Study On Steady-State Simulation And Energy-Saving Optimization Of Crude Oil Distillation Unit And Heat Exchanger Network

As the first unit operation,the atmospheric and vacuum distillation unit is a process of technology integration with a high energy consumption,according to statistics,about 25% of the energy consumption of refineries goes to the separation procedure of crude oil.Therefore,the process design,operation reliability,energy consumption level and technical management level have a significant influence on energy reduction,production management,equipment investment and operating efficiency.Aiming at reducing energy consumption and improving economic benefit,this study combines the operative optimization and the field retrofit which is based on the simulative modelling to increase the extraction rate of crude oil,and thus to improve the product values.By illustrating an example of a running atmospheric and vacuum unit and its coupled heat exchanger network,an Aspen Plus model is constructed to obtain the computational results.By using the sensitivity analysis of Aspen Plus,the operating conditions are diagnosed to propose adjustment scheme and optimize the operative parameters,thus to increase the yield of light components and reduce the energy consumption,undoubtedly,these all will lead to a higher economic benefit.For examples,optimizing the amount of heat transfer in the atmospheric column to increase the feeding temperature of crude oil and reduce the load of atmospheric furnace;analyzing the calculative data of the devices to check the running performance of the unit.The combination of the heat exchanger network and the Pinch point theory is also studied in this work.The model of the heat exchanger network is constructed to check the performances of heat exchangers and propose the retrofit schemes.Once the optimal minimum heat transfer temperature difference is ascertained,the optimization of the heat exchanger network will be conducted by means of cutting off the circuit and energy relaxation.The main missions of this study include: increasing the feeding temperature of the crude oil into the atmospheric furnace;proposing the retrofit schemes of the production field;reducing energy consumption and improving economic benefit;studying the hydraulic performance of the fractionation system to determine the feasibility of the optimization strategy;calculating the heat transfer data of the optimal heat exchanger network to check its adaptability.