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Multi-parameter optimization to improve the erosion resistance of coating by FE simulation

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Multi-parameter optimization to improve the erosion resistan...

ASME Turbo Expo 2021. Turbomachinery Technical Conference and Exposition, GT 2021

作者： Li, Fang Wang, Shunsen Cai, Liuxi Feng, Zhenping State Key Laboratory of Multiphase Flow in Power Engineering Institute of Turbomachinery Xi'an Jiaotong University No. 28 Xianning West Road Xi'an710049 China School of Chemical Engineering and Technology Xi'an Jiaotong University No. 28 Xianning West Road Xi'an710049 China

ISBN: (纸本)9780791885000

Finite element method (FEM) was used to study the stress peak of stress S1. (Radial stress component in X-axis) on the steam turbine blade surface of four typical erosion-resistant coatings (Fe2B, CrN, Cr3C2-NiCr and Al2O3-1.%TiO2). The effect of four parameters, such as impact velocity, coating thickness, Young's modulus and Poisson's ratio on the stress peak of stress S1. were analyzed. Results show that: the position of tensile stress peak and compressive stress peak of stress S1. are far away from the impact center point with the increase of impact velocity. When coating thickness is equal to or greater than 1.μm, the magnitude of tensile stress peak of stress S1. on the four coating surfaces does not change with the coating thickness at different impact velocities. When coating thickness is equal to or greater than 2μm, the magnitude of tensile stress peak of stress S1. of four coatings show a trend of increasing first and then decreasing with the increase of Young's modulus. Meanwhile, the larger the Poisson's ratio, the smaller the tensile stress peak of stress S1.. After optimization, When coating thickness is 2μm, Poisson's ratio is 0.35 and Young's modulus is 800 GPa, the Fe2B coating has the strongest erosion resistance under the same impact conditions, followed by Cr3C2-NiCr, CrN, and the Al2O3-1.%TiO2 coating, Al2O3-1.%TiO2 coating has the worst erosion resistance. Copyright © 2021.by ASME.

关键词： Finite element method

Experimental and Kinetic Modeling Study on the Oxidation and Laminar Combustion Characteristics of Natural Gas

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SSRN 2023年

作者： Chen, Xiaoxiao Zeng, Wen Zheng, Weilin Hu, Erjiang Ma, Hongyu Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System Shenyang Aerospace University Liaoning Shenyang110136 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shanxi Xi'An710049 China AECC Shenyang Engine Research Institute Shenyang110015 China

The oxidation process in the flow tube reactor at the conditions of P=0.1.MPa, T=500-1.50 K, f=0.5, 1.0, 3.5, and the laminar combustion process in the constant volume combustion bomb at the conditions of P=0.1. 0.2, 0.3 MPa, T=300, 350, 400 K, f= 0.7-1.4, the O2 contents of 1.%, 1.% and 21., the CO2 and H2O contents of 0%, 1.%, and 20% of natural gas (0.9 methane/0.07 ethane/0.03 propane, mole fraction) were experimental tested. In the oxidation process of natural gas, with the equivalence ratio increasing, the starting and ending temperatures for oxidation reaction of natural gas are increased, the reaction temperatures corresponding to CO generation and consumption are higher, and the amount of NO production is decreased. In the the laminar combustion process of natural gas, at the conditions of higher pressure, equivalence ratio, CO2 and H2O contents, the flame front is not smooth as a large number of cracks and cell structures appear, and the flame is unstable. Moreover, with the initial temperature and oxygen content increasing or the initial pressure, CO2 and H2O contents decreasing, the laminar flame speed is increased. Furthermore, combined the path sensitivity analysis, rate of production analysis, reaction path analysis and the decoupling method, a reduced reaction mechanism (including 40 species and 1.9 reactions) of natural gas was developed. Through comparing with the calculated results by the Aramco 2.0 mechanism and the corresponding test data, the reduced reaction mechanism can well predict the oxidation, ignition delay and laminar combustion characteristics of natural gas under various conditions. © 2023, The Authors. All rights reserved.

关键词： Sensitivity analysis

Energy and exergy analyses of a novel recirculated regenerative rotary desiccant wheelassisted dehumidification system 33

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Energy and exergy analyses of a novel recirculated regenerat...

