This work focuses on the development and implementation of a simulation-based approach for the detection of partial and extended blockages within an edible oil pipeline system. Blockages, whether partial or extended, ...This work focuses on the development and implementation of a simulation-based approach for the detection of partial and extended blockages within an edible oil pipeline system. Blockages, whether partial or extended, pose a significant operational and safety risks. This study employs computational fluid dynamics (CFD) simulations to model the flow behaviour of edible oil through pipeline under varying conditions. It leverages advanced computational fluid dynamics (CFD) simulations to analyze pressure, velocity, and temperature variations along the pipeline. By simulating scenarios with different blockage characteristics, there is establishment of distinctive patterns indicative of partial and extended obstructions. Through extensive analysis of simulation data, sensing element, and monitoring system, processing signal input and response output, the system can accurately pinpoint the location and severity of blockages, providing crucial insights for timely intervention. The detection system represents a significant advancement in pipeline monitoring technology, offering a proactive and accurate approach to identify blockages and mitigate potential risks and ensure the uninterrupted flow of edible oil, thereby enabling timely intervention and maintenance.展开更多
The ever-increasing deepwater oil and gas development in the Qiongdongnan Basin,South China Sea has initiated the need to evaluate submarine debris-flow hazard risks to seafloor infrastructures.This paper presents a c...The ever-increasing deepwater oil and gas development in the Qiongdongnan Basin,South China Sea has initiated the need to evaluate submarine debris-flow hazard risks to seafloor infrastructures.This paper presents a case study on evaluating the debris-flow hazard risks to the planned pipeline systems in this region.We used a numerical model to perform simulations to support this quantitative evaluation.First,one relict failure interpreted across the development site was simulated.The back-analysis modeling was used to validate the applicability of the rheological parameters.Then,this model was applied to forecast the runout behaviors of future debris flows originating from the unstable upslope regions considered to be the most critical to the pipeline systems surrounding the Manifolds A and B.The model results showed that the potential debris-flow hazard risks rely on the location of structures and the selection of rheological parameters.For the Manifold B and connected pipeline systems,because of their remote distances away from unstable canyon flanks,the potential debris flows impose few risks.However,the pipeline systems around the Manifold A are exposed to significant hazard risks from future debris flows with selected rheological parameters.These results are beneficial for the design of a more resilient pipeline route in consideration of future debris-flow hazard risks.展开更多
The design of aircraft hydraulic pipeline system is limited by many factors,such as the integrity of aviation structure or narrow installation space,so the limited clamp support position should be considered.This pape...The design of aircraft hydraulic pipeline system is limited by many factors,such as the integrity of aviation structure or narrow installation space,so the limited clamp support position should be considered.This paper studied the frequency adjustment and dynamic responses reduction of the multi-support pipeline system through experiment and numerical simulation.To avoid the resonance of pipeline system,we proposed two different optimization programs,one was to avoid aero-engine working range,and another was to avoid aircraft hydraulic pump pulsation range.An optimization method was introduced in this paper to obtain the optimal clamp position.The experiments were introduced to validate the optimization results,and the theoretical optimization results can agree well with the test.With regard to avoiding the aero-engine vibration frequency,the test results revealed that the first natural frequency was far from the aero-engine vibration frequency.And the dynamic frequency sweep results showed that no resonance occurred on the pipeline in the engine vibration frequency range after optimization.Additionally,with regard to avoiding the pump vibration frequency,the test results revealed that natural frequencies have been adjusted and far from the pump vibration frequency.And the dynamic frequency sweep results showed that pipeline under optimal clamp position cannot lead to resonance.The sensitivity analysis results revealed the changing relationships between different clamp position and natural frequency.This study can provide helpful guidance on the analysis and design of practical aircraft pipeline.展开更多
Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon i...Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon is caused by the coupling movement of the pipeline and its vertical pile support under certain conditions. It can induce excessive vibration and cause fatigue failure at pipe elbow. However, in some circumstances it does not exist. Numerical results in both frequency and time domains are presented to elucidate this phenomenon in a combined pipeline system. The conclusions of this paper could give constructive guidance to future design of simply supported pipeline systems.展开更多
The purpose of this paper is to adopt the uniform confidence method in both water pipeline design and oil-gas pipeline design.Based on the importance of pipeline and consequence of its failure,oil and gas pipeline can...The purpose of this paper is to adopt the uniform confidence method in both water pipeline design and oil-gas pipeline design.Based on the importance of pipeline and consequence of its failure,oil and gas pipeline can be classified into three pipe classes,with exceeding probabilities over 50 years of 2%,5% and 10%,respectively.Performance-based design requires more information about ground motion,which should be obtained by evaluating seismic safety for pipeline engineering site.Different from a city's water pipeline network,the long-distance oil and gas pipeline system is a spatially linearly distributed system.For the uniform confidence of seismic safety,a long-distance oil and pipeline formed with pump stations and different-class pipe segments should be considered as a whole system when analyzing seismic risk.Considering the uncertainty of earthquake magnitude,the design-basis fault displacements corresponding to the different pipeline classes are proposed to improve deterministic seismic hazard analysis(DSHA).A new empirical relationship between the maximum fault displacement and the surface-wave magnitude is obtained with the supplemented earthquake data in East Asia.The estimation of fault displacement for a refined oil pipeline in Wenchuan MS8.0 earthquake is introduced as an example in this paper.展开更多
