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Wang F.,Chinese Academy of Sciences | Yang J.-H.,Beijing Guodian Longyuan Environmental Engineering Co. | Li J.-T.,CAS Technical Institute of Physics and Chemistry
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2016

Si3N4 powder was fabricated by combustion synthesis using pelletized Si/Si3N4 reactant under a relatively low N2 pressure of 2.0 MPa. Relations between raw pellet sizes with porosity of green body and processing parameters of combustion synthesis were studied. The results indicate that the combustion mode using palletized materials is a two-step reaction. The porosity of reactant compacts, combustion temperature and propagation velocity of combustion waves can be controlled by DS/DL, which can improve the loading and nitriding rate of combustion synthesis. © 2016, Chinese Ceramic Society. All right reserved.

Nie F.,Dalian University of Technology | He D.,Dalian University of Technology | Guan J.,Dalian University of Technology | Bao H.,Dalian University of Technology | And 4 more authors.
Energy and Fuels | Year: 2017

The influence of temperature on the product distributions of oil sand fast pyrolysis was studied by a combined pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS) technique. Characteristics of the organic structure in bitumen deduced from the pyrolytic products and given by 1H/13C nuclear magnetic resonance (NMR) spectrometry were compared as well. The oil sand sample was pyrolyzed at temperatures from 300 to 650°C in intervals of 50°C in an inert atmosphere (helium gas), and more than 200 types of compounds were detected, including carbon dioxide, aliphatics (alkanes, cycloalkanes, olefins, dialkenes, cycloolefins), aromatics (alkyl benzenes, alkyl naphthalenes, alkyl indenes), oxygen-containing compounds, and sulfur-containing compounds. From the evolution of the product yields, it was clearly observed that temperature affected both the primary and secondary reactions during fast pyrolysis. Major thermal cracking took place until about 400°C, as evidenced by a dramatic increase in product species and yields. However, temperatures higher than 600°C were beneficial for generating smaller molecules as products. Among the pyrolytic products, alkanes and olefins were predominant and were mainly derived from the thermal cracking of abundant polymethylene substituents linking to the aromatic cores. It was found that the yields of alkanes and olefins decreased with increasing carbon number, and more olefins were generated at higher temperatures. Monoaromatics with more alkyl or alkenyl multisubstituent groups appeared above 400°C, but the substituent groups were no longer than isopropyl. In the range of 300-650°C, few polycyclic aromatic hydrocarbons were observed. Higher temperatures also obviously enriched the species of naphthalene, indene, and compounds with heteroatoms. In addition, the raw aliphatic sulfur in the sample tended to be converted into sulfur-containing heterocycles during fast pyrolysis in an inert atmosphere. The results of this study show that both the NMR and Py-GC/MS methods can provide information on the organic structures in oil sand. However, NMR spectrometry is able to present an overview of the structure of hydrocarbons, whereas Py-GC/MS can help to deduce some characteristics of the macromolecules in oil sand organics. © 2017 American Chemical Society.

Peng Y.,Tsinghua University | Li J.,Tsinghua University | Huang X.,Tsinghua University | Li X.,Tsinghua University | And 4 more authors.
Environmental Science and Technology | Year: 2014

A series of V2O5/CeO2 catalysts with different potassium loadings were prepared to investigate alkali deactivations for selective catalytic reduction of NOx with NH3. An alkali poisoning mechanism could be attributed to surface acidity, reducibility, and NOx adsorption/desorption behaviors. The detailed factors are as follows: (1) decrease of surface acidity suppresses NH3 adsorption by strong bonding of alkali to vanadia (major factor); (2) low reducibility prohibits NH3 activation and NO oxidation by formation bonding of alkali to vanadia and ceria (important factor); (3) active NOx - species at low temperature diminish because of coverage of alkali on the surfaces (minor factor); and (4) stable, inactive nitrate species at high temperature increase by generating new basic sites (important factor). © 2014 American Chemical Society.

Ting S.,Harbin Institute of Technology | Chao L.,Harbin Institute of Technology | Weilin L.,Harbin Institute of Technology | Chenhua D.,Harbin Institute of Technology | Kunpeng M.,Beijing Guodian Longyuan Environmental Engineering Co.
Conference Proceedings - 2012 IEEE 7th International Power Electronics and Motion Control Conference - ECCE Asia, IPEMC 2012 | Year: 2012

This paper aims to verify the effectiveness of parabolic approximate models for the solid phase diffusion process under the batteries actual discharge conditions. Choosing 1C, 4C constant current and FUDS discharge conditions, two-parameter, three-parameter parabolic approximate model and theory numerical algorithm are conducted to simulate the solid phase surface concentration curve in Maple environment after obtaining the reaction ion flux density jp curve of particle surface at the separator/cathode interface by COMSOL. The result shows that parabolic approximate model is effective when applied to the simulation of the solid phase diffusion process, and three-parameter model is better than two-parameter model in terms of tracking ability for dynamic loads. © 2012 IEEE.

Ruan M.,Dalian University of Technology | Guan J.,Dalian University of Technology | He D.,Dalian University of Technology | Meng T.,Beijing Guodian Longyuan Environmental Engineering Co. | Zhang Q.,Dalian University of Technology
RSC Advances | Year: 2015

Ni2P/CNTs was synthesized using an impregnation method. XPS revealed that CNTs could affect the electronic properties of bulk Ni2P. The catalyst shows superior activity for HYD of naphthalene with a conversion of 99%, and demonstrates superior tolerance towards potential catalyst poisons, which is higher than Ni/CNTs with a conversion of 89%. © The Royal Society of Chemistry 2015.

