关键词: 多流股换热器网络, 混合整数非线性规划, 改进遗传算法, 多样性保持算子, 并行算法结构

Abstract:

The synthesis of multi-stream heat exchanger network(MSHEN)is modeled as a mixed integer nonlinear programming problem (MINLP)that possesses large scale,many constraints and severe non.convexitv and nonlinearity,thus resulting in many local optima.The traditional gradient.based optimization algorithms fail to find the global optimum.In order to solve this problem,the genetic algorithm (GA)is adopted in this paper.Moreo-ver,to overcome the premature convergence and the dificulty in the appropriate determination of running parame.ters,an improved GA with diversity-maintaining operators and a multi-group evolution structure is proposed.in which the running parameters can be self-tuned and the simulated annealing algorithm is introduced during the evo.lution.Examples indicate that the adoption of the proposed algorithm helps solve the MINLP problem and guaran.tees the probability of finding the global optima in a MINLP problem.

Key words: multi-stream heat exchanger network, mixed integer nonlinear programming, improved genetic algo-rithm, diversity-retaining operator, parallel algorithm structure