【摘要】 多流体模型广泛用于生物质流化床快速热解过程的计算流体力学(Computational Fluid Dynamics,CFD)模拟。本文总结了常用模型对模拟结果的影响规律:热解动力学模型影响模拟结果中热解产物的分布,所预测热解产物产率的准确性随着热解模型精确程度的增加而提高;气-固曳力模型不仅影响热解产物分布,并影响着生物质/炭颗粒的夹带行为,采用考虑介尺度结构的气-固曳力模型能获得与实验更加吻合的模拟结果;在多流体模拟中往往采用简化的颗粒内传热模型描述颗粒内的传热效应,但在不同报道中该模型对模拟结果的影响存在显著差异;颗粒缩径模型可预测反应器内生物质颗粒的粒径分布,主要影响生物质颗粒的流动行为。并结合团队的研究经历,对模型的选用及未来研究方向提出了观点和建议。更多还原

【Abstract】 Multi-fluid model is widely used in the computational fluid dynamics(CFD) simulation of biomass fast pyrolysis in fluidized bed reactor.The effect laws of common models on simulation results are summarized:The pyrolysis kinetic model affects the distribution of pyrolysis products in the simulation results,andthe accuracy of the predicted pyrolysis product yield increases with the increase of the accuracy of the pyrolysis model;The gas-solid drag force model not only affects the distribution of pyrolysis products,but also the entrainment behavior of biomass/carbon particles,the gas-solid drag force model considering mesoscale structure can obtain more consistent simulation results with experiments;In multi-fluid simulation,simplified in-particle heat transfer model is often used to describe the heat transfer effect within particles,but there are significant differences in the impact of the model on the simulation results in different reports;The particle size reduction model can be used to predict the particle size distribution of biomass in the reactor,which mainly affects the flow behavior of biomass particles.Some opinions and suggestions on the selection and the future research direction of the models are put forward according to the experience of the research team.更多还原