When designing a complex pipeline with long distance and multi-supports for offshore platform,it is necessary to analyze the vibration characteristics of the complex pipeline system to ensure that there is no harmful ...When designing a complex pipeline with long distance and multi-supports for offshore platform,it is necessary to analyze the vibration characteristics of the complex pipeline system to ensure that there is no harmful resonance in the working conditions.Therefore,the optimal layout of support is an effective method to reduce the vibration response of hydraulic pipeline system.In this paper,a developed dynamic optimization method for the complex pipeline is proposed to investigate the vibration characteristics of complex pipeline with multi-elastic supports.In this method,the Kriging response surface model between the support position and pipeline is established.The position of the clamp in the model is parameterized and the optimal solution of performance index is obtained by genetic algorithm.The number of clamps and the interval between clamps are considered as the constraints of layout optimization,and the optimization objective is the natural frequencies of pipeline.Taking a typical offshore pipeline as example to demonstrate the effectiveness of the proposed method,the results show that the vibration performance of the hydraulic pipeline system is distinctly improved by the optimization procedure,which can provide reasonable guidance for the design of complex hydraulic pipeline system.展开更多
The fluid-structure interaction(FSI)in aircraft hydraulic pipeline systems is of great concern because of the damage it causes.To accurately predict the vibration characteristic of long hydraulic pipelines with curved...The fluid-structure interaction(FSI)in aircraft hydraulic pipeline systems is of great concern because of the damage it causes.To accurately predict the vibration characteristic of long hydraulic pipelines with curved segments,we studied the frequency-domain modeling and solution method for FSI in these pipeline systems.Fourteen partial differential equations(PDEs)are utilized to model the pipeline FSI,considering both frequency-dependent friction and bending-flexibility modification.To address the numerical instability encountered by the traditional transfer matrix method(TMM)in solving relatively complex pipelines,an improved TMM is proposed for solving the PDEs in the frequency domain,based on the matrix-stacking strategy and matrix representation of boundary conditions.The proposed FSI model and improved solution method are validated by numerical cases and experiments.An experimental rig of a practical hydraulic system,consisting of an aircraft engine-driven pump,a Z-shaped aero-hydraulic pipeline,and a throttle valve,was constructed for testing.The magnitude ratio of acceleration to pressure is introduced to evaluate the theoretical and experimental results,which indicate that the proposed model and solution method are effective in practical applications.The methodology presented in this paper can be used as an efficient approach for the vibrational design of aircraft hydraulic pipeline systems.展开更多
Crude oil spillage is a major challenge in Nigeria. It affects the environment, health, life, and livelihood of residents of the Niger Delta region, where oil is explored, processed, and transported via a network of p...Crude oil spillage is a major challenge in Nigeria. It affects the environment, health, life, and livelihood of residents of the Niger Delta region, where oil is explored, processed, and transported via a network of pipelines. Oil spillage is primarily caused by vandalization/sabotage and operational issues such as corrosion, equipment failure, operation, and maintenance errors. Thus, prompt response is required to mitigate the impact of oil spills. In this study, we deployed low-cost Arduino systems, including sensors (vibration and flow), modules (GPS and Wifi) and an IoT platform (ThingSpeak) to detect spillage caused by vandalism and operational inefficiencies proactively. The results demonstrate that low-cost sensors can detect changes in the flow volume between the inflow and outflow attributable to spillage, and vibration shocks caused by vandalism can be detected and linked to the cause of the spillage and communicated in real time to inform response action. Moreover, we proposed a framework for field validation utilizing KoboToolBox (a crowdsourcing/citizen science platform). The prototype system designed and programmed showed promising results, as it could detect spillage for vandalism and operational scenarios in real-time, quantify the volume of spillage, and identify the location and time of spillage occurrence;indicators relevant for response planning to minimize the impact of oil spillage. A video demonstration of the prototype system developed is accessible via: https://youtu.be/wKa9MZvYf1w. .展开更多
The batch transportation process of several kinds of crude oil is accomplished by an entire coupled pipeline system,which exhibits complex thermo-hydraulic characteristics.Based on the coupled characteristics among so...The batch transportation process of several kinds of crude oil is accomplished by an entire coupled pipeline system,which exhibits complex thermo-hydraulic characteristics.Based on the coupled characteristics among soil,pipelines and devices(including pumps,heating furnaces and valves),a coupled simulation model of batch transportation for the crude oil pipeline system is established,and a novel coupled simulation algorithm is proposed.The simulation results are in good agreement with the field data of an actual crude oil pipeline system.In addition,based on the numerical simulation,thermo-hydraulic characteristics of pipeline system are investigated,and some new thermo-hydraulic characteristics are obtained.In the batch transportation process with constant flowrate,the change trends of temperature at the outlet of each pipeline segment are hysteretic and the change ranges of temperature become small along mileage.And the adjustment of devices influences thermohydraulic characteristics to some extent.In the batch transportation process with variable flowrate,the complex thermo-hydraulic characteristics are exhibited,which are induced by the comprehensive influence of the changes of oil type,flowrate and absorbed/released heat.Compared with the transportation process with constant flowrate,the high-viscosity oil exhibits similar minimum temperature and lower maximum pressure in the transportation process with variable flowrate,which means that the higher transportation safety of pipeline system is obtained.This study can provide a scientific reference for making the safer batch transportation scheme of crude oil pipeline system.展开更多
In 2023,two consecutive earthquakes exceeding a magnitude of 7 occurred in Türkiye,causing severe casualties and economic losses.The damage to critical urban infrastructure and building structures,including highw...In 2023,two consecutive earthquakes exceeding a magnitude of 7 occurred in Türkiye,causing severe casualties and economic losses.The damage to critical urban infrastructure and building structures,including highways,railroads,and water supply pipelines,was particularly severe in areas where these structures intersected the seismogenic fault.Critical infrastructure projects that traverse active faults are susceptible to the influence of fault movement,pulse velocity,and ground motions.In this study,we used a unique approach to analyze the acceleration records obtained from the seismic station array(9 strong ground motion stations)located along the East Anatolian Fault(the seismogenic fault of the MW7.8 mainshock of the 2023 Türkiye earthquake doublet).The acceleration records were filtered and integrated to obtain the velocity and displacement time histories.We used the results of an on-site investigation,jointly conducted by China Earthquake Administration and Türkiye’s AFAD,to analyze the distribution of PGA,PGV,and PGD recorded by the strong motion array of the East Anatolian Fault.We found that the maximum horizontal PGA in this earthquake was 3.0 g,and the maximum co-seismic surface displacement caused by the East Anatolian Fault rupture was 6.50 m.As the fault rupture propagated southwest,the velocity pulse caused by the directional effect of the rupture increased gradually,with the maximum PGA reaching 162.3 cm/s.We also discussed the seismic safety of critical infrastructure projects traversing active faults,using two case studies of water supply pipelines in Türkiye that were damaged by earthquakes.We used a three-dimensional finite element model of the PE(polyethylene)water pipeline at the Islahiye State Hospital and fault displacement observations obtained through on-site investigation to analyze pipeline failure mechanisms.We further investigated the effect of the fault-crossing angle on seismic safety of a pipeline,based on our analysis and the failure performance of the large-diameter Thames Water pipeline during the 1999 Kocaeli earthquake.The seismic method of buried pipelines crossing the fault was summarized.展开更多
