ABSTRACTS

ON ALLOWABLE EXTERNAL LOAD VALUES OF PRESSURE VESSEL NOZZLES[1]

ZhangJunwen(SINOPECEngineeringIncorporation,Beijing,100101)

Abstract：At the beginning of a project,setting an allowable external load value related to the static equipment nozzle size and pressure level can facilitate the separate work of the equipment and piping stress engineers,thereby greatly accelerating the project progress.However,some problems often arise in the setting and use of the allowable external load values of nozzles and in the process of verification and calculation of values exceeding the specified value.Thispaper elaborates on these issues in the hope of helping designers avoid over-design while ensuring the safety of the designed products.

Keywords：allowableexternal load of nozzle;local stress;static equipment

DESIGN OF NATURAL GAS HIGH-PRESSURE GAS STORAGE WELL[4]

QinZongchuan,ZhuJinhua,YaoZuoquan,CuiJun(HefeiGeneralMachineryResearchInstituteCo.,Ltd.,Hefei,Anhui,230031)

Abstract：Gas storage well is the core equipment of gas filling station for compressed natural gas vehicles and is used for storage of high-pressure natural gas.The working pressure of gas storage well is up to 25 MPa.This paper took the natural gas high-pressure underground gas storage wells of certain company as an example.From the aspects of risk identification and control,material selection of main pressure-bearing components,structure design of wellhead,well bore and well bottom,stress analysis and fatigue assessment,drilling and well casing assembly during construction,cementing process control,cementing quality inspection,pressure resistance and leakage test,this paper elaborated the design process.It also analyzed and researched the control points and difficulties of each link.Then the paper put forward targeted solutions and countermeasures and clarified various technical requirements.This provides technical reference for the design and manufacture of such equipment.

Keywords：high-pressure storage of natural gas;wellhead device;casing;coupling;bottom hole device;well cementation

DESIGN OF GAS DISTRIBUTOR IN FLUIDIZED BED POLYMERIZATION REACTOR[11]

LiXiaoxia,WuLitao(SINOPECEngineeringIncorporation,Beijing,100101)

Abstract：Fluidized reactors are widely used in the production of polyethylene and polypropylene.The design of gas distributor is one of the key issues in the scale-up of fluidized bed reactors.Taking the conical cap porous distributor as an example,this paper introduced the design method of such key parameters as the opening rate,pressure drop,hole spacing and so forth.It presented the design steps of conical cap porous distributor and applied these steps to the design of gas distributor in fluidized bed reactor in actual industrial production.

Keywords：fluidized bed;olefin polymerization;gas distributor;design

FAILURE PROBABILITY CALCULATION OF HEAT EXCHANGER TUBE BUNDLE[14]

LiZhifeng1,WuJianping2,WangXiaobo1,ZengFanliang2(1.ChinaSpecialEquipmentInspection&ResearchInstitute,Beijing,100013;2.SINOPEC-Sk(Wuhan)PetrochemicalCompanyLimited,Wuhan,Hubei,430000)

Abstract：Following API RP 581-2016 and GB/T 26610.4-2014,the failure probability of heat exchanger tube bundle is calculated based on Weibull probability and statistical analysis method,but the calculation process is quite different.Out of consideration for engineering application,the parameter selection of Weibull probability and statistical formula in GB/T 26610.4 is relatively simple,and there is no other parameter selection method as given in API RP 581.In this paper,two-parameter and three-parameter Weibull calculation models are used to calculate the failure probability of the heat exchanger tube bundles.Compared with the standard calculation results,it is found that the fitting degree of the calculation methods in GB/T 26610.4 is poor.Meanwhile,a method to determine the value ofηparameter based on the design parameters is proposed and applied to the calculation of an example.The fitting degree of the method is close to the fitting degree obtained from the calculation method in GB/T 26610.4.And so this method can be used to calculate the failure probability of heat exchanger tube bundles.

