Simulation Of Atmospheric And Vacuum Distillation And Optimization Of The Heat Exchange Network

Atmospheric and vacuum distillation units is the first procedure of petroleum processing,which plays an important role in refinery.Atmospheric and vacuum units has the features like high relevance degree among operating parameters and huge energy consumption.The separation efficiency of atmospheric and vacuum distillation influence on integral benefits of refineries directly,so the simulation and optimization of this process is of great importance.Using pinch technology which bases on simulation of atmospheric and vacuum distillation unit to optimize heat exchange network has noticeable economic benefits because of the huge amount of energy the unit consumes.This paper takes the 10.0 Mt/a atmospheric and vacuum distillation units as the case study,and establishes the simulation flowsheet of crude unit by software Aspen Plus,which bases on the selection of reasonable thermodynamic method,certain unit modules and adding lightend according to the properities of crude oil,the calibration data collected from the unit and equipment operating parameters Compared engler distillation curve of the simulation results with the calibration values of products,it can determine the error is in a reasonable range,the simulation result is reliable.The results of simulation shows that atmospheric residue has a high content of fraction before 350? and great overlap degree of ASTM data between aviation and light diesel,which indicates that atmospheric tower has potential to be optimized.In this paper,sensitivity analysis tool is adopted to probe the effect of outlet temperature of the atmospheric furnace,flow rate of bottom steam and side products and pumparound reflux on products key parameters.Mass flow of the first intermediate pumparound reflux,top draw of atmospheric tower and the stripping steam mass flow of the second sidestream affect avaiation kerosene obviously.Then this paper improved the production of aviation,reduce the proportion of component fractions before 350? in atmospheric residue and decrease the overlap degree of ASTM data between aviation and light diesel by target optimizationBasing on the enthalpy of hot and cold stream obtained by simulation,this paper analyzed the initial heat exchange network and found that high temperature heat of heavy diesel did not get used reasonably.Pinch technology is used to optimize the heat exchange matches.In order to optimize heat exchange network,it can split stream reasonably and disconnect the heat loop,and do the energy consumption and economic analysis of the new heat exchange netwok.The result shows that heat transfer area of new heat exchange network is 8169 ? more than the initial one;the cross pinch point heat exchange decreases 777.9kW and the end temperature of the crude oil is enchanced 2.5?.This can save fuel cost about 9879 thousand and improve the flexibility of operation of vacuum residue.The optimized heat exchange network is a reference to oil refiner in conserving energy and transform.