裂解气压缩机复水器管束泄漏原因分析及预防措施.pdf

压缩机乙烯工业2 0 2 4,3 6(1）42 44ETHYLENE INDUSTRY裂解气压缩机复水器管束泄漏原因分析及预防措施尚永福，王晨宇，李文婷，代（中国石油天然气股份有限公司独山子石化分公司，新疆独山子8 3 3 6 9 9）川，高万峰摘要：乙烯装置裂解气压缩机复水器是裂解气压缩机的附属设备，其泄漏将影响乙烯装置长周期运行，对此换热器管束泄漏原因进行分析，并制定相应的预防措施，延长换热器运行周期，降低在装置运行期间换热器发生泄漏的概率，确保乙烯装置关键设备长周期运行。关键词：复水器泄漏管控措施中国石油天然气股份有限公司独山子石化分公司2 2 0 kt/a乙烯装置在2 0 11年大修期间将裂解气压缩机复水器（E13 1）更换为杭汽产品，型号N-720-31,其主要参数见表1。表1复水器主要参数项目管程冷却面积/m720设计压力（G)/MPa0.5设计温度/60工作压力(G)/MPa0.30.35最高工作温度/45水压试验压力（G)/MPa0.6工作介质冷却水流程数1壳体材料水室材料管板材料冷却水管材料冷却水管规格/mm冷却水管数量/根1复水器故障2021年4月16 日对裂解炉水质进行例行分析，发现6 号、7 号裂解炉的超高压蒸汽中二氧化硅含量超标。4月18 日，对裂解气压缩机复水器凝液进行排查，发现凝液中二氧化硅含量高达5 2.3g/kg（指标2 0 g/kg），立即开展全方位排查，4月19 日将凝液流程切出脱氧器，外送至动力装置新水池，避免不合格的凝液影响锅炉给水水质。经过排查和处理，蒸汽管网合格，但观察运行至2 0 2 2 年5 月，复水器凝液中二氧化硅仍然超标,判断复水器管束存在内漏。2故障处理情况壳程2.1复水器检修消缺2022年4月2 12 4日，乙烯装置利用控制室0.1950.012(A)800.2蒸汽1碳钢碳钢Q235-ABFe10-1-1/GB8890-8820 1 5 210(1 860 根)201.25210(320根)2180搬迁，装置短停的时机对复水器进行检修查漏。其中北侧通道上水后发现4处较为明显的漏点，均在其上部,在试压过程中进一步发现14处漏点，此次堵管18 根，泄漏区域主要集中在上部，含2015年至2 0 19 年堵管3 3 根，北侧通道合计堵管51根；南侧通道此次未发现漏点，4月2 4日对南侧通道进行了电涡流检测,抽检比例10%。根据检测结果，对减薄超过40%的6 根换热管进行了预防性堵管，含2 0 15 年至2 0 19 年堵管10 根，南侧通道合计堵管16 根。复水器总计堵管6 7 根。复水器电涡流检测及堵管情况示意见图1。2.2检修后的效果复水器检修后,凝液中二氧化硅含量下降至13.5g/kg，满足不大于2 0 g/kg的指标，复水器故障消除。收稿日期：2 0 2 2-11-0 7;修改稿收到日期：2 0 2 3-11-14。作者简介：尚永福，男，2 0 11年毕业于兰州理工大学过程装备与控制工程专业，工学学士，主要从事设备管理工作，高级工程师。第3 6 卷尚永福等.裂解气压缩机复水器管束泄漏原因分析及预防措施43图1复水器电涡流检测及堵管情况示意膨胀节3复水器故障原因分析3.1复水器历次检修情况3.1.12015年复水器检修情况该复水器投用后于2 0 13 年8 月首次发现泄漏，在2 0 15 年检修时试压发现北侧通道内9 根换热管存在泄漏，泄漏管主要在换热器中上部，对泄漏管进行了堵管处理。此次检修中，未发现管束胀口处存在缺陷，其中2 根换热管泄漏量较大，壳程灌水即开始泄漏流水,其余7 根为打压后发现的泄漏点。3.1.22019年复水器检修情况2019年检修时，该复水器因上一检修周期已进人真空喷射泵，其内部结构见图3。和透平连接和膨胀节连接图2复水器排放乏汽示意去真空喷射泵复水器本体1400发现泄漏点位，运行部申请进行电涡流检测。260此次抽检换热管2 2 1根，检测结果为均匀腐北蚀,根据电涡流检测结果进行了预防性堵管处理。2019年大修北侧通道堵管14根，南侧通道堵管10根，加上2 0 15 年堵管9 根，共计堵管3 3 根，主要集中在中下部。对换热器壳程进行试压，试压压力0.2 MPa,试压过程中未发现泄漏。3.2泄漏管束分布特点及分析从3 次检修情况看，发生泄漏的管束均集中在换热器北侧通道中上部（存在集中分布的现象）。通过电涡流检查存在减薄的管束分布较为均匀，但有集中在中下部的倾向。3.2.1复水器结构分析裂解气压缩机透平（DST-201)排放的乏汽通过一段竖直的排气管、膨胀节连接到复水器顶部,见图2。为确保复水器真空度，从其两侧相同位置各引出1股抽汽线，2 股抽汽线在复水器北侧汇合后100中7601225图3 复水器内部结构示意复水器在原设计时考虑到上部管束存在气液两相冲刷的可能，其换热管设计有2 种规格：20mm1 5210 mm(1 860 根)及20 mm1.2mm5210mm(320根）。其中,壁厚1.2 mm的管束均分布在复水器顶部。从历次检修管束泄漏堵管情况看，泄漏管束主要在复水器北侧通道中上部。因此，气液两相冲刷是导致管束泄漏的主因。44.因做完功的蒸汽（乏汽）从透平排出进人竖直排汽管时存在预旋，可能导致乏汽进入复水器上部时，主要分布在复水器北侧通道上部区域，造成泄漏管束的集中分布。3.2.2复水器电涡流检测情况2019年电涡流检测结论：管束管板均匀腐蚀，局部轻微坑蚀。换热管内壁附着1层污垢，垢下均匀腐蚀，换热管壁厚损失小于3 0%。2022年电涡流检测结论：管板及焊缝处均匀腐蚀。管内壁结垢,均匀腐蚀。涡流检测抽检换热管116 根。其中,壁厚损失大于40%的换热管6根，壁厚损失3 0%40%的换热管4根，其余换热管壁厚损失小于2 0%。3.2.3管束泄漏原因确定复水器上部空冷区气液两相冲刷是导致复水器泄漏的直接原因。间接原因有2 个：1）循环水侧垢下腐蚀造成换热管存在腐蚀减薄;2)乏汽进入复水器后存在偏流，使北侧通道上部管束存在冲刷。乙烯工业4复水器后期处理措施为从根本上解决复水器管束泄漏问题，延长复水器运行周期，联系复水器设计单位对设备制造单位提供的旧式和新式复水器结构并结合复水器运行工况进行流场模拟。从流场分析结果看，在用复水器入口处有防冲板，蒸汽速度为两边高中间低,且径向方向的速度存在较大波动,产生偏流使进入复水器左右腔室的蒸汽速度不一致。罩壳两端相比于防冲板附近为低速区，但最大速度仍能达到7 0 m/s,且高速流体冲刷复水器壳体壁面，形成循环流动。该结果与运行部分析原因一致。