热集成精馏系统优化和控制策略

Dynamic Optimization and Control Strategy of a Heat-Integrated Distillation Column System

热集成精馏系统是精馏过程中有效的节能操作方式,节能效果可达50%.为了能够达到理想的节能效果,必须对这两个塔进行合理的操作和控制,否则,反而会影响正常的生产.但由于采用了该热集成操作方式,使得两个塔之间的关联变得十分严重,给系统的操作和控制带来了很大的难度.考虑热集成精馏系统的进料为主要干扰时,提出了在保证产品质量的前提下,以最小能耗为目标的动态优化和控制二级策略.在该二级策略中,上一级为以最小能耗为经济目标的动态优化,其优化结果作为下一级的优化给定值,下一级是跟踪上一级优化结果的多变量控制.

Heat integration distillation system is an effective method of saving energy in the process of distillation, with 50% energy saved. To obtain an ideal energy saving effect, we nmst make a reasonable operation and control of the two columns, otherwise the normal production will be aftcted. However, the adoption of such heat integration operational method leads to a severe association between the two columus, and thus a significant difficuhy in operating and controlling the system. With guaranteeing the quality of products as its precondition , and with the minimum cost of energy as its purpose, this paper suggests a secondary stragegy of dynamic optimization and control when the feed of the heat integrated distillation system is regarded as a main disturbance. In the secondary strategy, the upper level is the economic optimization with minimum cost of energy as its purpose, and its optimized result is the given value of the optimization of the lower level, which is the multivariable control to track the optimal reference trajectories calculated on the upper level.