天津石化1200 kt_a乙烯装置裂解气压缩机设备设施及技术分析.pdf

压缩机乙烯工业2 0 2 4,3 6(1)5 8 6 1ETHYLENE INDUSTRY天津石化1 2 0 0 kt/a乙烯装置裂解气压缩机设备设施及技术分析侯楠，陈德明，吕家胜（中国石油化工股份有限公司天津分公司，天津3 0 0 2 7 1）摘要：近年来，随着乙烯装置规模不断扩大，裂解气压缩机组也向大型化发展。同时，对压缩机组的设计、性能等方面要求更高。基于某2 0 0 kt/a乙烯装置裂解气压缩机组在运行中出现的问题，介绍了天津石化1 2 0 0 kt/a乙烯装置裂解气压缩机及驱动汽轮机的设备设施和相关技术，其中多项技术的创新应用，解决了乙烯装置中部分关键问题，为后续更大规模乙烯装置的设计及建设提供有力的保障。关键词：裂解气压缩机汽轮机润滑油系统裂解气压缩机作为乙烯装置的关键设备，如果意外停车，将影响乙烯装置及其下游装置的平稳运行,造成严重的安全风险和经济损失 。随着科技的发展，机组的设计及配套设施不断完善创新。本文基于某2 0 0 kt/a乙烯装置裂解气压缩机组的运行情况，对中国石油化工股份有限公司天津分公司1 2 0 0 kt/a乙烯装置裂解气压缩机及驱动汽轮机的设备设施和采用的技术进行介绍。1某2 0 0 kt/a乙烯装置裂解气压缩机技术分析1.1裂解气压缩机运行情况某2 0 0 kt/a乙烯装置裂解气压缩机为三缸五段十九级压缩，在运行过程中存在以下问题：1)在停车检修时，发现裂解气压缩机流道和转子表面有结焦现象（见图1）。此外,附着在流道上的焦垢在离心力的作用下可能部分脱落，使转子的动平衡遭到破坏,造成轴振动和轴位移升高，严重时可造成机组损坏。通过分析,结焦原因是裂解气中含有的丁二烯、苯乙烯等不饱和烃和金属氧化物，在压缩过程中温度升高，不饱和烃在压缩机流道发生聚合反应形成焦垢。2)在一个检修周期后，发现压缩机段间换热器局部腐蚀结垢严重（见图2），影响换热效率，若发生内漏将严重影响装置安全稳定运行。图1 叶轮结焦情况图2 段间换热器腐蚀情况3)裂解气压缩机四段排出温度偏高，长期在90左右,最高达9 4,影响裂解气压缩机长周期稳定运行。分析原因发现：为四段吸入温度偏高导致。四段吸人温度由碱洗塔顶温度决定，若收稿日期：2 0 2 2-0 9-2 0；修改稿收到日期：2 0 2 3-0 8-1 3。作者简介：侯楠，男，2 0 2 0 年毕业于燕山大学化学工程专业，硕士，主要从事乙烯生产工作，助理工程师。第3 6 卷降低碱洗塔温度，则黄油产生量过大，可导致碱洗不合格。1.2汽轮机运行情况汽轮机在运行期间主要存在以下问题：1)汽轮机在启动时，排汽温度较高。排汽缸温度升高，会使低压缸轴封产生热变形，动、静之间可能产生摩擦，造成轴振动，严重时可能损坏轴封。2）在汽轮机启动和停车阶段，上下缸温差偏大。通常上汽缸温度高于下汽缸温度。上汽缸热膨胀大于下汽缸，汽轮机隔板汽封径向间隙较小，若上下缸温差过大，可使径向间隙消失，造成径向动静部分摩擦。1.3润滑油站运行情况润滑油站在运行期间主要存在以下问题：1）油箱油温不易控制。油箱加热管盘采用蒸汽加热，在开车跑油阶段，机组未产生热量，加热管盘导热油面积不够，加热速度较慢。在正常运行期间，采用蒸汽加热，油温不易控制，影响压缩机稳定运行。2)在机组停车后，盘车装置无法启动。经查盘车逻辑无问题，将汽轮机与压缩机联轴器拆开后,再次启动盘车装置，盘车正常运行。分析发现，盘车异常的主要原因是转子过重和轴承局部汽轮机2MCL1404中压缸侯楠等.天津石化1 2 0 0 kt/a乙烯装置裂解气压缩机设备设施及技术分析59.摩擦较大。3)润滑油主油泵采用汽轮机驱动，辅助油泵采用电泵驱动，事故油泵采用电机驱动。事故油泵电机功率较辅助油泵低，由柴油发电机提供电源。若发生意外,事故油泵仅为机组提供润滑油，无法维持机组正常运行。