最终运行部和复水器设计厂家确定改造方案为：1)将蒸汽入口位置直管段改为“喇叭口”形状，能使蒸汽快速扩散;2)将防冲板移除，在复水器上层管束上方布置不锈钢防冲管。该改造方案一方面能优化蒸汽流人口扩散；另一方面，蒸汽流动不直接受防冲板阻碍,利用不锈钢防冲管降低蒸汽流速并将其均匀分散，避免防冲管下方的铜管受到高速气流的冲刷。具体改造情况见图4。第3 6 卷?中我术数据N-720-31K移动岩5结语泄漏管束主要存在复水器北侧通道中上部，因此气液两相冲刷是导致管束泄漏的主因。为降低迎汽面汽流对管束冲刷而造成的泄漏，对复水器进行改进：1）疏水膨胀箱放汽口底部高于换热S1围定端G图4改型方案复水器外形示意管15 0 mm以上，且此处筒体保留，作为防冲板用。2)迎汽面的换热管相应增加厚度。3)复水器进汽口进行扩口设计、筒体开孔优化设计。通过严格执行工艺参数和优化措施的双管齐下，确保了复水器系统的安稳长周期运行。59S1K720m(+m)2200.Kg330003595t/m找热BFe10-1-1920X1X5210_A1860k020X1.2X5210A3204尧体材料0 2 3 5 8管板材料Q2358技术婴求水驾试修蓬力0.6 MPo(C)光解餐系分O.2MPo(C)提量时月不夕干3 0 分钟2#*#0-1713-400500执行。3.水室上之快安装石皮解特水宝益开关4.教入幕加工发配热7 8 K54.015-8秘冰.127XON4OPNENIRPFACONEOPNTOABSTRACTSaffecting the normal operation.The simulation calculation based onCFD technology can accurately predict the flow of decoking effluentin pipelines,providing technical reference for the piping layout forrecycling decoking effluent to firebox of large-scale cracking fur-nace.Key words:cracking furnace;CFD;recycling to firebox;piping;decoking effluentINFLUENCE OF OPERATING MODE OF FIVE OPERA-TING CRACKING FURNACES ON QUENCH SYSTEM ANDTHEOPTIMIZATIONMEASURES37Zhang Lei,Luo Lingli,Li Zhonghua,Ren Chongxin,LyuXiaogang.PetroChina Dushanzi Petrochemical Company,Dushanzi,Xinjiang,P.C.833699Abstract:In order to reduce the energy consumption of the 220 kt/aethylene plant in Dushanzi,it was proposed to change the operatingmode of cracking furnace from 6 for operation and 1 standby to 5 foroperation,1 stopped and 1 standby based on the energy consumptionanalysis of the ethylene plant and the current working conditions ofcracking furnace and cracking gas compressor.In order to select theoptimal operating mode of 5 for operation,1 stopped and 1 standby,the working conditions were tested in 5 stages.By comparing thedesign parameters of the No.2 gasoline fractionator(C-103),therelationship between the cracking gas load of the tower and themiddle pumparound and gasoline reflux was optimized and adjusted,ensuring the stable and controlled quench oil viscosity and quenchwater quality.Through optimizing the operating mode of crackingfurnace,the goal of energy saving and consumption reduction of theethylene plant was quickly achieved.Key words:cracking furnace;operating mode;quench system;optimizationCAUSE ANALYSIS AND PREVENTIVE MEASURES FORTUBEBUNDLELEAKAGEINCONDENSER OF CRACKINGGASCOMPRESSOR42Shang Yongfu,Wang Chenyu,Li Wenting,Dai Chuan,GaoWanfeng,PetroChina Dushanzi Petrochemical Company,Dushanzi,Xinjiang,P.C.833699Abstract:The condenser of cracking gas compressor in ethyleneplant is the accessory equipment of cracking gas compressor,and itsleakage will affect the long-term operation of the ethylene plant.Thecauses of tube bundle leakage in the heat exchanger are analyzed,and some corresponding preventive measures are developed