Failure of pipe networks due to blast loads resulting from terrorist attacks or construction facilities, may cause economic loss, environmental pollution, source of firing or even it may lead to a disaster. The presen...Failure of pipe networks due to blast loads resulting from terrorist attacks or construction facilities, may cause economic loss, environmental pollution, source of firing or even it may lead to a disaster. The present work develops a closed-form solution of buried pipe with barrier system subjected to subsurface detonation. The solution is derived based on the concept of double-beam system. Euler Bernoulli's beams are used to simulate the buried pipe and the barrier system. Soil is idealized as viscoelastic foundation along with shear interaction between discrete Winkler springs(advanced soil model). The finite SineFourier transform is employed to solve the coupled partial differential equations. The solution is validated with past studies. A parametric study is conducted to investigate the influence of TNT charge weight, pipe material, damping ratio and TNT offset on the response of buried pipe with and without barrier system. Further a statistical analysis is carried out to get the significant soil and pipe input parameters. It is perceived that peak pipe displacements for both the cases(with and without barrier) are increases with increasing the weight of TNT charge and decreases with increasing the damping ratio and TNT offset. The deformation of pipe also varies with pipe material. Pipe safety against blast loads can be ensured by providing suitable barrier layer. The present study can be utilized in preliminary design stage as an alternative to expensive numerical analysis or field study.展开更多
Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource engineering.Due to the interaction of waves,currents,seabed,and pipeline structures,the soil aroun...Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource engineering.Due to the interaction of waves,currents,seabed,and pipeline structures,the soil around submarine pipelines is prone to local scour,severely affecting their operational safety.With the Yellow River Delta as the research area and based on the renormalized group(RNG)k-εturbulence model and Stokes fifth-order wave theory,this study solves the Navier-Stokes(N-S)equation using the finite difference method.The volume of fluid(VOF)method is used to describe the fluid-free surface,and a threedimensional numerical model of currents and waves-submarine pipeline-silty sandy seabed is established.The rationality of the numerical model is verified using a self-built waveflow flume.On this basis,in this study,the local scour development and characteristics of submarine pipelines in the Yellow River Delta silty sandy seabed in the prototype environment are explored and the influence of the presence of pipelines on hydrodynamic features such as surrounding flow field,shear stress,and turbulence intensity is analyzed.The results indicate that(1)local scour around submarine pipelines can be divided into three stages:rapid scour,slow scour,and stable scour.The maximum scour depth occurs directly below the pipeline,and the shape of the scour pits is asymmetric.(2)As the water depth decreases and the pipeline suspension height increases,the scour becomes more intense.(3)When currents go through a pipeline,a clear stagnation point is formed in front of the pipeline,and the flow velocity is positively correlated with the depth of scour.This study can provide a valuable reference for the protection of submarine pipelines in this area.展开更多
During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow...During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow of the gathering pipeline in the Changning Shale Gas Field as an example to test the erosion rate and material removal mechanism of the test piece at different angles of the elbow through experiments and compares the four erosion models with the experimental results. Through analysis, it is found that the best prediction model for quartz sand-carbon steel erosion is the Oka model. Based on the Oka model, FLUENT software was used to simulate and analyze the law of erosion of the elbow of the gas gathering pipeline under different gas flow velocities, gas gathering pressure, particle size, length of L1,and bending directions of the elbow. And a spiral pipeline structure is proposed to reduce the erosion rate of the elbow under the same working conditions. The results show that this structure can reduce erosion by 34%.展开更多
Synchrotron microscopic data commonly suffer from poor image quality with degraded resolution incurred by instrumentation defects or experimental conditions.Image restoration methods are often applied to recover the r...Synchrotron microscopic data commonly suffer from poor image quality with degraded resolution incurred by instrumentation defects or experimental conditions.Image restoration methods are often applied to recover the reduced resolution,providing improved image details that can greatly facilitate scientific discovery.Among these methods,deconvolution techniques are straightforward,yet either require known prior information or struggle to tackle large experimental data.Deep learning(DL)-based super-resolution(SR)methods handle large data well,however data scarcity and model generalizability are problematic.In addition,current image restoration methods are mostly offline and inefficient for many beamlines where high data volumes and data complexity issues are encountered.To overcome these limitations,an online image-restoration pipeline that adaptably selects suitable algorithms and models from a method repertoire is promising.In this study,using both deconvolution and pretrained DL-based SR models,we show that different restoration efficacies can be achieved on different types of synchrotron experimental data.We describe the necessity,feasibility,and significance of constructing such an image-restoration pipeline for future synchrotron experiments.展开更多
A dent is a common type of defects for submarine pipeline.For submarine pipelines,high hydrostatic pressure and internal pressure are the main loads.Once pipelines bend due to complex subsea conditions,the compression...A dent is a common type of defects for submarine pipeline.For submarine pipelines,high hydrostatic pressure and internal pressure are the main loads.Once pipelines bend due to complex subsea conditions,the compression strain capacity may be exceeded.Research into the local buckling failure and accurate prediction of the compressive strain capacity are important.A finite element model of a pipeline with a dent is established.Local buckling failure under a bending moment is investigated,and the compressive strain capacity is calculated.The effects of different parameters on pipeline local buckling are analyzed.The results show that the dent depth,external pressure and internal pressure lead to different local buckling failure modes of the pipeline.A higher internal pressure indicates a larger compressive strain capacity,and the opposite is true for external pressure.When the ratio of external pressure to collapse pressure of intact pipeline is greater than 0.1,the deeper the dent,the greater the compressive strain capacity of the pipeline.And as the ratio is less than 0.1,the opposite is true.On the basis of these results,a regression equation for predicting the compressive strain capacity of a dented submarine pipeline is proposed,which can be referred to during the integrity assessment of a submarine pipeline.展开更多
