关键词: 换热网络, 非等温混合, 压降, 遗传/模拟退火算法, 混合整数非线性规划

Abstract: Pressure losses produced in streams flow through heat exchangers network is an important influencing factor of the heat exchangers network synthesis，and it also contributes to steady-state operation of the heat exchanger network. So the capital & operating costs of pumps should be considered together with the costs of heat exchangers equipment and utilities. Based on the model of non-isothermal mixing of splits stage-wise heat exchangers network superstructure，this paper presented MINLP model for simultaneous synthesis of heat exchangers network，and the heat-transfer coefficients were considered as the function of the velocity of streams instead of as constants. The total annual cost of the heat exchangers network was chosen as the objective function，and the capital & operating costs of pumps were also taken into consideration. The improved GA/SA was used to solve this mathematical model and optimal values of pressure drop and heat-transfer coefficients of streams were obtained. Finally，the validity and reliability of the proposed method were verified with an example，the objective to simplify the heat exchangers network and reduce the total annual cost of the heat exchangers network were achieved.

Key words: heat exchanger network, non-isothermal mixing, pressure drop, genetic/simulated annealing algorithm, MINLP