以聚烯烃产量与质量同时提升为目标，结合“持液操作”和“多区循环流动”的传递与反应特征，1.项目构建烯烃聚合新反应器——持液多区循环流化床，自主搭建反应器并进行实验测量。2.针对该反应器，理论分析反应器内颗粒受力，建立颗粒碰撞概率模型，采用模型并结合实验确定床层内流场操作稳定区域。3.在稳定区域，引入液体蒸发模型并应用计算流体力学模拟方法建立描述反应器中气-液-固的宏观流场模型，基于群体衡算和矩方法分别建立描述聚合物颗粒群行为的介尺度模型和描述聚合物微观流场的微观动力学模型。用本组提出的“关键参数传递”方法耦合三个尺度模型，建立描述反应器内多尺度流场的反应器模型。4.采用以上模型尤其反应器模型并结合实验数据对实际工况进行模拟获取新型流化床设计、稳定操作依据和产能与产品质量同时提升规律。研究成果将推进基于实验、理论分析并耦合数值模拟进行聚合反应器工程开发和优化设计的研究进展。

To achieve the enhancement of both productivity and quality of the polyolefin products simultaneously, this project firstly aims to construct a new type polymerization reactor (i.e. liquid-holdup multi-zone circulating fluidized bed polymerization reactor) based on the transfer and reaction characteristics of liquid-holdup operation and multi-zone circulating flow. The setup will be built for experimental study. Secondly, a particle collision model will be developed according to theoretical analysis of the particle force balance in the reactor. The stable operation region will be determined based on the developed model and experimental analysis in this study. Thirdly, liquid evaporation model will be coupled with computational fluid dynamic (CFD) model to describe the macroscale gas-liquid-solid flow behavior within stable operation region. The mesoscale model for description of particle behaviors and microscale kinetic model for simulation of microscopic polymer flow will be built based on population balance model (PBM) and quadrature method of moments (QMOM), respectively. A multi-scale model will be developed by coupling the sub-models in the three scales using the “key parameter transfer” method proposed in our research group. Lastly, this proposed model together with experimental data will be applied to simulate the production of polyolefin based on actual operating conditions. It will assist in guiding the design of new reactor, obtaining the stable operating conditions and optimizing the productivity and quality of products. This work will promote the development of polymerization engineering in terms of design and optimization of the reactor based on experimental study, theoretical analysis and numerical simulation.