The Development Of Simulation System Of Heat Exchanger Network

With the development of energy-saving technology, the heat exchanger networkplayed a more and more important role of enterprise energy-saving.The heatexchanger network simulation technology was the foundation of the synthesis andoptimization of heat exchanger networks. Based on the sequential modular approach,a heat exchanger network simulation system was developed which had more unitmodules and powerful functions. The simulation system could simulate the generalheat exchanger network, provide the basic data for the retrofit and optimization ofheat exchanger network, and could also play a guiding role for the engineeringdesign.The system consisted of four modules: decomposition and convergence module,physical property module, input and output module and unit module. Thedecomposition and convergence module consisted of decomposition module andconvergence module. The module was the difficulty of the system development, andalso was the core content of sequential module approach. The physical propertymodule consisted of physical property databases and calculating methods. Besides,the physical property module also could deal with petroleum distillate. Firstly theEngler distillation curve must be converted to true boiling point (TBP) curve, thencutting the TBP curve to generate pseudo-component, and then generating thenormal boiling point, relative density and molecular weight of thepseudo-component. Finally the critical temperature and other physical propertieswere generated with the three basic physical quantities.There were many unit modules in the simulation system developed in this paper.Every module had much functions, so it could truly simulate the actual heatexchanger network. The unit module of the system mainly included the followingsub-modules: mixer module, spiliter module, pump module, valve module, pipingmodule, flashing module, heat exchanger module. e.g., according to the pumpperformance curve the pump module could calculate the outlet pressure; according to the valve coefficient the valve module could calculate the pressure drop; accordingto the heat exchanger area the heat exchanger module could calculate the outlettemperature of the cold stream and the hot stream.Finally, taking the heat exchanger network of styrene and the heat exchangernetwork of hydrocracking as examples, the simulation system was verificated. Theresults of simulation can meet the requirements of engineering calculations, and itindicates that the establishment of the mathematical models of every unit module iscorrect, and the heat exchanger network developed in this paper is feasible.