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Motion characteristics and density separation of fine coal in an inflatable-inclined liquid-solid fluidized bed

Particuology 2021年第5期19卷 299-307页

作者： bo lv bobing Dong Xiaowei Deng Chaojun Fang College of Chemistry and Chemical Engineering Henan Polytechnic UniversityJiaozuo 454000China Henan Key Laboratory for Green and Efficient Mining&Comprehensive Utilization of Mineral Resources Henan Polytechnic UniversityJiaozuo 454000China Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization Henan Polytechnic UniversityJiaozuo 454000China

To improve the adaptability of fluidized beds for fine coal separation,a new type of liquid-solid fluidized bed was constructed,i.e.,the inflatable-inclined liquid-solid fluidized bed(IILSFB).A combination of simulation analysis and separation experiments was used to analyze the fluidization characteristics and separation performance of the *** results showed that there was upflow and downflow in the fluidized *** upflow was mainly composed of water flow,followed by light and heavy particles;on the other hand,the downflow was caused by the backflow of heavy particles that settled at the inclined *** addition,the light particles that settled at the inclined section could return to the rising water flow under the action of secondary *** the water velocity,separation time,and secondary gas velocity increased,the comprehensive separation efficiency of fine coal in the fluidized bed improved,while the value decreased as the feed quantity *** also indicated the order of importance for these four factors,i.e.,water velocity,separation time,feed quantity,and secondary gas velocity,on ***,the comprehensive separation efficiency of 0.1-1 mm fine coal varied significantly with various factors,while that of∼0.1 mm and 1-3 mm fine coal was always at a low *** the latter case,the classification process of the size fraction was significantly better than the separation process in the fluidized *** optimal working conditions,an IILSFB was used to separate the fine coal(0.1-1 mm).The yield of clean coal was 37.95% with an ash content of 12.11%,and the possible error was 0.085 g/cm^(3),indicating that the IILSFB had good separation performance for 0.1-1 mm fine coal.

关键词： Inflatable-inclined liquid-solid fluidized bed Fine coal separation Fluidization Separation efficiency Secondary gas velocity Size fraction

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Flow-field analysis of a continuous gas-solid separation fluidized bed equipped with a moving scraper

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Particuology 2021年第4期19卷 45-55页

作者： bo lv Xiaowei Deng Chaojun Fang Xiangnan Zhu College of Chemistry and Chemical Engineering Henan Polytechnic UniversityJiaozuo 454000China Henan Key Laboratory for Green and Efficient Mining&Comprehensive Utilization of Mineral Resources Henan Polytechnic UniversityJiaozuo 454000China School of Chemical&Environmental Engineering Shandong University of Science&TechnologyQingdao 266590China

Continuous gas-solid separation fluidized beds are one of the most widely used practical operation units for the dry separation of coal in China,particularly in Northwest China,and they can effectively promote the efficient and clean utilization of raw *** a continuous gas-solid separation fluidized bed,the bed flow field is the concrete manifestation of the fluidization ***,the complexity of the flow field increases under the action of a moving *** this study,a combination of computational fluid dynamics(CFD)simulations and experimental measurements was used to study the changes in the flow field of a fluidized *** results showed that when the scraper moved,the local flow field(mainly characterized by the movement of medium particles)near the scraper was affected not only by the common airflow or bubbles,but also by the lateral driving force of the *** the scraper speed was v_(l)<6.0 cm/s,it reduced the frequency of the formation of large bubbles and alleviated the random fluctuation of the nearby particle collision stress signals,which improved the fluidization stability of the ***,the movement of the scraper affected the global flow *** flow field shifted to the right near the scraper,with the direction of the scraper movement,while the flow field exhibited a leftward trend on the surface of the bed,accompanied by some vortices,in the middle and lower parts of the ***,the critical height of the area,directly affected by the scraper,increased from 52 to 54 mm with an increase in its operating speed from v_(l)=2.96 cm/s to v_(l)=4.44 cm/s,*** provides a theoretical basis for further understanding the hydrodynamic characteristics of fluidized beds.

关键词： Simulation analysis Moving scraper Flow-field Particle collision pressure Hydrodynamic characteristics

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Particle mixing behavior of fine coal in density control of gas-solid separation fluidized bed

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Particuology 2020年第3期18卷 76-87页

作者： bo lv Zhenfu Luo Yanhong Fu bo Zhang Xingzong Qin Xiangnan Zhu College of Chemistry and Chemical Engineering Henan Polytechnic UniversityJiaozuo 454000China Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education China University of Mining&TechnologyXuzhou 221116China School of Chemical Engineering and Technology China University of Mining and TechnologyXuzhou 221116China School of Chemical&Environmental Engineering Shandong University of Science&TechnologyQingdao 266590China

