检索结果-内蒙古大学图书馆

Roasting-induced phase change and its influence on phosphorus removal through acid leaching for high-phosphorus iron ore

引用

International Journal of Minerals,Metallurgy and Materials 2015年第4期22卷 346-352页

作者： Min Yang Qing-shan Zhu Chuan-lin Fan Zhao-hui Xie Hong-zhong Li State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Chemistry School of Chemistry and Biological Engineering University of Science and Technology Beijing

In the present study, roasting-induced phase change and its influence on phosphorus removal via leaching has been investigated for high-phosphorus iron ore. The findings indicate that phosphorus in the ore is associated with goethite and exists mainly in amorphous Fe3PO7 phase. The phosphorus remains in the amorphous phase after being roasted below 300℃. Grattarolaite （Fe3PO7） is found in samples roasted at 600-700℃, revealing that phosphorus phase is transformed from the amorphous form to crystalline grattarolaite during roasting. Leaching tests on synthesized pure grattarolaite reveal a low rate of phosphorus removal by sulfiaric acid leaching. When the roasting tem- perature is higher than 800℃, grattarolaite is found to react with alumina to form aluminum phosphate, and the reactivity of grattarolaite with alumina increases with increasing roasting temperature. Consequently, the rate of phosphorus removal also increases with increasing roasting temperature due to the formation of acid-soluble aluminum phosphate.

关键词： goethite phosphorus removal roasting leaching

来源：评论

学校读者我要写书评

暂无评论

Prediction of thermal performance of radiative radial fin with temperature-dependent thermal conductivity using spectral collocation method

引用

Journal of Computational and Theoretical Nanoscience 2016年第9期13卷 5822-5831页

作者： Ma, Jing Sun, Ya-Song Li, Ben-Wen Key Laboratory of Shaanxi Province for Development and Application of New Transportation Energy School of Automobile Chang'an University Xi'an710064 China Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy North China Electric Power University Beijing102206 China Institute of Thermal Engineering School of Energy and Power Engineering Dalian University of Technology Dalian116024 China

Spectral collocation method (SCM) is developed to solve coupled radiation and conduction in radiative radial fin with temperature-dependent thermal conductivity and volumetric heat generation. In this approach, energy conservation equation is discretized by SCM, and a particular algorithm is proposed to alleviate the nonlinearity of energy conservation equation. Numerical results by SCM are compared with available results in the literature, which indicate that SCM can provide high accuracy for combined radiative and conductive heat transfer in radiative radial fin, and the integral averaged relative error decreases exponentially with the increasing number of collocation points. Meanwhile, the effects of various parameters on the thermal performance, such as dimensionless thermal conductivity coefficient, radiation-conduction parameter, dimensionless ambient temperature, dimensionless radiation sink temperature and dimensionless volumetric heat generation are also investigated. Copyright © 2016 American Scientific Publishers All rights reserved.

关键词： Fins (heat exchange)

来源：评论

学校读者我要写书评

暂无评论

An experimental study on flow characteristics of homogeneous and stratified debris beds 16

An experimental study on flow characteristics of homogeneous...

引用

16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2015

作者： Li, Liangxing Zou, Xumao Lou, Jiaojiao Li, Huixiong Lei, Xianliang State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xian-ning West Road 28# Xi'an city710049 China

ISBN: (纸本)9781510811843

This paper is concerned with reducing uncertainty in quantification of debris bed coolability in a severe accident of light water reactors (LWRs). The experimental results on the flow characteristics of particulate homogeneous and stratified beds are reported here and the objective is to get an idea of how the particles bed characteristics (such as the stratified information and its hierarchical arrangement) affects its flow resistance which is crucially important to the debris bed coolability analysis. Three type beds are packed in a cylindrical test section with the inner diameter of 120 mm and the height of 600 mm. Type-1 bed is homogeneous bed packed with single size spheres. Type-2 bed is also a homogeneous bed with uniformly mixing by two sizes of spheres. Type-3 bed is the axially stratified bed which is composed of two sizes of glass spheres same as that in the Type-2 bed. Both single and two phase flow tests are carried out, the pressure gradients and its flow characteristics are measured and recorded during the tests. The results show that for gas-water co-current flow through a homogeneous bed, the predictions of Reed's model are more comparable with the measured pressure drops. For a bed packed with uniform mixture of particles, the measured pressure gradients are close to the predictions of Ergun equation with area mean diameter at low flowrate (e.g. Rep © Copyright (2015) by American Nuclcar Society All rights reserved.

