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Thermal management for thermoset automated fiber placement based on infrared heater structure arrangement

Chinese Journal of Aeronautics 2022年第1期35卷 173-183页

作者： Han WANG Weiwei WANG Haijin WANG Huiyue DONG Yinglin KE A State Key Laboratory of Fluid Power and Mechatronic System School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China

Layup temperature is a vital factor that affects the production quality of automated fiber placement for thermoset *** high quality production,this paper proposes a new prediction model of layup temperature by considering the structure of infrared heater of automatic fiber placement *** model was first verified by comparing with the temperature results of layup *** a prediction on the effects of heater structure arrangement on layup temperature was conducted in the *** research shows that the length of infrared tube and the radian of reflective-film have significant influences,rather than other *** to this investigation,a heater structure-based heating strategy was presented in the paper to efficiently achieve constant temperature control in variable speed layup process.

关键词： Automated fiber placement Heating strategy optimization Infrared heater structure Thermal management Variable speed

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Impact of Dual-Volume Helmholtz Dampers on Longitudinal and Azimuthal Thermo-Acoustic Instabilities in an Annular Combustor

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Journal of Thermal Science 2022年第6期31卷 2225-2243页

作者： YU Zhijian YANG Yang Advanced Gas Turbine Laboratory Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China Key Laboratory of Advanced Energy and Power Institute of Engineering ThermophysicsChinese Academy of SciencesNanjing 210000China Nanjing Institute of Future Energy System Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China

Dual-volume Helmholtz dampers with two resonant frequencies are proposed to simultaneously attenuate longitudinal and azimuthal thermo-acoustic instabilities in annular combustors. Thermo-acoustic instabilities in a swirled annular combustor equipped with dual-volume dampers are numerically investigated by the Helmholtz method, combined with a measured flame transfer function and the established damper impedance model. Furthermore, the influences of the damper number and circumferential configurations on oscillation attenuations and mode structures are explored. The established dual-volume damper model is well validated by the impedance tube tests. Numerical results indicate velocity fluctuation levels of the longitudinal and azimuthal modes decline after installing Helmholtz dampers, whereas those of the azimuthal modes further decrease by around 16% after using four retuned dual-volume dampers. The eigenfrequencies of the first longitudinal and azimuthal modes decrease and increase after installing dampers, respectively. After installing dual-volume dampers, the difference between the pressure fluctuation in the plenum and combustion chamber is reduced, and pressure waveforms of the azimuthal modes along the circumferential direction shifts. The pressure distribution of azimuthal modes becomes more uniform after using more dual-volume dampers. The specific absorption frequency band for azimuthal modes introduced by the dual-volume damper may lead to decreased oscillations and mode evolutions. The maximal absorbing ability can be approached by installing dampers with the same angle between adjacent dampers. When dampers are unevenly distributed, the symmetry between two azimuthal modes is broken and standing modes will emerge.

关键词： thermo-acoustic instability annular combustor passive control dual-volume damper Helmholtz method azimuthal mode structure

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Data-Efficient Synchronous Machine Winding Short Circuit Faults Diagnosis Based on Frequency Response Analysis and Active Learning

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IEEE Sensors Journal 2025年第11期25卷 19804-19815页

作者： Chen, Yu Zhao, Zhongyong Liu, Jiangnan Wang, Wei Yao, Chenguo Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Wuhan430074 China Southwest University College of Engineering and Technology Chongqing400716 China Yibin Academy of Southwest University Sichuang64400 China Guangzhou Power Supply Bureau of Guangdong Power Grid Co. Ltd Guangzhou510620 China Chongqing University State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing400044 China

Winding short-circuit (SC) faults are a prevalent issue in synchronous machines, and the accurate and timely identification of these faults is critical for maintaining power system stability. Current methods for inspecting synchronous machine windings often rely on periodic inspections based on human expertise. Numerous studies have explored the application of deep learning (DL) models for detecting synchronous machine winding SC faults. However, these models often exhibit excessive complexity and overlook physical overhead, leading to inefficient utilization of computational power and data resources. To address these limitations, this study proposes a dual-channel deep learning (DL) model integrated with the active learning (AL) query strategy. In this study, winding SC faults are manually simulated on a 5 kVA synchronous machine, and corresponding frequency response analysis (FRA) data are recorded. Subsequently, the proposed method is validated on the test set and benchmarked against previous studies. Experimental results demonstrate that the proposed method significantly reduces the data annotation effort and accelerates model training to the order of seconds (under 5 seconds) while maintaining satisfactory accuracy (≥ 95%). Comparative experimental results further indicate that the proposed model, requiring only 1/20th of the labeled training samples used in previous studies, achieves a substantial reduction of approximately 99.8% in both model parameters and training time. © 2001-2012 IEEE.

