提高延迟焦化装置加热炉热效率的技改措施

Measures for Improving Thermal Efficiency of Delayed Coking Furnaces

洛阳石化1400kt/a延迟焦化装置加热炉采用一炉两塔流程,于2008年6月投产,计算热负荷为45.41MW,加热炉为两室四管程双面辐射箱式结构,加热介质为减压渣油。为降低装置能耗,于2011年9月对加热炉进行改造。改造内容包括更换燃烧器、改造空气预热器、采用先进控制、改造炉墙和增加仪表监测。改造后,利用FLUENT软件,对燃烧室中燃料气的燃烧特性和新型燃烧器某截面的温度场进行数值模拟,分析得出,新型燃烧器大幅降低了燃烧过程中氮氧化物的生成,保证了燃料气在低过剩空气系数下的充分燃烧;计算表明,空气预热器的改造提高加热炉热效率0.92%。先进控制技术的应用,减轻了劳动强度,提高了调节精度和加热炉运行的平稳率,达到了提高加热炉热效率的目的。综合改造后,加热炉热效率高达93.45%,与改造前相比,热效率提高1.81%。

The heating furnace of Sinopec Luoyang Company＇s 1400kt/a delayed coking unit uses a one-fur- nace-and-two-column process.The furnace went into operation in June 2008 and the thermal load calculated for it is 45.41MW.The heating furnace is a two-chamber,four-tube-pass two-side radiation box-type struc- ture,using vacuum residuum as the heating medium.In order to reduce the unit＇s energy consumption,the company revamped the heating furnace in September 2011.The revamping included replacing the burners,re- vamping the air preheater,introducing advanced control,revamping the furnace wall,and strengthening instru- ment monitoring.After the revamping,the company conducted a numerical simulation of the combustion charac- teristics of fuel gas in the combustion chamber as well as the temperature field of a cross profile of the new burner,using the FLUENT software.The simulation results show that the new burner has dramatically re- dueed the production of nitrogen oxides duirng combustion and ensured sufficient burning of fuel gas when the excess air coefficient is low.Calculation results show that the air preheater revamping resulted in a 0.92% increase in the thermal efficiency of the heating furnace.The introduction of advanced control reduced the labor intensity, improved the accuracy of regulation and the and increased the thermal efficiency of the heating furnace.After ficiency of the heating furnace reached 93.45%,up 1.81% from stability of operation of the heating furnace, the comprehensive revamping,the thermal ef- that before the revamping.