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On a general theory for compressing process and aeroacoustics:linear analysis

Acta Mechanica Sinica 2010年第3期26卷 355-364页

作者： E .Mao Y. P. Shi J. Z. Wu State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University 100871 Beijing China University of Tennessee Space Institute Tullahoma TN 37388 USA

Of the three mutually coupled fundamental processes （shearing, compressing, and thermal） in a general fluid motion, only the general formulation for the compress- ing process and a subprocess of it, the subject of aeroacous- tics, as well as their physical coupling with shearing and thermal processes, have so far not reached a consensus. This situation has caused difficulties for various in-depth complex multiprocess flow diagnosis, optimal configuration design, and flow/noise control. As the first step toward the desired formulation in fully nonlinear regime, this paper employs the operator factorization method to revisit the analytic linear theories of the fundamental processes and their decomposi- tion, especially the further splitting of compressing process into acoustic and entropy modes, developed in 1940s-1980s. The flow treated here is small disturbances of a compressible, viscous, and heat-conducting polytropic gas in an unbounded domain with arbitrary source of mass, external body force, and heat addition. Previous results are thereby revised and extended to a complete and unified theory. The theory pro- vides a necessary basis and valuable guidance for developing corresponding nonlinear theory by clarifying certain basic issues, such as the proper choice of characteristic variables of compressing process and the feature of their governing equations.

关键词： Longitudinal （compressing） processTransversal （shearing） process Acoustic mode Entropy mode Aeroacoustics

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Thermodynamic model of sulphide capacity in CaO-SiO2-MgO-Al2O3 ironmaking slags

Beijing Keji Daxue Xuebao/Journal of University of Science a...

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Beijing Keji Daxue Xuebao/Journal of University of Science and Technology Beijing 2011年第9期33卷 1079-1084页

作者： Zhang, Meng Guo, Han-Jie Ding, Ru-Cai Wang, Xiao-Dong Shi, Cheng-Bin Yang, Xue-Min School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China State Key Lab. of Multiphase Complex Systems Institute of Process Engineering Chinese Acad. of Sci. Beijing 100190 China Shougang Qinhuangdao Metal Material Co. Ltd. Qinhuangdao 066326 China

A prediction model of sulphide capacity in CaO-SiO2-MgO-Al2O3 slag systems was developed based on the ion and molecule coexistence theory (IMCT) of slags, i.e., IMCT-CS2- model. The predicted sulphide capacity by the IMCT-CS2- model was compared with the measured one from experiments and the predicted one by other five prediction models of sulphide capacity. The predicted sulphide capacity of CaO-SiO2-MgO-Al2O3 slags at 1 773 K by the developed IMCT-CS2- model has a higher accuracy than the measured one as well as the predicted one by other sulphide capacity models. The developed IMCT-CS2- model can calculate not only the total sulphide capacity of the slags but also the respective sulphide capacity of free CaO and MgO in the slags. Increasing the Al2O3 content from 10% to 17%, increasing the CaO content from 38% to 44% and decreasing the MgO content from 12% to 4% can improve the contribution ratio of free CaO from 97% to 99 % and decrease the contribution ratio of free MgO from 3% to about 1% to the total sulphide capacity of CaO-SiO2-MgO-Al2O3 slags.

关键词： Aluminum oxide

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Effect of acidic surface functional groups on Cr(Ⅵ) removal by activated carbon from aqueous solution

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Rare Metals 2010年第3期29卷 333-338页

作者： ZHOU Hualei CHEN Yunfa School of Applied Sciences University of Science and Technology Beijing Beijing 100083 China State Key Laboratory of Multi-phase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China

The activated carbon with high surface area was prepared by KOH *** was further modified by H2SO4 and HNO3 to introduce more surface functional *** pore structure of the activated carbons before and after modification was analyzed based on the nitrogen adsorption *** morphology of those activated carbons was characterized using scanning electronic microscopy （SEM）.The surface functional groups were determined by Fourier transform infrared spectroscopy （FTIR）.The quantity of those groups was measured by the Boehm titration ***（VI） removal by the activated carbons from aqueous solution was investigated at different pH *** results show that compared with H2SO4,HNO3 destructs the original pore of the activated carbon more seriously and induces more acidic surface functional groups on the activated *** pH value of the solution plays a key role in the Cr（VI） *** ability of reducing Cr（VI） to Cr（III） by the activated carbons is relative to the acidic surface functional *** higher pH values,the Cr（VI） removal ratio is improved by increasing the acidic surface functional groups of the activated *** lower pH values,however,the acidic surface functional groups almost have no effect on the Cr（VI） removal by the activated carbon from aqueous solution.

