延迟焦化装置的能耗分析及节能优化实践

中国海油惠州炼油分公司420× 104t/a延迟焦化装置通过停用解吸塔上重沸器3.5MPa蒸汽、停用柴油汽提塔1.0MPa汽提蒸汽、降低循环比、采用先进控制(APC)提高加热炉热效率、降低高压水泵和罐区减渣原料泵电耗、提高水的回用率、加大装置处理量等工艺优化措施,装置综合能耗比设计能耗39.03kg标油/t原料降低3kg标油/t原料.为了进一步降低装置能耗,达到国内其他先进装置的能耗水平,该装置在2011年利用检修时机,通过加热炉节能改造降低排烟温度、利用柴油低温热发生0.45MPa蒸汽、焦化富气压缩机叶轮更换、焦炭塔区特阀汽封线改造等节能改造措施.加热炉热效率由89％提高至91.5％,节约3.5MPa蒸汽用量约6.5t/h,同时减少了燃料气、蒸汽和电的消耗,使装置能耗总体降低3.16kg标油/t原料.装置节能改造每年可增加4000万元的经济效益.

An Analysis of Energy Consumption and Saving Energy Practices for Delayed Coking Units

By taking a series of technical optimization measures such as stopping the use of 3.5MPa steam for the reboiler on the desorption column and 1.0MPa steam for the diesel stripper,reducing the circulation ratio,introducing APC to raise the heat efficiency of the heating furnace,lowering the power consumption by high-pressure water pumps and vacuum residue pumps in the tank area,raising the rate of wastewater recovered and increasing the volume of feedstock processed,CNOOC Huizhou Refinery successfully lowered the overall energy consumption of its 420 ×104t/a delayed coking unit by 3kg of oil equivalent per ton of feedstock processed from the unit′ s designed energy consumption level of 39.03kg of oil equivalent per ton of feedstock processed.To further cut energy consumption and raise the energy efficiency of the unit to the level of other advanced domestic units of the same type,the company took additional measures during a scheduled overhaul in 2011 to raise the heat efficiency of its heating furnace to 91.5% from 89%.These measures included reducing flue gas temperature for the heating furnace by means of energy-saving upgrades,generating 0.45MPa steam using the low-temperature heat from diesel production,replacing the impellers of the coker rich gas compressor,and upgrading the special valve steam seal lines in the coking drum area.As a result,3.5MPa steam consumption dropped by about 6.5t/h and consumption of fuel gas,steam and power also went down.The overall energy consumption of the delayed coking unit dropped by 3.16kg of oil equivalent per ton of feedstock processed.The energy savings are equivalent to increasing the company ′s revenues by 40 million yuan per year.