检索结果-内蒙古大学图书馆

Modelling of water transport in PEM fuel cell

Kung Cheng Je Wu Li Hsueh Pao/Journal of engineering Thermophysics 2010年第9期31卷 1504-1507页

作者： Xu, Cheng-Jie Zhang, Guang-Sheng Liu, Hong-Tan Guo, Lie-Jin State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China Dept. of Mechanical and Aerospace Engineering University of Miami Coral Gables FL 33124 United States

A mixed-domain, two-phase flow, non-isothermal model is developed to study the water transport phenomena, which has significant effects on the performance of PEM fuel cells. Modelling results show that: the total water concentration is decreasing along the channel in anode, while it is increasing in cathode, flooding is most likely to occur at the end of cathode flow channel;liquid water in cathode GDL presents opposite distribution at high current density and low current density, the saturation of liquid water is decreasing from inner side to outer side across the GDL at low current density while it is increasing at high current density.

关键词： Two phase flow

来源：评论

学校读者我要写书评

暂无评论

Numerical simulation of a buried hot crude oil pipeline during shutdown

引用

Petroleum Science 2010年第1期7卷 73-82页

作者： Xu Cheng Yu Bo Zhang Zhengwei Zhang Jinjun Wei Jinjia Sun Shuyu Beijing Key Laboratory of Urban Oil and Gas Distribution Technology China University of Petroleum Beijing 102249China Zhejiang Department Preparatory Team PetroChina West East Gas Pipeline Company Hangzhou Zhejiang 310000 China State Key Laboratory of Multiphase Flow in Power Engineering Xi＇an Jiaotong University Xi＇an Shaanxi 710049 China Department of Mathematical Sciences Clemson University Clemson SC 29634-0975 USA

In this paper a mathematical model is built for a buried hot crude oil pipeline during shutdown, and an unstructured grid and polar coordinate grid are respectively applied to generating grids for the soil region and the three layers in the pipe （wax layer, pipe wall, and corrosion-inhibiting coating）. The governing equations are discretized using the finite volume method. The variations in temperatures of static oil and soil were investigated during pipeline shutdown in both summer and winter, in which some important parameters of the soil and crude oils of a Northeast pipeline are employed.

关键词： Moving boundary stagnation point equivalent thermal conductivity thermal influence region unstructured grid

来源：评论

学校读者我要写书评

暂无评论

Experimental study on the characteristics of weak corrosive surfactant drag reducer

Experimental study on the characteristics of weak corrosive ...

引用

12th International Conference on engineering, Science, Construction, and Operations in Challenging Environments - Earth and Space 2010

作者： Su, Wen-Tao Li, Feng-Chen Dong, Yong Cai, Wei-Hua Jiao, Li-Fang Wei, Jin-Jia Yu, Bo School of Energy Science and Engineering Harbin Institute of Technology Harbin 150001 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiao Tong University Xi'an 710049 China Beijing Key Laboratory of Urban Oil and Gas Distribution Technology China University of Petroleum Beijing 102249 China

ISBN: (纸本)9780784410967

Experimental study on drag-reducing characteristics of a zwitterionic surfactant additive (C20H43NO) in a circulation system has been carried out. It was based on the optimum concentration, temperature effect and the characteristics of resisting shear in DN27.5 pipeline. The results showed that C20H43NO additive has a significant drag-reducing effect depending on concentration and temperature. The most effective concentration in the tested flow loop was 900ppm at 60°C. The temperature range of the drag-reducing effect was in the range of 40 ∼ 70°C. The maximum drag reduction (DR) of 900ppm C20H 43NO aqueous solution was 77% at the beginning of circulation with system running between 41°C and 43°C. The drag-reducing effect does not decrease remarkably after the circulation system ran for a period of seven hours, but reduces to only 5% of DR after a period of twenty-three hours. In order to study the drag-reducing characteristics of C20H 43NO aqueous solution in the practical district heating system, the experiments with C20H43NO aqueous solution flow in different inner-diameter pipelines including DN50 and DN100 with rough wall were performed. The results indicated that the optimum drag-reducing concentrations are 1500ppm and 2500ppm at 45∼50°C in the DN50 and DN100 circular pipes, respectively. Finally, the technique of drag-reducing additive applying into the district heating system is discussed. And some problems in the practical application were brought forward, such as, the poor life-span of surfactant, the instabilities of drag-reducing effect and the inherent corrosion of additive itself. According to these problems, the corrosion research of C 20H43NO aqueous solution was also conducted based on immersion method. The results show that: C20H43NO aqueous solution is weakly corrosive for iron-based metallic pipe comparing with CTAC aqueous solution and water. © 2010 ASCE.

