催化裂化过程动态模型及仿真──Ⅰ．过程动态模型

FLUID CATALYTIC CRACKING PROCESS DYNAMIC MODEL AND SIMULATION ──Ⅰ. PROCESS DYNAMIC MODEL

催化裂化过程动态仿真系统的开发是实施过程行为分析、过程控制和优化的关键。基于物料衡算、热量衡算和反应动力学建立的催化裂化过程动态模型是具有非线性、分布参数的模型形式。虽然一组偏微分方程可为系统的动态行为提供严格的数学描述，但这种模型结构并不适宜于系统的动态特性分析，故采用对空间离散化的分段处理方法把模型转化为非线性的集中参数模型。为便于过程的仿真研究，应用现代控制论中的状态空间法把非线性模型线性化以得到催化裂化这一高维、非线性、强耦合、时变、分布参数，且带有时延和不确定性过程的简化的九阶状态空间模型。

In this paper, a dynamic simulation system for fluid catalytic cracking process is developed. The system provides the basis for carrying out process dynamic behavior analysis, process controland optimization. Based on the material balance, energy balance and reaction kinetics, a dynamic model,having the form of a nonlinear distributed parameter has been presented for catalytic cracking process. Although a set of partial differential equations can give a strict mathematical description of system dynamicbehavior, it is not suited for the system dynamic characteristic analysis. The distributed parameter modelis then transformed into a lumped parameter model by discretizing the spatial variables. Applying the statespace method in modern cybernetics to model simplification, a ninth-order state space model for thecatalytic cracking process, characterized by the multidimensional, nonlinear, highly coupled,time-dependent and distributed parameters with time delay and uncertainty, is proposed.