Process Simulation And Heat Exchanger Network Optimization Of Atmosphere-Vacuum Distillation

In this paper, process simulation and heat exchanger network (HEN) optimization of the first set atmosphere-vacuum distillation device in a refinery are studied. The large-scale process simulation software Aspen Plus, which is based on the sequential modular approach, was used for process simulation of the distillation, the simulation results could meet the requirements of the system process; Extract data of process streams, which will exchange heat in the heat exchanger network, from the process simulation results to establish mathematical model, which is MINLP model, and a heat exchanger network without splits of the atmosphere-vacuum distillation device is designed and optimized by using an improved particle swarm optimization.(1) The large-scale chemical process simulation software Aspen Plus is used for the process simulation of the atmosphere-vacuum distillation device. During simulation the rigorous column model, which is provided by the software to simulate all complex gas-liquid fractional distillation in the petroleum refining industry, was selected from PetroFrac model. And the BK.10model, which is suitable for crude oil, is used for calculating of thermodynamic properties and transport properties. It could be found from the simulation results of the5,000,000t/a atmosphere-vacuum distillation device that the distribution of temperature, pressure and vapour and liquid flow rate in the column could meet the realistic conditions, and the qualities of products could meet the requirements of production process.(2) On the basis of superstructure of heat exchanger network, a particle swarm optimization model, which is to minimize the investment and operating costs, is established. And typical heat exchanger network is optimized by using improved PSO (the non-isothermal mixing was used for mixing of streams in HEN with splits). Optimization results shows that this heat exchanger network integration method can allocate the distribution of exchanged heat of heat transfer equipment more rational, and the feasibility of this method could also be proved; In addition, because not needing to guide a heat exchanger network integration with rich experiences, it is relatively simple and easy to be mastered.(3) A heat exchanger network without splits of the atmosphere-vacuum distillation device has been designed. Firstly, to extract basic stream data of the streams which will be integrated in the heat exchanger network from the simulation results as a basis of heat exchanger network integration. Then to establish the MINLP model of heat exchanger network, and optimize the heat exchanger network by using improved particle swarm optimization. A heat exchanger network without splits was obtained. The heat exchanger network could be as a guide to integrate the heat exchanger network of the atmosphere-vacuum distillation device after transform.