The transportation of oil and gas through pipelines is crucial for sustaining energy supply in industrial and civil sectors.However,the issue of pitting corrosion during pipeline operation poses an important threat to...The transportation of oil and gas through pipelines is crucial for sustaining energy supply in industrial and civil sectors.However,the issue of pitting corrosion during pipeline operation poses an important threat to the structural integrity and safety of pipelines.This problem not only affects the longevity of pipelines but also has the potential to cause secondary disasters,such as oil and gas leaks,leading to environmental pollution and endangering public safety.Therefore,the development of a highly stable,accurate,and reliable model for predicting pipeline pitting corrosion is of paramount importance.In this study,a novel prediction model for pipeline pitting corrosion depth that integrates the sparrow search algorithm(SSA),regularized extreme learning machine(RELM),principal component analysis(PCA),and residual correction is proposed.Initially,RELM is utilized to forecast pipeline pitting corrosion depth,and SSA is employed for optimizing RELM’s hyperparameters to enhance the model’s predictive capabilities.Subsequently,the residuals of the SSA-RELM model are obtained by subtracting the prediction results of the model from actual measurements.Moreover,PCA is applied to reduce the dimensionality of the original 10 features,yielding 7 new features with enhanced information content.Finally,residuals are predicted by using the seven features obtained by PCA,and the prediction result is combined with the output of the SSA-RELM model to derive the predicted pipeline pitting corrosion depth by incorporating multiple feature selection and residual correction.Case study demonstrates that the proposed model reduces mean squared error,mean absolute percentage error,and mean absolute error by 66.80%,42.71%,and 42.64%,respectively,compared with the SSA-RELM model.Research findings underscore the exceptional performance of the proposed integrated approach in predicting the depth of pipeline pitting corrosion.展开更多
A combined process was developed to inhibit the corrosion both in the pipeline of reclaimed water supplies（PRWS） and in downstream recirculating cooling water systems（RCWS）using the reclaimed water as makeup. Hydr...A combined process was developed to inhibit the corrosion both in the pipeline of reclaimed water supplies（PRWS） and in downstream recirculating cooling water systems（RCWS）using the reclaimed water as makeup. Hydroxyl carboxylate-based corrosion inhibitors（e.g.,gluconate, citrate, tartrate） and zinc sulfate heptahydrate, which provided Zn^2＋ as a synergistic corrosion inhibition additive, were added prior to the PRWS when the phosphate（which could be utilized as a corrosion inhibitor） content in the reclaimed water was below 1.7 mg/L, and no additional corrosion inhibitors were required for the downstream RCWS.Satisfactory corrosion inhibition was achieved even if the RCWS was operated under the condition of high numbers of concentration cycles. The corrosion inhibition requirement was also met by the appropriate combination of PO4^3- and Zn^2＋ when the phosphate content in the reclaimed water was more than 1.7 mg/L. The process integrated not only water reclamation and reuse, and the operation of a highly concentrated RCWS, but also the comprehensive utilization of phosphate in reclaimed water and the application of non-phosphorus corrosion inhibitors. The proposed process reduced the operating cost of the PRWS and the RCWS, and lowered the environmental hazard caused by the excessive discharge of phosphate. Furthermore, larger amounts of water resources could be conserved as a result.展开更多
The consumption of Chinas gas industry has increased rapidly, and the consumption structure of gas has been continuously adjusted: the proportion of natural gas consumption in gas has increased rapidly, while the prop...The consumption of Chinas gas industry has increased rapidly, and the consumption structure of gas has been continuously adjusted: the proportion of natural gas consumption in gas has increased rapidly, while the proportion of artificial gas and liquefied petroleum gas has decreased year by year. Natural gas consumption contributes to the major increase in the industry. According to statistics, the total natural gas supply in Chinas cities increased from 79.5 billion cubic meters in 2012 to 156.37 billion cubic meters in 2020, with a CAGR of 8.82% in 2012-2020. Among them, the total domestic gas supply was 38.16 billion cubic meters, with a CAGR of 11.85% in 2012-2020.展开更多
In order to realize the sustainable development of Chinese resources, we must realize development on the basis of saving resources and protecting the environment. Therefore, urban HVAC engineering should be improved a...In order to realize the sustainable development of Chinese resources, we must realize development on the basis of saving resources and protecting the environment. Therefore, urban HVAC engineering should be improved according to this form. At present, pipeline anticorrosion is a very important link in HVAC engineering. The anti-corrosion treatment of pipeline not only makes the pipeline have strong anti-corrosion ability, but also can improve the anti-pressure ability of pipeline and prolong the service life of pipeline. Therefore, we must attach great importance to the application of pipeline anticorrosion technology in HVAC engineering. In order to promote the development of HVAC engineering and pipeline anticorrosive technology in China, this paper will discuss the construction of HVAC engineering and pipeline anticorrosive technology in depth.展开更多