to extendthe operation cycle of heat exchanger and reduce the probability ofheat exchanger leakage during operation,thus ensuring the long-term operation of critical equipment in the ethylene plant.Key words:condenser;leakage;control measureCAUSE ANALYSIS AND SOLUTIONS TO LIQUID EN-TRAINMENT IN SUCTION LINE OF CRACKED GAS COM-PRESSORINETHYLENEPLANT45Zhang Lixia,Chen Quan,Hong Kun,Zhu Bin,Hao Fei.PetroChina Dushanzi Petrochemical Company,Dushanzi,Xinjiang,P.C.833699Abstract:This paper introduces the abnormal phenomenon of liquidentrainment in the suction line of cracked gas compressor in the 1100kt/a ethylene plant at PetroChina Dushanzi Petrochemical Company,analyzes the causes of the problem from various aspects,and putsforward some specific measures for alleviating the liquid entrainmentin the suction line of cracked gas compressor.The analysis resultsshow that the root cause of the liquid entrainment in suction line ofcracked gas compressor and the abnormal formation of grease incaustic wash tower is the serious blockage of demisters for theinterstage tank of cracked gas compressor and the knockout drum atinlet of caustic wash tower,which resulted in a decrease indemisting efficiency and then the liquid entrainment in suction lineof compressor.Therefore,the demister for the interstage tank ofcracked gas compressor was replaced as a whole,fundamentallysolving such problems as the liquid entrainment in suction line ofcompressor and the abnormal phenomenon in caustic wash.Key words:ethylene plant;compressor;liquid entrainment insuction line;cause and solutionDISCUSSION ON OPERATION MODE OF NEW CONTROLSYSTEM FOR THREEKEY COMPRESSORS IN ETHYLENEPLANT AFTER REVAMPING51ETHYLENEINDUSTRYStarted Publication in 1989,Quarterly.Mar.2024 Vol.36 No.1 Total 137thKong Lingjiang.SINOPEC Tianjin Company,Tianjin,P.C.300271Abstract:This paper briefly describes the revamping content andpurposes of the control system for three key compressors in ethyleneplant,and introduces the operating conditions and steps of the newsystem after revamping.The new system focuses on unit protectionand anti-surge,and over-speed protection,unit status monitoringand unit interlock protection（e me r g e n c y s h u t d o w n s y s t e m)a r ecombined into one set of ITCC system,providing a safe and reliableoperation platform for production.The performance of the controlsystem for three key compressors has been improved,the functionshave been further improved,the operating load has been reduced,the comprehensive control and operation of the unit has been realizedon the integrated operation interface,and the operating efficiencyhas been improved.Key words:control system of compressor;ITCC;module;inter-lock;statusOPERATIONAL PROBLEMS OF EXPANDER-RECOM-PRESSOR IN