关键词： activated carbon surface functional groups removal modification chromium（VI）

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A Novel Method of Recycling CO_2 for Slag Splashing in Converter

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Journal of Iron and Steel Research International 2010年第12期17卷 11-16页

作者： ZHAO Hong-xin YUAN Zhang-fu WANG Wen jing PAN Yi-fang LI Shu-qing State Key I.aboratory of Multiphase and Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China College of Engineering Peking University Beijing 100871 China Graduate University Chinese Academy of Sciences Beijing 100049 China Tianjin Iron and Steel Group Co Ltd Tianjin 300301 China

Converter off-gas, an important energy resource for steel industries, is one of the weak points in the recov ery and utilization of secondary energy resources. To improve the level of recycling converter off-gas in steel plants, a novel approach to the recycle of CO2 separated from converter off-gas or other off-gas for the green slag splashing technique was developed, and the CO2 equilibrium conversion ratio of the green CO2 slag splashing under different technological conditions was calculated by the program of enthalpy （H）, entropy （S）, and heat capacity （C）, i.e. HSC software. Furthermore, the experiments of CO2 injected into molten converter slag were carried out, and the influencing factors of the green slag splashing technique using CO2 were analyzed. The experimental results showed that the carbon content for smooth slag splashing using COs was about 4.0%.

关键词： converter slag converter off-gas slag splashing CO2

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Crystallization behavior of zeolite beta from acid-leached metakaolin

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Petroleum Science 2010年第4期7卷 541-546页

作者： Li Qiang Zhang Ying Cao Zhijun Gao Wei Cui Lishan Department of Materials Science and Technology China University of Petroleum Beijing 102249 China National Key Laboratory of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China Microstructure Laboratory for Energy Materials China University of Petroleum Beijing 102249 China

Well-crystallized zeolite beta was synthesized by using acid-leached metakaolin as the silica-alumina source and tetraethylammonium hydroxide structure-directing *** influence of the composition of the reaction mixture on product crystallinity was investigated,and the crystallization process was studied by examining solid samples obtained at different synthesis *** showed that the acid-leached metakaolin was fully converted into soluble aluminum and silicon species,which is crucial for the formation of well-crystallized zeolite *** the beginning of the crystallization process,these soluble aluminum and silicon species formed a aluminum-rich intermediate structure with layer *** the crystallization proceeding,more silicon species were incorporated into the zeolite beta framework and the layered structure was changed into spherical particles of zeolite beta with high SiO 2 /Al 2 O 3 ratio and crystallinity.

关键词： Zeolite beta acid-leached metakaolin tetraethylammonium hydroxide （TEAOH） liquid phase transformation mechanism

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Influence of synthesis parameters on the crystallinity and Si/Al ratio of NaY zeolite synthesized from kaolin

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Petroleum Science 2010年第3期7卷 403-409页

Well-crystallized high-silica NaY zeolites （Si/Al〉2.5） were prepared from a reaction mixture consisting of metakaolin, sodium silicate solution and seed solution via optimization of the mixture composition and reaction conditions. The transformation from kaolin to high-silica NaY zeolite was confirmed by XRD, SEM and IR techniques. Subsequently, the influence of synthesis parameters, i.e. initial SIO2/Al2O3, initial Na2O/SiO2, initial H2O/SiO2, aging time of the seed solution, crystallization temperature and crystallization time, on the NaY growth was investigated in terms of crystallinity and Si/Al ratio. The results showed that the effects of initial SiO2/Al2O3, initial Na2O/SiO2 and initial H2O/ SiO2 on the crystaIlinity and Si/Al ratio of NaY zeolite are similar to those observed in the conventional syntheses of NaY zeolites only using sodium silicate solution as silicon source. However, due to the use of metakaolin as the main silicon and aluminum sources in the present study, a long crystallization induction period of 20 h was achieved, which can be attributed to the dissolution of metakaolin. In addition, different from the conventional syntheses of zeolite NaY, pure NaY zeolites （i.e. without NaP zeolite impurity） were still obtained even at 120℃ because of the use of a large quantity of seed solution （23 wt%） in the reaction mixture. As the aging time of the seed solution increased from 3.5 h to 22 h, the relative crystallinity of the NaY zeolite first increased sharply and then reached a plateau, while the Si/Al ratio first increased rapidly up to a maximum value of 2.75 corresponding to an aging time of 6.5 h, and then decreased sharply with the aging time.

