The Research Of Node Importance Of Heat Exchanger Network Based On Complex Network Theory

With the enhancement of scale and complexity of chemical process,the heat exchanger network of its subsystems becomes relatively complex and more difficult to take control.The heat transfer efficiency of heat exchanger in the heat exchanger network changes and its interference transfer changes the heat transfer efficiency associated with heat exchanger.Due to the serious coupling of the system,the operation and stability of the whole heat exchanger network are affected.Therefore,it is of great significance to study the importance of heat exchanger node in heat exchanger network so as to carry out the necessary monitoring and setting bypass for specific heat exchanger.First,on the basis of literature review,this paper compares various modeling methods and chooses the complex network model which is based on the heat exchanger network with interference transfer building.The paper also describes and judges the complexity,small world and degree distribution characteristics of the network.Secondly,in order to evaluate the network model comprehensively,starting from the topological structure of the network,the paper firstly calculates the degree centrality,betweenness centrality,closeness centrality and eigenvector centrality of each node of the network without considering the direction of the network.Because of the different emphases of each index,a method based on multi-attribute decision algorithm is proposed to deal with the correlation index and the importance evaluation data of heat exchanger network node based on topology structure is obtained.The direction of the network is considered.The paper adopts PageRank algorithm to evaluate the importance of the network nodes and comprehensively uses these two different algorithm results get the final conclusion.Finally,based on the theory of complex network controllability,analyzes network's adjacency matrix,combining the node importance sequencing and the necessary condition of network strict control,the paper determines the optimal drive node group needed by a set of network control.With this result,we set bypass to related heat exchanger where driving node here.The case analysis shows that the strategy is effective and it can evaluate the node importance from different views and provide data support for designing bypass of heat exchanger network.