关键词： Pipelines

来源：评论

学校读者我要写书评

暂无评论

Investigation on the mechanism of abnormal heat transfer of supercritical pressure water in vertically‐upward tubes in the large specific heat region

引用

AIP Conference Proceedings 2010年第1期1207卷 531-536页

作者： J. G. Wang H. X. Li B. Guo S. Q. Yu Y. Q. Zhang T. K. Chen aState Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an 710049 China bCollege of Energy Xi’an University of Science and Technology Xi’an 710054 China

The heat transfer characteristics of water at supercritical pressures in a vertically‐upward internally‐ribbed tube are investigated experimentally to investigate the mechanism of abnormal heat transfer of supercritical pressure water in the so‐called large specific heat region. One kind optimized internally‐ribbed tube is used in this study. The tube is made of SA‐213T12 steel with an outer diameter of 31.8 mm and a wall thickness of 6 mm and the mean inside diameter of the tube is measured to be 17.63 mm. According to experimental data, the characteristics and mechanisms of the heat transfer enhancement and also the heat transfer deterioration of supercritical pressure water in the large specific heat region are discussed respectively. The heat transfer enhancement of the supercritical pressure water in the large specific heat region is believed to be a result of combined effect caused by the rapid variations of thermophysical properties of the supercritical pressure water in the large specific heat region, and the same is true of the heat transfer deterioration. The drastic changes in thermophysical properties near the pseudocritical points, especially the sudden rise in the specific heat of water at supercritical pressures, may result in the occurrence of the heat transfer enhancement, while the covering of the heat transfer surface by fluids lighter and hotter than the bulk fluid makes the heat transfer deteriorated eventually and explains how this lighter fluid layer forms. It is also found that the heat transfer deterioration of water at supercritical pressures is similar to the DNB (departure from nucleate boiling) at subcritical pressures in mechanism.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Hydrogen Production by CMC Gasification in Supercritical Water

Hydrogen Production by CMC Gasification in Supercritical Wat...

引用

IEEE PES Asia-Pacific power and Energy engineering Conference (APPEEC)

作者： Xiaohong Hao Liejin Guo Ximin Zhang School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an China

ISBN: (纸本)9781424448128;9781424448135

Hydrogen production by biomass supercritical water gasification is about to develop in the future because the process is closed and clean with high gasification efficiency in addition. Low concentration sodium carboxymethylcellulose (CMC) (2-3% mass fraction) can be mixed with particulate biomass and water to form a uniform and stable viscous paste which can be pumped to the continuous high-pressure reactor. In this paper, the supercritical water gasification of CMC was investigated in the tube flow apparatus to produce gas products consisting essentially of H 2 , CO, CH 4 and CO 2 .

关键词： Hydrogen Production Inductors Biomass Temperature Feeds Resistance heating Regulators Cooling Atmospheric measurements

来源：评论

学校读者我要写书评

暂无评论

Water cut measurement of crude oil slug flow with double-tube capacitance sensor 6

Water cut measurement of crude oil slug flow with double-tub...

引用

6th World Congress in Industrial Process Tomography

作者： Bai, Bofeng He, Denghui Xu, Yong Yang, Canghai Li, Li State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Oil and Gas Technology Research Institute Changqing Oilfield Company of CNP Xi’an710021 China National Engineering Laboratory for Exploration and Development of Low-permeability oil and gas Field CNPC Beijing100007 China

ISBN: (纸本)9780853163220

An online method for measurement of water cut in the crude oil slug flow in vertical pipes is presented. The water cut is obtained from the water film length, which is measured by a double-tube capacitance probe sensor, on the surface-insulated tube. The double-tube capacitance probe sensor consists of two stainless steel tubes, one tube is covered with an insulating film and the other is not. There is a heating wire in each tube, which provides a certain amount of heat to prevent the formation of waxes on the surface of the tube. The output of water cut variations is in the form of capacitance signal, which is independent of water salinity and electrical properties of the liquid. The water film length, capacitance and water cut are linearly proportional to each other. The field experiments indicate that the measurements are affected by both the natural gas entrained in the liquid and the flow patterns. A comparison with manual sampling measurement suggests that the mean water cut obtained by the sensor is lower than that of manual sampling value in the slug flow and the relative deviation is 11.58%. The measured values are revised according to the water holdup of the slug flow, and the relative deviation is reduced to 8.04% after revising. © 2010, International Society for Industrial Process Tomography. All rights reserved.

