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Particle motion simulation and pulverized coal injection combustion simulation of titanomagnetite pellets in rotary kiln for reduction process with coal

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Journal of Iron and Steel Research(International) 2022年第6期29卷 891-906页

作者： Peng Liu Bing-guo Liu Li-bo Zhang Jin-hui Peng State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093YunnanChina Yunnan Provincial Key Laboratory of Intensification Metallurgy Kunming 650093YunnanChina National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology Kunming 650093YunnanChina Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina

The production process of direct reduced iron from titanomagnetite by coal reduction in air in rotary kiln is a key step in the extraction of titanium and iron.This process is conducive to alleviating the stocking problem of a large amount of Tibearing blast furnace slag.The relationships between particle movement and pulverized coal injection combustion in rotary kiln were studied by the particle motion simulation and the pulverized coal injection combustion simulation.In particle motion simulation,the repose angle of ore particles was calculated to be 28.06°,and the reaction zone was roughly determined by the reaction temperature isothermal surface and the repose angle;the axial discrete distribution of ore particles would further cause the axial energy fluctuation due to the endothermic nature of the reduction.In pulverized coal injection combustion simulation,the rebound effect of coal injection under gravity would cause local overheating in the rebound region due to the benefits of heat and mass transfer processes,while this could strengthen the reduction reaction of ore particles and cause agglomerate by melting.Two suggestions on weakening the energy fluctuation and agglomerate were proposed based on the characteristics of particle motion and external carbon reaction.

关键词： Titanomagnetite rotary kiln Reaction zone Energy fluctuation Rebound effect

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Effects of key factors of rotary triboelectrostatic separator on efficiency of fly ash decarbonization

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International Journal of Mining Science and Technology 2017年第6期27卷 1037-1042页

作者： Tao Youjun Zhang Ling Tao Dongping Xian Yushuai Sun Qixiao Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education China University of Mining & Technology Xuzhou 221116 China School of Chemical Engineering and Technology China University of Mining & Technology Xuzhou 221116 China School of Mining Engineering University of Science and Technology Liaoning Anshan 114051 China

On the basis of understanding the principle of rotary triboelectrostatic separation, dynamic analysis of charged fly ash particles aimed at determining the key factors and separation experiments to improve decarbonization efficiency had been carried out Variables of electrode plate voltage and corrected wind speed are the key factors which affect the decarbonization efficiency on the separation of fly ash, The results of separation experiments show that:(1) With the plate voltage increasing, the efficiency of decarbonization continuously rises and in its selected range, the optimal voltage level is 45 KV;(2) The corrected wind speed can impact the efficiency of decarbonization significantly: with the speed increasing, the efficiency of decarbonization shows a trend of first decline, then increase and decrease again, and in its selected range, the optimal speed is 2.0 m/s. This study is of significance for the improvement of rotary triboelectrostatic separation performance and its decarbonization separation efficiency.

关键词： rotary triboelectrostatic separation Decarbonization Plate voltage Corrected wind speed Fly ash

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Periodic Motion Planning and Control for Double rotary Pendulum via Virtual Holonomic Constraints

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IEEE/CAA Journal of Automatica Sinica 2019年第1期6卷 291-298页

作者： Zeguo Wang Leonid B.Freidovich Honghua Zhang Beijing Institute of Control Engineering IEEE the Robotics and Control Laboratory (www.control.tfe.umu.se) Department of Applied Physics and ElectronicsUmea University

Periodic motion planning for an under-actuated system is rather difficult due to differential dynamic constraints imposed by passive dynamics, and it becomes more difficult for a system with higher underactuation degree, that is with a higher difference between the number of degrees of freedom and the number of independent control inputs. However, from another point of view, these constraints also mean some relation between state variables and could be used in the motion planning.We consider a double rotary pendulum, which has an underactuation degree 2. A novel periodic motion planning is presented based on an optimization search. A necessary condition for existence of the whole periodic trajectory is given because of the higher underactuation degree of the system. Moreover this condition is given to make virtual holonomic constraint(VHC) based control design feasible. Therefore, an initial guess for the optimization of planning a feasible periodic motion is based on this necessary condition. Then, VHCs are used for the system transformation and transverse linearization is used to design a static state feedback controller with periodic matrix function gain. The controller gain is found through another optimization procedure. The effectiveness of initial guess and performance of the closed-loop system are illustrated through numerical simulations.