关键词： Synchronous machinery

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Steady-State Operating Area Analysis and Full Unit-Circle Realization for Current Source Converter

Steady-State Operating Area Analysis and Full Unit-Circle Re...

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2024 CPSS and IEEE International Symposium on Energy Storage and Conversion, CPSS and ISESC 2024

作者： Song, Zhaoqi Wei, Xiaoguang Zhang, Wenwen An, Ronghui Shan, Yunhai Liu, Jinjun School of Electrical Engineering Xi'An Jiaotong University Xi'an China Advanced High Power Energy Conversion Institute Beijing Huairou Laboratory Beijing China State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing China

ISBN: (纸本)9798350380514

Current source converter (CSC) with dc fault ride-through capability and low-cost advantages, is attracting lots of attention in high-voltage direct current (HVDC) and renewable energy conversion fields. The steady-state operating area (SSOA) of voltage source converter (VSC) should be designed to achieve the full unit-circle in some utility applications. It's based on proper design of main parameters. But in existing studies on CSC, its main parameters are designed mostly based on unit power factor operation, without considering the full unit-circle realization of SSOA. To fill this gap, first the ranges of key parameters are summarized and then used to derive analytical expressions of SSOA constraints in per unit system for CSC. Second, the conditions for main parameters to realize the full unit-circle SSOA are investigated, revealing the L-C filter parameters' effects on the feasible domain of the rated ac voltage. Finally, while the full unit-circle conditions are satisfied, the minimum capacitor voltage is chosen as the optimization objective in the parameters design. Then the optimized parameters in typical HVDC applications are acquired. It's found that the rated ac voltage designed is relatively high for practical applications, indicating further tradeoffs between full unit-circle SSOA and system cost. © 2024 IEEE.

关键词： Voltage-source converters

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Additively Manufactured Electric Machine Conductors with Integrated End Turn Heat Exchangers

Additively Manufactured Electric Machine Conductors with Int...

引用

2022 International Conference on Electrical Machines, ICEM 2022

作者： Pecotich, James Klink, David Heins, Greg Bahrani, Behrooz Monash University Power Engineering Advanced Research Laboratory Department of Electrical and Computer System Engineering Melbourne Australia

ISBN: (数字)9781665414326

ISBN: (纸本)9781665414326

Conductors within a loaded electric machine commonly induce the highest loss. Numerous cooling solutions exist for high-power density electric machine conductors with external water jackets being the most common. The inherent disadvantage of water jacket cooling is the thermal resistance between the conductor and the cooling medium, which reduces the maximum cooling capacity, regardless of the jacket design. This restriction commonly leads designers to implement solutions such as end-turn cooling. The advances in additive manufacturing have unlocked new potential for conductor end-turn cooling. This paper investigates an additively-manufactured conductor with an integrated end-turn heat exchanger. The conductor is based around a Formula Student in-hub motor. This concept utilizes air-cooling and demonstrates a steady-state current density of 11 A/mm2 for a AlSi10Mg end-turn heat-exchanger conductor, without the added mass and complexity of liquid cooling solutions. If copper is used instead of AlSi10Mg, this value increases to approximately 22 A/mm2. © 2022 IEEE.

关键词： Electric losses

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Surface Charge Accumulation Characteristics on DC GIL Three-post Insulators Considering the Influence of Temperature Gradient

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CSEE Journal of power and Energy systems 2023年第5期9卷 1926-1934页

作者： Qi Hu Qingmin Li Zhipeng Liu Naifan Xue Jian Wang Manu Haddad North China Electric Power University Beijing 102206China.He is now with State Grid Jiangxi Electric Power Co.Ltd.Nanchang 330077China the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China the Advanced HV Engineering Research Centre Cardiff UniversityThe ParadeCardiff CF243AAU.K.

