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CFD simulation of effect of anode configuration on gas–liquid flow and alumina transport process in an aluminum reduction cell

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Journal of Central South University 2015年第7期22卷 2482-2492页

作者：詹水清李茂周孑民杨建红周益文 School of Energy Science and Engineering Central South University Zhengzhou Research Institute aluminum corporation of china Ltd.

Numerical simulations of gas–liquid two-phase flow and alumina transport process in an aluminum reduction cell were conducted to investigate the effects of anode configurations on the bath flow, gas volume fraction and alumina content distributions. An Euler–Euler two-fluid model was employed coupled with a species transport equation for alumina content. Three different anode configurations such as anode without a slot, anode with a longitudinal slot and anode with a transversal slot were studied in the simulation. The simulation results clearly show that the slots can reduce the bath velocity and promote the releasing of the anode gas, but can not contribute to the uniformity of the alumina content. Comparisons of the effects between the longitudinal and transversal slots indicate that the longitudinal slot is better in terms of gas–liquid flow but is disadvantageous for alumina mixing and transport process due to a decrease of anode gas under the anode bottom surface. It is demonstrated from the simulations that the mixing and transfer characteristics of alumina are controlled to great extent by the anode gas forces while the electromagnetic forces(EMFs) play the second role.

关键词： aluminum reduction cell anode configuration gas–liquid flow alumina transport process simulation alumina content distribution

Phase Behavior and Dew Point Pressure of Multicomponent Condensate Gas in Nanopores

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Fluid Dynamics & Materials Processing 2025年第2期21卷 279-292页

作者： Jichao Zhao Xu Yan Jing Sun Sheng Li Petroleum Engineering College Yangtze UniversityWuhan430199China Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering(Yangtze University) Wuhan430199China Exploration&Development Project Department of Mahu Area of Xinjiang Oilfield Company China National Petroleum CorporationKaramay834000China

Shale gas reservoirs typically contain numerous nanoscale pores,with pore size playing a significant role in influencing the gas *** better understand the related mechanisms,this study employs the Gauge-GEMC molecular simulation method to systematically analyze the effects of various pore sizes(5,10,20,and 40 nm)on the phase behavior and dew point pressure of the shale gas reservoir *** simulation results reveal that when pore sizes are smaller than 40 nm,the dew point pressure increases significantly as the pore size *** instance,the dew point pressure in 5 nmpores is 20.3%higher than undermacroscopic ***,larger hydrocarbon molecules exhibit a tendency to aggregate in smaller pores,particularly in the 5–10 nm range,where the relative concentration of heavy hydrocarbons(C_(4+))increases ***,as the pore size becomes larger,the component distribution gradually aligns with experimental results observed under macroscopic *** study demonstrates that pore effects are more pronounced for smaller sizes,directly influencing the aggregation of heavy hydrocarbons and the rise in dew point *** phenomena could significantly impact the diffusivity of shale gas reservoirs and the recovery of condensate *** findings provide new theoretical insights into phase behavior changes in nanopores,offering valuable guidance for optimizing shale gas reservoir extraction strategies.

关键词： Condensate gas nanopores molecular simulation dew point pressure confinement effect

Comprehensive Ecosystem Service Changes and Their Drivers in the Middle Reaches of Jinsha River

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Huanjing Kexue/Environmental Science 2025年第3期46卷 1585-1596页

作者： Zhang, Xiu Zhang, Xuan Cui, Lei Chen, Hao Song, Jia Wan, Fan Li, Chong College of Water Sciences Beijing Normal University Beijing100875 China china Renewable Energy Engineering Institute Beijing100120 China Northwest Engineering corporation Limited POWERCHINA Xi'an710065 China Shaanxi Union Research Center University and Enterprise for River and Lake Ecosystems Protection and Restoration Xi'an710065 China