关键词： Pressure drop

来源：评论

学校读者我要写书评

暂无评论

Nanoscale noble metals with a hollow interior formed through inside-out diffusion of silver in solid-state core- shell nanoparticles

引用

Nano Research 2015年第2期8卷 512-522页

作者： Pengfei Hou Penglei Cui Hui Liu Jianling Li Jun Yang State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing 30 College Road Beijing 100083 China State Key Laboratory of Multiphase Complex Sys tems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

Noble metal nanoparticles with hollow interiors and customizable shell com- positions have immense potential for a wide variety of applications. Herein, we present a facile, general, and cost-effective strategy for the synthesis of noble metal nanoparticles with hollow structures, which is based on the inside-out diffusion of Ag in solid-state core-shell nanoparticles. This approach starts with the preparation of core-shell nanoparticles with Ag residing in the core region, which are then loaded on a solid substrate and aged in air to allow the inside-out diffusion of Ag from the core region, leading to the formation of monometallic or alloy noble metal nanoparticles with a hollow interior. The synthesis was carried out at room temperature and could be achieved on different solid substrates. In particular, the inside-out diffusion of Ag calls for specific concern with respect to the evaluation of the catalytic performance of the Ag-based core--shell nanoparticles since it may potentially interfere with the physical and chemical properties of the core-shell particles.

关键词： noble metal nanoparticle inside-out diffusion solid-state core-shell hollow

来源：评论

学校读者我要写书评

暂无评论

Experimental study on enrichment of low concentration coal bed methane with solar energy

引用

Kung Cheng Je Wu Li Hsueh Pao/Journal of engineering Thermophysics 2015年第12期36卷 2637-2640页

作者： Yu, Hao-Tian Li, Na Zhou, Qu-Lan State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China

A large number of low concentration methane gas is emitted directly into the atmosphere during the coal production, resulting in a serious waste of energy and the greenhouse effect. Aiming at the shortcomings of conventional coal mine methane enrichment technology existed, the papar presented separation and enrichment coal mine methane with the Soret effect. The theoretical analysis proposed the main parameters of the enrichment process is the initial methane concentrations and the temperature gradient. The effect law of these parameters is studied by experiments and numerical simulations. © 2015, Science Press. All right reserved.

关键词： Coal

来源：评论

学校读者我要写书评

暂无评论

Effect of groove size on heat transfer performance of loop heat pipe with flat evaporator

引用

Kung Cheng Je Wu Li Hsueh Pao/Journal of engineering Thermophysics 2015年第3期36卷 611-614页

作者： Lü, Xiao Wei, Jin-Jia Long, Yan State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China

The effect of groove size on heat transfer performance of a loop heat pipe (LHP) with flat evaporator was investigated experimentally, and the comparison of two different kinds of groove size was conducted under different title angles and fluid charging ratios. The results showed that the minimum start-up heat load is same under the same conditions for two different grooves of 2 mm×1.5 mm and 1 mm×1 mm (hight × width), but the former has shorter start-up and transient times. After running steadily, the former has smaller temperature oscillation and lower operating temperature than the latter except for the fluid charging ratio of 55% and the heat load less than 150 W. With increasing heat load, the former has a smaller change in temperature than the latter and the temperature oscillation decreases. As for the heat transfer performance, the thermal resistance decreases with increasing heat load and then levels off for the two different grooves. When the LHP under horizontal position with working fluid charging ratio of 55%, a larger thermal resistance appears for the former initially, and it decreases dramatically with the increase of heat load, and the minimum value of 0.12℃/W is achieved at the heat load of 215 W. © 2015, Science Press. All right reserved.

关键词： Thermal load

来源：评论

学校读者我要写书评

暂无评论

CFD study on the optimal nozzle exit position in a CO2 two-phase ejector 24

CFD study on the optimal nozzle exit position in a CO2 two-p...

引用

24th IIR International Congress of Refrigeration, ICR 2015

作者： He, Yang Deng, Jianqiang Zhang, Zaoxiao Zheng, Lixing State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China School of Chemical Engineering and Technology Xi'an Jiaotong University Xi'an710049 China

ISBN: (纸本)9782362150128

The nozzle exit position (NXP) is a significant parameter for an ejector. In this work, a two dimensional (2D) homogeneous CFD model is developed to simulate the two-phase ejector used in transcritical CO2 refrigeration cycle and NXP is focused on. After model validation, the flow fields in ejectors with different NXPs are simulated and an optimal NXP is obtained. According to the numerical results, with the increase of the NXP, a higher velocity and lower pressure are achieved for the primary fluid in the suction chamber which enhances the entrainment of the secondary fluid. Oppositely, the flow area of the primary fluid at the mixer inlet increases with the NXP which reduces the secondary flow rate. A compromise between these two factors leads to the optimal NXP with the highest entrainment ratio under the same operating condition. The results are helpful to the optimal design and control of the ejector.