关键词： Double rotary pendulum periodic motion planning under-actuated mechanical systems virtual holonomic constraint (VHC)

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Effects of Four Types of Pre-swirls on the Leakage, Flow Field, and Fluid-Induced Force of the rotary Straight-through Labyrinth Gas Seal

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Chinese Journal of Mechanical Engineering 2019年第3期32卷 119-133页

作者： Qingfeng Wang Lidong He Beijing Key Laboratory of Health Monitoring and Self-Recovery for High-End Mechanical Equipment Beijing University of Chemical TechnologyBeijing 100029China College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100029China

The labyrinth seal in turbomachinery is a key element that restricts leakage flow among rotor-stator clearances from high-pressure regions to low-pressure regions. The fluid-induced forces on the rotor from seals during machine operation must be accurately quantified to predict their dynamic behavior effectively. To understand the fluid-induced force characteristics of the labyrinth seal more fully, the effects of four types of pre-swirls on the leakage, flow field, and fluid-induced force of a rotary straight-through labyrinth gas seal (RSTLGS) were numerically investigated using the proposed steady computational fluid dynamics (CFD) method based on the three-dimensional models of the RSTLGS. The leakage, flow field, and fluid-induced force of the RSTLGS for six axial pre-swirl velocities, four radial preswirl angles, four circumferential positive pre-swirl angles, and four circumferential negative pre-swirl angles were computed under the same geometrical parameters and operational conditions. Mesh analysis ensures the accuracy of the present steady CFD method. The numerical results show that the four types of pre-swirls influence the leakage, flow field, and fluid-induced force of the RSTLGS. The axial pre-swirl velocity remarkably inhibits the fluid-induced force, and the circumferential positive pre-swirl angle and circumferential negative pre-swirl angle remarkably promote the fluid-induced force. The effects of the radial pre-swirl angle on the fluid-induced force are complicated, and the pressure forces and viscous forces show the maximum or minimum values at a specific radial pre-swirl angle. The pre-swirl has a negligible impact on the leakage. The four types of pre-swirls affect the leakage, flow field, and fluidinduced force of the RSTLGS to varying degrees. The pre-swirl is the influence factor affecting the leakage, flow field, and fluid-induced force of the RSTLGS. The conclusions will help to understand the fluid-induced force of labyrinth seals more fully, by providing helpful suggestions for engi

关键词： rotary straight-through labyrinth gas seal Pre-swirl Leakage Flow field Fluid-induced force

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Experimental research on the heating performance of a single cylinder refrigerant injection rotary compressor heat pump with flash tank

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Science China(Technological Sciences) 2018年第12期61卷 1814-1823页

作者： SUN JinFei ZHU DongSheng YIN YingDe LI XiuZhen Guangzhou Institute of Energy Conversion Chinese Academy of Sciences Guangzhou 510640 China Key Laboratory of Renewable Energy Chinese Academy of Sciences Guangzhou 510640 China Guangdong Key Laboratory of New and Renewable Energy Research and Development Guangzhou 510640 China University of Chinese Academy of Sciences Beijing 100049 China

A single cylinder rotary compressor was applied in the refrigerant injection air-source heat pump to improve the heating performance in cold regions. In this study, the performance of an R410 A single cylinder rotary compressor vapor injection(SCRCVI) system was measured and analyzed by varying the compressor frequency f and injection pressure Pi njat the ambient temperature To d=–10°C.The experimental results indicated that an optimum injection pressure to gain the maximum COP_h (coefficient of performance) existed in the SCRCVI cycle. However, the maximum COP_h of the SCRCVI system decreased as the increase of the frequency, and the maximum COPhwas even lower than that of the CSVC system at high compressor frequency. Therefore, in view of the energy saving and emission reduction, the SCRCVI system should be switched to single stage compression system when the heating capacity demand could be satisfied at high compressor frequency f. Compared to the conventional single-stage vapor compression(CSVC) system, refrigerant injection could enhance the heating capacities and COP_h by 28.2% and 7.91%, respectively. The average total mass flow rate of the SCRCVI system was 24.68% higher than that of the CSVC system. As the SCRCVI system worked at the optimum injection pressure, the variation trends of the different system parameters were investigated in detail. These trends were reliably used to optimize the refrigerant injection system design and the control strategy. The parameter of(P_(inj)–P_s) could be adopted as the signals to control the opening of the upper stage electronic expansion valve EEV1.

关键词： rotary compressor refrigerant injection DC (direct current) inverter heat pump heating performance injection pressure

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Design and implementation of robot serial integrated rotary joint with safety compliance

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Journal of Central South University 2017年第6期24卷 1307-1321页

作者：李帅李健李思奇黄宗林 School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China School of Automation Beijing Institute of TechnologyBeijing 100081China

In order to guarantee safety and stability during physical human-robot-interaction(p HRI) in the occasion of service or industrial operation, a serial integrated rotary joint with the characteristics of passive and active compliance is proposed. Passive compliance is achieved by a designed elastic element, such that the compliant joint may minimize large force which occurs during accidental impacts and, further, may offer more accurate and stable force control and a capacity for energy storage. Meanwhile, the modeling of the compliant joint is comprehensively analyzed, including the effect of the motor model on the overall control system. In order to realize the active compliance, a new method of impedance control is proposed. On the basis of PD control, a more compliant impedance controller is introduced. Experimental results show that the serial integrated rotary joint can provide more effective safety compliance during physical interaction, which has also been well applied in our designed massage robot and rehabilitation robot.

