Abstract:

When optimizing the synthesis of heat exchange networks, the optimization of integer variables, which are structural variables, is a major challenge due to the mixed integer nonlinear nature of the problem. It is found that the dominant position of the pre-generated heat exchange units, the strong coupling relationship between the units and the limitation of accepting the difference solution are the reasons for the optimization falling into local extremum. To tackle these issues, a strategy for strengthening the competitiveness of heat exchange units was proposed. This strategy involved generating competitive heat exchange units at specific intervals, disrupting the original stable network structure, and redistributing the heat load of flow heat exchange units to enhance the viability and competitiveness of the competitive units. It diminished the advantageous position of the original structure and reinforces unit competition by imposing heat load gaps and mandating the acceptance of competitive structures. This approach eliminated disadvantaged structures, enriches structural diversity, and broadened the search domains. The influence of the generation cycle of competitive units, the quantity of competitive units, and the reallocation ratio on the strategic role was also examined. Verification using 20sp and 10sp examples produced results of 1717757.75USD/a and 5586693USD/a, respectively, confirming the effectiveness of the proposed strategy.

Key words: algorithm, optimize design, process system, optimization of heat exchange network, integral variables, competition of heat exchange units

摘要：

在优化换热网络综合这一混合整数非线性问题时，作为结构变量的整型变量优化是一大难点。研究换热网络结构优化过程中的障碍，发现前期生成换热单元占据优势地位、单元之间的强耦合关系以及接受差解局限性是优化陷入局部极值的原因。为此，本文提出了换热单元竞争强化策略，通过间隔一定周期在结构中生成竞争换热单元，破坏网络原有稳固结构，然后进行流股换热单元热负荷再分配，来提升竞争单元生存能力和竞争能力，削弱原有结构的优势地位。并通过流股热负荷缺口设置和竞争结构的强制接受强化单元竞争来消去劣势结构，提升结构多样性和搜索域。讨论了竞争单元生成周期、竞争单元数量以及再分配比例对策略作用的影响。通过20sp和10sp算例进行验证，得到了1717757.75USD/a和5586693USD/a的结果，验证了策略的有效性。

关键词: 算法, 优化设计, 过程系统, 换热网络优化, 整型变量, 换热单元竞争