Simultaneous optimization of combined heat and mass exchange network synthesis considering lean stream bypass
Combined heat-mass exchange network(CHMEN)is an important field in system engineering.Processing the lean stream in the mass exchange subnetwork can effectively recover the excess heat in the mass transfer process and achieve efficient mass and heat transfer.The current simultaneous optimization methods ignore the impact of lean stream bypass on the structure and annual total cost of the CHMEN.Therefore,this paper proposes the intermittent heat exchange strategy based on the lean streams bypass transformation to develop the node-unstructured model,before that the coupling relationship between the mass exchanger sub-network and the heat exchanger sub-network is analyzed.On the one hand,the lean stream with single heat exchange property is divided into some streams to undertake stepwise heat exchange tasks,expanding network structure.On the other hand,the difference of the location of the lean streams bypass will also affect the optimization effect.Moreover,it is difficult to obtain the best solution due to the wide domain of the mathematical model,so random walk with compulsive evolution algorithm is adopted,where accepting bad solutions ensures the global search ability.The simultaneous optimization method proposed in this paper is used for two CHMEN examples.The results show that a new network structure can be found via changing the position of the lean streams bypass,improving the structural diversity.Meanwhile,the annual total cost is reduced through structure variation.This method is of great significance for the further promotion of energy conservation and emission reduction.
process systemsmodelcombined heat and mass exchange networkalgorithmlean streams bypass
万方数据
维普