33rd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2020

作者： Han, Xiaoqu Wu, Wenxiang Chong, Daotong Su, Minqi Zhang, Dan Yan, Junjie State Key Laboratory of Multiphase Flow in Power Engineering Xi'An Jiaotong University Xi'an China MOE Key Laboratory of Thermal Fluid Science and Engineering Xi'An Jiaotong University Xi'an China

The indoor air humidity and temperature in the marine cabins could be as high as 80% and 40 &#1.6;C - 50 &#1.6;C, respectively, which may cause security risks to crews and devices. The incorporation of solid desiccant... 详细信息

The indoor air humidity and temperature in the marine cabins could be as high as 80% and 40 °C - 50 °C, respectively, which may cause security risks to crews and devices. The incorporation of solid desiccant wheel for improved dehumidification and air quality control would contribute to energy saving in air conditioning system through waste heat recovery for regeneration. In the present work, a novel recirculated regenerative rotary desiccant wheel-assisted dehumidification system was proposed. The energy and exergy performances of the system under variable working conditions were quantitatively studied based on experimental tests. The dehumidification effectiveness, dehumidification performance coefficient (DCOP), sensible energy ratio and coefficient of performance (COP) were introduced as key energetic indicators. The effects of air bypass ratio (50% - 85%), process air temperature (28 °C - 40 °C), relative humidity of process air (60%RH - 80%RH) and regeneration air temperature (1.0 °C - 1.0 °C) on the system performances were obtained. It was found the COP of the system ranged between 0.4 and 1.8, while the exergy efficiency was only 4% - 1.%. An optimal bypass ratio existed which was determined 55%-60%. Overall, the energy saving and exergy consumption characteristics of the proposed system at various working conditions were explored to prompt its practical application. © ECOS *** right reserved.

关键词： Waste heat

An Experimental Study on the Hypergolic Process Enhanced by Pre-Ignition Heat Release: [Amim][Dca]/Furfuryl Alcohol Blends Reacting with White Fuming Nitric Acid

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SSRN 2022年

作者： Wu, Yingtao Wang, Zhi Fei, Lihan Guo, Yang Liu, Yang Tang, Chenglong Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Research Center of Energetic Material Genome Science Institute of Chemical Materials China Academy of Engineering Physics Mianyang China

The hypergolic ignition behaviors of [AMIM][DCA] (1.allyl-3-methylimidazolium dicyanamide)/furfuryl alcohol (FA) blends reacting with white fuming nitric acid (WFNA) are investigated using drop test approach. Morphology results from two high speed cameras and temperature profiles from an infrared camera are combined in analyzing the hypergolic process. A typical hypergolic process observed in this work involves a mixing dominant stage, a stage with moderate temperature rising and vapor/secondary droplets emerging, and a stage with violent temperature rising accompanied by flame occurrence. Two kinds of delay times are used to characterize the hypergolic process which are found to be nonmonotonic with the variations of FA fractions. FA, though not hypergolic with WFNA, exhibits extensive pre-ignition heat release due to its physical and chemical properties, which enhances the hypergolic process of [AMIM][DCA]/FA blends with WFNA. © 2022, The Authors. All rights reserved.

关键词： Ionic liquids

Waterside Corrosion of M5 Alloy in Simulated Primary Coolant and Supercritical Water: Influences of Aqueous Environments

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SSRN 2022年

作者： Jiang, Guanyu Liu, Lu Xu, Donghai Li, Yanhui Kuang, Wenjun Wang, Mingjun Key Laboratory of Thermo-Fluid Science & Engineering Ministry of Education School of Energy and Power Engineering Xi’an Jiaotong University Shaanxi Province Xi’an710049 China State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Xi'An710049 China State Key Laboratory of Multiphase Flow in Power Engineering Department of Nuclear Science and Technology Xi'an Jiaotong University Xi'An China

