大型炼油厂蒸汽动力系统优化研究

大型炼油厂蒸汽消耗是影响全厂能耗的重要因素。使用先进蒸汽动力系统模拟软件结合生产现状与发展规划,综合考虑蒸汽生产、传输、使用三个环节,建立热电运行部、全厂中压系统、低压系统模型,系统分析全厂蒸汽动力系统运行情况,找到存在的问题与瓶颈。采用Willan模型对汽轮机负荷进行优化,发电量增加了4 298(k W·h)/h;对中压管网进行提压操作,在维持锅炉的产汽量不变的前提下,汽轮机总发电量增加了1 442(k W·h)/h;针对夏季低压放空蒸汽量较大,利用炼油厂现有的蒸汽管线把放空低压蒸汽回供到热电运行部,节省低压蒸汽30 t/h;针对重整装置内部减温减压损失较大,用1台背压蒸汽轮机取代2套减温减压器,新增发电1 487(k W·h)/h。为企业提高蒸汽利用效率、降低蒸汽能耗和提高经济效益提供了技术支撑。

Optimization of steam power system in large-capacity refinery

The steam consumption of the large refinery is an important factor affecting the energy consumption of refinery.The models of power plant,medium pressure steam system and low pressure steam system are established with application of advanced steam power system simulation software and in consideration of production conditions,future development as well as production,transportation and utilization of steam.The operation of plant-wide steam power system is analyzed and root causes and bottlenecks of the problems are found out.After optimization of the steam turbine load with Willan model,the power generation is increased by 4 300 (kW · h)/h.By increasing the operation pressure of mid-pressure pipelines,the total generation capacity is increased by 1 442 (kW · h)/h without changing the steam generation of boiler.The existing pipeline can be used to transport the low pressure steam back to power plant for large amount of low-pressure vent steam in summer,saving 30 t/h of low pressure steam.As the losses from temperature reduction and pressure reduction of catalytic reforming unit are high,one back-pressure steam turbine is installed to replace two temperature and pressure reducers,which increases the power generation by 1 487 (kW · h)/h.A strong technical support is provided for improving steam utilization efficiency,reducing steam consumption and improving economic benefits.