芳烃联合装置蒸汽系统节能分析与优化

洛阳石化公司芳烃联合装置由芳烃抽提和对二甲苯装置组成,2012年装置综合能耗为310.39kg标油/t,其中蒸汽能耗为124.44kg标油/t,占总能耗的40.09%。蒸汽能耗高主要与减温减压器的用损、闪蒸汽的不合理利用和浪费,以及装置蒸汽网络能级不匹配等因素有关。采用能量平衡和用分析的方法,对芳烃联合装置蒸汽用能现状进行分析,提出以蒸汽喷射式热泵替代减温减压器和蒸汽网络优化方案。蒸汽喷射式热泵能有效回收闪蒸蒸汽,并能提供介于高、低压蒸汽压力间各种压力等级的蒸汽,实现不同压力等级的蒸汽综合利用。以蒸汽喷射式热泵替代减温减压器,是优化蒸汽网络、提高能源综合利用效率的有效途径。装置经蒸汽网络优化后,蒸汽管网用效率可从84.53%提高至90.77%,蒸汽能级匹配更为合理,年节约标煤3657t,年创经济效益366×104元,投资回报期不超过一年。

Energy Saving Analysis and Optimization for Steam System of Integrated Aromatics Plant

Sinopec Luoyang Company′s integrated aromatics plant consists of an aromatics extraction unit and a paraxylene unit.The comprehensive energy consumption of the plant in 2012 was 310.39kg of oil equivalent per ton,including 124.44kg of oil equivalent per ton of steam consumption,which accounted for 40.09% of the plant′s total energy consumption.High steam consumption is attributable mainly to the damage of the tem perature and pressure reducer,the irrational use and dissipation of flash vapor and the dismatch of energy levels of the steam network of the plant.Using an energy balance and analysis method,the article examines the current steam use of the integrated aromatics plant and proposes a plan to replace the temperature and pressure reducer with a steam-jet heat pump as well as to optimize the steam network.The steam-jet heat pump can effectively recover flash vapor and provide various pressure grades of steam that is in between high and low-pressure steam,enabling an integrated use of various pressure grades of steam.Replacing temperature and pressure reducer with steam-ject heat pump is an effective approach to optimizing steam network and raising energy efficiency.After an optimization of the steam network,the efficiency of the steam network can rise to 90.77% from 84.53%,the steam energy levels will match better,annual energy savings will reach 3657 tons of coal equivalent,and annual returns on the optimization will reach 366 ×104yuan.Investors should be able to begin receiving returns on investment within 12 months.