During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and...During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines,resulting in production reduction,shutdowns,and pressure build-ups.Consequently,a cascade of risks is prone to occur.To address this issue,this study focuses on the operational process of natural gas gathering and transmission pipelines,where a comprehensive framework is established.This framework includes theoretical models for pipeline temperature distribution,pipeline pressure distribution,multiphase flow within the pipeline,hydrate blockage,and numerical solution methods.By analyzing the influence of inlet temperature,inlet pressure,and terminal pressure on hydrate formation within the pipeline,the sensitivity patterns of hydrate blockage risks are derived.The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate,potentially mitigating pipeline blockage during natural gas transportation.Furthermore,an increase in inlet temperature and terminal pressure,and a decrease in inlet pressure,results in a displacement of the most probable location for hydrate blockage towards the terminal station.However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system,contradicting the operational goal of energy efficiency and reduction of energy consumption.Consequently,for high-pressure gathering pipelines,measures such as raising the inlet temperature or employing inhibitors,electrical heat tracing,and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation.Moreover,considering abnormal conditions such as gas well production and pipeline network shutdowns,which could potentially trigger hydrate formation,the installation of methanol injection connectors remains necessary to ensure production safety.展开更多
Local scour around pipelines crossing rivers or in marine environments is a significant concern.It can lead to failure of the pipelines resulting in environmental side effects and economic losses.This study developed ...Local scour around pipelines crossing rivers or in marine environments is a significant concern.It can lead to failure of the pipelines resulting in environmental side effects and economic losses.This study developed an experimental method to reduce local scour around pipelines with a steady flow of clear water by installing cylindrical and cubical sacrificial piles.Three sizes of sacrificial piles were examined in a linear arrangement.Sacrificial piles were installed on the upstream side of the pipeline at three distances.Maximum scour depth reduction rates below the pipeline were computed.The results showed that sacrificial piles could protect a pipeline from local scour.A portion of scoured sediment around the sacrificial piles was deposited beneath the pipeline.This sediment accumulation reduced the scour depth beneath the pipeline.Analysis of the experimental results demonstrated that the size of piles(d),the spacing between piles,and the distance between the pipe and piles(Xp)were the variables that reduced the maximum scour beneath the pipeline with a diameter of D.For the piles with d=0.40D and 0.64D,X_(p)=4OD was the optimal distance to install a group of piles,and cubical piles could mitigate scour more effectively than cylindrical piles under similar conditions.For the piles with d=D,the greatest reduction in scour depth was achieved at X_(p)=50D with any desired spacings between piles,and cylindrical piles in this dimension could protect the pipeline against scour more effectively than cubical piles.展开更多
Pipeline isolation plugging robot (PIPR) is an important tool in pipeline maintenance operation. During the plugging process, the violent vibration will occur by the flow field, which can cause serious damage to the p...Pipeline isolation plugging robot (PIPR) is an important tool in pipeline maintenance operation. During the plugging process, the violent vibration will occur by the flow field, which can cause serious damage to the pipeline and PIPR. In this paper, we propose a dynamic regulating strategy to reduce the plugging-induced vibration by regulating the spoiler angle and plugging velocity. Firstly, the dynamic plugging simulation and experiment are performed to study the flow field changes during dynamic plugging. And the pressure difference is proposed to evaluate the degree of flow field vibration. Secondly, the mathematical models of pressure difference with plugging states and spoiler angles are established based on the extreme learning machine (ELM) optimized by improved sparrow search algorithm (ISSA). Finally, a modified Q-learning algorithm based on simulated annealing is applied to determine the optimal strategy for the spoiler angle and plugging velocity in real time. The results show that the proposed method can reduce the plugging-induced vibration by 19.9% and 32.7% on average, compared with single-regulating methods. This study can effectively ensure the stability of the plugging process.展开更多
Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thi...Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thickness measurement limits its widespread application. This paper proposes a method that utilizes cylindrical shear horizontal(SH) guided waves to estimate pipeline thickness without prior knowledge of shear wave velocity. The inversion formulas are derived from the dispersion of higher-order modes with the high-frequency approximation. The waveform of the example problems is simulated using the real-axis integral method. The data points on the dispersion curves are processed in the frequency domain using the wave-number method. These extracted data are then substituted into the derived formulas. The results verify that employing higher-order SH guided waves for the evaluation of thickness and shear wave velocity yields less than1% error. This method can be applied to both metallic and non-metallic pipelines, thus opening new possibilities for health monitoring of pipeline structures.展开更多
文摘This work focuses on the development and implementation of a simulation-based approach for the detection of partial and extended blockages within an edible oil pipeline system. Blockages, whether partial or extended, pose a significant operational and safety risks. This study employs computational fluid dynamics (CFD) simulations to model the flow behaviour of edible oil through pipeline under varying conditions. It leverages advanced computational fluid dynamics (CFD) simulations to analyze pressure, velocity, and temperature variations along the pipeline. By simulating scenarios with different blockage characteristics, there is establishment of distinctive patterns indicative of partial and extended obstructions. Through extensive analysis of simulation data, sensing element, and monitoring system, processing signal input and response output, the system can accurately pinpoint the location and severity of blockages, providing crucial insights for timely intervention. The detection system represents a significant advancement in pipeline monitoring technology, offering a proactive and accurate approach to identify blockages and mitigate potential risks and ensure the uninterrupted flow of edible oil, thereby enabling timely intervention and maintenance.
