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Preparation of Core/Shell Electrically Conductive Fibers by Efficient Coating Carbon Nanotubes on Polyester

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Advanced Fiber Materials 2021年第3期3卷 180-191页

作者： Liangyu Ma Yi Nie Yanrong Liu Feng Huo Lu Bai Qian Li Suojiang Zhang College of Chemistry and Chemical Engineering Henan UniversityHenan 475000China Beijing Key Laboratory of Ionic Liquids Clean Process CAS Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China Zhengzhou Institute of Emerging Industrial Technology Henan 450040China

Conducting fibers with improved properties and functionalities are needed for diverse *** we report the fabrica-tion of core/shell conductive Dacron fibers by dip-coating method through originating from multi-walled carbon nanotubes(MWCNTs)coated on polyester *** annealing process was conducted to enhance interaction between the conductive shell and polyester core as well as within the MWCNTs *** properties of two kinds of MWCNTs dispersions and the electrical properties of conductive fibers were studied,*** results show that both MWCNTs-polyurethane resin(MWCNTs-WPU)dispersion and MWCNTs-acrylic resin(MWCNTs-PAA)dispersion present a typical characteristic of pseudo-plastic fluid and an excellent wetting ability to polyester *** ultimate tensile stress and elongation at break for the MWCNTs-PAA coated fiber are 261 MPa and 25.43%.The ultimate tensile stress and the elongation at break are both increasing with the increasing of MWCNTs contents,due to the strong interface bonding ability between the conduc-tive shell and polyester core and strengthen the MWCNTs *** electrical resistance of the obtained fibers can be controlled in the range from 732 to 30Ω/cm by changing MWCNTs content,dipping times and annealing *** was found that it is able to light a *** results suggest that the conductive fibers embody a good synergy effect of carbon nanotubes and ***,the fabricated conductive fibers have a widely prospect for being applied in the field of flexible electronics.

关键词： MWCNTs dispersion Conductive polyester fiber Electrical resistance Interface

Experimental Study on Slagging and Fouling Behaviors During Oxy-Fuel Combustion of Zhundong Coal Using a Drop Tube Furnace 9th

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Experimental Study on Slagging and Fouling Behaviors During ...

9th International Symposium on Coal Combustion, ISCC 2019

作者： Zhao, Lei Wang, Chang’an Hu, Yueyi Sun, Ruijin Tang, Guantao Guo, Jin Jiang, Zhiming Du, Yongbo Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China Guangdong Institute of Special Equipment Inspection and Research Foshan528251 China Shunde Institute of Inspection Guangdong Institute of Special Equipment Inspection and Research Foshan528251 China

ISBN: (纸本)9789811616563

Zhundong coal featuring high content of alkali metals induces severe slagging and fouling problems during its utilization in utility boilers. Oxy-fuel combustion technology can achieve a large amount of CO2 capture and reduce the NOx emission. Unfortunately, in-depth investigation has been seldom carried out on the process of ash deposition and slagging of high-alkali coal during oxy-fuel combustion. In the present study, the oxy-fuel combustion of high-alkali coals were experimentally studied using a non-cooled sampling probe in a drop tube furnace. The fouling and slagging mechanisms were investigated in various atmospheres, temperatures and different O2 concentrations. In addition, the slag samples were characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Spectrometer (EDS). Experimental results indicated that under air and oxy-fuel conditions with the same O2 content, the types of elements and minerals were almost the same. With the temperature increased, the adhesion between the slag samples was strengthened and the pore structure slag was increased. The degree of slag melting and sintering was aggravated at the temperature of 1200 °C and the slag structure was complicated. As the oxygen concentration was increased, some of the spherical particles had completely melted on the surface of the massive ash, resulting in an uneven surface. The present work can provide new insights into the slagging and ash deposition of Zhundong high-alkali coal during oxy-fuel combustion. © 2022, Tsinghua University Press.

关键词： Coal

Condensation Characteristic of Sulfuric Acid Vapor on Low-Temperature Surface of Tube Heat Exchanger 9th

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Condensation Characteristic of Sulfuric Acid Vapor on Low-Te...

9th International Symposium on Coal Combustion, ISCC 2019

作者： Sun, Ke Yan, Yu Hu, Fangfang Deng, Lei Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China Huadian Electric Power Research Institute Hangzhou310030 China China Energy Engineering Group Shaanxi Electric Power Design Institute Co. Ltd Xi’an710054 China

ISBN: (纸本)9789811616563

In the low-low temperature flue gas system, a part of the H2SO4 vapor is adsorbed by the ash particles, and the other part will condense on the surface of the heat exchanger, resulting in low-temperature corrosion. In this paper, a numerical model for the condensation of H2SO4 vapor on low-temperature surface is constructed. This model combines the thermodynamic phase equilibrium theory, the multicomponent transport theory and the heat transfer theory. The effects of flue gas properties, the size and arrangement of heat exchanger are studied. The results show that, the condensation rate is mainly related to the concentration gradient of H2SO4 vapor near the surface. As the flue gas or surface temperature increases, condensation rate decreases. When the flue gas velocity increases, the mass transfer resistance is reduced, thereby the condensation rate is increased. As the content of H2SO4 in the flue gas increases, the concentration gradient of H2SO4 vapor near the surface increases, and the condensation rate of increases linearly. But the content of water vapor has little effect on the H2SO4 condensation rate. For the tube heat exchanger, when the working conditions keep the same, the smaller the outer diameter of the tube, the greater the condensation rate of the H2SO4 vapor. Compared with the inline arrangement, when the tubes are staggered, the disturbance of flue gas is stronger, and the condensation rate is larger. © 2022, Tsinghua University Press.

