基于Petri Net的动态并发特性和逻辑表述能力,构造最小传热温差优化、夹点分析、网络综合及结构调优模块。首先,根据Petri Net激发规则和垂直传热原则,实现最小允许传热温差的优化;然后,根据Petri Net四则运算机制,实现夹点分析数据流辗转传递,确定夹点、最大热回收和最小冷、热公用工程等信息;进而,根据Petri Net监督学习机制,拓扑夹点设计可行性经验规则,综合初始换热网络结构;最终,根据Petri Net自组织机制,通过断裂环路、松弛路径,实现换热网络渐进调优。通过实例计算说明提出方法的可行性和有效性。
Based on the logic expression of Petri Net and its dynamic and concurrent characteristics,optimization modules were established for the minimum heat transfer temperature difference,analysis and synthesis of pinch design.First,with the excitation rule of Petri Net and vertical heat transfer,the minimum temperature difference was optimized.Secondly,data was transferred in the modules according to the arithmetic mechanism of Petri Net,so that the pinch point,the maximum heat recovery,the minimum loads of cold and hot utility were determined.Then,the initial heat exchanger network was synthesized based on the heuristic feasible rules for pinch design and the supervision mechanism of Petri Net.Finally,an evolutionary heat exchanger network was obtained by loop fracture and path relaxation according to the self-organizing mechanism of the Petri Net.An example was presented to demonstrate the validity and advantages of the proposed approach.