低负荷下延迟焦化能耗分析及优化措施

目前中国石油化工股份有限公司洛阳分公司延迟焦化装置加工负荷仅为设计负荷的58%。对焦化装置低负荷生产背景进行了介绍,描述了低负荷条件下工艺流程的变动情况以及优化前生产情况。分析了延迟焦化2014,2015,2016年1—6月的能耗数据,通过对比分析,从燃料气、3.5 MPa蒸汽、循环水、电等方面,指出了低负荷下装置能耗偏高的原因。提出了以下措施:加热炉备用炉室闷炉操作,可节省燃料气1.5 kg/t;利用柴油与燃料气换热,可节省燃料气0.4 kg/t;备用炉室用干气代替3.5 MPa蒸汽,可减少3.5 MPa蒸汽用量5.8 t/h;气压机入口引入柴油加氢装置轻烃;优化气压机控制系统,每小时节省3.5 MPa蒸汽2~5 t;循环水串级;提高机泵效率。经过低负荷下有针对性地优化改造,装置能耗降至901.62 MJ/t,低于装置低负荷优化前的980.21 MJ/t,年增加效益约为435万元,取得了显著的经济效益和社会效益。

Analysis and optimization of delayed coking energy consumption under low load

At present,the delayed coking unit of SINOPEC Luoyang Company is operated at only 58％ of the design capacity.The low-load operation background of the units is introduced,and the process flow variations under the low operating load and production conditions before optimization are described.The energy consumption data of delayed coking unit from of 2014,2015 to June 2016 are analyzed.From comparative analysis in respect of fuel gas,3.5 MPa steam,cooling water and electricity,etc,the root causes of higher energy consumption of the unit at low operating load are pointed out.The following effective measures are recommended:standby furnace chamber is damped down and 1.5 kg/t fuel gas can be saved per ton of feedstock;the diesel is heat exchanged with fuel gas to save 0.4 kg fuel gas per ton of feed;the dry gas is used for stand-by furnace chamber to replace 3.5 MPa steam,and 3.5 MPa steam consumption is reduced by 5.8 t/h;light hydrocarbons from diesel hydrotreating unit is directed to the inlet of gas compressor;the gas compressor control system is optimized and 2 to 5 tons of 3.5 MPa steam are saved per hour;The cooling water is cascaded to improve pump efficiency.After optimization and revamping for low-load operation,the energy consumption of the unit is reduced to 901.62 MJ/t,which is lower than the 980.21 MJ/t of feed before optimization.The annual economic benefit is about 4 350 000 Yuan RMB.Good social and economic benefits have been achieved.