Hydropower development is an important starting point for china to implement the dual carbon strategy in the energy field in the new era,and the influence mechanism of a large-scale hydropower development mode with ecological priority on watershed ecosystem service has become complicated. Therefore,exploing the ecosystem services change under the influence of hydropower development is highly important. As one of the frequent anthropogenic activity areas in southwest china,the investigation on the impact of hydropower development on ecosystem service is developing from single factor and single process to multi-factor comprehensive ecosystem service functions. This study conducted a multi-scale analysis in the middle reaches of Jinsha River,a hydropower development base in southwest china,to quantitatively evaluate the spatio-temporal characteristics of water yield,carbon storage,and habitat quality before(2000)and after(2020)hydropower development using the InVEST model;to assess the three ecosystem services based on a comprehensive ecosystems service index(CESI)from the perspective of balanced development;and to investigate the mechanism of CESI change under hydropower development. The results indicated that:① At the watershed level,water yield showed a decreasing trend(by 18.22%),whereas carbon storage(by 0.26%)and habitat quality(by 0.45%)showed a subtle increasing trend from 2000 to 2020. ② The three ecosystem services in the sub-watershed with different levels of hydropower development exhibited different changing characteristics: the three ecosystem services in sub-watersheds with higher levels of hydropower development decreased,whereas carbon storage and habitat quality in sub-watersheds without hydropower development increased. ③ The CESI showed a downward trend(by 8.13%),and pinpointed regions of increasing CESI were in the up and down reaches of the regions, whereas those of decreasing CESI were in the middle reaches of the regions. The sustained hot spots

关键词： Carbon sequestration

Organic acids and inorganic anions in Bayer liquors by ion chromatography after solid-phase extraction

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Journal of Central South University of Technology 2007年第2期14卷 191-195页

作者：钟付金陈晓青张树朝李跃平 School of Chemistry and Chemical Engineering Central South University Zhengzhou Research Institute China Aluminum Corporation

A method for the simultaneous separation and determination of organic acids and inorganic anions in Bayer liquors was developed by gradient ion chromatography with suppressed conductivity detection. Formate, acetate, propionate, oxalate, succinate, glutarate, fluoride, chloride and sulfate were separated and determined in 33 min. The samples were pretreated with solid-phase extraction, which has high selectivity for removing a large number of metallic ions in the Bayer liquors, and filtered with a 0.45 μm filter membrane before being injected into the ion chromatographic system. The separation of six organic acids and three inorganic anions was achieved on an IonPac AS11-HC column with KOH as the eluent, and the detection was performed by a conductivity detection mode. No interference is found in the presence of fluorate, chlorate and sulphate when organic acids are determined. The calibration graphs of peak area for all the analytes are linear over a wide range. The relative standard derivation of the peak area of analytes is less than 2.14%. Under optimum conditions the detection ranges from 0.2 to 100.0 mg/L. The average recoveries of the added standards are between 94.3% and 102.8%.

关键词： Bayer liquors organic acid inorganic anion ion chromatography solid-phase extraction

Analytical Modelling of Shot-peening Residual Stress on Welding Carbon Steel Surface Layer

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Journal of Wuhan University of Technology(Materials Science) 2016年第6期31卷 1352-1362页

作者：王军强韩建民 LI Weijing YANG Zhiyong LI Zhiqiang ZHAO Yingxin School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing 100044 China aluminum corporation of china Beijing 102209 China

The residual stress distribution was studied by an analytical model, due to shot peening on the welding carbon steel surface layer. The initial welding residual stresses before shot peening were taken into consideration in this analytical model. The Hertzian elastic contact theory was used to get the elastic compression stress state after impact on the surface layer. The initial welding stress field and the shot peening stress field would superpose and the welding surface layer would yield based on the elastic-plastic evaluation, then the residual stress after shot peening can be achieved. The influence of initial welding residual stress on the stress distribution after shot peening was analyzed and discussed. A series of experiments were carried out and the residual stress on the welding surface was determined by X-ray diffractometer before and after shot peening. The calculation results of the analytical model are consistent with the experimental results. The critical shot velocities when welding surface layer yielded and reverse yielded were calculated. While the welded joint surface material reversely yielded, the maximum compressive residual stress would not obviously increase with the increase of shot velocity, the thickness of the compressive stress layer would be increased. Welding residual tensile stress can enlarge the thickness of the compressive stress layer at the same shot velocity when reverse yield appeared.

