基于夹点分析技术的常减压装置换热网络优化
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摘要
常减压装置是原油深度加工的基础,同时也是炼油企业用能大户。针对国内某企业的常减压装置,应用流程模拟软件Aspen HYSYS,建立装置的换热网络模型。以加工原油性质、初馏塔、常压塔、减压塔模拟过程参数及常减压装置对产品质量的要求作为换热网络调整的基础参数,利用Aspen Pinch软件,对装置原有换热网络进行夹点分析,根据原油常减压装置内部冷、热物流特点,分析装置用能瓶颈,得出换热网络初底原油的最高理论换热终温。按照消除原换热物流跨夹点传热、中高温位热源多次合理利用、调整换热效率偏低的设备、现有设备布置变动小、投资省的原则,对换热网络进行改造优化。通过换热流程优化调整,初底油进常压加热炉温度由原来的278℃提高到288℃;降低常压炉加热负荷及燃料消耗,可节省加热炉负荷约60×10~4kcal/h,装置能耗降低约0.7kg标油/t,折合每年创造效益约126万元。
The atmospheric and vacuum unit is basic equipment in crude oil deep processing and is also a ma-jor energy consumer in a refinery.Technicians used the process simulation software,Aspen HYSYS,to establish a heat exchanger network model for a domestic oil refiner ′ s atmospheric and vacuum unit.Using crude oil properties,primary tower,atmospheric tower and vacuum tower simulation process parameters and the require-ments of the atmospheric and vacuum unit on product quality as the basic parameters used in the adjustment of the heat exchanger network as well as the Aspen Pinch software,they conducted a pinch point analysis for the existing heat exchanger network of the atmospheric and vacuum unit.Based on the characteristics of the unit′ s internal cold and hot streams,these technicians analyzed the bottlenecks affecting the efficient use of energy in the unit and calculated the highest theoretical end temperature for heat exchange for initial bot-toms in the heat exchanger network.Based on the principles of eliminating original cross-pinch point heat transfer of heat exchange streams,utilizing high and medium-temperature heat sources in a repeated and rational manner,replacing equipment with low heat exchange efficiencies and minimizing changes in equipment arrangement and capital investment,they optimized the heat exchanger network.As a result of the optimization of the heat exchange process,the temperature of initial bottoms entering the atmospheric heating furnace has increased to 288℃ from 278℃.As a result of the declines in the heating load on the atmospheric furnace and fuel consumption,heating furnace load savings could reach around 60 ×10~4kcal/h and the atmospheric and vacuum unit′ s energy use could drop some 0.7kg of oil equivalent per ton.Annual energy savings reach about 1.26 million yuan.
The atmospheric and vacuum unit is basic equipment in crude oil deep processing and is also a ma-jor energy consumer in a refinery.Technicians used the process simulation software,Aspen HYSYS,to establish a heat exchanger network model for a domestic oil refiner ′ s atmospheric and vacuum unit.Using crude oil properties,primary tower,atmospheric tower and vacuum tower simulation process parameters and the require-ments of the atmospheric and vacuum unit on product quality as the basic parameters used in the adjustment of the heat exchanger network as well as the Aspen Pinch software,they conducted a pinch point analysis for the existing heat exchanger network of the atmospheric and vacuum unit.Based on the characteristics of the unit′ s internal cold and hot streams,these technicians analyzed the bottlenecks affecting the efficient use of energy in the unit and calculated the highest theoretical end temperature for heat exchange for initial bot-toms in the heat exchanger network.Based on the principles of eliminating original cross-pinch point heat transfer of heat exchange streams,utilizing high and medium-temperature heat sources in a repeated and rational manner,replacing equipment with low heat exchange efficiencies and minimizing changes in equipment arrangement and capital investment,they optimized the heat exchanger network.As a result of the optimization of the heat exchange process,the temperature of initial bottoms entering the atmospheric heating furnace has increased to 288℃ from 278℃.As a result of the declines in the heating load on the atmospheric furnace and fuel consumption,heating furnace load savings could reach around 60 ×10~4kcal/h and the atmospheric and vacuum unit′ s energy use could drop some 0.7kg of oil equivalent per ton.Annual energy savings reach about 1.26 million yuan.
引文
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[6]LIEW P Y,ALWI S R W,VARBANOV P S,et al.Centralised Utility System Planning for a Total Site Heat Integration Net work[J].Computer&Chemical Engineering,2013,57:104-111.
[7]魏志强,孙丽丽.基于夹点技术的炼油过程多装置热集成策略研究与应用[J].石油学报:石油加工,2016,32(2):221-229.
[8]LINNHOFF B,EASTWOOD A R.Overall Site Optimization by Pinch Technology[J].Chemical Engineering Research and Design,1997,75(Suppl.):138-144.
[2]LINNHOFFB,FLOWER J R.Synthesis of Heat Exchanger Networks:I.Syntematicgenetation of Energy Optimal Networks[J].AICh EJ,1978,24(4):633-642.
[3]DHOLE V R,LINNHOFF B.Total Site Targets for Fuel,Cogen eration,Emissions and Cooling[J].Comp Chem Eng,1993,17(Suppl.):101-109.
[4]高维平,刘谦.常减压换热网络的优化节能研究[J].化工科技,1999(2):49-54.
[5]魏艳艳,吴明.夹点理论及其在炼厂换热网络优化中的应用[J].西安石油大学学报:自然科学版,2009,24(5):71-74.
[6]LIEW P Y,ALWI S R W,VARBANOV P S,et al.Centralised Utility System Planning for a Total Site Heat Integration Net work[J].Computer&Chemical Engineering,2013,57:104-111.
[7]魏志强,孙丽丽.基于夹点技术的炼油过程多装置热集成策略研究与应用[J].石油学报:石油加工,2016,32(2):221-229.
[8]LINNHOFF B,EASTWOOD A R.Overall Site Optimization by Pinch Technology[J].Chemical Engineering Research and Design,1997,75(Suppl.):138-144.