Yao X.,Beijing Guodian Longyuan Environmental Engineering Co. | Shen B.,Beijing Guodian Longyuan Environmental Engineering Co. | Zheng P.,Beijing Guodian Longyuan Environmental Engineering Co. | Zheng W.,Beijing Guodian Longyuan Environmental Engineering Co.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2013

Urea hydrolyser is an important device for power plants choosing urea as a primary reactant in flue gas denitration. According to literature surveys and theory analyses on the chemical reaction, this study analyzed the influence of feed concentration and operation conditions on the hydrolytic production. Meanwhile, the kinetic empirical formula of the reaction was obtained (frequency factor A 8.23×1011, while activated energy equals to 98.09 kJ/mol). Kinetic characteristics together with phase-equilibrium model were utilized to simulate the behavior of an imported hydrolyser. The calculation result was well accorded with the operation history, verifying the reliability of the analysis. The conclusion can be used as the guideline to the research and design of domestic hydrolyser for DeNOx projects in China.

Zheng P.,Beijing GUODIAN Longyuan Environmental Engineering Company Ltd | Yao X.,Beijing GUODIAN Longyuan Environmental Engineering Company Ltd | Zheng W.,Beijing GUODIAN Longyuan Environmental Engineering Company Ltd
Frontiers in Energy | Year: 2013

Ammonia is highly volatile and will present substantial environmental and operation hazards when leaking into the air. However, ammonia is the most common reactant in the DENOX project to eliminate NOx in the flue gas. The storage and transportation of liquid ammonia has always been a dilemma of the power plant. Urea is a perfect substitute source for ammonia in the plant. Urea hydrolysis technology can easily convert urea into ammonia with low expense. Presently, there is still no self-depended mature urea hydrolysis technology for the DENOX project in China; therefore, this paper proposes several guidelines to design the urea hydrolyser by theoretical analysis. Based on theoretical analysis, a simulation model is built to simulate the chemical reaction in the urea hydrolyser and is validated by the operational data of the commercial hydrolyser revealed in the literature. This paper endeavors to propose suggestions and guidelines to develop domestically urea hydrolysers in China. © 2013 Higher Education Press and Springer-Verlag Berlin Heidelberg.

Guo T.-T.,Beijing Guodian Longyuan Environmental Engineering Co. | Wu D.-W.,Datang Shandong Renewable Power Co. | Wang C.-Y.,Datang Shandong Renewable Power Co. | Li S.-H.,Northeast Dianli University
Dongli Gongcheng Xuebao/Journal of Chinese Society of Power Engineering | Year: 2010

Four different sizes of pre-bend designs were performed for a 1.2 MW wind turbo-generator blade. While numerical simulation was made for its flow field using SST κ-ω turbulence models, during which the influence of pre-bending size on wind turbo-generator power output was obtained, and thus an appropriate pre-bending size was determined. Results show that the wind turbo-generator power output reduces nonlinearly with growing pre-bending size, and the pre-bending profile can effectively regulate the wind turbo-generator power output when wind speed changes. For a pre-bending size of 0.6 m, the design power of 1.2 MW can be reached with only a relative error of 0.0006%. However, the interaction induced by blade rotation is inevitable.

Song B.,University of Science and Technology Beijing | Sheng Z.-H.,University of Science and Technology Beijing | Sheng Z.-H.,Hebei University of Engineering | Xu M.-L.,Beijing Guodian Longyuan Environmental Engineering Co. | Wang L.,Beijing Guodian Longyuan Environmental Engineering Co.
Beijing Keji Daxue Xuebao/Journal of University of Science and Technology Beijing | Year: 2010

The simulated earthquake experimental study on a large desulfurization tower was carried out using shaking table test. A 1:15 reduced-scale thin-walled steel structure model of the desulfurization tower was designed for testing and the dynamic responses of the model were discussed. The responses of peak acceleration were studied under a sine wave, Tianjin wave and Hyuga seismic wave in various angles and the most unfavorable input angle was analyzed. The results show that the influence of the input angle of an excitation wave can not be ignored, the maximum influence is in the direction of 30° and the minimum is in the direction of 60°. The complexity of the thin-wall desulfurization tower can affect the dynamic characteristics of the structure to a great extent. The weight of the tower top is one of the main factors causing the distribution of peak acceleration uneven in tower height.

Guo T.,Beijing Guodian Longyuan Environmental Engineering CO. | Wu D.,Northeast Dianli University | Zhang Q.,Northeast Dianli University | Li S.,Northeast Dianli University
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | Year: 2011

In this paper, blades of a 1.2MW wind turbine were designed based on MATLAB programming by using the preflex method. Four blades were respectively designed by un-bended, and with the preflex sizes being 0.3, 0.6 and 0.9 meters, and the SST k-ω turbulence model was adopted to simulate them. The optimum preflex size of the blade was selected after comparing the effects of the preflex sizes on the output power. The results shown that: the output power of un-bended turbine is larger than design power and the relative error is 2.48%, the 0.9 meter's output is less than design power with the relative error of 3.9%, and the 0.6 meter's output approaches the design power with the relative error of 0.0006%. The output power of the wind turbine decreases following with the increase of the preflex sizes, and the characteristics is not linear.

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