The effect of Ca^2＋ on CO2 corrosion to X65 pipeline steel was investigated in the simulated stratum water of an oil field containing different concentrations of Ca^2＋. It is found that Ca^2＋ can enhance the corros...The effect of Ca^2＋ on CO2 corrosion to X65 pipeline steel was investigated in the simulated stratum water of an oil field containing different concentrations of Ca^2＋. It is found that Ca^2＋ can enhance the corrosion rate, especially in the Ca^2＋ concentration from 256 to 512 mg/L, which can be attributed to the growing grain size and loosing structure of corrosion scales with increasing Ca^2＋ concentration. X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS） investigations reveal that a complex carbonate （Fe, Ca）CO3 forms at high Ca^2＋ concentration due to the gradual replacement of Fe^2＋ in FeCO3 by Ca^2＋.展开更多
A set of generalized solutions are proposed for estimating ultimate load capacity of pipeline with arbitrary corrosion shapes subjected to combined internal pressure, axial force and bending moment. Isotropic and anis...A set of generalized solutions are proposed for estimating ultimate load capacity of pipeline with arbitrary corrosion shapes subjected to combined internal pressure, axial force and bending moment. Isotropic and anisotropic material characteristics in longitudinal and circumferential direction of pipeline are also considered in the proposed equations. Simplified numerical method is used to solve the generalized expressions. The comparisons of numerical results based generalized solutions and full-scale experimental results are carried out. The predicted results agree reasonably well with the experiment results. Meanwhile, the effects of corrosion shapes and locations on the ultimate load capacity are studied.展开更多
The short-term corrosion behavior of API X100 steel in an acidic simulated soil was investigated by electrochemical measurements and soaking experiments,followed by corrosion morphology observations and X-ray photoele...The short-term corrosion behavior of API X100 steel in an acidic simulated soil was investigated by electrochemical measurements and soaking experiments,followed by corrosion morphology observations and X-ray photoelectron spectroscopy analyses.The results show that X100 steel exhibits an obvious pitting susceptibility in an acidic soil environment.Pits nucleate after approximately 10 h of immersion.Along with the nucleation and growth of the pits,the charge-transfer resistance and open-circuit potential first increase sharply,then decrease slowly,and eventually reach a steady state.The maxima of the charge-transfer resistance and open-circuit potential are attained at approximately 10 h.The evolution of the electrochemical process is confirmed by the analysis of the product film.The product film exhibits a porous and loose structure and could not protect the substrate well.The product film is primarily composed of ferrous carbonate and ferrous hydroxide（Fe（OH）2）.The concentration of Fe（OH）2 in the product film increases from the inside to the outside layer.展开更多
Based on the elastic-plastic, large-deformation finite element method, burst capacity of steel pipeline with longitudinal corrosion defect subjected to internal pressure is studied. The appropriate stress-based criter...Based on the elastic-plastic, large-deformation finite element method, burst capacity of steel pipeline with longitudinal corrosion defect subjected to internal pressure is studied. The appropriate stress-based criterion is used to predict the failure pressure of finite element model of corroded pipeline under internal pressure. By considering the pipe steel grades and geometries of corrosion defects, a series of finite element analyses is conducted. The effects of corrosion depth, length and width on burst capacity are also discussed. A specific failure pressure solution for the assessment of corrosion defects in moderate-to-high strength pipeline is proposed on the base of numerical results. The failure pressures predicted by the proposed method are in better agreement with the experimental results than the results by the other methods.展开更多
Hydrogen induced cracking（HIC） behaviors of a high strength pipeline steel with three different microstructures, granular bainite ＆ lath bainite（GB ＋ LB）, granular bainite ＆ acicular ferrite（GB ＋ AF）, and qu...Hydrogen induced cracking（HIC） behaviors of a high strength pipeline steel with three different microstructures, granular bainite ＆ lath bainite（GB ＋ LB）, granular bainite ＆ acicular ferrite（GB ＋ AF）, and quasi-polygonal ferrite（QF）, were studied by using corrosion experiment based on standard NACE TM0284. The HIC experiment was conducted in hydrogen sulfide（H_2S）-saturated solution. The experimental results show that the steel with GB ＋ AF and QF microstructure present excellent corrosion resistance to HIC, whereas the phases of bainite lath and martensite/austenite in LB ＋ GB microstructure are responsible for poor corrosion resistance. Compared with ferrite phase, the bainite microstructure exhibits higher strength and crack susceptibility of HIC. The AF ＋ GB microstructure is believed to have the best combination of mechanical properties and resistance to HIC among the designed steels.展开更多
基金Supported by the Natural Science Foundation of Shandong Province of China(ZR2022QE091)the Special fund for Taishan Industry Leading Talent Project(tsls20230605)Key R&D Program of Shandong Province,China(2023CXGC010407).
