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Wang X.-J.,Tianjin University | Liu Y.-Q.,Tianjin University | Huang Y.-P.,China Construction Installation Engineering Co. | Ma D.-Y.,Tianjin University | And 3 more authors.
Huaxue Gongcheng/Chemical Engineering (China) | Year: 2017

A new continuous polysilicon slurry dryer with a cone and ribbons was designed. The fluid flow and particle track were simulated by Fluent and proved by experiment. The result shows that the simulation method in fluid flow and particle track (DPM) and UDF code are correct. Tracked particle's residence time in cone is 15.8%-25.4% of it in outer cylinder, cone extended slurry's residence time. The rotational structure composed of cone, spoke and ribbon can push the fluid to move: one is axial movement to the exit; the other is the rotary motion along the walls. This movement can form whirlpools and then strengthen heat transfer, and the intensive degree increased with the increase of rotating speed. And inlet velocity had little influence on flow field, it can only affect the flow capacity: the residence time became shorter when the inlet velocity increased, so the drying level decreased. © 2017, Editorial Office of "CHEMICAL ENGINEERING"(CHINA). All right reserved.

Liu Y.,Tianjin University of Technology | Jia S.-Y.,Tianjin University | Wu S.-H.,Tianjin University | Li P.-L.,Tianjin University | And 4 more authors.
Catalysis Communications | Year: 2015

Highly dispersed metallic nanoparticles immobilizing inside the pores of MIL-101(Cr) were prepared using double solvent method (DSM). The particle size of Au, Ag, Pd, and AuPd NPs were 2.9 ± 0.7 nm, 1.9 ± 0.6 nm, 2.1 ± 0.6 nm and 2.8 ± 0.7 nm, respectively. The catalytic activity determined by the reduction of p-nitrophenol by NaBH4 to p-aminophenol of Pd and AuPd prepared by DSM is 9.6 and 8.3 times higher than that of Pd and AuPd prepared by conventional impregnation method. The structure and activity of the catalysts prepared by DSM have no significant changes after three cycles. © 2015 Published by Elsevier B.V.

Gao Y.,Jiangsu Huayi Technology Co. | Xu Z.,Jiangsu Huayi Technology Co. | Wu K.,Tsinghua University | Wang X.,China Construction Installation Engineering Co. | And 2 more authors.
Chinese Journal of Chemical Engineering | Year: 2016

Accurate simulation of water distillation system for oxygen-18 (18O) isotope separation is necessary to guide industrial practice, since both deuterium (D) and oxygen-18 isotope get enriched and interfere with each other. In the present work, steady-state and dynamic distillation models are established based on a classic method and a cascade distillation system with 5 towers is introduced to test the models. The theoretical expressions of separation factor α H/D for protium/deuterium and separation factor α 16O/18O.for oxygen-16/oxygen-18 were derived, with the existence of deuterium and oxygen-18, respectively. The results of the steady-state simulation by the classical method proposed in the present work agreed well with the results of the lumping method. The dynamic process could be divided into 5 stages. Impressively, a peak value of product withdraw was observed before the final steady state, which was resulted from the change of 16O/18O separation factor and isotope distribution. An interesting low concentration zone in the towers of T2-T5 existed at the beginning of the dynamic process and it required industrial evidence. © 2016 Elsevier B.V.

Wang H.,Harbin Institute of Technology | Qian H.,Harbin Institute of Technology | Fan F.,Harbin Institute of Technology | Zhang F.,Harbin Institute of Technology | And 3 more authors.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2014

Key issues in construction process of hyper-hemispherical single-layer spherical shell in Hangzhou International Expo Center were investigated. According to the structural features and construction requirements, the sub-section or sub-block installing construction scheme was adopted, and the mechanical properties of standard unit in the lifting process were analyzed. The construction simulation model of the whole structure was established with the developed simulation technique of the construction full-process. The full-process analysis of installing and uninstalling schemes was carried out for obtaining the mechanical response law. The results indicate that stress levels of hoisting units are relatively low and components have elastic deformation during the hoisting process, both of which can guarantee the construction safety and assembly accuracy. In the process of assembling and uninstalling, the maximum stress ratio is less than 0.3, and deformation can meet the requirements of related specification. The construction schemes are reliable. The results can not only provide the theoretical guidance of construction safety and precision control, but also accumulate experience for the construction.

Fan F.,Harbin Institute of Technology | Wang Z.,Harbin Institute of Technology | Wang H.,Harbin Institute of Technology | Qian H.,Harbin Institute of Technology | And 3 more authors.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2014

By comparing several erection methods of streamer grid structure of Hangzhou International Expo Center, the structure division erection scheme was determined. Hoisting state of block element was simulated in static analysis method. The analysis model for hoisted structure division unit, which is based on the principle of the coincidence between the center of gravity and the intersection of hoisting points, was established to obtain structure response under the condition of different hoisting points or cable length. Furthermore, reasonable hoisting scheme was obtained based on stress ratio, vertical displacement of node, cable length and cable force. The results of analysis indicate that both force and definition methods of calculating center of gravity position are viable and which one to be used depends on the construction situation. The hoisting point position should be arranged evenly around the center of gravity. The cable length can be determined by construction condition.

