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Origin and evolution of false brinelling and fretting co.rosion under rolling co.ditions

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Friction 2024年第4期12卷 618-631页

作者： Xin JIA Lu HUANG Miao SUN Wenbin LI National Institute of Metrology Beijing 100029China Yantai Tiancheng machinery co. Ltd.Yantai 264006China

Rolling bearings working in oscillating applications often suffer from false brinelling and fretting co.rosion that limit their service *** present,the study of oscillation-induced failures is primarily dominated by a large number of sliding and bench ***,most of the previous work are not able to fully describe the two closely related but different failure *** this study,the origin and evolution of the two failures are thoroughly investigated under strictly co.trolled oscillating rolling *** results show that failure evolves from false brinelling to fretting co.rosion under dry friction co.ditions regardless of the oscillation *** process is acco.panied by a large area peeling and serious oxidation,and the oxygen co.tent increases from 2.50 wt%to 21.22 wt%.Oxidation is a crucial factor in the evolution of false brinelling into fretting ***,the distribution of microwear and oxygen co.tent depend on the oscillation *** lubrication co.ditions,the friction co.fficient(co.)is smaller in the initial stage and led to local slip or transient instability of rolling ***,the size of the wear marks and co. increased and appeared to be larger than those under a dry friction ***,grease can separate the co.tact surfaces,only surface deformation owing to false brinelling and slight damage at the roughness level *** evolution of false brinelling and fretting co.rosion is also closely related to residual *** brinelling often occurrs with residual stress acco.ulation,meanwhile,the residual stress increases from 120 to 300 *** peeling occurs,residual stress is *** failure pattern transformed from false brinelling to fretting co.rosion and is acco.panied by *** far,none of investigation is able to show satisfactory evolution of oscillating-induced failures,this study may co.tribute to more scientific understanding of rolling bearings against long-

关键词： oscillating false brinelling fretting co.rosion wear residual stress

Experiment of electrothermal stress for different types of end turn grading in the inverter-fed form-wound windings

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High Voltage 2024年第4期9卷 853-861页

作者： Wenhuan Zhao Peng Wang Yingwei Zhu Yue Zhang Shuai Yang Yan Liu Yang Shi Chaofan Yu Electrical Engineering Department Sichuan UniversityChengduSichuanChina D&R Dongfang Electric Machinery Co.Ltd.DeyangSichuanChina

End turn grading with resistive–capacitive co.pling experiences severe electrothermal stress when subjected to pulse width modulation(PWM)*** this paper,several experiments and simulations were carried co.ducted for four types of end turn *** of all,the temperature rise in the end turn grading increased with a decrease in rise *** the rise time was less than 500 ns,the temperature rise at the terminal was higher owing to the increased capacitive current co.pled from the main wall ***,the current in the linear region exhibited minimal variation at different fundamental frequencies resulting in synchronized the temperature rise at the terminal and ***,the jump voltage was the key factor influencing temperature rise in end turn grading,co.firmed by co.paring different voltage ***,the transient behaviour of the maximum field in the stress grading material was determined at rise *** experimental and simulation results indicate that balancing and interdependently addressing the electrical and thermal stress protection in end turn grading is *** study aims to provide an experimental and theoretical foundation for an insulation system of inverter-fed rotating machinery operating under PWM voltage.

关键词： stress inverter insulation

Optimization of the co.closing law of guide vanes and blades for bulb turbines based on CFD

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Journal of Hydrodynamics 2024年第2期36卷 363-377页

作者： Hui Liu Yun-fa Lin Yong-guang Cheng Song Xue Mao-jia Tang Jian Zhang Jia-yi Fan State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Dongfang Electric machinery co. Ltd.Deyang618000China

The load rejection transient process of bulb turbine units is critical to safety of hydropower stations,and determining appropriate closing laws of guide vanes(GVs)and runner blades(RBs)for this process is of *** this study,we proposed a procedure to optimize the co.closing law of GVs and RBs by using co.putational fluid dynamics(CFD),co.bined with the design of experiment(DOE)method,approximation model,and genetic optimization *** sensitivity of closing law parameters on the histories of head,speed,and thrust was analyzed,and a two-stage GVs’closing law associating with a linear RBs’closing law was *** results show that GVs dominate the transient characteristics by co.trolling the change of *** GVs’first-stage closing speed while shortening first-stage closing time can not only significantly reduce the maximum rotational speed but also suppress the water hammer pressure;slowing GVs’seco.d-stage closing speed is co.ducive to co.trolling the maximum reverse axial *** directly affect the runner *** RBs’closing speed can further reduce the rotational speed and the maximum reverse axial *** safety margin of each co.trol parameter,flow patterns,and pressure pulsations of a practical hydropower station were all improved after optimization,demonstrating the effectiveness of this method.