文摘The transportation of oil and gas through pipelines is crucial for sustaining energy supply in industrial and civil sectors.However,the issue of pitting corrosion during pipeline operation poses an important threat to the structural integrity and safety of pipelines.This problem not only affects the longevity of pipelines but also has the potential to cause secondary disasters,such as oil and gas leaks,leading to environmental pollution and endangering public safety.Therefore,the development of a highly stable,accurate,and reliable model for predicting pipeline pitting corrosion is of paramount importance.In this study,a novel prediction model for pipeline pitting corrosion depth that integrates the sparrow search algorithm(SSA),regularized extreme learning machine(RELM),principal component analysis(PCA),and residual correction is proposed.Initially,RELM is utilized to forecast pipeline pitting corrosion depth,and SSA is employed for optimizing RELM’s hyperparameters to enhance the model’s predictive capabilities.Subsequently,the residuals of the SSA-RELM model are obtained by subtracting the prediction results of the model from actual measurements.Moreover,PCA is applied to reduce the dimensionality of the original 10 features,yielding 7 new features with enhanced information content.Finally,residuals are predicted by using the seven features obtained by PCA,and the prediction result is combined with the output of the SSA-RELM model to derive the predicted pipeline pitting corrosion depth by incorporating multiple feature selection and residual correction.Case study demonstrates that the proposed model reduces mean squared error,mean absolute percentage error,and mean absolute error by 66.80%,42.71%,and 42.64%,respectively,compared with the SSA-RELM model.Research findings underscore the exceptional performance of the proposed integrated approach in predicting the depth of pipeline pitting corrosion.
基金supported by the Key Laboratory of Drinking Water Science and Technology, Chinese Academy of Sciences (No. 15Z01KLDWST)the National Natural Science Foundation of China (Nos. 51378491 and 51578533)
文摘A combined process was developed to inhibit the corrosion both in the pipeline of reclaimed water supplies（PRWS） and in downstream recirculating cooling water systems（RCWS）using the reclaimed water as makeup. Hydroxyl carboxylate-based corrosion inhibitors（e.g.,gluconate, citrate, tartrate） and zinc sulfate heptahydrate, which provided Zn^2＋ as a synergistic corrosion inhibition additive, were added prior to the PRWS when the phosphate（which could be utilized as a corrosion inhibitor） content in the reclaimed water was below 1.7 mg/L, and no additional corrosion inhibitors were required for the downstream RCWS.Satisfactory corrosion inhibition was achieved even if the RCWS was operated under the condition of high numbers of concentration cycles. The corrosion inhibition requirement was also met by the appropriate combination of PO4^3- and Zn^2＋ when the phosphate content in the reclaimed water was more than 1.7 mg/L. The process integrated not only water reclamation and reuse, and the operation of a highly concentrated RCWS, but also the comprehensive utilization of phosphate in reclaimed water and the application of non-phosphorus corrosion inhibitors. The proposed process reduced the operating cost of the PRWS and the RCWS, and lowered the environmental hazard caused by the excessive discharge of phosphate. Furthermore, larger amounts of water resources could be conserved as a result.
文摘The consumption of Chinas gas industry has increased rapidly, and the consumption structure of gas has been continuously adjusted: the proportion of natural gas consumption in gas has increased rapidly, while the proportion of artificial gas and liquefied petroleum gas has decreased year by year. Natural gas consumption contributes to the major increase in the industry. According to statistics, the total natural gas supply in Chinas cities increased from 79.5 billion cubic meters in 2012 to 156.37 billion cubic meters in 2020, with a CAGR of 8.82% in 2012-2020. Among them, the total domestic gas supply was 38.16 billion cubic meters, with a CAGR of 11.85% in 2012-2020.
文摘In order to realize the sustainable development of Chinese resources, we must realize development on the basis of saving resources and protecting the environment. Therefore, urban HVAC engineering should be improved according to this form. At present, pipeline anticorrosion is a very important link in HVAC engineering. The anti-corrosion treatment of pipeline not only makes the pipeline have strong anti-corrosion ability, but also can improve the anti-pressure ability of pipeline and prolong the service life of pipeline. Therefore, we must attach great importance to the application of pipeline anticorrosion technology in HVAC engineering. In order to promote the development of HVAC engineering and pipeline anticorrosive technology in China, this paper will discuss the construction of HVAC engineering and pipeline anticorrosive technology in depth.