关键词： analytical model welding residual stress shot peening stress distribution

Coating of Fe, Ni on α-alumina microspheres by heterogeneous precipitation

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Journal of Central South University of Technology 2006年第1期13卷 22-26页

作者：沈湘黔李东红景茂祥李旺兴 School of Materials Science and Engineering Jiangsu University Zhenjiang 212013 China School of Materials Science and Engineering Jiangsu University Zhenjiang 212013 ChinaZhengzhou Research Institute China Aluminum Corporation Zhengzhou 450041 China Zhengzhou Research Institute China Aluminum Corporation Zhengzhou 450041 China

The precursors with NiCO3·2Ni（OH）2·2H2O, Fe2O3·nH2O coated alumina microspheres were prepared by the aqueous heterogeneous precipitation using metal salts, ammonium bicarbonate and α-Al2O3 micropowders as the starting materials. Magnetic metal Ni, α-Fe coated alumina, core-shell structural microspheres were successfully obtained by thermal reduction of the precursors at 700℃ for 2h, respectively. Powders of the precursors and the resultant metal （Ni, α-Fe） coated alumina micropowders were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. The results show that optimized precipitation parameters are concentration of alumina micropowders of 15g/L, rate of adding reactants of 5mL/min and pH value of 7.5. And under the optimized conditions, the spherical precursors without aggregations or agglomerations are obtained, then transferred into Ni, α-Fe coated alumina microspheres by thermal reduction. It is possible to adjust metal coating thicknesses and fabricate a multilayer structured metal/ceramics, core-shell microspherical powder materials.

关键词： heterogeneous precipitation metal-coated alumina microsphere Ni α-Fe

Development of A New Lime Adding Technology in Two-Stream Digestion Process of Diasporic Bauxite

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Journal of Rare Earths 2005年第S1期23卷 642-645页

作者：尹中林 Zhengzhou Research Institute Aluminum Corporation of China Limited. Zhengzhou 450041 ChinaSchool of Material and Metallurgy Northeastern University Shenyang 110004 China

Indirect heating and intensified digestion technology can be applied to reduce greatly the energy consumption in Bayer process of diasporic bauxite. A great advantage of two-stream process is to avoid or reduce efficiently serious scaling problem of bauxite slurry on indirect heating surface, which certainly happens in the single stream process and brings about great troubles to the indirect heating. As a result of a great number of experiments and the theoretical analysis, a new lime adding technology for the two-stream digestion process is developed in this paper that lime is added into spent liquor stream instead of bauxite slurry, which is more suitable to the two-stream process of diasporic bauxite. The influences of the new lime addition technology on preheating and digestion process were discussed. It was deduced that the new technology can be used efficiently in the two-stream process of non-diasporic bauxite.

关键词： diasporic bauxite bayer process two-stream process lime addition

Influence Factors for Impact Actions and Transient Trajectories of Fan Blades after Fan Blade Out in Typical 2-Shaft High Bypass Ratio Turbofan Engine

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Journal of Thermal Science 2022年第1期31卷 96-110页

作者： XU Xue LI Hongxin FENG Guoquan Shenyang Engine Research Institute Aero Engine Corporation of ChinaShenyang 110015China corporation Headquarter Aero Engine Corporation of ChinaBeijing 100097China