In a gas-solid separation fluidized bed,mixing of fine coal is necessary to achieve a suitable bed density to enable effective separation of low rank *** the basis of a variety of mixture models,a gas-solid separation fluidized bed was judged,where fine coal particles of 0.6-1.0mm were uniformly mixed with magnetite ***-speed dynamic camera technology was combined with a slump-sampling method to study the mixing process of the fine coal in the fluidized *** results showed that limitations of the fluidized bed structure cause the mixing process to be dominated by lateral diffusion and supplemented by axial *** diffusion was mainly achieved through the ascension of bubbles,whereas lateral diffusion was determined by the bursting action of the gas bubbles at the surface of the bed and the undulating characteristics of the *** effective lateral diffusion coefficient increased exponentially with gas velocity but had no strong relationship with the bed *** the feed point moved toward the center,fine coal began to diffuse to both sides,which shortened the time for the bed density stabilization from 20 to 5 *** bed density of the layer was stabilized at approximately 1.75 g/*** separation efficiency of the gas-solid separation fluidized bed containing binary mixtures was more obvious for 6-50 mm raw coal,with a probable error E of 0.16.

关键词： Gas-solid separation fluidized bed Density control Fine coal Diffusion behavior Separation process

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Channel selection against electrode shift enables robust myoelectric control without retraining

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Science China(Technological Sciences) 2021年第8期64卷 1653-1662页

作者： lv bo HE JiaYuan SHENG XinJun DING Han ZHU XiangYang State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China Department of Systems Design Engineering Faculty of EngineeringUniversity of WaterlooWaterlooN2L 3G1Canada

Myoelectric controlled interfaces driven by muscle activities have achieved good performance in ideal conditions and showed many potential medical-related and industrial ***,in practical applications,the performance could be drastically degraded due to the electrode(sensor)shift,which is inevitable in donning and doffing the *** this study,we presented a novel channel selection method against electrode shift for robust pattern-recognition based myoelectric *** proposed method was evaluated on twenty-four subjects,including twenty-two able-bodied subjects and two amputees,and compared with two traditional channel selection methods,i.e.,uniform selection(UNI)and sequential feature selection(SFS).We demonstrated that the offline error rates of the proposed method were significantly lower than those of the other two methods(P<0.05),and its online performance in shift conditions was comparable to that in ideal *** outcomes benefit the practical applications of robust myoelectric controlled interfaces.

关键词： myoelectric control high-density electrodes channel selection electrode shift surface electromyography

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Design Method of Equipment Optimization Development Based on Standardization Theory

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Defence Technology（防务技术） 2013年第3期9卷 140-145页

作者： lv-bo MAI China North Standardization Research Center

The matters of equipment optimization development are usually discrete,fuzzy and *** is difficult directly to optimize the equipment development with a mathematical model.A set of methods for designing the equipment optimization development with six dimensions and eight main elements is established based on the theory and method of *** top-tier design space of systematic development of equipment is built up by the relations of basic models,series and model *** relations of time and space for equipment optimization development are *** design processes of a six dimension systematic space are *** connotation of each plan in the main system space is analyzed.A design method for an entire equipment is established with standardization *** coordinating design methods of equipment technical system and the optimization design methods of equipment integration are *** design methods for universalization and serialization of components and parts are *** design methods of equipment optimization development highlight the relations of the basic model of platform,the serialization of platform basic models,the modularization of equipment functions,the model spectrum of variant equipment,and the universalization and serialization of components and parts.

关键词：优化设计方法优化开发化设备标准化优化发展数学模型设计空间设备系统

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Development and application of an instrument for simulating wetting-drying cycles of expansive soils under loads

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Journal of Mountain Science 2018年第11期15卷 2552-2560页

作者： DONG Jun-gui lv Hai-bo WU Wei School of Civil Engineering and Transportation South China University of Technology Guangzhou 510641 China College of Civil Engineering and Architecture Guilin University of Technology Guilin 541004 China

Alternating rainfall and evaporation in nature severely impact the shear strength of expansive soils. This study presents an instrument for simulating the effect of wetting–drying cycles on the strength of expansive soils under different loads, and its testing error is verified. With this instrument,direct shear tests were performed on samples experiencing 0-6 cycles under vertical loads of 0 kPa,5 kPa, 15 kPa, and 30 k Pa. The results found that this instrument provides a new method for evaluating the effects of wetting–drying cycles on soils, and this method represents actual engineering conditions more accurately than do preexisting methods. It accurately controls the water content within 1% while simulating the specified loads at different soil *** is significantly affected by wetting–drying cycles, while the friction angle is not as sensitive to these cycles. Decrease in shear strength can be attributed to the fissures in soils caused by wetting–drying cycles. The existence of vertical loads effectively restricts shrinkage fissuring and cohesion attenuation, consequently inhibiting the attenuation of shear strength.