基金The National Natural Science Foundation of China under contract Nos 42106198 and 41720104001the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract No.GML2019ZD0210.
文摘The ever-increasing deepwater oil and gas development in the Qiongdongnan Basin,South China Sea has initiated the need to evaluate submarine debris-flow hazard risks to seafloor infrastructures.This paper presents a case study on evaluating the debris-flow hazard risks to the planned pipeline systems in this region.We used a numerical model to perform simulations to support this quantitative evaluation.First,one relict failure interpreted across the development site was simulated.The back-analysis modeling was used to validate the applicability of the rheological parameters.Then,this model was applied to forecast the runout behaviors of future debris flows originating from the unstable upslope regions considered to be the most critical to the pipeline systems surrounding the Manifolds A and B.The model results showed that the potential debris-flow hazard risks rely on the location of structures and the selection of rheological parameters.For the Manifold B and connected pipeline systems,because of their remote distances away from unstable canyon flanks,the potential debris flows impose few risks.However,the pipeline systems around the Manifold A are exposed to significant hazard risks from future debris flows with selected rheological parameters.These results are beneficial for the design of a more resilient pipeline route in consideration of future debris-flow hazard risks.
基金Supported by National Natural Science Foundation of China(Grant No.51875460)Aviation Power Foundation(Grant No.6141B090320)Foundation of Innovation and Creation for Graduate Students in Northwestern Ploytechnical University(Grant No.ZZ2019124).
文摘The design of aircraft hydraulic pipeline system is limited by many factors,such as the integrity of aviation structure or narrow installation space,so the limited clamp support position should be considered.This paper studied the frequency adjustment and dynamic responses reduction of the multi-support pipeline system through experiment and numerical simulation.To avoid the resonance of pipeline system,we proposed two different optimization programs,one was to avoid aero-engine working range,and another was to avoid aircraft hydraulic pump pulsation range.An optimization method was introduced in this paper to obtain the optimal clamp position.The experiments were introduced to validate the optimization results,and the theoretical optimization results can agree well with the test.With regard to avoiding the aero-engine vibration frequency,the test results revealed that the first natural frequency was far from the aero-engine vibration frequency.And the dynamic frequency sweep results showed that no resonance occurred on the pipeline in the engine vibration frequency range after optimization.Additionally,with regard to avoiding the pump vibration frequency,the test results revealed that natural frequencies have been adjusted and far from the pump vibration frequency.And the dynamic frequency sweep results showed that pipeline under optimal clamp position cannot lead to resonance.The sensitivity analysis results revealed the changing relationships between different clamp position and natural frequency.This study can provide helpful guidance on the analysis and design of practical aircraft pipeline.
文摘Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon is caused by the coupling movement of the pipeline and its vertical pile support under certain conditions. It can induce excessive vibration and cause fatigue failure at pipe elbow. However, in some circumstances it does not exist. Numerical results in both frequency and time domains are presented to elucidate this phenomenon in a combined pipeline system. The conclusions of this paper could give constructive guidance to future design of simply supported pipeline systems.
基金supported by the National Scientific and Technological support project MST (2006BAC13B02-0106)spe-cial research funds from the Public Institute of China,Institute of Geophysics (IGP),China Earthquake Ad-ministration (CEA) (DQJB06A01)The contribution No. is 10FE3004,IGP,CEA
文摘The purpose of this paper is to adopt the uniform confidence method in both water pipeline design and oil-gas pipeline design.Based on the importance of pipeline and consequence of its failure,oil and gas pipeline can be classified into three pipe classes,with exceeding probabilities over 50 years of 2%,5% and 10%,respectively.Performance-based design requires more information about ground motion,which should be obtained by evaluating seismic safety for pipeline engineering site.Different from a city's water pipeline network,the long-distance oil and gas pipeline system is a spatially linearly distributed system.For the uniform confidence of seismic safety,a long-distance oil and pipeline formed with pump stations and different-class pipe segments should be considered as a whole system when analyzing seismic risk.Considering the uncertainty of earthquake magnitude,the design-basis fault displacements corresponding to the different pipeline classes are proposed to improve deterministic seismic hazard analysis(DSHA).A new empirical relationship between the maximum fault displacement and the surface-wave magnitude is obtained with the supplemented earthquake data in East Asia.The estimation of fault displacement for a refined oil pipeline in Wenchuan MS8.0 earthquake is introduced as an example in this paper.
基金This work is supported by Natural Science Foundation of Shandong Province(Grant no.ZR2018MEE021)Equipment Pre Research Fund Project(Grant no.61402100501).