关键词： elastic element impedance control safety compliance active compliance serial integrated rotary joint

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Nonlinear Dynamical Responses of rotary Cylindrical Shells with Internal Resonance

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Acta Mechanica Solida Sinica 2019年第2期32卷 186-200页

作者： Yufei Zhang Jintang Liu Bangchun Wen School of Aerospace Engineering Shenyang Aerospace University Shenyang 110136 China School of Mechanical Engineering and Automation Northeastern University Shenyang 110819 China

The nonlinear forced vibration response of a thin, elastic, rotary cylindrical shell to a harmonic excitation is investigated in this study. Nonlinearities due to the large-amplitude shell motion are considered by using Donnelfs nonlinear shallow-shell theory, with consideration of the effect of viscous structural damping. Different from the conventional DonnclFs nonlinear shallow-shell equations, an improved nonlinear model without employing the Airy stress function is utilized to study the nonlinear dynamics of thin shells. The system is discretized using the Galerkin method, while a model involving two degrees of freedom and allowing for the traveling wave response of the shell is adopted. The method of harmonic balance is applied to study the nonlinear dynamic responses of the t wo-degree-of-freedom system. In addition, the st ability of steady-state solutions is analyzed in detail. Finally, results are given for exploring the effects of different parameters on the nonlinear dynamic response with internal resonance.

关键词： Cylindrical shells rotary Nonlinear vibrations Internal resonance Dynamical response

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Self-adaptive PID controller of microwave drying rotary device tuning on-line by genetic algorithms

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Journal of Central South University 2013年第10期20卷 2685-2692页

作者：杨彪梁贵安彭金辉郭胜惠李玮张世敏李英伟白松 Faculty of Information Engineering and Automation Kunming University of Science and Technology Faculty of Metallurgical and Energy Engineering Kunming University of Science and Technology Key Laboratory of Unconventional Metallurgy of Ministry of Education Kunming University of Science and Technology Yunnan Copper Science and Technology Development Corporation Limited

The control design, based on self-adaptive PID with genetic algorithms(GA) tuning on-line was investigated, for the temperature control of industrial microwave drying rotary device with the multi-layer(IMDRDWM) and with multivariable nonlinear interaction of microwave and materials. The conventional PID control strategy incorporated with optimization GA was put forward to maintain the optimum drying temperature in order to keep the moisture content below 1%, whose adaptation ability included the cost function of optimization GA according to the output change. Simulations on five different industrial process models and practical temperature process control system for selenium-enriched slag drying intensively by using IMDRDWM were carried out systematically, indicating the reliability and effectiveness of control design. The parameters of proposed control design are all on-line implemented without iterative predictive calculations, and the closed-loop system stability is guaranteed, which makes the developed scheme simpler in its synthesis and application, providing the practical guidelines for the control implementation and the parameter design.

关键词： industrial microwave drying rotary device self-adaptive PID controller genetic algorithm on-line tuning selenium-enriched slag

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Densification laws and properties of sintered powder compacts in rotary forging process

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中国有色金属学会会刊：英文版 2000年第1期10卷 84-87页

作者：王广春赵国群贾玉玺杨艳山东工业大学山东济南

In order to obtain high property powder metallurgy products, at present rotary forging process has often been used to further densify the sintered powder compact, but the densification law and property analysis have very rarely been studied, therefore the densification laws of sintered powder compacts being composed of Fe 0.8%C 4.0%Cu 0.2% zinc stearate and formed as cylindrical shape by double action pressing, and then further densified as well in a rotary forging process was studied by orthogonal experiment and regression analysis. The experimental results show that the H / D ratio and the rotary forging force are major factors affecting the density of the sintered powder compacts in the rotary forging process. The effect of the H / D ratio and the rotary forging force on the density were discovered. By determining both the density and the hardness of compacts, it was found that the density distributions show no difference from the hardness distributions and that the gradients of the density and the hardness in the axial direction are larger than those in the radial direction.

关键词： sintering powder compact rotary forging densification mechanical properties

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Simulation of cavitation in rotary valve of hydraulic power steering gear

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Science China(Technological Sciences) 2009年第11期52卷 3142-3148页

作者： LIU YaHui JI XueWu Department of Automotive Engineering Tsinghua UniversityBeijing 100084

Hydraulic power steering gear supplies assistant power by liquid stream. The stream will be changed greatly for the flow field formed by the rotary valve will vary during steering. And the change of the stream in this narrow field will (be big enough to) cause the fluctuation of the assistance power and noise of the steering gear. 3-D meshes of the flow field between the sleeve and the rotor of the valve with different structure parameters such as entry caliber and groove depth were set up and a general CFD code-Fluent was used to analyze the stream performance. The results including pressure and gas-phase's volume fraction were analyzed under certain operation flow rate. It was found that the entry caliber did not affect the operation pressure of the valve under the same flow rate but affected the gas-phase's volume fraction of the flow field, and so did the groove depth of the valve' sleeve and rotor. Many researches have pointed that the noise of steering valve is almost cavitation noise, that is, the gas-phase in the flow field has great correlation with rotary valve noise. Based on these analyses of the stream in the rotary steering valve, this paper gave suggestion that increasing entry caliber of the rotary valve and choosing appropriate groove depth will reduce the valve noise.

关键词： rotary valve computational fluid dynamic cavitation noise

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