ETHYLENE PLANT AND THE COUNTER-MEASURES55Zhao Pan,Wang Zhengying,Duan Zhongxin,Long Xianhuang,Liang Duo.PetroChina Tarim Oilfield Company,Korla,Xinjang,P.C.841000Abstract:As an important part of the cryogenic separation ofethylene plant,expander-recompressor is used to purify the exhaustgas in cryogenic zone and provide cooling capacity for the cold boxin process system.It is the core equipment of the cryogenicseparation system,and its long period and stable operation plays avital role in reducing the ethylene loss of ethylene plant.This paperintroduces the process flow and operational problems of expander-recompressor in ethylene plant,and puts forward some optimizationand improvement measures based on the analysis of the operationalproblems,so as to ensure the stable operation of the expander-recompressor system.Key words:expander-recompressor;operational problem;optimiza-tion measureEQUIPMENT,FACILITIES AND TECHNOLOGIES FORCRACKINGGASCOMIPRESSORIN1200kt/aETHYLENEPLANTIN TIANJIN58Hou Nan,Chen Deming,Lyu Jiasheng.SINOPEC Tianjin Com-pany,Tianjin,P.C.300271Abstract:In recent years,the capacity of ethylene plant has beencontinuously expanded,and cracking gas compressor unit isdeveloping towards large scale.At the same time,the requirementsfor the design and performance of compressor unit are higher:Basedon the problems in the operation of cracking gas compressor unit of a200 kt/a ethylene plant,this paper introduces the equipment,facilities and related technologies for the cracking gas compressorand driving steam turbine of the 1 200 kt/a ethylene plant ofSINOPEC Tianjin Company.The innovative application of a numberof advanced technologies has solved some of the key problems in theethylene plant,providing a strong guarantee for the design andconstruction of subsequent larger-scale ethylene plants.Key words:cracking gas compressor;steam turbine;lubricating oilsystemINFLUENCE OF INJECTING API GROUP V BASE OIL ONBEARING BUSH TEMPERATURE OF PROPYLENE RE-FRIGERATIONCOMPRESSOR TURBINE62Zhang Liguo,Wang Zixuan,Dai Chuan,Zhou Lijing,You Zhi-heng.PetroChina Dushanzi Petrochemical Company,Dushanzi,Xin-jiang,P.C.833699Abstract:After the shutdown of the ethylene plant at PetroChinaDushanzi Petrochemical Company for maintenance,the radialbearing bush temperature at the turbine side of propylenerefrigeration compressor kept rising during operation.The causes ofthe rise of bearing bush temperature were investigated,and APIGroup V base oil was injected into the propylene refrigerationcompressor in advance to solve the problem of radial bearing bushtemperature rise at the turbine side according to the previousexperience,thus ensuring the long-term operation of compressorunit.Key words:turbine;bearing bush temperature;varmnish;APIGroup V base oil