Liang Dongyu
A. Leon Linton Department of Mechanical, Robotics and Industrial Engineering, Lawrence Technological University, Southfield, MI, 48075, United States.
Heliyon. 2024 Nov 15;10(22):e40419. doi: 10.1016/j.heliyon.2024.e40419. eCollection 2024 Nov 30.
Co-firing of biomass with coal combines the environmental benefits of renewable biomass with the high energy content of coal. Although the common numerical simulation treats the biomass and coal particles with ideal morphology, real particles often demonstrate nonsmoothed surface and irregular shape. To understand the impact of particle morphology in a group of biomass and coal particles co-firing together and to inform simple models appropriate, this study investigated the interparticle effects among particles using realistic particle morphology, focusing on fluid dynamics such as temperature distribution, flow patterns and drag coefficients. Particle-scale computational fluid dynamics (CFD) simulations using micro-CT imaging showed that realistic particle shapes resulted in nonuniform flow fields and temperature distributions with different reaction intensities due to the species transportation. It is in contrast to traditional ideal shape models, which often rely on simplified spherical representations of particles and cannot capture the intricacies of real particle shapes. Realistic models revealed more complex surfaces, highly irregular particle structures, and varied reaction zones that affected the overall dynamics. In addition, changing the orientation of one particle affects the combustion characteristics of neighboring particles. This effect is also not captured while using the spherical structure. These differences underscore the critical impact of particle morphology on drag and heat transfer, thereby challenging conventional spherical models. The findings of this study advocate for a paradigm shift in CFD modeling approaches, emphasizing the importance of realistic particle representation to improve the accuracy of predictions and enhance the co-firing system efficiency.
生物质与煤的混烧将可再生生物质的环境效益与煤的高能量含量结合在一起。尽管常见的数值模拟将生物质和煤颗粒视为具有理想形态，但实际颗粒通常呈现出不光滑的表面和不规则的形状。为了了解颗粒形态对一组共同燃烧的生物质和煤颗粒的影响，并为合适的简单模型提供依据，本研究使用实际颗粒形态研究了颗粒间的相互作用，重点关注诸如温度分布、流动模式和阻力系数等流体动力学。使用微CT成像进行的颗粒尺度计算流体动力学（CFD）模拟表明，由于物质传输，实际颗粒形状导致了不均匀的流场和温度分布，且反应强度不同。这与传统的理想形状模型形成对比，传统模型通常依赖于颗粒的简化球形表示，无法捕捉实际颗粒形状的复杂性。实际模型揭示了更复杂的表面、高度不规则的颗粒结构以及影响整体动力学的不同反应区。此外，改变一个颗粒的方向会影响相邻颗粒的燃烧特性。在使用球形结构时也无法捕捉到这种影响。这些差异凸显了颗粒形态对阻力和传热的关键影响，从而对传统的球形模型提出了挑战。本研究的结果主张在CFD建模方法上进行范式转变，强调实际颗粒表示对于提高预测准确性和提高混烧系统效率的重要性。
