基于结构多样性评价的换热网络全局最优化

针对启发式方法在优化换热网络时由于个体团聚而出现搜索能力下降，建立一种换热网络结构多样性评价方法，对种群中个体结构团聚程度进行衡量，并指导算法改进.对种群进行集团划分，将一定数目的具有公共结构的个体归为一个集团，从而得到个体结构分布；提出分散搜索策略，对于各集团中除集团最优个体外的其它个体，从其公共结构中随机选择若干个换热器进行摄动以分散集团中的个体结构；提出集中搜索策略，通过使其它个体获得最优集团对应公共结构以加强对较优结构的集中开发；采用9股流与15股流两个算例，验证分散搜索策略增强了全局搜索能力，集中搜索策略增强了局部搜索能力，优化结果分别较原算法降低了7 008针对启发式方法在优化换热网络时由于个体团聚而出现搜索能力下降,建立一种换热网络结构多样性评价方法,对种群中个体结构团聚程度进行衡量,并指导算法改进.对种群进行集团划分,将一定数目的具有公共结构的个体归为一个集团,从而得到个体结构分布;提出分散搜索策略,对于各集团中除集团最优个体外的其它个体,从其公共结构中随机选择若干个换热器进行摄动以分散集团中的个体结构;提出集中搜索策略,通过使其它个体获得最优集团对应公共结构以加强对较优结构的集中开发;采用9股流与15股流两个算例,验证分散搜索策略增强了全局搜索能力,集中搜索策略增强了局部搜索能力,优化结果分别较原算法降低了7 008■·a~(-1)与17 973■·a~(-1)且均优于文献结果.

Global Optimization of Heat Exchanger Network Based on Structure Diversity Evaluation

Individual gathering could cause decline of search ability as heuristic methods are applied to heat exchanger network (HEN) optimization. An evaluation methodology for HEN structure diversity was designed to measure degree of individual structure gathering, and guided algorithm improvement. Firstly, group division of population was performed, individuals of a certain scale with a common structure were classified as a group to get individual structure distribution. Then dispersal search strategy was proposed to give perturbation to heat exchangers randomly selected from common structure of individuals in each group except the best one, which aimed at dispersing individual structures in groups. Concentration search strategy was then proposed to enhance exploitation for excellent structure by making other individuals accept a common structure of the optimal group. Finally, two cases involving nine and fifteen streams proved that dispersal search strategy strengthened global search ability and concentration search strategy strengthened local search ability. It obtained results decreased by 7 008 $·a^-1 and 17 973 $·a^-1, respectively, compared to those obtained by original algorithm. They are superior to results in literature.