关键词： Crude oil

来源：评论

学校读者我要写书评

暂无评论

Numerical Simulation of Low Pressure Natural Gas Injector

引用

AIP Conference Proceedings 2010年第1期1207卷 961-967页

作者： D. T. Chong G. S. Wu S. Q. Liu J. J. Yan J. P. Liu aState Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University China bSouthwest Petroleum University China cOil & Gas Technology Research Institute PetroChina Changqing Oilfield Company China

The maximum total recovery from all gas wells are highly desired to be got and the production is to be maintained when the gas well reaches the end of its economic life. Although the injector has been known for about one century, sparse investigations have been performed on the injector of natural gas, and no structural optimization on the natural gas injectors has been reported. In the present paper, the structural parameters of natural gas injectors was optimized numerically with the motive pressure ranging from 2.5 to 3.5 MPa, induced pressure ranging from 0.5 to 1.5 MPa and discharged pressure being 1.5 MPa. The numerical results showed that the optimal values of diffuser gradient, mixing tube length to diameter ratio, mixing chamber length to diameter ratio and mixing chamber gradient were 40, 5, 0 and 0.25, respectively. The performance of optimized injectors was also investigated numerically. The motive natural gas flowrate increased linearly with increase of motive pressure and was independent of induced pressure. The induced flowrate and entrainment ratio of natural gas were both increased with the increase of induced pressure.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Experimental Study on the Treatment of low C/N ratio disposal of sewage with BAF

引用

AIP Conference Proceedings 2010年第1期1207卷 157-161页

作者： W. J. Wang T. Ma W. Cheng aKey Laboratory of Northwest Water Resources and Environmental Ecology of Education Ministry Xi’an University of Technology Xi’an 710048 China bState Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiao tong University China

The Biological Aerated Filter (BAF) is a simple, high‐efficient, low‐consumptive for new biological membrane method correspond to the situation of china, will be one of the main technical measures to solve the progressive deterioration of water environment problem faced china especially medium and small towns. This paper focuses on the experimental study and mechanism analysis in which the up flow, cocurrent gas‐water, single‐stage BAF was adopted on treatment domestic wastewater, the results showed that BAF has good performance in treating domestic sewage, and it had steady treatment effect with different pollution loads.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Photocatalytic desulfurization of gasoline by TiO2 coupling with ultrasonic

引用

Ranliao Huaxue Xuebao/Journal of Fuel Chemistry and Technology 2010年第4期38卷 428-433页

作者： Chen, Song-Xuan Zhao, Jing-Lian Su, Ci State Key Laboratory of Multiphase Flow in Power Engineering Department of Environmental Engineering Xi'an Jiaotong University Xi'an 710049 China

The photocatalytic oxidation of dibenzothiophen (DBT) in octance (as solvent) was conducted using O2 in air as the oxidant, TiO2 prepared by sol-gelatin method as the photocatalyst and coupling with ultrasonic. The effect of light distance, photocatalyst amount, reaction time, DBT initial concentration and ultasonic power on the removal of DBT were investigated deeply. The results show that the degradation rate of DBT increases by 10% by using ultrasonic. Under the conditions of TiO2 dosage of 2 g/L, air flow rate of 800 mL/min, distance of UV light of 20 cm, initial concentration of DBT of 600 mg/L, reaction time of 150 min, ultrasound power of 500 W, the degradation rate of DBT can reach up to 72.6%.

关键词： Ultrasonics

来源：评论

学校读者我要写书评

暂无评论

Research on the flow Pattern of Bubble Plume in an Aeration Tank

引用

AIP Conference Proceedings 2010年第1期1207卷 646-652页

作者： W. H. Liu T. Wan W. Cheng Yuichi Murai aKey Laboratory of Northwest Water Resources and Environmental Ecology of Education Ministry Xi’an University of Technology Xi’an 710048 China bState Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an 710048 China cDivision of Energy and Environmental System Hokkaido University Sapporo Japan

The flow pattern of gas‐liquid two‐phase flow in an aeration tank is of critical effect upon mass transfer by the convection. Bubble plume provides unsteadily fluctuating two‐phase flow during the aeration. This paper the study on the unsteady structure of bubble plume is dealt with from experiment. The time‐serial bubble plume images of different cases in tank have been analyzed. The RCC‐PIV has been employed to calculate the velocities in those cases, and then the time‐serial vortex, the total turbulence intensity, the time‐serial streamline are obtained. It has been shown that the aspect ratio and void fraction are the dominant factors influencing the unsteady structure of bubble plume. When the aspect ratio is unity and the void fraction gets higher, the bubble plume has symmetrical vortex structure and longest residence time, which is beneficial for optimizing the aeration system and enhancing the applied range of bubble plume.

关键词：

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：