文摘When designing a complex pipeline with long distance and multi-supports for offshore platform,it is necessary to analyze the vibration characteristics of the complex pipeline system to ensure that there is no harmful resonance in the working conditions.Therefore,the optimal layout of support is an effective method to reduce the vibration response of hydraulic pipeline system.In this paper,a developed dynamic optimization method for the complex pipeline is proposed to investigate the vibration characteristics of complex pipeline with multi-elastic supports.In this method,the Kriging response surface model between the support position and pipeline is established.The position of the clamp in the model is parameterized and the optimal solution of performance index is obtained by genetic algorithm.The number of clamps and the interval between clamps are considered as the constraints of layout optimization,and the optimization objective is the natural frequencies of pipeline.Taking a typical offshore pipeline as example to demonstrate the effectiveness of the proposed method,the results show that the vibration performance of the hydraulic pipeline system is distinctly improved by the optimization procedure,which can provide reasonable guidance for the design of complex hydraulic pipeline system.
基金supported by the National Natural Science Foundation of China(Nos.51975025 and 51890822)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2016QNRC001)the National Key Research and Development Program of China(No.2019YFB2004500)。
文摘The fluid-structure interaction(FSI)in aircraft hydraulic pipeline systems is of great concern because of the damage it causes.To accurately predict the vibration characteristic of long hydraulic pipelines with curved segments,we studied the frequency-domain modeling and solution method for FSI in these pipeline systems.Fourteen partial differential equations(PDEs)are utilized to model the pipeline FSI,considering both frequency-dependent friction and bending-flexibility modification.To address the numerical instability encountered by the traditional transfer matrix method(TMM)in solving relatively complex pipelines,an improved TMM is proposed for solving the PDEs in the frequency domain,based on the matrix-stacking strategy and matrix representation of boundary conditions.The proposed FSI model and improved solution method are validated by numerical cases and experiments.An experimental rig of a practical hydraulic system,consisting of an aircraft engine-driven pump,a Z-shaped aero-hydraulic pipeline,and a throttle valve,was constructed for testing.The magnitude ratio of acceleration to pressure is introduced to evaluate the theoretical and experimental results,which indicate that the proposed model and solution method are effective in practical applications.The methodology presented in this paper can be used as an efficient approach for the vibrational design of aircraft hydraulic pipeline systems.
文摘Crude oil spillage is a major challenge in Nigeria. It affects the environment, health, life, and livelihood of residents of the Niger Delta region, where oil is explored, processed, and transported via a network of pipelines. Oil spillage is primarily caused by vandalization/sabotage and operational issues such as corrosion, equipment failure, operation, and maintenance errors. Thus, prompt response is required to mitigate the impact of oil spills. In this study, we deployed low-cost Arduino systems, including sensors (vibration and flow), modules (GPS and Wifi) and an IoT platform (ThingSpeak) to detect spillage caused by vandalism and operational inefficiencies proactively. The results demonstrate that low-cost sensors can detect changes in the flow volume between the inflow and outflow attributable to spillage, and vibration shocks caused by vandalism can be detected and linked to the cause of the spillage and communicated in real time to inform response action. Moreover, we proposed a framework for field validation utilizing KoboToolBox (a crowdsourcing/citizen science platform). The prototype system designed and programmed showed promising results, as it could detect spillage for vandalism and operational scenarios in real-time, quantify the volume of spillage, and identify the location and time of spillage occurrence;indicators relevant for response planning to minimize the impact of oil spillage. A video demonstration of the prototype system developed is accessible via: https://youtu.be/wKa9MZvYf1w. .
基金supported by the fund of the Beijing Municipal Education Commission(No.22019821001)Award Cultivation Foundation from Beijing Institute of Petrochemical Technology(No.BIPTACF-002)。
文摘The batch transportation process of several kinds of crude oil is accomplished by an entire coupled pipeline system,which exhibits complex thermo-hydraulic characteristics.Based on the coupled characteristics among soil,pipelines and devices(including pumps,heating furnaces and valves),a coupled simulation model of batch transportation for the crude oil pipeline system is established,and a novel coupled simulation algorithm is proposed.The simulation results are in good agreement with the field data of an actual crude oil pipeline system.In addition,based on the numerical simulation,thermo-hydraulic characteristics of pipeline system are investigated,and some new thermo-hydraulic characteristics are obtained.In the batch transportation process with constant flowrate,the change trends of temperature at the outlet of each pipeline segment are hysteretic and the change ranges of temperature become small along mileage.And the adjustment of devices influences thermohydraulic characteristics to some extent.In the batch transportation process with variable flowrate,the complex thermo-hydraulic characteristics are exhibited,which are induced by the comprehensive influence of the changes of oil type,flowrate and absorbed/released heat.Compared with the transportation process with constant flowrate,the high-viscosity oil exhibits similar minimum temperature and lower maximum pressure in the transportation process with variable flowrate,which means that the higher transportation safety of pipeline system is obtained.This study can provide a scientific reference for making the safer batch transportation scheme of crude oil pipeline system.
基金funded by the China National Key Research and Development Program(No.2022YFC3003505)the Fundamental Research Fund for the Central Public-interest Scientific Institutes(No.DQJB23Y01)+1 种基金the National Natural Science Foundation of China(No.52278540)the Fundamental Research Fund for the Central Public-interest Scientific Institutes(No.DQJB22B28).
