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Methane Conversion Using Dielectric Barrier Discharge: Comparison with thermal process and Catalyst Effects

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Journal of Natural Gas Chemistry 2006年第2期15卷 87-92页

作者： Antonius Indarto Jae-Wook Choi Hwaung Lee Hyung Keun Song Korea Institute of Science and Technology Clean Technology Research CenterP.O. Box 131CheongryangSeoul 130-650Korea

The direct conversion of methane using a dielectric barrier discharge has been experimentally studied. Experiments with different values of flow rates and discharge voltages have been performed to investigate the effects on the conversion and reaction products both qualitatively and quantitatively. Experimental results indicate that the maximum conversion of methane has been 80% at an input flow rate of 5 ml/min and a discharge voltage of 4 kV. Experimental results also show that the optimum condition has occurred at a high discharge voltage and higher input flow rate. In terms of product distribution, a higher flow rate or shorter residence time can increase the selectivity for higher hydrocarbons. No hydrocarbon product was detected using the thermal method, except hydrogen and carbon. Increasing selectivity for ethane was found when Pt and Ru catalysts presented in the plasma reaction. Hydrogenation of acetylene in the catalyst surface could have been the reason for this phenomenon as the selectivity for acetylene in the products was decreasing.

关键词： plasma dielectric barrier discharge thermal process methane conversion catalyst

Numerical simulation of dynamic thermal process during doublesided asymmetrical TIG backing welding of large thick plates

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China Welding 2011年第1期20卷 44-48页

作者：刘殿宝赵慧慧李福泉张广军吴林 Zhang Guangjun and Wu Lin National Key Laboratory of Science and Technology on Precision Heat Processing of Metals Harbin Institute of Technology Harbin 15000

The dynamic thermal process during double-sided asymmetrical TIG backing welding of large thick plates （ 1 000 mm×700 mm×50 mm） is numerically simulated using MSC. MARC. The effect of arc distance on the thermal cycle in weld zone during double-sided asymmetrical T1G backing welding is investigated. The results show that the workpiece experiences double-peak thermal cycle in double-sided asymmetrical TIG backing welding. On the one hand, the fore arc has the pre- heating effect on the rear pass, and the pre-heating temperature depends on the distance between the double arcs, the heat input of fore arc, and the initial temperature of workpiece. On the other hand, the rear arc has the post-heating effect on the fore pass. The mutual effects of two heat sources decrease with the increase of arc distance.

关键词： numerical simulation double-sided asymmetrical TIG backing welding thermal process double heat sources on double sides

Model Identification of Typical thermal process in thermal Power Plant Based on PSO-CS Fusion Algorithm

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维普期刊数据库

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Model Identification of Typical Thermal Process in Thermal P...

Nanocrystalline ZrO_2 preparation and kinetics research of phase transition

第30届中国控制与决策会议

作者： Congzhi Huang Tianyang Zhang Xuanju Dang Hui Jiang School of Control and Computer Engineering North China Electric Power University Colleges and Universities Key Laboratory of Intelligent Integrated Automation Guilin University of Electronic Technology

The model identification issue of typical thermal process in a thermal power plant is investigated in the paper. It is crucial to further develop the PID controller parameters tuning approach or designing various advanced control laws. A CS-PSO fusion identification algorithm is proposed to identify the optimal model of the thermal process based on the process input and output data. In the algorithm, the conventional particle swarm optimization algorithm is employed to identify the model parameters of the typical thermal process, where the cuckoo searching algorithm is used to optimize its velocity parameters, and thus the identification accuracy is improved. The effectiveness of the proposed approach is validated by the extensive simulation results about the ultra supercritical unit and the circulating fluidized bed thermoelectric unit.

关键词： thermal process thermal Power Plant Transfer Function Model Identification PSO-CS Fusion Algorithm

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cnki会议

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Rare Metals 2012年第1期31卷 51-57页

作者： Wu, Wenwei Cai, Jinchao Wu, Xuehang Li, Yongni Liao, Sen School of Chemistry and Chemical Engineering Guangxi University Nanning 530004 China

The precursor of nanocrystalline ZrO2 was synthesized by solid-state reaction at low heat using ZrOCl2·8H2O, and Na2CO3·10H2O as raw materials. The nanocrystalline ZrO2 was obtained by calcining the precursor. The precursor and its calcined products were characterized using TG/DTA, FT-IR, XRD, and SEM. The results showed that the precursor dried at 353 K was a zirconyl carbonate compound. When the precursor was calcined at 673 K for 150 min, highly crystallization ZrO2 with tetragonal structure (space group P42/nmc (137)) was obtained with a crystallite size of 24 nm. However, when the precursor was calcined at 1023 K for 150 min, highly crystallization ZrO2 with monoclinic structure (space group P21/c(14)) was obtained with a crystallite size of 20 nm. The mechanism and kinetics of the thermal process of the precursor were studied using DTA and XRD techniques. Based on the Kissinger and Arrhenius equation, the values of the activation energies associated with the thermal process of the precursor were determined to be 26.80 and 566.73 kJ·mol−1 for the first and third steps, respectively. The mechanism of ZrO2 phase transition from tetragonal to monoclinic structure is the random nucleation and growth of nuclei reaction.

关键词： inorganic compounds nanocrystalline thermal process kinetics solid-state reaction at low heat

HEAT TRANSFER ANALYSIS DURING ROLLING OF THIN SLAB IN CSP

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Acta Metallurgica Sinica(English Letters) 2006年第4期19卷 244-250页

作者： W.F. Wu Y.H. Feng X.X. Zhang Inner Mongolia University of Science and Technology Baotou 014010 China University of Science and Technology Beijing Beijing 100083 China

A mathematical model has been built to numerically predict the thermal history of thin slab during CSP （compact strip process） rolling. To estimate the temperature distribution in the slab mare accurately, the mathematical model combines heat transfer in the slab, in the roll, and at the roll-slab interface during bite. The numerical results agree with on-site running data, which proves the reliabili~, of the mathematical model. The results show that roll chilling has a significant effect on the temperature distribution in the slab.

关键词： numerical simulation heat transfer CSP（compact strip process） rolling thermal process