关键词： Flue gases

Preparation, improvement, and application of metal–organic framework-based sensing materials for gas leakage and emission: A review

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Nano Materials Science 2025年

作者： Liu, Manyi Wang, Liang Ren, Shan Bai, Bofeng Chai, Shouning He, Chi Zheng, Chunli Yin, Xitao Li, Fengguang College of Materials Science and Engineering Chongqing University Chongqing400044 China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an710049 China School of Physics and Optoelectronic Engineering Ludong University Yantai264000 China School of Materials Science and Engineering Hubei University of Automotive Technology Shiyan442002 China

Industrial gas leaks and flue gas emissions pose significant threats to the safety of industrial operations and the atmospheric ecological environment. Traditional gas sensing materials often struggle to meet the challenges posed by complex industrial environments. Recently, metal-organic framework (MOF)-based gas sensing materials have garnered significant attention in industrial gas detection due to their high sensitivity, selectivity, and tunable properties. The exponential increase in related publications highlights the growing research interest in this field. This paper presents a comprehensive review of the advantages of various types of metal-organic frameworks and their derivatives for detecting industrial gas leaks and flue gas emissions, alongside an introduction of representative MOF synthesis methods. Furthermore, the primary sensing mechanisms of MOF-based gas sensing materials and strategies for enhancing the sensing performance are summarized. The current state of MOF-based gas sensing materials in industrial gas detection is also discussed. Finally, the potential limitations, existing challenges, and future directions of MOF-based industrial gas sensing materials are systematically analyzed, with suggestions for addressing these challenges to advance industrial gas detection technologies. © 2025 Chongqing University

关键词： Application Improvement Industrial gas detection MOF-Based sensing materials Preparation

Novel Fast Predesign Methodology of Centrifugal Compressor Used for Pemfcs Based on 1d Loss Mechanism and Interpretable Machine Learning Models

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SSRN 2024年

作者： Chen, Zhikai Sun, Jieshuai Chen, Ziying Spence, Stephen Peng, Xueyuan Feng, Jianmei School of Energy and Power Engineering Xi'an Jiaotong University Xi'An710049 China School of Mechanical Manufacturing and Biomedical Engineering Trinity College Dublin Dublin 2 Ireland State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'An710049 China

The significant challenge of balancing accuracy, time, and cost has consistently compelled designers to develop more efficient and economical predesign methods. To tackle this issue, a novel predesign method amalgamating one-dimensional (1D) loss model with gradient boosting decision tree (GBDT) model has been proposed. A high-precision 1D loss model was developed and experimentally tested for rapid performance assessment. Furthermore, two machine learning models, named Extreme Gradient Boosting (XGBoost) and Light Gradient Boosting Machine (LightGBM), were trained, and compared to construct surrogate models. Hyperparameter optimization was executed utilizing a Bayesian algorithm to identify the optimal hyperparameter set. Additionally, the Sobol sensitivity analysis and Shapley Additive Explanations (SHAP) based interpretability were used to explore the paramount factors affecting the model's outputs and the interactions among the sensitive parameters. The findings underscore that the blade outlet angle, impeller outlet diameter, impeller outlet width, inlet shroud diameter, and blade inlet angle(shroud) are the most five important parameters influencing the model's indexes. Some beneficial design guidelines are distilled from their feature importance and interactions. and The implement of new design yields powerful evidence for the developed prior knowledge with an increase of 2.5830% in isentropic efficiency and a reduction of 1.5202% in power consumption. © 2024, The Authors. All rights reserved.

关键词： Sensitivity analysis

Science for This Age: Paradigm Shifts and Global Challenges

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engineering 2022年第12期19卷 22-23页

作者： Chao Dong Jinghai Li Daya Reddy National Natural Science Foundation of China Beijing 100085China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Cape Town Rondebosch 7701South Africa

Whether the goal is to meet global challenges or to enable a paradigm shift,it is always essential for science to move beyond conventional ***,the mutually beneficial interactions between global challenges and paradigm shifts require a great deal of *** this end,it is imperative for the scientific community not only to respond to major challenges by shifting paradigms in science but also to drive paradigm shifts in science by responding to major *** aim sets a higher bar for scientists as,in order to achieve it,we must properly identify the scientific questions in research and better utilize existing *** present,however,we are not paying sufficient attention to this aim,nor are we sufficiently competent in this *** is essential for the global scientific community to pay more attention to these interconnected issues of global challenges and paradigm shifts.

