常减压蒸馏装置节能降耗优化措施

Energy saving and consumption reduction optimization measures in atmospheric and vacuum distillation unit

针对某炼油厂13.0 Mt/a常减压蒸馏装置能耗高的问题,结合实际运行工况,重点围绕如何降低燃料和1.0 MPa蒸汽消耗,实施了减二线至产品储罐区的流程改造,用燃料气替代产品储罐氮封的技措,以及Robust-IPC全流程智控技术应用的节能综合优化措施。结果表明:技改后,装置常压炉、减压炉的含氧体积分数均降至1.8%,热效率分别提高了0.12,0.14个百分点;燃料气中含N2体积分数月平均降幅4.9个百分点,燃料气热值提高了3443.02 J/g;换热网络的换热终温提高了3.59℃,节约燃料消耗330.5 kg/h;稳控了减压塔残压,使1.0 MPa蒸汽能耗(以标准油计,下同)月平均降低了0.128 kg/t;装置综合能耗由8.550 kg/t降至7.750 kg/t,降幅为9.36%。

In view of the high energy consumption of the 13.0 Mt/a atmospheric and vacuum distillation unit of a refinery,the actual operating conditions were taken into consideration while focusing on how to reduce fuel and 1.0 MPa steam consumption,the following countermeasures such as the process flow revamp from the second line to the product storage tank area,the technical measures of replacing nitrogen sealing with fuel gas sealing in product storage tank,along with the comprehensive optimization measures provided by the application of Robust-IPC full-process intelligent control technology were carried out.The results showed that after the technical revamp and operation optimization,the oxygen volume fraction of the atmospheric and vacuum furnaces of the unit both decreased to 1.8%,and their thermal efficiency was correspondingly increased by 0.12 and 0.14 percentage points respectively.And the volume fraction of N2 in fuel gas decreased by 4.9 percentage points averagely per month,which made the calorific value of the fuel gas increase by 3443.02 J/g.And the final heat exchange temperature of the heat exchange network increased by 3.59℃,which led to the fuel consumption reduced by 330.5 kg/h.The residual pressure of the vacuum distillation tower was stabilized,which resulted in the 1.0 MPa steam′s energy consumption(based on the equivalent standard oil,the same below)monthly reduced by 0.128 kg/t.And the comprehensive energy consumption of the unit reduced from 8.550 kg/t to 7.750 kg/t,with a decline of 9.36%.