延迟焦化装置分馏塔侧线取热优化

某公司延迟焦化装置分馏塔侧线循环取热不充分,导致分馏塔热量过剩,整体温度高于设计值,影响产品质量和下游设备的正常运行,造成能量浪费。为解决该问题,运用Aspen Plus软件,采用合适的模拟策略,建立了分馏塔系统模型,分析了分馏塔的用能情况。通过流程模拟和正交试验法,以渣油换热终温为目标变量,优化得到了各侧线循环流量的最佳组合。结果表明,增加柴油循环和塔底循环油循环流量、降低顶循环、中段循环和重蜡油循环流量,可以将减压渣油换热后的温度从295.8℃提高到306.6℃,减少加热炉燃料气耗量约275.02 Nm³/h,提高了分馏塔用能效率,降低了装置能耗。

Optimization of Pump-Round Energy Recovery Ratios in the Main Fractionation Column of Delayed Coking Units

The pump-round energy recovery ratios in the main fractionation column of delayed coking units were insufficient, resulting in more excessive heat in fractionation column and higher temperature of the entire fractionation column than design values, which would affect the normal operation of equipments downstream and cause waste of energy. In order to solve the problem, a model of the fractionation column system was established and its operation status was analyzed by using the Aspen Plus with proper simulation strategy. Based on the analysis above, aiming at improving the final temperature of vacuum residue, a best combination of the pump-round flow rates of the fractionation column was obtained by optimizing with simulation and orthogonal experiment method. The results proved that, the final temperature of vacuum residue could be increased from 295.8℃ to 306.6℃ by increasing the pump-round flow rate of diesel and bottom circulating oil and decreasing that of top reflux, middle and heavy wax oil. Thus the consumption of furnace gas could be reduced by 275.02 Nm³/h, the energy utilization efficiency of the fractionation column was enhanced and the energy consumption of the unit was reduced.