关键词： utilize properly mutually

Influence Study of the Anisotropic Scattering and Solar Radiation on the Radiation Working Performance of Liquid Droplet Radiator

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SSRN 2024年

作者： Fei, Yiheng Fu, Jianghan Wang, Chenglong Tian, Wenxi Guanghui, S.U. Qiu, Suizheng 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 Xi’an710049 China

The Liquid Droplet Radiator (LDR), a lightweight frameless radiant heat rejection system, is widely regarded as the optimal heat rejection solution for megawatt-scale space nuclear power systems. The LDR dissipates heat to space through its droplet layer, which plays a crucial role in determining its radiative rejection capacity. Radiation beams undergo a series of emission, scattering, and absorption processes within the layer before being emitted into space. Prior studies typically assume isotropic scattering in this process. However, this study introduces a 3D model of the LDR layer based on Mie theory and Monte-Carlo methods to investigate the impact of anisotropic scattering and solar radiation. Our calculations reveal that the working fluid exhibits strong forward anisotropic scattering characteristics. Under the anisotropic assumption, the heat rejection capability of the LDR is 27-33% higher compared to the isotropic assumption. Regarding the temperature distribution within the LDR, under the anisotropic assumption, the layer's temperature is 6 K lower at the XY boundary surface and 3 K higher at the layer median, as opposed to the isotropic assumption. We introduce the concept of the probability of a light beam escape to elucidate the distinct beam transmission mechanisms and temperature distribution. When the distance between the LDR and the sun is in the vicinity of 1 AU, the impact of solar radiation on the LDR's ability to operate is on the order of 1E-5, which is almost negligible. This study provides a theoretical foundation for calculating the heat rejection capacity during the LDR design phase. © 2024, The Authors. All rights reserved.

关键词： Solar radiation

Numerical and Experimental Investigation of Proton Exchange Membrane Fuel Cell with Perpendicular Gas Supply Through the Ridge

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SSRN 2023年

作者： Zhang, Yan Lu, Xinyu Su, Jinzhan School of International Trade and Economics China International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering School of Energy & Power Engineering Xi’an Jiaotong University Xi’an710049 China

The structural design of the cathode flow field in proton exchange membrane fuel cell (PEMFC) is essential for efficient gas supply and effective water removal. For investigating the mechanism behind the effect of gas flow direction on improving the performance of PEMFC, a novel modified serpentine flow channel with vertical inlets through the ridge for PEMFC was proposed and investigated by numerical and experimental methods. Under the operating voltage of 0.4 V, the vertical air supply mode exhibits a 7% higher current density compared to the parallel air supply mode. Compared with conventional air supply mode through the serpentine flow channel, vertical air supply mode modified serpentine through a tunnel inside the ridge exhibited higher oxygen uniformity and higher current density. Furthermore, we conducted research on the impact of physical parameters, including the porosity and thickness of the GDL, as well as the vertical gas supply pore density, on the performance of the PEMFC within the vertical gas supply mode. At an operating voltage of 0.4 V, the current density of PEMFC with a GDL thickness of 0.28 mm is 1.0009 A/cm2, which is 3.02% and 6.13% higher than that of PEMFC with vertical inlets with GDL thickness of 0.38 and 0.48 mm, respectively. With a porosity of 0.6, the current density of PEMFC reaches 1.0395 A/cm2, surpassing that of PEMFCs with porosities of 0.2 and 0.4 by approximately 24.8% and 6.6%, respectively. Moreover, higher vertical inlet densities lead to improved PEMFC performance. Simulation and experimental results demonstrate that this modified flow field effectively addresses uneven current density distribution and enhances power output at low voltage. © 2023, The Authors. All rights reserved.

关键词： Porosity

Experiments and Predictions for Severe Slugging of Gas-Liquid Two-Phase flows in a Long-Distance Pipeline-Riser System

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SSRN 2023年

作者： Chang, Yingjie Xu, Qiang Zou, Suifeng Zhao, Xiangyuan Wu, Quanhong Wang, Yechun Thévenin, Dominique Guo, Liejin State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Laboratory of Fluid Dynamics and Technical Flows Otto-von-Guericke-Universität Magdeburg Magdeburg39106 Germany

Experiments concerning the flow regimes observed in gas-liquid two-phase flows in a long pipeline-riser system have been carried out and are analyzed in this paper. The test loop with 0.075 m inner diameter consists of a 314 m horizontal pipeline, followed by a 25 m downward-inclined pipe, and finally a 21.5 m riser pipe. An industrial-scale global flow regime map is derived from differential pressure measurements in the riser. Electrical capacitance volume tomography installed in the horizontal section was used to reconstruct the phase interface in order to calculate the average gas void fraction (GVF). An appropriate model for this system is selected by comparing the experimental GVF with different, widely used models. The occurrence of a severe slugging flow (SS) can be well predicted using the model involving additional corrections (taking into account pipeline length, accurate GVF results, and gas density). This study supports the development of a suitable SS prediction model enabling safe design, operation, and control of practical systems. © 2023, The Authors. All rights reserved.

关键词： Pipelines