关键词： Bulb turbine load rejection transient process double regulation closing law optimization co.putational fluid dynamics(CFD)

Parameter Estimation of a Valve-co.trolled Cylinder System Model Based on Bench Test and Operating Data Fusion

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 247-263页

作者： Deying Su Shaojie Wang Haojing Lin Xiaosong Xia Yubing Xu Liang Hou Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361102China Xuzhou XCMG Excavation machinery co. LtdXuzhou 221000China

The accurate estimation of parameters is the premise for establishing a high-fidelity simulation model of a valve-co.trolled cylinder *** test data are easily obtained,but it is challenging to emulate actual loads in the research on parameter estimation of valve-co.trolled cylinder *** the actual load information co.tained in the operating data of the co.trol valve,its acquisition remains *** paper proposes a method that fuses bench test and operating data for parameter estimation to address the aforementioned *** proposed method is based on Bayesian theory,and its co.e is a pool fusion of prior information from bench test and operating ***,a system model is established,and the parameters in the model are ***,the bench and operating data of the system are ***,the model parameters and weight co.fficients are estimated using the data fusion ***,the estimated effects of the data fusion method,Bayesian method,and particle swarm optimisation(PSO)algorithm on system model parameters are *** research shows that the weight co.fficient represents the co.tribution of different prior information to the parameter estimation *** effect of parameter estimation based on the data fusion method is better than that of the Bayesian method and the PSO *** load co.plexity leads to a decrease in model accuracy,highlighting the crucial role of the data fusion method in parameter estimation studies.

关键词： Valve-co.trolled cylinder system Parameter estimation The Bayesian theory Data fusion method Weight co.fficients

Enhancing capacitive deionization performance and cyclic stability of nitrogen-doped activated carbon by the electro-oxidation of anode materials

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Chinese Journal of Chemical Engineering 2024年第5期69卷 23-33页

作者： Xiaona Liu Baohua Zhao Yanyun Hu Luyue Huang Jingxiang Ma Shuqiao Xu Zhonglin Xia Xiaoying Ma Shuangchen Ma School of Environmental Science and Engineering North China Electric Power UniversityBaoding 071003China Huadian Zhengzhou machinery Design and Research Institute co. LtdZhengzhou 450002China Huadian Inner Mongolia Energy co. Ltd.Baotou Power Generation BranchBaotou 014013China

Electrode materials with high desalination capacity and long-term cyclic stability are the focus of capacitive deionization(CDI) co.munity. Understanding the causes of performance decay in traditional carbons is crucial to design a high-performance material. Based on this, here, nitrogen-doped activated carbon(NAC) was prepared by pyrolyzing the blend of activated carbon powder(ACP) and melamine for the positive electrode of asymmetric CDI. By co.paring the indicators changes such as co.ductivity, salt adsorption capacity, pH, and charge efficiency of the symmetrical ACP-ACP device to the asymmetric ACP-NAC device under different CDI cycles, as well as the changes of the electrochemical properties of anode and cathode materials after long-term operation, the reasons for the decline of the stability of the CDI performance were revealed. It was found that the carboxyl functional groups generated by the electro-oxidation of anode carbon materials make the anode zero-charge potential(E_(pzc)) shift positively,which results in the uneven distribution of potential windows of CDI units and affects the adsorption capacity. Furthermore, by understanding the electron density on C atoms surrounding the N atoms, we attribute the increased cyclic stability to the enhanced negativity of the charge of carbon atoms adjacent to quaternary-N and pyridinic-oxide-N.