M5 alloy is highly potential to serve as cladding materials in nuclear reactors. In this work, corrosion characteristics of M5 alloy in lithiated/borated water and pure supercritical water were investigated, and influences of aqueous environments on the corrosion process were clarified. Oxide films formed on the alloy mainly consisted of m-ZrO2. In the coolant environment, Li+ and OH- shared a synergistic effect on the occurrence and acceleration of waterside corrosion. Boric acid can react with OH- to induce B-(OH) formation and participate in the generation of zirconium borate to alleviate the accelerated corrosion effect by LiOH. In supercritical water, M5 alloy showed weight loss due to localized oxide exfoliation, and dissolved oxygen resulted in serious pitting of the oxide film. The microcrack density and porosity were significantly larger than those in the coolant environment, and long transverse cracks parallel to the O/M interface existed. Oxide deposition in two environments was both observed, and the phenomenon was discussed. © 2022, The Authors. All rights reserved.

关键词： Coolants

Numerical Study on the Impact Characteristics of a Single Molten Lead Bismuth Droplet on Water

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SSRN 2024年

作者： Lin, Yue Zhang, Dalin Chen, Yutong Zhang, Xisi Deng, Jian Du, Peng Tian, Wenxi Qiu, Suizheng Su, Guanghui Department of Nuclear Science and Technology State Key Lab. of Multiphase Flow in Power Engineering Shaanxi Key Lab. of Advanced Nuclear Energy and Technology Xi’an Jiaotong University No.28 Xianningxilu Beilinqu Shaanxi Xi’an710049 China Institute of Reactor Engineering Technology China Institute of Atomic Energy Beijing102413 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Sichuan Chengdu610213 China

As an important link in the possible occurrence of steam explosions, the interaction between molten materials and coolant is of great significance for safety analysis in severe accidents of nuclear reactors. This study is based on the two-dimensional multiphase and multi-component fluid dynamics code ACENA to model the process of single molten lead bismuth droplet impacting a water tank and obtain the velocity changes of the molten droplet as it moves through the water tank. Furthermore, a sensitivity analysis of relevant factors such as the heat transfer area fraction and drag coefficient of the droplet is carried out. To verify models in ACENA, the computation results are compared to experimental data. It is demonstrated that the overall trend of the velocity curve acquired by the ACENA code during the interaction between a molten lead bismuth droplet and water is consistent with the experimental results. The droplet falling velocity increases with the increase in droplet temperature when the temperature of water is the same, and the droplet falling velocity increases with the increase of water temperature at the same droplet temperature. The simulation results by ACENA code for MFCI are in good agreement with experiments which verifies the accuracy of relevant models in ACENA. It can provide an effective means for safety analysis of nuclear reactors in China. © 2024, The Authors. All rights reserved.

关键词： Drops

Study on the effect of particle flow {1. on the stability of LIBS carbon content detection signal 7

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Study on the effect of particle flow state on the stability ...

7th International Conference on power {1., ICOPE 201.

作者： Pan, Yuqing Hu, Zhengtao Xu, Heng Zhou, Qulan Li, Na Deguchi, Yoshihiro State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Graduate School of Engineering Science Osaka University Japan

Rice husk, a type of biomass fuel, is rich in amorphous silica. Laser-induced breakdown spectroscopy (LIBS) is a fast-responding non-contact detection method which can realize on-line detection of rice ash components. This paper aims to explore the optimum working conditions of LIBS and extend the compatibility of LIBS technology. The paper uses the sample motion state simulation system to simulate ash, so that the particles can be laser-induced breakdown during the vertical drop and horizontal motion, and then the effect of particle {1. state on the stability of the LIBS detection signal can be determined. In addition, the paper compares the effects of two laser pulse widths on the stability of LIBS detection signal by using a 1.ns pulse width laser and a 6 ns pulse width laser to improve the detection error. Experimental studies have found that long pulse width laser provides better stability of spectrum, and the relative standard deviation (RSD) of the detection result is smaller than that of short pulse width laser, and the RSD is smaller in the state of horizontally transferring samples, which can obtain the spectral signal with stronger line intensity. Moreover, sample in conveyor, by contrast, leads to more stable signals. © ICOPE 201. - 7th International Conference on power engineering, Proceedings. All rights reserved.