文摘In 2023,two consecutive earthquakes exceeding a magnitude of 7 occurred in Türkiye,causing severe casualties and economic losses.The damage to critical urban infrastructure and building structures,including highways,railroads,and water supply pipelines,was particularly severe in areas where these structures intersected the seismogenic fault.Critical infrastructure projects that traverse active faults are susceptible to the influence of fault movement,pulse velocity,and ground motions.In this study,we used a unique approach to analyze the acceleration records obtained from the seismic station array(9 strong ground motion stations)located along the East Anatolian Fault(the seismogenic fault of the MW7.8 mainshock of the 2023 Türkiye earthquake doublet).The acceleration records were filtered and integrated to obtain the velocity and displacement time histories.We used the results of an on-site investigation,jointly conducted by China Earthquake Administration and Türkiye’s AFAD,to analyze the distribution of PGA,PGV,and PGD recorded by the strong motion array of the East Anatolian Fault.We found that the maximum horizontal PGA in this earthquake was 3.0 g,and the maximum co-seismic surface displacement caused by the East Anatolian Fault rupture was 6.50 m.As the fault rupture propagated southwest,the velocity pulse caused by the directional effect of the rupture increased gradually,with the maximum PGA reaching 162.3 cm/s.We also discussed the seismic safety of critical infrastructure projects traversing active faults,using two case studies of water supply pipelines in Türkiye that were damaged by earthquakes.We used a three-dimensional finite element model of the PE(polyethylene)water pipeline at the Islahiye State Hospital and fault displacement observations obtained through on-site investigation to analyze pipeline failure mechanisms.We further investigated the effect of the fault-crossing angle on seismic safety of a pipeline,based on our analysis and the failure performance of the large-diameter Thames Water pipeline during the 1999 Kocaeli earthquake.The seismic method of buried pipelines crossing the fault was summarized.
文摘Failure of pipe networks due to blast loads resulting from terrorist attacks or construction facilities, may cause economic loss, environmental pollution, source of firing or even it may lead to a disaster. The present work develops a closed-form solution of buried pipe with barrier system subjected to subsurface detonation. The solution is derived based on the concept of double-beam system. Euler Bernoulli's beams are used to simulate the buried pipe and the barrier system. Soil is idealized as viscoelastic foundation along with shear interaction between discrete Winkler springs(advanced soil model). The finite SineFourier transform is employed to solve the coupled partial differential equations. The solution is validated with past studies. A parametric study is conducted to investigate the influence of TNT charge weight, pipe material, damping ratio and TNT offset on the response of buried pipe with and without barrier system. Further a statistical analysis is carried out to get the significant soil and pipe input parameters. It is perceived that peak pipe displacements for both the cases(with and without barrier) are increases with increasing the weight of TNT charge and decreases with increasing the damping ratio and TNT offset. The deformation of pipe also varies with pipe material. Pipe safety against blast loads can be ensured by providing suitable barrier layer. The present study can be utilized in preliminary design stage as an alternative to expensive numerical analysis or field study.
基金China Postdoctoral Science Foundation,Grant/Award Number:2023M731999National Natural Science Foundation of China,Grant/Award Number:52301326。
文摘Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource engineering.Due to the interaction of waves,currents,seabed,and pipeline structures,the soil around submarine pipelines is prone to local scour,severely affecting their operational safety.With the Yellow River Delta as the research area and based on the renormalized group(RNG)k-εturbulence model and Stokes fifth-order wave theory,this study solves the Navier-Stokes(N-S)equation using the finite difference method.The volume of fluid(VOF)method is used to describe the fluid-free surface,and a threedimensional numerical model of currents and waves-submarine pipeline-silty sandy seabed is established.The rationality of the numerical model is verified using a self-built waveflow flume.On this basis,in this study,the local scour development and characteristics of submarine pipelines in the Yellow River Delta silty sandy seabed in the prototype environment are explored and the influence of the presence of pipelines on hydrodynamic features such as surrounding flow field,shear stress,and turbulence intensity is analyzed.The results indicate that(1)local scour around submarine pipelines can be divided into three stages:rapid scour,slow scour,and stable scour.The maximum scour depth occurs directly below the pipeline,and the shape of the scour pits is asymmetric.(2)As the water depth decreases and the pipeline suspension height increases,the scour becomes more intense.(3)When currents go through a pipeline,a clear stagnation point is formed in front of the pipeline,and the flow velocity is positively correlated with the depth of scour.This study can provide a valuable reference for the protection of submarine pipelines in this area.
基金supported by the Petrochina's “14th Five-Year plan” Project(2021DJ2804)Sichuan Natural Science Foundation(2023NSFSC0422)。
文摘During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow of the gathering pipeline in the Changning Shale Gas Field as an example to test the erosion rate and material removal mechanism of the test piece at different angles of the elbow through experiments and compares the four erosion models with the experimental results. Through analysis, it is found that the best prediction model for quartz sand-carbon steel erosion is the Oka model. Based on the Oka model, FLUENT software was used to simulate and analyze the law of erosion of the elbow of the gas gathering pipeline under different gas flow velocities, gas gathering pressure, particle size, length of L1,and bending directions of the elbow. And a spiral pipeline structure is proposed to reduce the erosion rate of the elbow under the same working conditions. The results show that this structure can reduce erosion by 34%.
基金supported by the Beijing Natural Science Foundation(No.1234042)the National Key Research and Development Program for Young Scientists(No.2023YFA1609900)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB37000000)the National Natural Science Foundation of China(No.12305371)。
文摘Synchrotron microscopic data commonly suffer from poor image quality with degraded resolution incurred by instrumentation defects or experimental conditions.Image restoration methods are often applied to recover the reduced resolution,providing improved image details that can greatly facilitate scientific discovery.Among these methods,deconvolution techniques are straightforward,yet either require known prior information or struggle to tackle large experimental data.Deep learning(DL)-based super-resolution(SR)methods handle large data well,however data scarcity and model generalizability are problematic.In addition,current image restoration methods are mostly offline and inefficient for many beamlines where high data volumes and data complexity issues are encountered.To overcome these limitations,an online image-restoration pipeline that adaptably selects suitable algorithms and models from a method repertoire is promising.In this study,using both deconvolution and pretrained DL-based SR models,we show that different restoration efficacies can be achieved on different types of synchrotron experimental data.We describe the necessity,feasibility,and significance of constructing such an image-restoration pipeline for future synchrotron experiments.