To enhance the understanding of design characters, which have prominent influences during the fan blade out event, a simplified geometrical and dynamic analysis method was derived, and a typical 2-shaft high bypass ratio turbofan engine was selected and modeled. Based on analytical deriving and engineering experience learned from the real engine failure case, three determinative impact actions were recognized from the fan blade out process. The transient trajectories of these impact actions were researched in analytical method, and then thickness of acoustic lining, quantity of fan blades and threshold load of structural fuse were analyzed as key design characters. 36 serialized fan blade out transient dynamic simulations were conducted by using the 2-shaft high bypass ratio turbofan engine model within different combinations of the three key design factors. The results from geometrical and dynamic analysis matched mainly well with the results from simulations. Characteristic phenomenon in simulation can be explained theoretically. Five conclusions can be summarized from these results. (1) If thickness fan acoustic lining was thinner, the deviation between simplified analytical calculation and simulation were not outstanding to predict Blade-Casing the first impact time and angular position. (2) An appropriate thickness of acoustic lining could make a lower impact stress of fan casing at the first impact. (3) Different thickness of acoustic linings leaded to two impact modes for blade 2, which were tip impact and root impact. (4) Different impact conditions between blade 1 and blade 2 caused remarkable speed components distinction of blade 1, and leaded to a wide range of transient trajectory of blade 1 during FBO event. (5) Thicker acoustic lining in this research can usually find the porper threshold loads setting, which can give a satisfactory outbound vibration. Two details were raised for further research, which were impact behavior of composite material fan bl

关键词： fan blade out transient trajectory design character structural fuse high bypass ratio turbofan

Effects of maternal feeding of clofibrate on hepatic fatty acid metabolism in suckling piglet

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Journal of Animal Science and Biotechnology 2025年第1期16卷 424-440页

作者： Jinan Zhao Brandon Pike Feng Wang Lin Yang Paige Meisner Yanling Huang Jack Odle Xi Lin Laboratory of Developmental Nutrition Department of Animal ScienceNorth Carolina State UniversityRaleighNC 27695USA Sales Department Zinpro CorporationEden PrairieMN 55344USA Extension Agent NC State UniversityN.C.Cooperative Extension-Northampton County Center9495 NC Highway 305PO Box 636JacksonNC 27845USA Key Laboratory of Animal Science of State Ethnic Affairs Commission Southwest Minzu UniversityChengdu 610041People’s Republic of China

Background Energy deficiency is a leading cause of the high pre-weaning mortality of neonatal piglets in the swine ***,optimal energy metabolism is of crucial importance for improving the survivability of neonatal *** effective utilization of milk fat as primary energy is indispensably *** Pregnant sows(n=27)were randomly assigned into 3 *** treatment received a standard diet(3,265 kcal ME/kg)supplemented with either 0,0.25%or 0.5%clofibrate(w/w)from d 107 of gestation to d 7 of *** effects of maternal clofibrate on their milk fatty acid(FA)and performance of the piglets were *** evaluations were performed via measuring sow productive performance,milk FA composition,and hepatic FA oxida-tion of the piglets at birth and d 1,7,14 and 19 after *** Maternal supplementation of clofibrate had no effect on reproductive performance of the sows at farrowing and weaning(P>0.05).However,the mortality at weaning was reduced for piglets from sows with 0.25%of clofi-brate,and the average weekly(and daily)gain was higher in piglets from sows that received clofibrate than sows without clofibrate in the first week(P<0.0001).Maternal clofibrate increased percentage of milk C12:0 and C14:0 FAs but decreased C18:2 and n-6 polyunsaturated *** clofibrate also increased plasma ketone body levels and hepatic FA oxidation measured at the first day of birth,but the increase was not detected in piglets on d 7,14 or *** was not detected in milk collected from the clofibrate-treated *** percentage of FA oxidation decreased,and the percentage of FA esterification increased with increasing in postnatal *** carni-tine increased FA oxidation regardless of succinate dehydrogenase inhibition,and the increase had no effect on FA *** Maternal supplementation of clofibrate during late gestation and early lactation increases hepatic FA oxidative metabolism at birth and imp

关键词： Clofibrate Hepatic fatty acid oxidation and metabolism Newborn pigs Postnatal age PPARα