Experimental and numerical analysis for the derivation of a dynamic solid bed model in rotary drums considering mixing and segregation processes

考虑混合和分离过程的转鼓动态固体床模型推导的实验和数值分析

• 批准号: 238769554
• 负责人: Professor Dr.-Ing. Viktor Scherer
• 金额: --
• 依托单位: Institut für Strömungstechnik und Thermodynamik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/238769554?language=en
• 关键词: Experimental; numerical; analysis; derivation; dynamic

In a process simulation for rotary kilns always transient start-up procedures appear. During the process segregation effects and different motion behaviors arise inside the bed, which are caused by the change of the filling degree and the material properties. The heat penetration into the bed is transient due to the incomplete mixing, whereby a temperature difference between the core and the surface is emerged. Furthermore the transient behavior occurs by the change in mass flow, the type of fuel, the flame control and the energy input.In this project, the existing experiences, experiments and tools of the two research institutes will be used to model the segregation and mixing behavior of mono and poly-disperse solid beds in the cross section of a rotary kiln. This model will represent the transient heat transfer into the bed and the temperature distribution in the bed in dependence of the particle size, the material properties and the operational parameters. The dynamic model (unit operation module) will then be converted into a corresponding flow sheet simulation.Starting point of the work are several experiments and phenomenological models derived therefrom, which were developed for steady state situations by one of the two research groups cooperating on this topic. The transfer of this knowledge to particulate flow systems, reflecting in a time resolved manner the effect of transient inner and outer boundary conditions, will be carried out by the second partner, using of particle based Discrete Element (DEM) simulations, which allow a rigorous description of the underlying physical processes. These simulations will be verified with already available steady state experiments and new, transient investigations conducted within the planned project. The results obtained will be introduced into the unit operation module under development and will be used to complement and modify the already known relations and equations.

在回转窑的过程模拟中，总是会出现瞬态启动程序。在此过程中，由于填充程度和物料性质的变化，床内会出现偏析效应和不同的运动行为。由于混合不完全，渗透到床中的热量是瞬态的，因此在核心和表面之间出现温差。此外，瞬态行为是通过质量流量、燃料类型、火焰控制和能量输入的变化而发生的。在该项目中，两个研究所的现有经验、实验和工具将用于模拟分离和混合回转窑横截面中单分散和多分散固体床的行为。该模型将代表进入床的瞬态热传递以及床中的温度分布，这取决于颗粒尺寸、材料特性和操作参数。然后，动态模型（单元操作模块）将转换为相应的流程图模拟。工作的起点是几个实验和由此得出的唯象模型，这些模型是由两个合作研究小组之一针对稳态情况开发的。话题。将这些知识转移到颗粒流系统，以时间分辨的方式反映瞬态内部和外部边界条件的影响，将由第二个合作伙伴使用基于粒子的离散元 (DEM) 模拟进行，该模拟允许严格的底层物理过程的描述。这些模拟将通过现有的稳态实验和计划项目中进行的新的瞬态研究进行验证。所得结果将被引入正在开发的单元运行模块中，并用于补充和修改已知的关系式和方程。