Surface charge accumulation is considered to be a critical factor in flashover failure of three-post ***,surface charge accumulation characteristics on threepost insulators with complex structures and uneven electric fields are still ***,the temperature gradient field makes charge accumulation more *** this presentation,surface charge profiles of DC three-post insulators under electro-thermal coupling stress are studied by establishing a multi-degree-of-freedom movement measurement *** abdominal area of the three-post insulator accumulaftes charges of identical polarity as the DC voltage,while the leg area accumulates heteropolar *** density from the bottom of the leg to the center of the abdomen presents a trimodal distribution pattern,including two homopolar charge peaks and one heteropolar charge *** surface conductance distribution arising from the temperature gradient leads to a significant increase in amplitude and distribution range of the homopolar charge peak at the legs of *** of the temperature gradient will further magnify the homopolar charge peak at the *** DC voltage is 100 kV and conductive pole temperature is 70℃,surface charge density of the three-post insulator can reach 100μC/m^(2).Therefore,surface conductance regulation of the leg region is the key to charge regulation and insulation optimization design of DC three-post insulators.

关键词： Charge accumulation charge measurement surface charge temperature gradient three-post insulator

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Enhancing the high-temperature corrosion resistance of HVOF-sprayed NiCoCrAlY coating in marine environment by Pt modification and pre-oxidation

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Journal of Materials Science & Technology 2024年第34期201卷 222-235页

作者： Y.Y.Li Y.M.Jiang C.Zhang H.Z.Ji S.Li N.Xu Z.B.Bao S.L.Zhu F.H.Wang School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China National Engineering Research Center of Special Equipment and Power System for Ship and Marine Engineering No.703 Research Institute of CSSCHarbin 150078China Shenyang National Laboratory for Materials Science Northeastern UniversityShenyang 110819China

To prolong the service lifetime of hot-section components used in marine environment at elevated tem-peratures,it is crucial to explore and develop high-temperature corrosion-resistant ***-velocity oxygen fuel(HVOF)sprayed NiCoCrAlY,Pt-modified NiCoCrAlY and pre-oxidized Pt-modified NiCoCrAlY coatings were prepared and *** study is concerned with the performance of three coat-ings in a simulated marine environment based on the phase composition of corrosion products and mi-crostructure evolution of coating samples combined with first-principles density functional *** results show that the NiCoCrAlY coating was subject to accelerated corrosion and extensive aluminum depletion,leading to premature coating *** high-temperature corrosion resistance of Pt-modified NiCoCrAlY coating was found to be better than that of NiCoCrAlY *** contrast,the pre-oxidized Pt-modified NiCoCrAlY coating offered long-lasting protection and exhibited the best corrosion resistance,which is attributed to the positive synergistic effect between Pt modification and pre-oxidation.

关键词： High-temperature corrosion HVOF-sprayed MCrAlY coating Pt modification Pre-oxidation marine environment

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RESEARCH ON LONG TERM TREND PREDICTION OF NUCLEAR power PLANTS BASED ON INTEGRATED FRAMEWORK 31

RESEARCH ON LONG TERM TREND PREDICTION OF NUCLEAR POWER PLAN...

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2024 31st International Conference on Nuclear engineering, ICONE 2024

作者： Canyi, Tan Biao, Liang Bo, Wang Jiangkuan, Li Rui, Han Sichao, Tan Ruifeng, Tian Heilongjiang Provincial Key Laboratory of Nuclear Power System & Equipment Harbin Engineering University Harbin150001 China Key Laboratory of Nuclear Safety and Advanced Nuclear Energy Technology Ministry of Industry and Information Technology Harbin Engineering University Harbin150001 China

ISBN: (纸本)9780791888261

In the current field of nuclear energy, the development of the third generations nuclear power plants(NPPs) are the mainstream, and its safety and economy are the important direction of nuclear energy development. Therefore, the normal, stable and safe operation of the nuclear reactor system is particularly important. In order to improve the safety and stability of the nuclear power system, this paper proposes a life prediction model of a NPP based on a comprehensive framework. In this study, an integrated framework based on BP, LSTM, Informer and other models is built, and the model is verified by the running data of Qinshan simulator. The results show that, compared with the traditional BP and LSTM, the long-term trend prediction model of NPP based on integrated framework has lower MAE and MSE values, indicating that the long-term trend prediction model of NPP based on integrated framework has lower error, which provides strong support for the safe and stable operation of nuclear power system. © 2024 by ASME.

