基于节点非结构模型的换热网络结构多样性分析及改进优化策略

强制进化随机游走算法优化换热网络过程中会出现个体结构相似现象，导致种群结构多样性下降，算法全局搜索能力不足，难以进一步优化换热网络结构。针对基于节点非结构模型的换热网络结构相似现象展开研究，制定两个评价指标衡量优化过程中个体结构相似水平，发现个体结构内相似换热单元数逐步增加，而相似换热单元的热负荷差距逐步减小，个体结构相似水平越来越高。基于此，以提升种群多样性为指导，提出换热单元排斥性进化策略，通过增大相似换热单元的热负荷差距，激励相似换热单元的差异性进化，从而改变结构进化方向，降低相似结构规模。最后应用20SP和15SP两个算例验证该策略的有效性，结构年综合费用与文献最优结果相比分别下降了12 105＄·a^-1和52 535＄·a^-1，说明该策略可以有效提升算法全局搜索能力。

Structural Diversity Analysis and Improved Optimization Strategy of Heat Exchanger Networks Based on NW-NSM Model

In optimizing heat exchanger networks by random walk algorithm with compulsive evolution (RWCE), individual structures become similar, which leads to a decline in population diversity and algorithmic global search capability. It becames difficult to optimize the structure of heat exchanger networks further. To explore similarity of individual structures, two evaluation indexes were established to measure similarity level of individual structures.It was found that the number of similar heat units in individual structure increases gradually and the difference of heat load between similar heat units decreases during the optimization process which resulting the evolution of individual structures in the same direction. Therefore, taking the improvement of population diversity as guiding direction, a repulsive-evolution strategy for heat units was proposed. It changes the direction of structure evolution and reduces the scale of similar structure through increasing the heat load gap of similar heat exchange units and promoting differential evolution of similar heat exchange units.Finally, 20SP and 15SP were used to verify effectiveness of the strategy. Total annual cost of the structure saved 12 105 ＄·a^-1 and 52 535 ＄·a^-1, respectively, compared with the optimal result in literature, which indicating that the strategy enhances the algorithmic global search capability effectively.