The Process Simulation And Heat Exchanger Network Optimization Of Crude Distillation Unit With ASPEN PLUS

Crude oil atmospheric and vacuum distillation unit is the first processing device in refinery. It plays an important role in the total process. Petrochemical enterprises consume huge energy every year, while the crude oil atmospheric and vacuum distillation unit is one of the most consumers with 10-20 percent of the total energy consumption. So the optimum design of distillation column and maximizing the energy-saving of the heat exehanger network of crude oil are critical to petrochemical companies. In this paper, the simulation software ASPENPLUS and HEXTRAN were used to simulate the distillation process and optimize the heat exchanger network. Furthermore tray and the main column design solutions are proposed for the capacity expansion revamp. Detailed researches were summarized as below.According to the flow of atmosphere-vacuum distillation unit, the paper applies sequential modular method in flash tower, atmospheric tower and vacuum tower to perform process simulation. The petroleum components, production and streams flow rates etc. of the two conditions of the locale 400×10~4 ton per year are made certain, which established the foundation of the optimization of the locale heat exchanger network. Simultaneously, the basic data of the four conditions of 500×10~4 ton per year were simulated to settle the base of the capacity expansion revamp.Through the pinch point calculations, it is found that the heat exchanger networks have great energy-saving potential. According to the pinch theory, if cooling utility is used up the pinch, heating utility is used down the pinch or the heat exchange streams across the pinch, there will be double loss in the utility. By means of improving the streams match properly, we can decrease the consumption of the utility in the heat exchanger network. In this paper, the heat exchanger network is optimized by using the maximum amount of heat recovery as the objective function, and HEXTRAN heat exchanger network simulation software is used to determine the final temperature of preheating of crude oil.In order to meet the needs of capacity expansion and ensure the safe and efficient working of the atmospheric-vacuum distillation plant, the optimum design solutions of the tray and packing according to the simulated basic data of the 5 million tons per year were presented.