聚丙烯Unipol流化床反应器建模的重要算法——循环气密度实时计算

An important algorithm for modeling Unipol fluidized bed reactor--Real-time calculation of circulating gas density

在APC系统中或是在现有DCS系统实现高级自动控制功能,对反应器的建模是其关键步骤。聚丙烯Unipol流化床建模的基础之一是对反应器循环气密度进行实时计算,它是计算表观气速、床重的必须参数。因反应器内是多组分、多相(液相、气相混合),使得计算较为复杂。DOW化学公司已经在其APC系统中实现了这一功能,然而这些定律是有专利权且机密的,并未公开。本文阐述如何自行利用BWRS方程进行循环气密度实时计算,其有助于UNIPOL工艺的聚丙烯工厂实现APC系统国产化及装置利用ASPEN系统实现高级的自动化控制。

The modeling of the reactor is the key step to achieve advanced automatic control functions in the Advanced Process Control(APC)system or in the existing Distributed Control System(DCS)system.One of the foundations of polypropylene(PP)fluidized bed modeling of UNIPOL process is the real-time calculation of the reactor circulating gas density,which is a necessary parameter for superficial gas velocity and bed weight.The calculation is complicated in that the reactor is multi-component and multi-phase(mixed with liquid and gas).DOW Chemical Company has implemented this function in its APC system,but related laws are patented and confidential,which has not been made public.This article explains how to use the Benedict-Webb-Rubin(BWRS)equation to calculate the circulating gas density in real time,which helps the plants of UNIPOL process to realize the localization of the APC system and the plants to realize the advanced automatic control making use of the ASPEN system.