关键词： Kaolin NaY zeolite high-silica seed solution aging time crystallinity

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A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO_4-H_2O and NaF-H_2O binary solutions and NaClO_4-NaF-H_2O ternary solution

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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 546-557页

作者： Xue-min Yang Wei-jie Zhao Han-jie Guo Qiang Zhang Jian Zhang State Key Lab of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Metallurgical Equipment Research ＆ Design Corporation Ltd. China Metallurgical Group Corporation Beijing 100029 China

A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions and NaClO4-NaF-H2O ternary strong electrolyte aqueous solutions was developed based on the ion and molecule coexistence theory （IMCT）. A transformation coefficient was needed to compare the calculated mass action concentration and the reported activity, because they were usually obtained at different standard states and concentration units. The results show that transformation coefficients between the calculated mass action concentrations and the reported activities of the same components change in a very narrow range. The transformed mass action concentrations of structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions agree well with the reported activities. The transformed mass action concentrations of structural units or ion couples in NaClO4-NaF-H2O ternary solution are also in good agreement with the reported activities in a total ionic strength range from 0.1 to 0.9 mol/kg H2O by the 0.1 mol/kg step with different ionic strength fractions of 0, 0.2, 0.4, 0.5, 0.6, 0.8, and 1, respectively. The results indicate that the developed thermodynamic model can reveal the structural characteristics of binary and ternary strong electrolyte aqueous solutions, and the calculated mass action concentrations of structural units or ion couples also strictly follow the mass action law.

关键词： binary systems ternary systems thermodynamic model activity coefficient structural unit

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On the in vitro hyperthermia of magnetic fluid in AC magnetic field

On the in vitro hyperthermia of magnetic fluid in AC magneti...

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ASME 2009 Micro/Nanoscale Heat and Mass Transfer International Conference 2009, MNHMT2009

作者： Junfeng, Jiang Ruoyu, Hong Xiaohui, Zhang Hongzhong, Li College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou Jiangsu province China State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Beijing China Department of Physics Soochow University Suzhou Jiangsu province China

ISBN: (纸本)9780791843895

Hyperthermia therapy for cancer has attracted much attention nowadays. The study on the heat transfer in the magnetic fluid and the tumor is crucial for the successful application of magnetic fluid hyperthermia (MFH). Water-based Fe304 magnetic fluid is expected to be a most appropriate candidate for MFH due to the good biocompatibility, high saturation magnetization, super-paramagnetization and high chemical stability. In this paper, we explore the heat generation and transfer in magnetic fluid which is placed under an AC magnetic field. It is found that the amplitude and the frequency of alternating magnetic field, particle size and volume fraction have a pronounce influence on maximum temperature of hyperthermia. Copyright © 2009 by ASME.

关键词： Magnetic fluids

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Adsorption and diffusion behaviors of methane and carbon dioxide on various rank coals

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Meitan Xuebao/Journal of the China Coal Society 2011年第10期36卷 1693-1698页

作者： Zhang, Deng-Feng Cui, Yong-Jun Li, Song-Geng Song, Wen-Li Lin, Wei-Gang State Key Laboratory of Multi-Phase Complex Systems Institute of Process Engineering Chinese Acad. of Sci. Beijing 100190 China Graduate University Chinese Acad. of Sci. Beijing 100049 China Beijing Research Institute China Shenhua Coal to Liquid and Chemical Co. Ltd. Beijing 100011 China

The adsorption and diffusion behaviors of methane(CH4)and carbon dioxide(CO2)on various rank coals were investigated with a volumetric method at temperature range from 35°C to 65°C and a pressure of 1.4 MPa. The experimental results show that the second Fick's Law can well describe the diffusion behaviors of CH4 and CO2 on various rank coals under the experimental conditions. The effective diffusivities of CH4 and CO2 increase with an increase of temperature and present a U-shaped trend with coal rank, which is indicated by maximum vitrinite reflectance coefficient, Ro, max. The effective diffusivity of CO2 is larger than that of CH4 under the same conditions. The diffusion of CH4 and CO2 on various rank coals is mainly dependent on surface diffusion in micropore.

关键词： Diffusion

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NO reduction over biomass char in the combustion process

NO reduction over biomass char in the combustion process

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作者： Dong, Li Gao, Shiqiu Xu, Guangwen State Key Laboratory of Multi-Phase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

In the biomass combustion process, fuel N in biomass can be oxidized into NOx, causing acid rain and photochemical smog. Some measures should be taken to control NOx emissions from biomass combustion. In this paper, NO reduction over rice husk char in the combustion process was studied in a fixed-bed reactor to optimize the biomass combustion process. The results showed that biomass char was more active in the presence of oxygen to reduce NO than it was in the inert atmosphere. With the increase of oxygen, moreNOcan be reduced by biomass char. From 973 to 1173 K,NOreduction over rice husk char increased with increasing temperature, whereas the difference between NO reduction with and without oxygen decreased with increasing temperature. Moreover, the presence of CO and SO2 in the combustion process was shown to enhance NO reduction over biomass char to different degrees. Therefore, it is an effective way to reduce NO from biomass combustion by emphasizing NO reduction over biomass char. © American Chemical Society.

关键词： Oxygen

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