Keywords：failure probability;heat exchanger tube bundles;Weibull probability and statistical analysis method;fitting degree

COMPARISON AND ANALYSIS OF STANDARDS FOR NICKEL STEELS FOR CRYOGENIC STORAGE TANKS[20]

ChenKaili(SINOPECEngineeringIncorporation,Beijing,100101)

Abstract：Nickel steel plates including 5% Ni,7% Ni and 9% Ni steel are mainly used for cryogenic storage tanks with temperatures ranging from -90 ℃ to -196 ℃.Many national standards have been established for these Nickel steels.Due to the complexity of these standards of low-temperature nickel steels and enormous distinctions of the technical specifications in these standards,this paper's focus is to analyze and compare the main properties of the above materials,including chemical composition,mechanical properties and heat treatment processes,set in American ASTM,European EN,Japanese JIS,Chinese GB standards and some industrial enterprise standards as well.The paper not only summarizes the similarities and differences between the above standards and specifications,but also investigates some critical issues such as heat treatment temperatures,supply conditions and impact performance requirements which are directly related to low-temperature performance.Furthermore,it provides certain referential criteria for the selection of material for cryogenic storage tanks under different conditions.

Keywords：nickel series low temperature steel;cryogenic storage tank;performance comparison;standard

RISK ASSESSMENT AND OPERATION RELIABILITY ANALYSIS OF OIL PUMPS IN OIL DEPOT BASED ON RCM[27]

YeLin1,WangXingwang2,WeiLixin1,LiuBingyi3,ChuYongqiang1(1.NortheastPetroleumUniversity,Daqing,Heilongjiang,163318;2.ExplorationandProductionResearchInstitute,SINOPEC,Beijing,China,100083;3.QinhuangdaoOil&GasTransportationSub-Company,Qinhuangdao,Hebei,066001)

Abstract：The centrifugal pump is important equipment in the external pipeline.It's safe and reliable operation is the basis for the oil depot to complete the oil transportation activity.As advanced maintenance management technology,reliability-centered maintenance (RCM) can strengthen the management of equipment and standardize the use of equipment.This technology can be used to analyze the effects and hazards of failure modes so as to determine medium and high risk and high failure frequency equipment.Takingthe centrifugal pumps of certain oil depot as an example,this paper analyzed the running time data of the centrifugal pumps in this oil depot through collecting the overhaul time of the pumps over the years;then it determined their compliance with the Weibull distribution byK-Stest;and this model was used to obtain the trend of centrifugal pump reliability.Based on this,the paper provided the inspection maintenance period of the centrifugal pumps under four kinds of reliability.After using the RCM method to analyze the maintenance cycle,the problems of over-maintenance and under-maintenance could be avoided;maintenance costs could be controlled and the utilization of equipment was improved.The results show that the average trouble-free time of the centrifugal pumps of the oil depot at this stage is 3046.179 hours,and a preventive maintenance should be carried out in about 34 days.

Keywords：Weibull distribution;K-Ssimulation;reliability-centered maintenance;reliability analysis;preventative maintenance

ANALYSIS ON THE INFLUENCE OF BLADE WRAP ANGLE ON FLOW FIELD AND HYDRAULIC VIBRATION OF MEDIUM-HIGH SPECIFIC SPEED PUMP[33]

MaFengbo(PetroChinaDaqingPetrochemicalCompany,Daqing,Heilongjiang,163711)

Abstract：In this paper,the influence of blade wrap angle on the hydraulic vibration of a centrifugal pump with a specific speed of 103 was analyzed.Three different blade wrap angles of 116°,122° and 128° were adopted to study the external characteristics of the centrifugal pump under different working conditions.Through computer simulation,the pressure fluctuation characteristics of the monitoring points in the impeller passage and volute passage under three conditions were measured,and the frequency domain distribution diagram of pressure fluctuation was drawn.Finally,the following conclusions were drawn:the optimal blade wrap angle of the medium-high specific speed centrifugal pump is 122° and under this angle,the medium-high specific speed centrifugal pump can achieve the highest head and efficiency,and the optimal efficiency point is in the direction of the pump when the flow direction is extended;the pressure fluctuation in the impeller passage is inversely proportional to the blade wrap angle,and the pressure fluctuation amplitude is directly proportional to the blade wrap angle;the pressure in the volute increases with the increase of the blade wrap angle,but the variation law of the pressure value at each monitoring point in the volute is not the same,and the pressure fluctuation amplitude at each monitoring point in the internal volute increases with the increase of the blade wrap angle as well as with the increase of the blade wrap angle;it decreases with the increase of blade wrap angle.On the whole,increasing the blade wrap angle can reduce the hydraulic vibration of centrifugal pump with medium-high specific speed.