关键词： Carbon dioxide

来源：评论

学校读者我要写书评

暂无评论

Hot corrosion behavior of TP347HFG without and with external stresses in molten salts

Hot corrosion behavior of TP347HFG without and with external...

引用

International Conference on Power engineering, ICOPE 2015

作者： Fu, Jiapeng Zhou, Qulan Li, Na Liu, Zhuhan Liu, Taisheng State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Dongfang Boiler Group Corporation Limited Zigong643000 China

The hot corrosion tests of the austenitic TP347HFG in molten sulfates with and without external stresses were conducted at 700 and 750 oC. The corroded specimens of different conditions were investigated through measurements of o xide morphology, corrosion thickness and composition. Through the analysis to the corrosion specimens, we knew that the corrosion reaction of the alloy was strongly related to the formation of an oxidation progress of metallic elements. The unstressed specimens had more complex products and thicker corrosion layers than those under 20MPa external stresses at 700 and 750 oC, which meant mo re fierce corrosion behaviors. It seemed that the applied stress led to a faster formation of a continuous, dense oxides layer that protected the inner specimens fro m further corrosion reaction. Generally, the exertion of the stresses caused many micro cracks and defects in the metal. These defects acted as faster and easier diffusion paths for the Cr atoms to diffuse to the surface, and thus, promote a faster formation of the protective Cr2O3 oxide layer. © 2015 The Japan Society of Mechanical Engineers.

关键词： Austenitic stainless steel

来源：评论

学校读者我要写书评

暂无评论

Experimental study on liquid nitrogen spray in atmospheric environment 24

Experimental study on liquid nitrogen spray in atmospheric e...

引用

24th IIR International Congress of Refrigeration, ICR 2015

作者： Xue, Rong Liu, Xiufang Cao, Feng Hou, Yu School of Energy and Power Engineering Xi'an Jiaotong University Xi'an710049 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China

ISBN: (纸本)9782362150128

In spray cooling system, the liquid coolant is broken into numerous fine droplets through a spray nozzle to cool the target. The liquid nitrogen spray could obtain low cooling temperature and excellent heat transfer performance with phase change in a large temperature difference. It can be widely used in low temperature tunnel cooling, ground simulation environment and laser therapy. The open loop liquid nitrogen spray platform is built to investigate the nitrogen spray characteristics. The solid cone vortex nozzle WL32 (3.18 mm diameter) and fine fog nozzle P66 (1.68 mm diameter) are used in the experiment. The spray pressure differences (0.25MPa to 0.8MPa) are sourced by the high pressure room temperature gas nitrogen and controlled through a manual valve. In the experiment, the spray field is recorded by a high speed camera (HG-100K from Redlake Co.) and the diameter of the spray droplet from WL32 is analyzed through the Malvern Spraytec laser particle size analyzer. The pressure difference between nozzle inlet and outlet has different influence on the spray angle of WL32 and P66. The quantity of spray droplets of WL32 increases with the increasing pressure, which leads to the improvement of the atomizing effect and the decline of Sauter Mean Diameter.

关键词： Liquid nitrogen

来源：评论

学校读者我要写书评

暂无评论

Characterization of heat transfer in R134 - A spray cooling 24

Characterization of heat transfer in R134 - A spray cooling

引用

24th IIR International Congress of Refrigeration, ICR 2015

作者： Liu, Jionghui Qian, Yang Shuangtao, Chen Hou, Yu Liu, Xiufang State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China School of Energy and Power Engineering Xi'an Jiaotong University Xi'an710049 China

ISBN: (纸本)9782362150128

A closed loop spray cooling system with R134 - A as spray medium was used to investigate the performance of spray cooling characteristic. The heat transfer parameters such as heat flux, heat transfer coefficient and target surface temperature were studied under different volumetric flow rate and spray chamber pressure. The single-phase heat transfer region and the phase-change heat transfer region were analyzed at different heat fluxes. The results show that the heat flux, critical heat flux (CHF) and heat transfer coefficient directly relate with volumetric flow rate. The higher flow rate and spray chamber pressure could achieve higher CHF with better heat transfer performance. And the different relationship between heat transfer coefficient and surface temperature was obtained at different spray cooling period.

关键词： Heat flux

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：