒子采样相结合在固体燃料表征方面取得了进展。焙干的芒草在层流反应器中燃烧。对原位测量方法以及收集的样品的粒度和纵横比进行评估。结果表明两种分析程序之间具有良好的相关性，表明改进的光学技术与粒子采样相结合在固体燃料表征方面取得了进展。焙干的芒草在层流反应器中燃烧。对原位测量方法以及收集的样品的粒度和纵横比进行评估。结果表明两种分析程序之间具有良好的相关性，表明改进的光学技术与粒子采样相结合在固体燃料表征方面取得了进展。