Keywords：blade wrap angle;centrifugal pump with medium-high specific speed;numerical simulation;hydraulic vibration;pressure fluctuation

ON AXIAL FORCE OF CENTRIFUGAL COMPRESSOR UNDER VARYING DUTY[36]

XiongAobo(SINOPECEngineeringIncorporation,Beijing,100101)

Abstract：This paper takes the eight-stage in-line impeller as a reference prototype and adopts NREC Compal software to model and analyze the axial force of the rotor impeller of centrifugal compressor.First,it obtainedthe aerodynamic thrust of impellers at all stages under the reference working condition and the residual axial force of the rotor after being balanced by the balance disc.Then,based on this,the change rule of the residual axial force of the rotor is obtained by changing parameters such as the pressure ratio of the whole machine,the sealing gap between stages and so forth.The relevant analysis results can provide reference for designing measures forthe axial force balance of centrifugal compressor and the actual production operation.

Keywords：centrifugal compressor;axial force;pressure ratio;varying duty;balance

OPTIMIZATION AND APPLICATION OF THE PROTECTION MEASURES FOR AMMONIUM SALT UNDER-DEPOSIT CORROSION FOR ATMOSPHERIC DISTILLATION COLUMN OVERHEAD HEAT EXCHANGER[41]

MaHongjie1,SunCunlong2,JiangChen1(PetroChinaDushanziPetrochemicalCompany,Dushanzi,Xinjiang,833699)

Abstract：Corrosion leakage occurs frequently in the atmospheric distillation column overhead heat exchanger of certain petrochemical company.There are many corrosion pits on the inner wall of the tube bundle where the ammonium salt scaling is serious.These corrosion pits are linear and there're obvious corrosion grooves,which are typical characteristics of ammonium salt under-deposit corrosion.The management of the electrical desalting process,operation,inspection and monitoring of the device was optimized.The results show that the salt content of the electrical desalting unit decreased obviously after the secondary desalination,and only 0.15% of the data exceeded the standard.A series of process and material protective measures were adopted for the atmospheric distillation column overhead heat exchanger,such as carrying out multi-point water injection for the distillate line,installing sprinklers for each water injection line,increasing water injection volume to 24 t/h and maintaining 30% of liquid water,selecting neutralizer with lower salt scaling temperature,upgrading the tube bundle material to titanium alloy and so on.And the application effects indicated that the salt scaling area of the tube bundlewas reduced and there was slight salt scaling;there was no abnormal thinning of the inlet and outlet pipelines of the atmospheric distillation column overhead heat exchanger;and the titanium alloy tube bundle that had run for three years was corroded slightly.

Keywords：distillation unit;heat exchanger;ammonium salt;under-deposit corrosion;protection

REAL-TIME PREDICTION METHOD OF FURNACE TEMPERATURE FIELD BASED ON CONVOLUTIONAL LONG SHORT-TERM MEMORY NETWORK[46]

LiTao,WangYanli(SINOPECTianjinCompany,Tianjin,300271)

Abstract：Due to the unstable combustion process,local over-temperature may occur on the tube of the heating furnace which is prone to coking,leading to its failure.Therefore,it is necessary to measure the temperature of the heating furnace in the actual project.At present,computational fluid dynamics (CFD) numerical method is used for direct real-time temperature field prediction.Although the method is of high accuracy,it is very time-consuming and the prediction cannot be achieved with the existing calculation capability.To solve this problem,this paper proposes a real-time prediction method for the temperature field of heating furnaces based on a convolutional long short-term memory network.The method is completely driven by data and uses ConvLSTM to extract the internal relationship of the time sequence dynamically for temperature field prediction.This can realize the soft sensor of the temperature field of industrial heating furnace and the MAE (mean absolute error) of the predicted temperature field is 31.7 K.

