基于模拟分析技术和随机搜索算法的化工过程能量集成方法研究

夹点和模拟分析技术已在化工能量集成中广泛应用.今以夹点技术为基础,对化工过程系统用能进行诊断,根据"过程用能一致性"原则提出能量集成改造方案,通过改变塔压实现塔顶冷凝器与塔底再沸器的热集成多效蒸馏.夹点技术实现的优化目标仅是热回收最大或公用工程能耗最小,不能实现包括设备整体费用最小的过程全局最优化.研究基于模拟技术,通过灵敏度分析,得到精馏塔各操作参数的样本映射数据,通过多项式拟合得到参数关联方程,并在遗传算法及模式搜索中设计过程费用函数,提出了将模拟分析技术与随机搜索算法相结合的,以过程费用函数最小化为优化目标的能量集成方法.工业实例的成功设计应用证明了其有效性和可行性.

Energy Integration Based on Simulation Analysis and Stochastic Search

Pinch analysis technology has been widely used for energy integration throughout the process industry. However, it targets only the minimization of energy cost rather than total cost function minimization which includes the investment cost in addition to the utility cost. Here a study on energy integration of process system was presented, which is based on combined applications of Stochastic Search and Simulation Analysis. Simulation and pinch analysis is implemented on ASPEN engineering suite, and Genetic Algorithm (GA) and Pattern Search (PS) are implemented in MATLAB toolbox. After simulating the process system in AspenPlus, the stream data are generated automatically by the interface between AspenPlus and AspenPinch, then the heating and cooling curves are drawn in AspenPinch, via which ways of debottlenecking for energy integration are found. An appropriate Cost Function of process system is easily embedded in GA or PS, which helps target the cost function minimization in process system. The energy integration of petrochemical gas separation plant was taken as a case to demonstrate the validity and feasibility of the proposed method.