流态化技术与计算机模拟

Fluidization technology and computer simulation

流态化技术作为一门新的化工学科已有60年的发展史。流态化技术已被广泛应用于煤的气化和燃烧、石油的催化裂化、矿物的焙烧、颗粒物料的制备、生物质的加工等过程工业。气泡、颗粒聚团(絮团)、液滴的存在及其尺寸和浓度的不均匀分布是聚式流态化床内部结构的特征。这种不均匀结构大大降低了流态化床中气、液、固相间的接触效率。聚式流态化的散式化,流态化床结构的理论预测和优化调控,流态化床中流动、传递和化学反应的计算机模拟是当前流态化技术研究的热点课题。由于计算机的帮助,流态化技术进入了一个高速发展的阶段。流态化技术的研究方法需由单一的实验研究改变为实验研究、理论分析和计算机模拟三者相结合。计算机模拟将成为流态化床结构预测与优化调控以及流态化床设备放大的有力手段。

Fluidization as a new subject of chemical engineering has undergone 60 years development. Fluidization technology has been applied in many process industries such as coal combustion and gasification, catalytic cracking of petroleum, ore roasting, preparation of particle materials, biomass processing. The existence of gas bubbles, particle agglomerates and clusters, and liquid drops in fluid- ized beds and their heterogeneous distribution in size and in concentration are the characteristics of structure of aggregative fluidized beds. This heterogeneous structure greatly reduced the contacting efficiency among gas, liquid, and solid phases. The particularization of the aggregative fluidization, the theoretical prediction and optimal adjustment of the fluidized bed structure and the computer simulation of flow, transfer, and chemical reaction in fluidized beds are the focal issues of the fluidization technology. With the help of computer, the study of fluidization reaches a stage of high speed development. The research method of fluidization should be changed from alone experimental investigation to combination of experimental investigation, theoretical analysis, and computer simulation. The computer simulation will become the powerful means for the prediction and optimal adjustment of the fluidized bed structure, and the scale up of fluidized beds.