关键词： Prediction models

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Dynamic Characteristics of the Subsea Direct Drive Hydraulic Servo Rotary Valve

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China Ocean engineering 2025年第2期39卷 329-339页

作者： SHI You-cheng SHAN Jun-feng ZHANG Hu-cheng LIU Yin-shui College of Energy and Fluid Power Engineering Lanzhou University of TechnologyLanzhou 730050China Key Laboratory of Advanced Pumps Valves and Fluid Control System of the Ministry of EducationLanzhou University of TechnologyLanzhou 730050China

Hydraulic technology has the outstanding advantages of easy pressure compensation and high power *** is an indispensable part of subsea equipment,such as deep-sea operations and submersible *** are few studies on electrohydraulic servo valves(EHSVs)in the deep *** this work,a novel electro-hydraulic servo rotary valve is designed,and its mathematical model is *** analysis considers the variations in physical parameters such as temperature,ambient pressure,and oil viscosity resulting from changes in sea *** study focuses on the deformation of the rotary valve and the consequent alterations in leakage and friction *** findings indicate that at a depth of 12000 m,the fit clearance between the valve spool and the valve sleeve is 0.00413 mm,representing a 17%reduction compared with the clearance in a land ***,the response of the rotary valve to depth is *** results indicate that the bandwidth of the rotary valve decreases with increasing *** study provides a reference for the use of the EHSV in the deep sea.

关键词： subsea hydraulic technology electro-hydraulic servo rotary valve valve deformation fit clearance dynamic characteristics response

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Dynamic Characteristics of Lubricating Oil Film of Slipper Pair in Radial Piston Pump under Impact Load

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International Journal of Fluid Machinery and systems 2024年第3期17卷 164-177页

作者： Li, Shaonian Yun, Zhengang Wang, Kaifeng Fu, Liting College of Energy and Power Engineering Lanzhou University of Technology No.287 Langongping Road Lanzhou730050 China Key Laboratory of Advanced Pumps Valves and Fluid Control System Ministry of Education Lanzhou University of Technology No.287 Langongping Road Lanzhou730050 China College of Energy Engineering Xinjiang Institute of Engineering No.1350 Aidinghu Road Urumqi830023 China

To reduce the failure, deformation, and damage of slipper pair in radial piston pumps, Theoretical research and numerical modeling were conducted on the structure, kinematics principle, and stroke ring-slipper components force analysis of the radial piston pump, Through the theoretical analysis of the hydrostatic bearing oil film of the slipper pair, The obtained the static characteristic curve of the slipper pair, the oil film backthrust, the oil film stiffness, the power loss, and the optimal oil film thickness, reflecting the relationship between the oil film thickness, operating pressure, and the former. Subsequently, the dynamic characteristics equation of the oil film for the slipper pair under impact load was established, and the conclusion obtained by using the fourth-order Runge-Kutta method is as follows: during the oil film squeezing process, the fluctuation of the oil film increases monotonically with time t, during the establishment of the oil film, oil film fluctuation generates damping oscillations, eventually tending to balance the oil film thickness. Conversely, without considering the squeezing effect, the dynamic process of the oil film diverges. Finally, the influence of the slipper structural parameters on the dynamic characteristics of the slipper pair oil film under impact load was studied, The results show that when the sealing strip area decreases or Δp and h0 increases, the fluctuation caused by oil film squeezing becomes larger. However, as the oil film establishes, the fluctuation amplitude of the oil film varies directly with the sealing strip area 、Δp and h0, When the adjustment time ts＜t is reached, the ratio of the fluctuation of the oil film to the equilibrium oil film thickness is less than 3%. © 2024, Turbomachinery Society of Japan. All rights reserved.

关键词： Runge Kutta methods

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