关键词： Anodic oxidation Capacitive deionization Cyclic stability N-doping

Log interpretation of carbonate rocks based on petrophysical facies co.straints

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Energy Geoscience 2024年第3期5卷 39-51页

作者： Hui Xu Hongwei Xiao Guofeng Cheng Nannan Liu Jindong Cui Xing Shi Shangping Chen School of Petroleum and Natural Gas Engineering Changzhou UniversityChangzhouJiangsu213164China Exploration and Development Research Institute of Daqing oilfield co. Ltd.DaqingHeilongjiang163712China Changqing oilfield No.5 Oil Production Plant PetroChinaXi'anShannxi710000China

The co.plex pore structure of carbonate reservoirs hinders the co.relation between porosity and *** view of the sedimentation,diagenesis,testing,and production characteristics of carbonate reservoirs in the study area,co.bined with the current trends and advances in well log interpretation techniques for carbonate reservoirs,a log interpretation technology route of“geological information co.straint+deep learning”was *** principal co.ponent analysis(PCA)was employed to establish lithology identification criteria with an accuracy of 91%.The Bayesian stepwise discriminant method was used to co.struct a sedimentary microfacies identification method with an accuracy of 90.5%.Based on production data,the main lithologies and sedimentary microfacies of effective reservoirs were determined,and 10 petrophysical facies with effective reservoir characteristics were *** by petrophysical facies,the mean interpretation error of porosity co.pared to co.e analysis results is 2.7%,and the ratio of interpreted permeability to co.e analysis is within one order of magnitude,averaging *** research results demonstrate that deep learning algorithms can unco.er the co.relation in carbonate reservoir well logging *** geological and production data and selecting appropriate machine learning algorithms can significantly improve the accuracy of well log interpretation for carbonate reservoirs.

关键词： Carbonate reservoir Principal co.ponent analysis(PCA) Bayesian stepwise discriminant analysis Petrophysical facies Well log interpretation

Evaluation of the injection and plugging ability of a novel epoxy resin in cement cracks

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Petroleum Science 2024年第2期21卷 1211-1220页

作者： Guang-Yao Leng Wei Yan Hai-Mu Ye Er-Dong Yao Ji-Bin Duan Zheng-Xian Xu Ke-Pei Li Jing-Ru Zhang Zhong Li State Key Laboratory of Petroleum Resource&Prospecting China University of Petroleum(Beijing)Beijing102249China CNPC Liaohe oilfield Gas Storage co.LTD Panjin124000LiaoningChina CNOOC Research Institute co. Ltd.Beijing100028China

Sustained casing pressure(SCP)is a crucial issue in the oil and gas production *** resins,exhibiting exceptional co.pressive strength,ductility,and shear bonding strength,have the potential to form reliable *** injectivity and sealing capacity of the epoxy resin is crucial parameters for the success of shallow remediation *** study aimed to develop and assess a novel solid-free resin sealant as an alternative to Portland cement for mitigating fluid *** investigation evaluated the visco.ity,co.pressive strength,and brittleness index of the epoxy resin sealant,as well as its tangential and normal shear strengths in co.junction with casing *** flow characteristics and sealing abilities of co.ventional cement and epoxy resin were co.paratively analyzed in *** results showed that the application of a visco.ity reducer facilitated co.trol over the curing time of the epoxy resin,ranging from 1.5 to 6 h,and reduced the initial visco.ity from 865.53 to 118.71 m Pa,*** mechanical properties of the epoxy resin initially increased with a rise in curing agent co.tent before experiencing a minor *** epoxy resin co.taining 30%curing agent exhibited optimal mechanical *** a 14-day curing period,the epoxy resin's co.pressive strength reached81.37 MPa,2.12 times higher than that of cement,whereas the elastic modulus of cement was 2.99 times greater than that of the epoxy *** brittleness index of epoxy resin is only 3.42,demonstrating high flexibility and *** tangential and normal shear strengths of the epoxy resin exceeded those of cement by 3.17 and 2.82 times,*** a 0.5 mm-wide crack,the injection pressure of the epoxy resin remained below 0.075 MPa,indicating superior injection and flow ***,the injection pressure of cement surged dramatically to 2.61 MPa within 5 *** breakthrough pressure of0.5 PV epoxy resin reached 7.53 MPa,decreasing the crack's perme

关键词： Sustained casing pressure Epoxy resin sealant Curing agent Visco.ity reducer Mechanical properties Crack sealing

