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，往往会出现瞬态启动过程。在此过程中，由于充填程度和物料性质的变化，料层内部产生了不同的运动行为和偏析效应。由于混合不完全，热量渗透到床层中是短暂的，从而在核心和表面之间出现温度差。此外，瞬态行为发生的质量流量的变化，燃料的类型，火焰控制和能量输入。在这个项目中，现有的经验，实验和工具的两个研究所将被用来模拟的单分散和多分散固体床的分离和混合行为在回转窑的横截面。该模型将代表进入床层的瞬态热传递和床层中的温度分布，其取决于颗粒尺寸、材料性质和操作参数。动态模型（单元操作模块）将被转换成相应的流程模拟。工作的起点是几个实验和由此导出的现象学模型，这些模型是由两个研究小组之一在此主题上合作开发的稳态情况。将这一知识转移到颗粒流系统，以时间分辨的方式反映瞬态内外边界条件的影响，将由第二个合作伙伴进行，使用基于颗粒的离散元（DEM）模拟，允许严格描述基本的物理过程。这些模拟将通过现有的稳态实验和计划项目内进行的新的瞬态调查进行验证。所获得的结果将被引入正在开发的单元操作模块，并将用于补充和修改已知的关系和方程。