This study delves into the combustion behavior of various lignite types within a circulating fluidized bed boiler (CFBB), with a primary focus on the impact of different bed material sphericity ratios (0.5, 0.7, and 0.9). Utilizing bed material with a sphericity ratio of 0.9 sourced from the Çan power plant and verified through experimentation, the research reveals several key findings. Notably, furnace temperatures tended to rise with higher sphericity ratios, albeit with variations between lignite types, particularly highlighting the complexity of this relationship in the case of GLI-Tunçbilek lignite. Pressure levels in the combustion chamber remained consistent across different sphericity ratios, indicating minimal influence on pressure dynamics. Improved combustion efficiency, especially at the bottom of the boiler, was observed at lower sphericity levels (0.5 and 0.7) for Çan lignite, as reflected in CO mole fractions. While NO emissions generally decreased with lower sphericity, the sensitivity to sphericity varied by lignite type, with Ilgın lignite showcasing low NO but high SO emissions, underscoring the intricate interplay between lignite properties, sphericity, and emissions. Overall, this study advances our understanding of CFBB combustion dynamics, offering insights valuable for optimizing performance and emissions control, particularly in lignite-based power.

中文翻译：

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循环流化床锅炉不同床料球度下劣质褐煤燃烧特性的数值研究

本研究深入研究循环流化床锅炉 (CFBB) 内各种褐煤类型的燃烧行为，主要关注不同床料球形比（0.5、0.7 和 0.9）的影响。该研究利用来自 Çan 发电厂的球度比为 0.9 的床料并通过实验验证，揭示了几个关键发现。值得注意的是，尽管褐煤类型之间存在差异，但炉温往往会随着球度比的升高而升高，特别是在 GLI-Tunçbilek 褐煤的情况下凸显了这种关系的复杂性。燃烧室中的压力水平在不同的球形比下保持一致，表明对压力动态的影响最小。在较低的球形度水平（0.5 和 0.7）下，可以观察到 Çan 褐煤的燃烧效率有所提高，特别是在锅炉底部，如 CO 摩尔分数所反映。虽然 NO 排放量通常随着球形度降低而降低，但对球形度的敏感性因褐煤类型而异，Ilgın 褐煤表现出较低的 NO 排放量和较高的 SO 排放量，强调了褐煤特性、球形度和排放之间复杂的相互作用。总体而言，这项研究增进了我们对 CFBB 燃烧动力学的理解，为优化性能和排放控制提供了宝贵的见解，特别是在褐煤发电方面。