差速循环流化床的数学模型研究

Study on the mathematical model of the differential velocity fluidized bed

介绍了差速循环流化床，即利用不同气速下飞灰携带率的差异，使燃烧室内具有３个不同的气速区，形成飞灰在燃烧室的内循环，构成差速内循环。针对差速循环流化床的结构及特有形式，采用小室模型的方法，对炉内煤的燃烧及其物理、化学反应过程进行了相应的仿真计算。模型结构为模块化方式，分为流动、传热、燃烧及求解等部分；而差速循环流化床的模型又可作为一个整体模块，成为联合循环系统的一部分，为其性能预测及结构设计提供仿真计算。清华大学热能工程系根据现有技术及锅炉设备于１９９２年提出差速循环流化床的构想并获得了专利。

A internal bed material circulation in combustor is introduced, which can be established by the discrepancy of entrainment at different air velocity, and separates the combustor into three different velocity regions. According to the special structure of the differential velocity bed, a simulation calculation of the coal combustion and the physical and chemical process was carried out by the cell model. The whole model adopted different modules, such as fluidization mechanism, heat transfer, combustion and solution, which can be also taken as a part of the combined cycle to simulate the prediction performance and design structure. The scheme of the differential velocity fluidized bed was put forward by Thermal Engineering Department of Tsinghua University in 1992 and got patent simultaneously in accordance with the present technologies and boiler installation.