4)油箱为常压设计，运行期间出现油箱压力偏高、回油不畅。若润滑油回油背压升高,回油受阻，严重时可造成压缩机停车。具体原因为：装置波动时回油量较大，回油温度较高，产生的油烟较多。油气分离器分离效果差，造成密封油回油中存在烃类，进人油箱，造成油箱压力波动。5)润滑油带水。润滑油带水原因有:油箱加热管盘存在泄漏,使润滑油系统带水。梳齿密封腐蚀损坏，裂解气中的水通过梳齿密封与密封油接触进人油箱。21200kt/a乙烯装置裂解气压缩机技术分析天津石化1 2 0 0 kt/a乙烯装置裂解气压缩机由沈阳透平机械股份有限公司设计制造，采用三缸五段十五级压缩，以满足裂解气压缩机各段压力和温度要求，缸体型号为DMCL1404+2MCL1404+2MCL1207。裂解气压缩机设备布置示意见图3。裂解气压缩机工艺流程见图4。DMCL14042MCL1207低压缸高压缸图3 裂解气压缩机布置示意段二段三段四段五段裂解气干燥器碱洗塔图4 裂解气压缩工艺流程示意60.在三段与四段之间设置碱洗塔，以除去裂解气中的酸性气体。在五段出口设置裂解气干燥器，脱除裂解气中的水分，防止微量水在深冷分离系统与烃类形成结晶水合物，堵塞设备及管道。2.1裂解气压缩机采用的技术1）为防止裂解气结焦，采用注水、注油技术。在压缩机壳体及1 5 段吸入管道上设置注油系统,通过喷嘴把雾化的油分散在裂解气中，使压缩机流道和叶轮表面形成一层油膜,附着在流道内壁的聚合物溶解在洗油中，随段间罐凝液排出，从而抑制结焦。为保证洗油在压缩机流道形成油膜，洗油注人量为裂解气流量（质量分数）的2%左右。在注油的同时在洗油中注人阻聚剂,抑制聚合反应发生。但注油仅能抑制减缓结焦，无法从根本上解决高温结焦问题。为此，在压缩机1 5 段壳体上设置注水喷嘴，采用连续注水方式向裂解气中喷人冷却后的锅炉给水,注水的液滴平均直径小于1 0 0 m，喷入的水滴与高温裂解气直接混合进行热量交换。由于水的蒸发潜热大，水汽化吸收大量的热，使每段出口裂解气温度降低。采用压缩机级间注水后,3 种工况的段间出口温度均明显降低（见图5），可有效防止介质中的不饱和烃聚合结焦，有利于裂解气压缩机的长周期稳定运行。此外，由于采用压缩机级间注水，使压缩过程更接近于等温压缩,注水后,3 种工况下的压缩机轴功率均大幅降低（见图6），使压缩机实际处理能力增加。94CaselACaselB92Case2A90Case2B/甲菲88828078一段二段三段四段五段图5 裂解气压缩机有无注水段间排出温度对比2)为防止裂解气压缩机段间换热器结垢腐蚀,采用防腐涂层及高效防护剂注入系统。在前两段后冷器裂解气侧压力低于冷却水侧时，若换乙烯工业热器腐蚀发生内漏,冷却水如泄漏至裂解气中,可能导致短时间内压缩机吸人罐液位上升，严重时可触发高液位停车联锁，使压缩机停车。在后三段后冷器裂解气侧压力大于冷却水侧时，若换热器腐蚀发生内漏,裂解气泄漏至冷却水中,将影响整个冷却水系统的稳定运行。压缩机段间换热器采用防腐涂层技术，在换热器管束表面及内壁喷涂防腐材料,使其表面形成一层致密的薄膜,可有效阻止腐蚀性物质与内壁接触，解决换热器腐蚀问题。CaselA14000CaselBCase2ACase2B13.500Case3ACase3B1300012.50012.00011 50011 000一段二段三段四段五段图6 裂解气压缩机有无注水轴功率对比由于前三段裂解气未经碱洗，裂解气中的酸性气体会腐蚀设备和管道，采用高效防护剂注人系统，在前三段后冷器入口设置中和剂注人，大幅减少酸性腐蚀。防护剂具有高效的成膜和中和双重作用,成膜组分中分子一端在金属表面吸附,另一端吸附某些烃类,在金属表面形成一层致密的保护膜。同时中和剂在气液两相有一定配比,可实现气液两相的中和作用。3)与传统压缩工艺相比，碱洗温度控制采用温差控制，取碱洗塔水洗段下部温度与三段排出Case3A罐温度差值，控制裂解气加热器急冷水的流量，避Case3B免碱洗温度波动。