关键词： Expansive soils Wetting-drying cycle Instrument Load Shear strength

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Effect of the secondary air distribution layer on separation density in a dense-phase gas–solid fluidized bed

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International Journal of Mining Science and Technology 2015年第6期25卷 969-973页

作者： lv bo Luo Zhenfu Zhang bo Zhao Yuemin Zhou Chenyang Yuan Wenchao School of Chemical Engineering and Technology China University of Mining and Technology

Dry coal separation has been the most significant process in the field of coal beneficiation to date, because of its special advantage of operation with no water consumption. Mineral dry separation research has received wide attention, particularly in countries and regions experiencing drought and water shortages. During the process of dense coal gas-solid fluidized bed beneficiation, the material is stratified according to its density; the high density material layer remains at the bed bottom, and thus the high density coarse particle bed becomes an important infuencing factor in fluidized bed stability. In the steady fluidization stage, a small number of large radius bubbles are the direct cause of unsteady fluidization in the tradi- tional fluidized bed. The dispersion effect of the secondary air distribution bed for air flow is mainly apparent in the gas region; when the particle size exceeds 13 mm, the secondary air distribution bed has a synergistic effect on the density stability of the upper fluidized layer. When the particle size is small, especially when less than 6 ram, particles will constantly move, accounting for instability of the secondary air distribution bed and distorting the stability of the upper fluidized bed. Under optimum operation conditions, the probable deviation E of gas-solid separation fluidized with a high density coarse particle layer can be as low as 0.085 g/cm3.

关键词： Secondary air distribution layerDry coal separationGas-solid fluidized bedParticle size

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A novel graphite/phenolic resin bipolar plate modified by doping carbon fibers for the application of proton exchange membrane fuel cells

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Progress in Natural Science:Materials International 2020年第6期30卷 876-881页

作者： bo lv Zhigang Shao Liang He Yong Gou Shucheng Sun Fuel Cell System and Engineering Laboratory Key Laboratory of Fuel Cells & Hybrid Power Sources Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

In this study, the carbon fibers treated by three methods were selected as a reinforcement to investigate the influence on the properties of composite bipolar plates. The properties and microstructure of the composite bipolar plate were characterized by the four-point probe, universal test machine, contact angle tester and scanning electron microscopy. The optimum treatment methods and the fiber content were analysed. The results showed that the carbon fibers treated by Fenton reagent for 2 h exhibited the best performance, which could improve the electrical conductivity and the flexural strength for composite bipolar plate. Besides, the optimal content content of carbon fibers treated by Fenton reagent was 4%. The maximum power density of the PEMFC with the composite bipolar plates could reach 662.75 m W cmin H-air conditions. Therefore, the phenolic resin/graphite composite bipolar plate modified by doping carbon fibers was a promising candidate for bipolar plate materials for PEMFC.

关键词： PEM fuel Cell Natural graphite Phenolic resin Composite bipolar plate

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Numerical simulation of the thermal non-equilibrium flow-field characteristics of a hypersonic Apollo-like vehicle

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Chinese Physics B 2022年第9期31卷 376-385页

作者： Minghao Yu Zeyang Qiu bo lv Zhe Wang Faculty of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048China

In order to investigate the relationship between the flow-field parameters outside the vehicle and the altitude,this paper takes the Atmospheric Reentry Demonstrator(ARD)with an angle of attack of-20°as the research object and adopts a two-temperature model coupled with the shear-stress transport k-ωturbulence model to focus on the variation of flow-field parameters including flow-field pressure,Mach number and temperature with the reentry *** is found that the flow-field high-pressure region and low-Mach region both appear in the shock layer near the head of the ARD,while the maximum pressure of the surface appears on the windward side of the ARD's head with a toroidal distribution,and the numerical magnitude is inversely proportional to the radius of the *** fluid through the shoulder of the ARD flow expansion plays a dominant role,the airflow velocity increases,the Mach number of the windward side of the rear cone increases and the flow-field pressure and surface pressure rapidly *** the fluid passes through the shock layer,the translational-rotation temperature will increase before the vibration-electron temperature,there is a thermal non-equilibrium effect and the two temperatures will rapidly decrease again when approaching the surface of the ARD due to the existence of temperature *** the same time,both the windward side of the shoulder and the back cover of the ARD suffer from a large thermal load and require thermal protection.

关键词： atmospheric reentry demonstrator reentry altitude flow-field characteristics two-temperature model

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Research on early warning of electric power customers’ credit risk based on SVM 36

Research on early warning of electric power customers’ cred...

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第36届中国控制会议

作者： Zhongfeng Wang Haifei Yu bo Hu Tao Zhang bo lv Shenyang Institute of Automation Chinese Academy of Sciences College Of Business Administration Northeastern University State Grid Liaoning Electric Power Co.Ltd.Huludao Power Supply Company State Grid Liaoning Electric Power Co.Ltd.Anshan Power Supply Company

ISBN: (纸本)9781538629185

Aiming at the deception phenomena in the electric power market that disorder the power trading,the early warning problem of power users’ credit risk in the power market was *** solve the problem,an early warning model based on SVM（Support Vector Machine） was *** the evaluation criteria system and grading standard were discussed in *** the early warning model based on SVM was built and the optimization of parameters was *** the data of Liaoning Electric Power Co.,Ltd.,from 2013 to 2016 is chosen as the sample data for verifying and simulating the early-warming model of power customers’ credit *** results showed the effectiveness of the proposed method.

关键词： SVM credit risk early-warning model power market

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