Keywords：ConvLSTM;softsensor;temperature field of heating furnace;coking;furnace

QUALITY CONTROL OF CONSTRUCTION OF COAL-WATER SLURRY GASIFIER[51]

ZhangYongming(SINOPECFifthConstructionCo.,Guangzhou,Guangdong,510145)

Abstract：Coal-water slurry gasifier is high-temperature and high-pressure reaction equipment.A series of reactions of coal slurry in the gasifier are completed in a combustion chamber built of refractory materials.Refractory materials have to withstand high temperature,humidity,scouring and wear as well as the alternating hot and cold conditions of shutdown and startup caused by the replacement of the burner.If the construction quality of the gasifier is not good,the gasifier cannot withstand the above-mentioned harsh working conditions.This paperelaborates on the key points of quality control in the process of gasifier construction.Through strict quality control,the expected gasifier construction quality has been achieved and the goal of long-term operation of the gasifier has been realized.

Keywords：gasifier;furnace-constructing;quality control

CRACK FAILURE ANALYSIS AND IMPROVEMENT SUGGESTIONS FOR FLUE GAS ELBOW OF CONTINUOUS REFORMING REGENERATION[54]

WangChaoping(SINOPECShanghaiGaoqiaoPetrochemicalCo.,Ltd.,Shanghai,200137)

Abstract：This paper analyzes the crack failure of regenerated flue gas bending pipe in continuous catalytic reforming unit (CCR),and conducts macro-morphology,microstructure,macro-micro fracture,SEM and EDX non-damage detection on the crack location.The flow of medium in the pipe and the position of the pipe are analyzed by means ofnumerical simulation.The results show that the bending pipe increases the medium flowvelocity,leading to the inner wall of the elbow to produce pits quickly under constant washing,which finally causes stress corrosion cracking (SCC) under the action of Cl-.In order to avoid cracks during service again,the position of the branch pipe and main pipe is improved so that the fluid gets a greater buffer at the elbow and reduces the corrosion strength.

Keywords：CCR;bendingpipe;crack;washing;SCC;failure analysis

APPLICATION OF TORQUE STRETCHING METHOD WITH NO REACTION ARM IN HIGH RISK FLANGE FASTENING IN PETROCHEMICAL INDUSTRY[59]

YiYihu1,GaoWei2(1.SINOPECManagementInstitute,Beijing,100020;2.HYTORCGroupLimited,Beijing,100036)

Abstract：Bolted flange connection is widely used in petrochemical enterprises and it is also leak-prone part.At present,the hydraulic wrench is often used to tighten the bolts in refining and chemical companies,but this method will not only increase the friction coefficient between the threads,but also cause the bolt to clamp and affect the sealing performance of the joints.This paper introduces the application practice of the torque stretching method with no reaction arm and analyzes the fastening principles of the method.The results from the demonstration application in the reforming reactor show thatthis method can not only improve the accuracy of bolt preload and ensure the reliability of flange sealing,but also reduce VOCs emissionsgreatly,which can improve the sealing grade of flange sealing jointssignificantly.

Keywords：bolt tightening;no reaction arm;risk classification;flange

CAUSE ANALYSIS AND REPAIR OF WELD CRACKING IN 347H REACTOR OF MTO UNIT[62]

SiHaitao(SINOPECZhongyuanPetrochemicalCorp.Ltd.,Puyang,Henan,457000)

Abstract：Thereactor material of the MTO plant of a petrochemical company is 347H and the plant was completed and put into use in October 2011.In September 2017,cracks were first found near the circumferential weld of the reactor head.On May 2,2018,the company stopped production for overhaul.Larger cracks were found again at the position of the circumferential weld of the head,and micro-cracks appeared in many places.Through expanded test,defect removal and fitness-for-service assessment and formulating strict operational monitoring measures,the smooth operation of the device has been ensured.This paper analyzes and explores the causes of the weld cracking from various aspects,and makes relevant recommendations.

Keywords：347H;austenitic stainless steel;stress relaxation crack;reheat cracking;welding quality