| The efficiency of heat transfer process has a significant impact on petrochemicalindustry energy and other fields of energy efficient use energy. Until now, the heatexchanger network optimization technology is a hot spot in the field of the process ofsystem research worldwide. At present, some optimization methods such as Pinch tech-nology, mathematical programming and heuristic methods are used in the optimizationof heat exchanger networks widely and maturely, however, with the shortage ofoptimization and calculation technology, they meet a bottleneck difficult to breakthrough in the face of networks with mixed-integer nonlinear factors. So, the concept ofheat exchanger networks integral strengthen is presented and the factor of temperaturedifference uniformity of evaluating of the effectiveness of heat exchanger networks wasestablished, based on studying optimization methods of them, the field synergy theoryand optimization of temperature difference uniformity principle. Then the application ofintegral strengthen technology is studied to improve networks efficiency essentially inthe paper.Firstly, the optimization methods of heat exchanger networks using the coordinaterotation and steepest descent method are established respectively, and the optimizingefficiency and quality of them are compared as for the same problem. The results showthat the first one is better at aspect of the efficiency and quality to the optimization ofnetworks, which is a mixed-integral nonlinear programming problem.Secondly, the fields of thermal flowing and temperature difference are analyzed basedon the field synergy, and the concept of the factor of temperature uniformity in the heatexchanger is applied to the networks. So, the factor of temperature difference uniformityof networks is presented. The application of it to the optimization of networks is provedto be feasible by the Entransy dissipation extremum principle.Then, the concept of heat exchanger networks integral strengthen is presented basedon the field synergy theory, while there is only a term of optimization in the networks,and the quantity evaluation index of it is established by composite curve.Furthermore, Based on the integral strengthen concept and temperature uniformitydifference optimization principle of networks above, it is proved to be valid byexamples using Monte Carlo sampling method that the application of the integralstrengthen technology to the networks can improve the efficiency.In a word, the concept of integral strengthen concept is given based on optimization of the networks, and the quantity evaluation index of it is established in this paper, thatis, the factor of temperature difference uniformity. It can provide a novel method foroptimization and strengthen of heat exchanger networks. |
