Heat exchange network(HEN)synthesis is an important part of chemical process system engineering. Time,equipment and scheduling should be considered regarding to the design of the HEN for batch process,which brings complexity to the design of batch process. This paper focused on direct heat integration for multi-stage batch process considering scheduling. By using overlapping and non-overlapping operation and adjusting the limited cycle time,the opportunity of direct heat exchange was increased and the equipment idle time was reduced. Thus,three different production plans were obtained. Then for each production plan,an initial HEN was synthesized using heuristic method. Based on this method,HEN structure evolution was conducted by using the proposed progressive evolution rules and the trade-off between utility cost and equipment cost. After that,the number of heat exchangers and the branch streams was decreased. HEN with minimum total annual cost and less heat exchangers was gotten. The comparison between the three plans shows the scheduling effect on the HEN synthesis. Finally,an example was used to show the application and effectiveness of the proposed method.%间歇过程换热网络综合是化工系统工程研究的重要部分,设计时需要考虑时间、设备、生产排序等多方面因素,具有一定的复杂性.本文围绕多批次间歇过程的直接换热问题,考虑生产排序的影响,采用覆盖操作和非覆盖操作,通过调整批间隔增加流股直接换热的可能性,减少设备闲置,得到3种不同的生产方案;针对每一个生产方案,采用启发式方法综合得到初始换热网络,并对该网络进行结构调优,提出渐进调优规则,在公用工程费用和设备费用间作权衡,减少换热器个数和流股分流,得到年度总费用最低且换热设备个数较少的换热网络,使其更符合实际应用;将3种生产方案对比,可以发现生产排序对换热网络的影响.最后将所提方法应用于实际算例,验证所提方法的可行性.
展开▼