Zhou X.,Tianjin University | Wang X.,Tianjin University | Zhu C.,Tianjin University | Ma Y.,Tianjin University | Xu Y.,China Construction Installation Engineering Co.
Huagong Xuebao/CIESC Journal | Year: 2016

A high-speed camera was used to investigate the mass transfer process of CO2 chemical absorption into diethanolamine (DEA)/ethanol solution in microchannel. The volume evolution of the bubbles in the microchannel was obtained by the image-analysis method. By means of the gas pressure at the inlet and outlet of the microchannel, the average mass transfer coefficient (k) from the contact of two phases to equilibrium was attained. The influences of flow rates of gas and liquid and DEA concentration on the mass transfer coefficient were investigated. The experiment results indicated that k increased with increasing liquid flow rate and DEA concentration. For a given liquid flow rate and DEA concentration, k increased gradually up to a constant value with increasing gas phase flow rate. A correlation for estimating k was proposed and the calculated values by the present model agreed well with the experimental data. © All Right Reserved.

Wang X.-J.,Tianjin University | Sun Q.-M.,Tianjin University | Huang Y.-P.,China Construction Installation Engineering Co. | Chen Z.,China Construction Installation Engineering Co. | And 2 more authors.
Huaxue Gongcheng/Chemical Engineering (China) | Year: 2015

The flow field and temperature field of bellows with twisted tape inserts were investigated using FLUENT under various configuration and operation parameters. The fitting formulas were obtained based on the simulation results. Compared with smooth tube and normal bellows for Reynolds numbers between 5600 and 57000, the Nusselt number increased by 80%-239% and 5.3%-44%, friction factor by 661%-890% and 70%-168%, respectively. The thermal-hydraulic performance PEC-1 was in the range of 0.897-1.726, decreasing with larger Reynolds number. When twisted ratio was 4, bellows with twist tape inserts had better performance compared with other twisted ratios, and best performance appeared when Reynold number was 6000. ©, 2015, Editorial Office of Chemical Engineering (China). All right reserved.

Chen Y.,Zhejiang University | Xu Y.,China Construction Installation Engineering Co. | Cheng D.-G.,Zhejiang University | Chen Y.,China Construction Installation Engineering Co. | And 4 more authors.
Journal of Chemical Technology and Biotechnology | Year: 2015

BACKGROUND: The synthesis of C2-C4 hydrocarbons from coal or biomass-derived syngas has received increasing attention because of the resource constraints of petroleum. The present study explores direct production of hydrocarbons from syngas over bifunctional catalyst containing methanol synthesis catalyst CuO-ZnO-Al2O3 (CZA) and SAPO-34 zeolite. RESULTS: The synthesis of C2-C4 hydrocarbons from syngas was investigated over CZA/SAPO-34 bifunctional catalyst at temperatures ranging from 240 to 440°C. The results indicate that higher temperatures aggregate Cu metal and lead to the deactivation of CZA. The predominant products are dimethyl ether (DME) and methanol at temperatures from 280 to 360°C and a small amount of hydrocarbons are found due to the deactivation of SAPO-34 caused by a type of coke named 'inert coke'. While 96.5% selectivity of C2-C4 hydrocarbons in products of all hydrocarbons can be obtained at 400°C with less coke named 'active coke'. CONCLUSION: Reaction temperatures have significant effect on the selectivity of C2-C4 hydrocarbons and coke species of SAPO-34. The 'active coke' of poly methyl-substituted benzene/naphthalene (MB/MN) acts both as an intermediate and as coke deposition. The 'inert coke' of poly methyl-substituted adamantine (MA) and other groups-substituted benzene/naphthalene acts only as coke depositions. Comprehensive consideration of the characteristics of this bifunctional catalyst, shows that a moderate temperature for C2-C4 hydrocarbons synthesis from syngas might be approximately 400°C. © 2014 Society of Chemical Industry.

Yang W.-D.,China Construction Installation Engineering Co. | Zhong Q.,China Construction Installation Engineering Co. | Wang J.-B.,China Construction Installation Engineering Co.
Huaxue Gongcheng/Chemical Engineering (China) | Year: 2015

This paper is about the dimethyl succinate (DMS) purification process with heat-matching to use the heat evolution in hydrogenation, which is based on the product technology of dimethyl succinate by esterification method of maleic anhydride to further use C4 resource. Aspen Plus software was used to simulate the process, and the optimal results were as follows: the proper feed stage, the optimized reflux ratio and distillate rate were 5th stage, 7 and 19 kg/h for lights removal column; the proper feed stage, the optimized reflux ratio and distillate rate were 11st stage, 3 and 764 kg/h for refinery column; the purity (mass fraction) and recovery rate of dimethyl succinate can reach 99.9% and 99.8% respectively. Moreover, Aspen Dynamics software was used to investigate the dynamic performance of the purification process. The results show that the control system is effective to maintain process unit running smoothly by changing the operating conditions in 2-4 h, and a simple temperature control scheme is sufficient to ensure the purity and recovery rate of dimethyl succinate under the disturbances of feed flow rate and feed composition respectively. The steady and dynamic simulation results offer references for the industry design and actual operation of dimethyl succinate process. © 2015, Editorial Office of "CHEMICAL ENGINEERING" (China). All right reserved.

Zhang L.-X.,Northeastern University China | Fu J.-Y.,Northeastern University China | Jiang H.-T.,China Construction Installation Engineering Co. | Che L.-N.,Northeastern University China
Dongbei Daxue Xuebao/Journal of Northeastern University | Year: 2016

Focused on six regional central cities (RCCs) which play such roles as leading, radiation, distribution, an indicator system is constructed for evaluating RCCs' competitiveness of sci-tech human resources, and then the competitiveness is evaluated by using the analysis method of conforming to natural rules based on the individual advantages and characteristics, with the RCCs' competitiveness advantages and their ranking clarified. On the basis, the relevant government departments can develop sci-tech human resource planning and related policies to upgrade the competitiveness of sci-tech human resources of RCCs in China. © 2016, Editorial Department of Journal of Northeastern University. All right reserved.

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