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Fault Diagnosis of Rolling Bearing Using Cnn and Pca Fractal Based on Feature Extraction

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SSRN 2023年

作者： Xiao, Junqing Li, Chun Yue, Minnan Xu, Zifei Liu, Qingsong School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093 China Department of Maritime and Mechanical Engineering Liverpool John Moores University Byrom Street LiverpoolL3 3AF United Kingdom

A novel adaptive decomposition algorithm based on CEMMDAN and fractal dimension is proposed in this study in order to overcome the limitations like redundancy and mode confusion that exist in traditional EMD based algorithms. An intelligent fault diagnosis model is developed based on CNN and the proposed CEMMDAN for improving the performance of states recognition of rolling bearings. all sub-signals generated by CEEMDAN are selected and reconstructed by the PCA and fractal dimension. In the part if feature extraction and pattern recognition, the proposed ICEEMDAN uses CNN to extract advanced features from the reconstructed signal for developing the intelligent diagnosis model. The performance of the proposed method is examined by rolling bearing experiments. The superiority and reliability of the proposed ICEEMDAN method are compared with some CNN-based diagnosis method. Due to the investigation and examination, the proposed ICEEMDAN method has strong robustness even dealing with the noisy testing background. © 2023, The Authors. All rights reserved.

关键词： Empirical mode decomposition

A MEMS density sensor based on mircro-rectangular cantilever

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A MEMS density sensor based on mircro-rectangular cantilever

2010 International Conference on Mechanic Automation and Control engineering, MACE2010

作者： Zhao, Libo Huang, Enze Jiang, Zhuangde Liu, Zhigang State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University Xi'an China State Key Lab. of Multiple Flow in Power Engineering Xi'an Jiaotong University Xi'an China

ISBN: (纸本)9781424477388

A rectangle cantilever-type micro density sensor was researched based on MEMS (Micro Electro-mechanical System) technology. A Ti-Pt-Au coil and a Wheatstone full bridge were made on the top of the rectangle cantilever-type sensitive chip. The sensitive chip was placed in uniform strong magnetic field. The resonant frequency of the sensitive chip was changed with the change of the AC current's frequency. The resonant frequency of rectangle cantilever could be measured through the Wheatstone full bridge circuit and lock-in amplifier, and then the fluid density associated with the resonant frequency of the sensitive chip could be calculated. The static analysis, modal analysis, a first-order and third-order harmonic response analysis of the rectangle cantilever were performed with ANSYS software. The best locations of the four force-sensitive resistor of Wheatstone bridge were studied. ©2010 IEEE.

关键词： Natural frequencies

Influence of dolomite additive on the ash fusion and potassium fixation characteristics of rice straw

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Ranliao Huaxue Xuebao/Journal of Fuel Chemistry and Technology 2020年第7期48卷 795-803页

作者： Yu, Zhi-Hao Jin, Jing Zhang, Rui-Pu Zhao, Bing Zhu, Yi-Zhou Wang, Guang-Xu School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093 China

The influence of dolomite as an additive on the slagging and potassium fixation characteristics of rice straw upon burning was investigated in a tube furnace;the slagging mechanism as well as the interaction between the rice straw ash and dolomite were explored by using the inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray diffraction (XRD). The results show that the slagging characteristics of rice straw are significantly influenced by adding 5% dolomite. Dolomite can greatly improve the potassium fixation ability, especially at 900-1000℃;moreover, the Mg and Ca elements rich in dolomite can react with SiO2 in the rice straw ash, forming high-melting silicate minerals including diopside, monticellite and merwinite. © 2020, Science Press. All right reserved.

关键词： Dolomite

Development, Validation and Application of Sub-Channel Thermal-Hydraulic Analysis Code for Liquid Metal Cooled Reactor

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SSRN 2024年

作者： Wang, Jinshun Chen, Ronghua Liang, Yu Gui, Minyang Zhu, Xinyang Tian, Wenxi Qiu, Suizheng Su, Guanghui School of Nuclear Science and Technology Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Nuclear Power Institute of China 328 Changshun Avenue Chengdu610213 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China College of Nuclear Science and Technology Harbin Engineering University Harbin150001 China

