渣油加氢脱硫装置分馏塔优化模拟

以分馏塔进料温度、操作压力和汽提蒸汽流量为自变量,柴油侧线抽出量为因变量,经济效益为优化目标,通过Unisim软件对分馏塔系统工艺参数进行模拟。模拟结果显示,当分馏塔进料温度为349℃,汽提蒸汽流量为11.5t/h时,可抽出柴油量达32t/h,此为最佳效益工况,每年可增加效益2044万元,并且满足分馏塔水力学要求,亦为合理运行工况,此工况是提高分馏塔进料温度和增大汽提蒸汽量的协同作用的结果。模拟显示,单独提高分馏塔进料温度或增大汽提流量以及降低塔顶操作压力均有利于增加柴油收率和经济效益,但也会增加能耗,并受硬件条件制约,还会降低分馏塔设备的利用率。就大连石化300×104t/a渣油加氢脱硫装置分馏塔的优化而言,应在不超出限制条件下,以能否增加经济效益为判别依据,根据判断结果调整操作条件。

Optimization Modeling for Fractionators of Residue Hydrodesulfurizing Units

To increase economic benefits,using the charging temperature,operating pressure and stripper steam rate of a fractionator as the independent variable and diesel side stream extracted as the dependent variable,technicians modeled the process parameters of a fractionator system with the help of Unisim software.The modeling results show that when the charging temperature of the fractionator is 349℃ and the stripping steam flow is 11.5t/h,32t of diesel fuel can be extracted per hour.This is the operating conditions that can lead to the best economic results.Revenue could rise by 20.44 million Yuan annually as a result of this optimization.The hydraulic requirements of the fractionator can also be met and these are also good operating conditions.These conditions are a result of the rise in charging temperature of the fractionator as well as the volume of stripper steam combined.The modeling shows that any of such methods as raising the charging temperature for the fractionator,increasing stripping steam flow and reducing the operating pressure at the top of the fractionator is instrumental in raising the yield of diesel fuel and economic returns.But these methods also increase energy consumption and are limited by hardware.They will also reduce the uptime of fractionator equipment.When optimizing the fractionator of its 300 ×104t/a residue hydrodesulfurizing unit,PetroChina Dalian Petrochemical Company should make increasing economic returns a priority in deciding on the unit＇s parameters,having regard to the unit＇s limitations.