基金financially supported by the National Natural Science Foundation of China(Grant No.52171285)。
文摘A dent is a common type of defects for submarine pipeline.For submarine pipelines,high hydrostatic pressure and internal pressure are the main loads.Once pipelines bend due to complex subsea conditions,the compression strain capacity may be exceeded.Research into the local buckling failure and accurate prediction of the compressive strain capacity are important.A finite element model of a pipeline with a dent is established.Local buckling failure under a bending moment is investigated,and the compressive strain capacity is calculated.The effects of different parameters on pipeline local buckling are analyzed.The results show that the dent depth,external pressure and internal pressure lead to different local buckling failure modes of the pipeline.A higher internal pressure indicates a larger compressive strain capacity,and the opposite is true for external pressure.When the ratio of external pressure to collapse pressure of intact pipeline is greater than 0.1,the deeper the dent,the greater the compressive strain capacity of the pipeline.And as the ratio is less than 0.1,the opposite is true.On the basis of these results,a regression equation for predicting the compressive strain capacity of a dented submarine pipeline is proposed,which can be referred to during the integrity assessment of a submarine pipeline.
基金supported by 111 Project (No.D21025)Open Fund Project of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Nos.PLN2021-01,PLN2021-02,PLN2021-03)+2 种基金High-end Foreign Expert Introduction Program (No.G2021036005L)National Key Research and Development Program (No.2021YFC2800903)National Natural Science Foundation of China (No.U20B6005-05)。
文摘During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines,resulting in production reduction,shutdowns,and pressure build-ups.Consequently,a cascade of risks is prone to occur.To address this issue,this study focuses on the operational process of natural gas gathering and transmission pipelines,where a comprehensive framework is established.This framework includes theoretical models for pipeline temperature distribution,pipeline pressure distribution,multiphase flow within the pipeline,hydrate blockage,and numerical solution methods.By analyzing the influence of inlet temperature,inlet pressure,and terminal pressure on hydrate formation within the pipeline,the sensitivity patterns of hydrate blockage risks are derived.The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate,potentially mitigating pipeline blockage during natural gas transportation.Furthermore,an increase in inlet temperature and terminal pressure,and a decrease in inlet pressure,results in a displacement of the most probable location for hydrate blockage towards the terminal station.However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system,contradicting the operational goal of energy efficiency and reduction of energy consumption.Consequently,for high-pressure gathering pipelines,measures such as raising the inlet temperature or employing inhibitors,electrical heat tracing,and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation.Moreover,considering abnormal conditions such as gas well production and pipeline network shutdowns,which could potentially trigger hydrate formation,the installation of methanol injection connectors remains necessary to ensure production safety.
文摘Local scour around pipelines crossing rivers or in marine environments is a significant concern.It can lead to failure of the pipelines resulting in environmental side effects and economic losses.This study developed an experimental method to reduce local scour around pipelines with a steady flow of clear water by installing cylindrical and cubical sacrificial piles.Three sizes of sacrificial piles were examined in a linear arrangement.Sacrificial piles were installed on the upstream side of the pipeline at three distances.Maximum scour depth reduction rates below the pipeline were computed.The results showed that sacrificial piles could protect a pipeline from local scour.A portion of scoured sediment around the sacrificial piles was deposited beneath the pipeline.This sediment accumulation reduced the scour depth beneath the pipeline.Analysis of the experimental results demonstrated that the size of piles(d),the spacing between piles,and the distance between the pipe and piles(Xp)were the variables that reduced the maximum scour beneath the pipeline with a diameter of D.For the piles with d=0.40D and 0.64D,X_(p)=4OD was the optimal distance to install a group of piles,and cubical piles could mitigate scour more effectively than cylindrical piles under similar conditions.For the piles with d=D,the greatest reduction in scour depth was achieved at X_(p)=50D with any desired spacings between piles,and cylindrical piles in this dimension could protect the pipeline against scour more effectively than cubical piles.
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.51575528)the Science Foundation of China University of Petroleum,Beijing(No.2462022QEDX011).
文摘Pipeline isolation plugging robot (PIPR) is an important tool in pipeline maintenance operation. During the plugging process, the violent vibration will occur by the flow field, which can cause serious damage to the pipeline and PIPR. In this paper, we propose a dynamic regulating strategy to reduce the plugging-induced vibration by regulating the spoiler angle and plugging velocity. Firstly, the dynamic plugging simulation and experiment are performed to study the flow field changes during dynamic plugging. And the pressure difference is proposed to evaluate the degree of flow field vibration. Secondly, the mathematical models of pressure difference with plugging states and spoiler angles are established based on the extreme learning machine (ELM) optimized by improved sparrow search algorithm (ISSA). Finally, a modified Q-learning algorithm based on simulated annealing is applied to determine the optimal strategy for the spoiler angle and plugging velocity in real time. The results show that the proposed method can reduce the plugging-induced vibration by 19.9% and 32.7% on average, compared with single-regulating methods. This study can effectively ensure the stability of the plugging process.
基金Project supported by the Natural Science Foundation of Jilin Province of China(Grant Nos.20240402081GH and 20220101012JC)the National Natural Science Foundation of China(Grant No.42074139)the State Key Laboratory of Acoustics,Chinese Academy of Sciences(Grant No.SKLA202308)。
文摘Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thickness measurement limits its widespread application. This paper proposes a method that utilizes cylindrical shear horizontal(SH) guided waves to estimate pipeline thickness without prior knowledge of shear wave velocity. The inversion formulas are derived from the dispersion of higher-order modes with the high-frequency approximation. The waveform of the example problems is simulated using the real-axis integral method. The data points on the dispersion curves are processed in the frequency domain using the wave-number method. These extracted data are then substituted into the derived formulas. The results verify that employing higher-order SH guided waves for the evaluation of thickness and shear wave velocity yields less than1% error. This method can be applied to both metallic and non-metallic pipelines, thus opening new possibilities for health monitoring of pipeline structures.