The liquid metal reactor, specifically the lead-based fast reactor and the sodium-cooled fast reactor, are generally recognized as the most significant representatives of the Gen IV reactors due to their sustainability, economy, security and reliability. In order to conduct thermal-hydraulic safety analysis for liquid metal cooled fast reactors, adaptive improvements are made to the model and solution algorithms based on the sub-channel analysis method, and a Sub-channel Analysis Code Of Safety for Liquid Metal cooled Reactor (SACOS-LMR) is developed. The validation of SACOS-LMR is conducted using classic experimental data of liquid metal. The results show that the dimensionless temperature deviations of ORNL 19-pin test and Toshiba 37-pin test are within 10%, and the relative temperature deviations of KIT-KALLA 19-pin test are within 25%. These findings confirm the accuracy and reliability of SACOS-LMR in predicting the temperature distribution of liquid metal reactors. Ultimately, calculations conducted on the ALFRED lead-cooled fast reactor demonstrated the practical utility of the code and have certain guiding significance for its subsequent design and development. © 2024, The Authors. All rights reserved.

关键词： Liquid metals

Development of Polyamine/Alkanolamine-Based Hypergolics with Hydrogen Peroxide: A New Route to N-Methylimidazole with Mdea as a Promising Green Fuel

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SSRN 2023年

作者： Mota, Fábio A.S. Liu, Mingyang Mohsen, Abrar A.A. Yao, Xiaoxin Mai, Zhaoming Tang, Chenglong State Key Laboratory of Multiphase Flows in Power Engineering Xi’an Jiaotong University Shanxi Xi’an710049 China SP Santo Andre09210-580 Brazil

A novel non-ionic liquid fuel based on a mixture of N-methylimidazole (MIm) and N-methyldiethanolamine (MDEA) called PAHyp 2 which reacts hypergolically with hydrogen peroxide is presented in this work. To study the hypergolic behaviors, a drop test setup able of capturing simultaneous high-speed schlieren, infrared and visible imaging were used. While infrared images capture the temperature history of the ignition process, schlieren images offer advantages of capturing the pressure waves as well as providing better visualization of the morphological description of the liquid dynamics. PAHyp 2 with hydrogen peroxide (98%) has specific impulse 6% lower than hydrazine-based fuels but because of its higher density it requires smaller propellant tanks for a given mission. In order to meet the requirements of good chemical stability and low viscosity of less than 30 cP, the proportion of MIm should range between 40 and 50% (or 60 to 50% of MDEA) and the amount of catalyst should be no more than 3 wt%. FTIR spectra showed no chemical degradation. By adding 3 wt% catalyst, the shortest ignition delay time of 8.8 ms was recorded. Based on these preliminary results, we believe that just like the other polyamiane/akanolamine-based fuels recently reported by our group, this new recipe is also a promising candidate and as such should be further studied. © 2023, The Authors. All rights reserved.

关键词： Hydrogen peroxide

Effects of CO/H2 ratio on turbulent combustion characteristics for CO/H2/CO2/O2 mixtures at high pressure

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Effects of CO/H2 ratio on turbulent combustion characteristi...

9th Asia-Pacific Conference on Combustion, ASPACC 2013

作者： Sato, Ryota Matsuno, Futoshi Wang, Jinhua Kudo, Taku Kadowaki, Satoshi Kobayashi, Hideaki Institute of Fluid Science Tohoku University 2-1-1 Katahira Aoba-ku Sendai Miyagi 980-8577 Japan State Key Laboratory of Multiphase Flows in Power Engineering Xi'An Jiaotong University Xi'an 710049 China Graduate School of Management of Technology Nagaoka University of Technology Nagaoka 940-2188 Japan

Characteristics of turbulent premixed flames of CO/H2/CO 2/O2 mixtures at high pressures of 0.5 MPa were experimentally investigated. Using OH-PLIF images, flame surface density, mean volume of turbulent flame regions and turbulent burning velocity were calculated. Flame surface density, turbulent burning velocity and intensity of flame radiation of CO/H2/CO2/O2 flames are larger than those of CH4/air flames while the mean volume of the turbulent flame region, Vf, of CO/H2/CO2/O 2 flames is smaller than that of CH4/air flames. As the H2 mole fraction increases, turbulent burning velocity and intensity of flame radiation for CO/H2/CO2/O2 flame becomes larger while the mean volume of the turbulent flame region becomes smaller. When the ratio of the H2 mole fraction to that of CO is more than 0.5, Vf and ST/SL of CO/H 2/CO2/O2 flames become almost the same. It is presumed that the effect of H2 concentration is dominant for CO/H2/CO2/O2 flame for high H2 mole fractions.