基金supported by the National Natural Science Foundation of China (No.50571012)
文摘The effect of Ca^2＋ on CO2 corrosion to X65 pipeline steel was investigated in the simulated stratum water of an oil field containing different concentrations of Ca^2＋. It is found that Ca^2＋ can enhance the corrosion rate, especially in the Ca^2＋ concentration from 256 to 512 mg/L, which can be attributed to the growing grain size and loosing structure of corrosion scales with increasing Ca^2＋ concentration. X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS） investigations reveal that a complex carbonate （Fe, Ca）CO3 forms at high Ca^2＋ concentration due to the gradual replacement of Fe^2＋ in FeCO3 by Ca^2＋.
基金financially supported by the National Natural Science Foundation of China(Grant No.51309236)Doctoral Foundation of the Ministry of Education of China(Grant No.20120007120009)+2 种基金the Opening Fund of State Key Laboratory of Ocean Engineering(Shanghai Jiao Tong University,Grant No.1314)the Opening Fund of State Key Laboratory of Hydraulic Engineering Simulation and Safety(Tianjin University,Grant No.HESS-1411)the Science Foundation of China University of Petroleum(Beijing)(Grant No.QD-2010-08)
文摘A set of generalized solutions are proposed for estimating ultimate load capacity of pipeline with arbitrary corrosion shapes subjected to combined internal pressure, axial force and bending moment. Isotropic and anisotropic material characteristics in longitudinal and circumferential direction of pipeline are also considered in the proposed equations. Simplified numerical method is used to solve the generalized expressions. The comparisons of numerical results based generalized solutions and full-scale experimental results are carried out. The predicted results agree reasonably well with the experiment results. Meanwhile, the effects of corrosion shapes and locations on the ultimate load capacity are studied.
基金financially supported by the National High-Tech Research and Development Program of China (No.2012AA040105)the National Nature Science Foundation of China (Nos. 51131001 and 51741034)the Beijing Higher Education Young Elite Teacher Project
文摘The short-term corrosion behavior of API X100 steel in an acidic simulated soil was investigated by electrochemical measurements and soaking experiments,followed by corrosion morphology observations and X-ray photoelectron spectroscopy analyses.The results show that X100 steel exhibits an obvious pitting susceptibility in an acidic soil environment.Pits nucleate after approximately 10 h of immersion.Along with the nucleation and growth of the pits,the charge-transfer resistance and open-circuit potential first increase sharply,then decrease slowly,and eventually reach a steady state.The maxima of the charge-transfer resistance and open-circuit potential are attained at approximately 10 h.The evolution of the electrochemical process is confirmed by the analysis of the product film.The product film exhibits a porous and loose structure and could not protect the substrate well.The product film is primarily composed of ferrous carbonate and ferrous hydroxide（Fe（OH）2）.The concentration of Fe（OH）2 in the product film increases from the inside to the outside layer.
基金financially supported by Ministry of Science and Technology of China(Grant No.2011CB013702)the Program for New Century Excellent Talents in University(Grant No.NCET-11-0051)
文摘Based on the elastic-plastic, large-deformation finite element method, burst capacity of steel pipeline with longitudinal corrosion defect subjected to internal pressure is studied. The appropriate stress-based criterion is used to predict the failure pressure of finite element model of corroded pipeline under internal pressure. By considering the pipe steel grades and geometries of corrosion defects, a series of finite element analyses is conducted. The effects of corrosion depth, length and width on burst capacity are also discussed. A specific failure pressure solution for the assessment of corrosion defects in moderate-to-high strength pipeline is proposed on the base of numerical results. The failure pressures predicted by the proposed method are in better agreement with the experimental results than the results by the other methods.
基金supported by the National High Technology Research and Development Program of China(Grant No.2015AA03A501)the National Natural Science Foundation of China(Grant No.51274063)
文摘Hydrogen induced cracking（HIC） behaviors of a high strength pipeline steel with three different microstructures, granular bainite ＆ lath bainite（GB ＋ LB）, granular bainite ＆ acicular ferrite（GB ＋ AF）, and quasi-polygonal ferrite（QF）, were studied by using corrosion experiment based on standard NACE TM0284. The HIC experiment was conducted in hydrogen sulfide（H_2S）-saturated solution. The experimental results show that the steel with GB ＋ AF and QF microstructure present excellent corrosion resistance to HIC, whereas the phases of bainite lath and martensite/austenite in LB ＋ GB microstructure are responsible for poor corrosion resistance. Compared with ferrite phase, the bainite microstructure exhibits higher strength and crack susceptibility of HIC. The AF ＋ GB microstructure is believed to have the best combination of mechanical properties and resistance to HIC among the designed steels.