在碱洗塔顶出口增加冷却水换热器，满足碱A:不注水洗温度的同时，通过冷却水对碱洗塔顶裂解气进B:注水行降温，可以使压缩机四段吸人温度降低，从根本上解决了四段排出温度偏高问题。2.2汽轮机采用的技术天津石化1 2 0 0 kt/a乙烯装置裂解气压缩机驱动汽轮机由杭州汽轮机股份有限公司设计制造，采用抽汽冷凝式结构，功率7 3 MW，可满足1 3第3 6 卷A:不注水B:注水第3 6 卷个典型运行工况 2 该汽轮机采用排汽缸注水设计，在排汽缸末级叶片设置注水喷头，注水采用凝结水泵出口透平凝结水。通过监测排汽温度，若排汽温度达到80,将自动打开喷淋阀喷水至排汽缸,1 5 min后关闭喷淋。排汽缸注水技术的应用，可较好的控制排汽温度，从根本上解决了排汽温度偏高的问题。同时该汽轮机采用汽缸温度补偿设计，温度补偿采用电加热器，布置在下缸。在机组暖管同时启动加热装置，在温差过大时将自动启动，温差在允许范围内，自动关闭加热装置。汽缸温度补偿技术的应用，可以调节下缸温度，从根本上解决上下缸温差偏大问题。排汽缸注水和汽缸温度补偿技术在汽轮机上的应用，解决了排汽温度偏高及上下缸温差偏大的问题,大幅降低了装置安全风险。2.3润滑油站采用的技术1)油箱加热器采用多组电加热器,在1 2 h内可将油加热到启动条件。电加热器加热速度快，且可稳定控制油温，可避免蒸汽泄漏风险。油箱配置具有除水、除杂功能的固定式油净化器，可有效避免润滑油系统带水问题。2)随着机组增大,转子重量增大，裂解气压缩机及汽轮机配置顶升油系统，在盘车时开启顶升装置，使转子稳定转动。顶升油系统有效地减小了转动力矩且避免轴瓦磨损。3)3台油泵均采用三螺杆式，主泵采用汽轮机侯楠等.天津石化1 2 0 0 kt/a乙烯装置裂解气压缩机设备设施及技术分析业出版社，2 0 1 7：2 0 0-5 0 3.2王文，李宏福，李金波，1 0 0 MW裂解气压缩机驱动用抽凝式汽轮机的国产化工程应用与优化 J.石油化工设备技术，2 0 2 1.:61驱动,配置2 个辅助油泵,不设事故油泵。2 台辅助油泵采用不同电源、功率相同的电动机驱动,其提供的润滑油量均可满足机组正常运行，降低了油路系统中断的风险。4)油箱采用微负压设计，在排气口设置排油烟风机,带油气分离内件，使油箱压力稳定,且可回收油雾，减少污染，从而解决了回油压力波动的问题。润滑油站新技术的应用，降低了以往乙烯装置润滑油带水、回油压力高、盘车力矩过大等安全风险，使裂解气压缩机更加稳定运行，同时润滑油系统的智能化水平也得到明显提高。3结语随着科技的发展，天津石化1 2 0 0 kt/a乙烯装置裂解气压缩机的设计及配套设施不断完善创新,新型配置及新技术的应用,大幅降低了乙烯装置的能耗，提高了乙烯装置的智能化水平。该裂解气压缩机在满足1 2 0 0 kt/a处理量的基础上，兼顾未来扩容至1 5 0 0 kt/a的能力,装置开车后将为后续乙烯装置的设计和建设提供数据支持。参考文献：1胡杰,王松汉乙烯工艺与原料 M北京：化学工(上接第5 7 页)1）对关键性仪表实行定期预防性检查。2)对膨胀再压缩机电磁阀重新进行HAZOP和FAME分析评估,根据评估结果,将部分切断阀的单电磁阀改为二取二或三取二余电磁阀,并在乙烯装置2 0 2 3 年停工大检修期间实施整改。3结语膨胀再压缩机作为乙烯装置尾气回收和提供冷分离冷量的设备，是降低乙烯损失，提升乙烯收率的重要机组。膨胀再压缩机的稳定运行，是提高装置安全、经济运行效益重要保障。在装置低负荷运行期间，如进料流量低于设计值,接近喘振点，此时打开2 个防喘振阀,则不存在压缩机喘振的风险。在运行和维护上，停车检修期间要避免转子转动，严格执行膨胀再压缩机长期停车程序。ABSTRACTSaffecting 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