关键词： Mixtures

Highly accurate meshless method for convection-diffusion problems

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Kung Cheng Je Wu Li Hsueh Pao/Journal of engineering Thermophysics 2008年第9期29卷 1561-1563页

作者： Wu, Xue-Hong Li, Zeng-Yao Ma, Liang-Dong Tao, Wen-Quan State Key Lab. of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

Meshless local Petrov-Galerkin method (MLPG) as a new computational method has been developed in recent years, which disposes a group of scatter points in the computational domain and construct the interpolation function through these nodes. The Smith-Hutton problem was selected as the demonstrated test problem and solved by the MLPG. The results of the MLPG method were compared with the results of finite volume method with high order scheme. The results indicate that the MLPG method is a highly accurate numerical method and can deal effectively with high Pe number fluid flow problems.

关键词： Finite volume method

Customizable Ligand Exchange for Tailored Surface Property of Noble Metal Nanocrystals

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研究（英文） 2020年第3期 192-203页

作者： Qikui Fan Hao Yang Juan Ge Shumeng Zhang Zhaojun Liu Bo Lei Tao Cheng Youyong Li Yadong Yin Chuanbo Gao Frontier Institute of Science and Technology State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong University Xi'an Shaanxi 710054 China Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices Joint International Research Laboratory of Carbon-Based Functional Materials and Devices Soochow UniversitySuzhou Jiangsu 215123 China Department of Chemistry University of California Riverside California 92521 USA

It is highly desirable,while still challenging,to obtain noble metal nanocrystals with custom capping ligands,because their colloidal synthesis relies on specific capping ligands for the shape control while conventional ligand exchange processes suffer from 'the strong replaces the weak' limitation,which greatly hinders their ***,we report a general and effective ligand exchange approach that can replace the native capping ligands of noble metal nanocrystals with virtually any type of ligands,producing flexibly tailored surface *** key is to use diethylamine with conveniently switchable binding affinity to the metal surface as an intermediate *** a strong ligand,it in its original form can effectively remove the native ligands;while protonated,it loses its binding affinity and facilitates the adsorption of new ligands,especially weak ones,onto the metal *** this means,the irreversible order in the conventional ligand exchange processes could be *** efficacy of the strategy is demonstrated by mutual exchange of the capping ligands among cetyltrimethylammonium,citrate,polyvinylpyrrolidone,and *** novel strategy significantly expands our ability to manipulate the surface property of noble metal nanocrystals and extends their applicability to a wide range of fields,particularly biomedical applications.

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Comparison of Lifetime Performance of Pemfc Stacks with Two Cooling Strategies Under Different Humidity

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SSRN 2024年

作者： Yang, Yunjie Bai, Minli Zhou, Zhifu Wu, Wei-Tao Lv, Jizu Hu, Chengzhi Li, Yang Li, Yubai Song, Yongchen Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education Dalian University of Technology Dalian116024 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi’an710049 China School of Mechanical Engineering Nanjing University of Science and Technology Nanjing210094 China School of Mechanical Engineering Guangdong Ocean University Zhanjiang524088 China

While reducing the size and Pt loading can achieve a lower proton exchange membrane fuel cell (PEMFC) stack cost, it is also very important to focus on the performance changes of the PEMFC stack during the long-term operation. A 3D PtCo catalysts long-term performance model is established in this study, and PEMFC stacks with one cooling unit per cell (1-cell stack) and three cells (3-cell stack) are employed as the computational domains, respectively. The effective area of each cell is 50 cm2, and the changes in current density as well as effective catalytic area of PEMFC stacks with two cooling strategies before and after long-term operation under different humidity conditions are investigated at low Pt loadings. The results show that there are large differences in the output voltage and current density distributions between the three cells due to the poor membrane hydration affected by the non-uniform temperature distribution, although the 3-cell stack can significantly reduce the size. Localized catalyst degradation in both 3-cell and 1-cell stacks is closely related to the geometry of the cathodic flow field, and non-uniform catalyst degradation is found to increase the activation and mass transfer losses and change the distribution of current density within the membrane. In addition, the 3-cell stack is found to perform even better in terms of durability, especially under high humidity conditions, which provides a potential solution to improve the durability of PEMFC stacks operating in harsh conditions. © 2024, The Authors. All rights reserved.

关键词： Durability