关键词： Stability

Experimental Study on flow Patterns in Narrow Rectangular Channels

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SSRN 2022年

作者： Lv, Xindi Zhang, Dalin Song, Gongle Su, Guanghui Tian, Wenxi Qiu, Suizheng State Key Laboratory of Multiphase Flow in Power Engineering Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology School of Nuclear Science and Technology Xi’an Jiaotong University Xi’an710049 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610041 China

Plate fuel elements are commonly used in compact nuclear reactors due to the advantages of high fuel consumption. In this paper, the two-phase flow pattern in the coolant channel of plate fuel elements, i.e. the rectangular narrow channel was studied. Visualization flow pattern experiments of upward steam-water two-phase flow in narrow rectangular channels, 745mm long and 67mm wide with gap widths of 1.3mm and 1.9mm, were investigated. The experiments were performed in the conditions of pressure ranging from 1.to 2MPa, mass flow rate ranging from 200 to 1.00kg/(m2 ⋅s), inlet subcooling ranging from 20~1.0°C and tilt angle ranging from 0~ 45°. Three flow patterns, consisting of bubble flow, churn flow and annular flow, were obtained in a wide range of thermal parameters. flow patterns maps were plotted and the influences of pressure, mass flow rate, inlet subcooling, channel gap and tilt angle on the flow pattern transformation of narrow rectangular channel were studied. This study is of great significance for investigating the subsequent heat transfer process of two-phase flow in compact nuclear reactors. © 2022, The Authors. All rights reserved.

关键词： Two phase flow

Atomic Nickel on Graphitic Carbon Nitride as a Visible Light-Driven Hydrogen Production Photocatalyst Studied by X-ray Spectromicroscopy

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ACS Sustainable Chemistry and engineering 2023年第14期11卷 5390-5399页

作者： Huang, Yu-Cheng Li, Yanrui Arul, K. Thanigai Ohigashi, Takuji Nga, Ta Thi Thuy Lu, Ying-Rui Chen, Chi-Liang Chen, Jeng-Lung Shen, Shaohua Pong, Way-Faung Dong, Chung-Li Chou, Wu-Ching Department of Electrophysics National Yang Ming Chiao Tung University Hsinchu30010 Taiwan Research Center for X-ray Science & Department of Physics Tamkang University New Taipei City25137 Taiwan International Research Center for Renewable Energy State Key laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China Photon Factory Institute of Materials Structure Science High Energy Accelerator Research Organization Tsukabu305-0801 Japan UVSOR Synchrotron Facility Institute for Molecular Science Okazaki444-8585 Japan National Synchrotron Radiation Research Center Hsinchu30010 Taiwan

The photocatalytic production of solar hydrogen through water splitting by graphitic carbon nitride (g-C3N4) has gained substantial interest due to its advantageous characteristics, such as eco-friendliness, wealth on the earth, favorable bandgap, and easy preparation. Nevertheless, the performance for photocatalytic overall water splitting has been significantly restricted owing to the rapid recombination of charge carriers and slow catalytic kinetics. This investigation demonstrates the utilization of a single-atom Ni-terminating agent to coordinate with the heptazine moieties of g-C3N4, resulting in the formation of a new electronic orbital. g-C3N4 with single-atom Ni-termination can achieve highly efficient photocatalytic overall water splitting into H2 and H2O2 upon visible light irradiation, without requiring the use of any additional cocatalysts. The underlying cause of the enhanced photocatalytic performance of single-atom Ni-incorporated g-C3N4 in hydrogen evolution reaction is identified using synchrotron X-ray spectroscopy and microscopy. The X-ray spectro-microscopic results discover that the new hybrid orbital that is critical for optimizing photocatalysis is associated with carbon defects. The atomic and electronic structures and the band gap of g-C3N4 are adjusted by the new hybrid orbital. Moreover, it synergistically enhances visible light absorption, thereby promoting the separation and transfer of photogenerated charge carriers. The single-atom Ni and the adjacent C atom are recognized as the active sites for water oxidation and reduction, respectively, supporting the efficient photocatalytic splitting of water via a two-electron transfer pathway. This study demonstrated a promising material design for promoting photocatalytic activity in solar energy conversion applications. © 2023 American Chemical Society

关键词： Electronic structure