Three-dimensional parametric co.tact analysis of planetary roller screw mechanism and its application in grouping for selective assembly

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Frontiers of Mechanical Engineering 2024年第1期19卷 53-72页

作者： Huilin HE Peitang WEI Huaiju LIU Xuesong DU Rui HU Genshen LIU Yajun WU State Key Laboratory of Mechanical Transmission for Advanced Equipment Chongqing UniversityChongqing 400044China Taiyuan Heavy machinery Group co. Ltd.Taiyuan 030024China

The planetary roller screw mechanism(PRSM)is a novel precision transmission mechanism that realizes the co.version between linear and rotary *** co.tact characteristics of helical surfaces directly determine PRSM’s performance in load-carrying capacity and transmission ***,studying the co.tact characteristics of PRSM forms the fundamental basis for enhancing its transmission *** this study,a three-dimensional parametric analysis method of co.tact characteristics is proposed based on the PRSM meshing principle and PyVista(a high-level API to the Visualization Toolkit).The proposed method co.siders the influence of machining errors among various thread *** effects of key machining errors on co.tact positions and axial clearance,as well as their sensitivities,are *** excellent solution accuracy,this method exhibits higher calculation efficiency and stronger robustness than the analytical and numerical meshing *** influence of nominal diameter and pitch errors of the screw,roller,and nut on the axial clearance follows a linear relationship,whereas flank angle errors have negligible effects on the axial *** co.responding influence co.fficients for these three machining errors on the axial clearance are 0.623,0.341,and *** variations in co.tact positions caused by individual errors are *** angle errors and roller diameter errors result in linear displacements of the co.tact points,whereas pitch errors cause the co.tact points to move along the arc of the roller *** on the proposed threedimensional parametric co.tact characteristics analysis method,the Fuzzy C-Means clustering algorithm co.sidering error sensitivity is utilized to establish a co.ponent grouping technique in the selective assembly of critical PRSM co.ponents,ensuring the rational and co.sistent clearances based on the given co.ponent’s machining *** study provides effective guidance for analyzing co.ta

关键词： planetary roller screw mechanism(PRSM) co.tact position axial clearance machining error grouping for selective assembly

The Middle Miocene lobe-shaped and band-shaped submarine fans in the Lingshui Sag,Qiongdongnan Basin:source-to-sink system,genesis and implication

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Acta Oceanologica Sinica 2024年第4期43卷 61-79页

作者： Xingzong Yao co.gjun Feng Hongjun Qu Min Zhang Daming Li State Key Laboratory of co.tinental Dynamics Northwest UniversityXi’an 710069China Department of Geology Northwest UniversityXi’an 710069China Exploration and Development Technology Research Center of Yanchang oilfield co. Ltd.Yan’an 716000China Chexplor Resource Exploration Technology co. Ltd.Huaibei 235000China

Deepwater oil and gas exploration is the key to sustainable breakthroughs in petroleum exploration *** Central Canyon gas field has co.firmed the Lingshui Sag is a hydrocarbon-generating sag,and the deepwater reservoirs in the Lingshui Sag still have more fabulous oil and gas exploration *** on drilling data and three-dimensional(3D)seismic data,this paper uses seismic facies analysis,seismic attribute analysis,and co.erence slice analysis to identify the types of submarine fans(lobe-shaped and band-shaped submarine fans)that developed in the Lingshui Sag during the Middle Miocene,clarify the source-to-sink system of the submarine fans and discuss the genesis mechanism of the submarine *** results show that:(1)the deepwater source-to-sink system of the Lingshui Sag in the Middle Miocene mainly co.sisted of a“delta(sediment supply)-submarine canyon(sediment transport channel)-submarine fan(deepwater sediment sink)”association;(2)the main factor co.trolling the formation of the submarine fans developed in the Lingshui Sag was on the relative sea level decline;and(3)the bottom current reworked the lobe-shaped submarine fan that developed in the northern Lingshui Sag and formed the band-shaped submarine fan with a greater sand *** paper aims to provide practical geological knowledge for subsequent petroleum exploration and development in the deepwater area of the Qiongdongnan Basin through a detailed analysis of the Middle Miocene submarine fan sedimentary system developed in the Lingshui Sag.

关键词： submarine fan source-to-sink system genesis mechanism Middle Miocene Lingshui Sag