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Experimental study of heat transfer of ultra-supercritical pressure water in vertical upward internally ribbed tube

High Technology Letters 2007年第1期13卷 17-22页

作者：王为术 Chen Tingkuan Luo Yushan　 Gu Hongfang Yin Fei National Key Laboratory of Multiphase Flow in Power Engineering Xi＇ an Jiaotong University Xi＇ an 710049 P.R. China School of Power Electric North China Institute of Water Conservancy and Hydroelectric Power Zhengzhou 450011 P.R. China

Under ultra-supercritical pressure, the heat transfer characteristics of water in vertical upward 4- head internally ribbed tubes with a diameter of 28.65mm and thickness of 8mm were experimentally studied. The experiments were performed at P = 25- 34MPa, G = 450- 1800kg/（m^2·s） and q = 200 600kW/m^2. The results show that the pressure has only a moderate effect on the heat transfer of uhra-supercritical water when the water temperature is below the pseudocritical point. Sharp rise of the wall temperature near the pesudocritical region occurs earlier at a higher pressure. Increasing the mass velocity improves the heat transfer with a much stronger effect below the pesudocritical point than that above the pesudocritical point. For given pressure and mass velocity, the inner wall heat flux also shows a significant effect on the inner wall temperature, with a higher inner wall heat flux leading to a higher inner wall temperature. Increasing of inner wall heat flux leads to an early occurrence of sharp rise of the wall temperature. Correlations of heat transfer coefficients are also presented for vertical upward internally ribbed tubes.

关键词： heat transfer supercritieal ultra-supereritieal vertical upward internally fibbed tube

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New revised correlation to predict pressure drop for oil-gas two-phase flow through horizontal pipe

New revised correlation to predict pressure drop for oil-gas...

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International Petroleum Technology Conference 2007, IPTC 2007

作者： Liu, Wenhong Guo, Liejin Zhang, Ximin Lin, Kai Yang, Long Feng, Yaorong Tubular Goods Research Center of CNPC Key Laboratory for Mechanical and Environmental Behavior of Tubular Goods China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University China

ISBN: (纸本)9781615673360

An experimental investigation on oil-gas two-phase flow through a straight horizontal plexiglas pipe within 40mm inner diameter was conducted. The superficial velocity ranges of oil and air were 0.05-0.612m/s and 0.024-50.64m/s, respectively. The atmospheric temperature condition was maintained throughout the *** frictional pressure drop multiplier of two-phase flow was expressed using the Lockhart-Martinelli parameter correlation in accordance with typical flow pattern, but the modification factor C in the correlations was defined afresh according to flow conditions. New predict correlations for pressure gradient in accordance with typical flow patterns were proposed and the mechanisms of pressure drop production were analyzed for each flow patterns. The proposed models give a good agreement with the experimental data. Copyright 2007, International Petroleum Technology Conference.

关键词： Two phase flow

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New Method of Online Measurement of Oil and Suspended Material Concentration In flowing Waste Water

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AIP Conference Proceedings 2007年第1期914卷 215-220页

作者： Hongwei Liao Guobing Xu Xinqiang Xu Fangde Zhou Key State Laboratory of Multiphase Flow and Power engineering Xian Jiaotong University Xian China

At present, the most of the measurements of oil and suspended material concentration in waste water measuring are not online surveys. A new method of online measurement of oil and suspended material concentration in flowing waste water is presented. The room experiments and field tests showed that it is suitable to waste water treatment on line. After sampling, It needed to measure immediately the concentration in first time. Then let sample to be in still in 10 – 20 seconds. After that the bulk concentration was measured in second time. Because of the suspended solids having heavy density, they would be dropped from waster water. During ultrasonic operation, emulsify the oil in waster water, the oil and suspended solid would be depart. After that the third time measurement was done. In thus way the concentrations of oil and suspended solids can be measured. At present there are two on‐site equipments operating in the Changqing oilfield, and the results are pretty well.

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Orientation-dependent Hydrodynamic Instabilities from Chemo-Marangoni Cells to Large Scale Interfacial Deformations

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Chinese Journal of Chemical engineering 2007年第5期15卷 748-753页

作者：石英 Kerstin Eckert State Key Laboratory of Multiphase Flow in Power Engineering Xi＇an Jiaotong University Xi＇an 710049 China Institute for Aerospace Engineering Technische Universitat Dresden D-01062 Dresden Germany

The interplay between chemistry and interfacial-tension-driven hydrodynamic instabilities has been studied experimentally. The system on hand consists of two immiscible liquids separated along an initially plane interface at which an interfacial reaction takes place to produce in situ a surfactant. It is identified that the dynamics of the system depends on the orientation of the Hele-Shaw cell with respect to the vector of gravity. If the nele-Shaw cell is placed vertically, Marangoni cells with vigorous convection develop in both phases along a nearly planar interface. However, if the Hele-Shaw cell is tilted off the gravity, the instabilities in the system are characterized by the large scale interracial deformation with a spatio-temporal periodicity together with the chemo-Marangoni convection. The focus is on the exploration of the transition from the cellular mode to the large scale interfacial deformation.

关键词： interfacial reaction in situ produced surfactant Marangoni convection interfacial deformation

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A novel design of the collector's cover of solar induced convection power plant

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International Solar Energy Society Solar World Congress 2007, ISES 2007

作者： Li, Ping Mei, Danhua Li, Zaoyang Chen, Weixiong Zhang, Yongzhi Zhao, Liang School of Energy and Power Engineering Xi'an Jiaotong University P.O. Box 2264 Xi'an 710049 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

ISBN: (纸本)9781622765447

Solar Induced Convection power Plant is a technology of new energy using. It has a very broad perspective. However, the efficiency of the technology not so acceptable. This paper focuses on improving the efficiency of the technology. The thermal physical properties of common glass, polycarbonate and polycarbonate with CO2 ware compared in this paper to study the superiority and scientificity of polycarbonate with CO2. The results show that, the heat transfer coefficient of polycarbonate with CO2 is the smallest so that it has the best effect of warm-keeping. and it can improve the efficiency of the system to large extent. According to the study, the polycarbonate with CO2 is the best one for solar radiation to go through and it is not easy for Far Infrared ray to do that. Base on the results and other advantages of the polycarbonate with CO2, we conclude that polycarbonate with CO2 is the best choice for the material of the slope solar collector cover.

关键词： Polycarbonates

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Coupled double-distribution-function lattice Boltzmann method for the compressible Navier-Stokes equations

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Physical Review E 2007年第5期76卷 056705-056705页

作者： Q. Li Y. L. He Y. Wang W. Q. Tao State Key Laboratory of Multiphase Flow School of Energy and Power Engineering Xi’an Jiaotong University Xi’an Shaanxi 710049 China

A coupled double-distribution-function lattice Boltzmann method is developed for the compressible Navier-Stokes equations. Different from existing thermal lattice Boltzmann methods, this method can recover the compressible Navier-Stokes equations with a flexible specific-heat ratio and Prandtl number. In the method, a density distribution function based on a multispeed lattice is used to recover the compressible continuity and momentum equations, while the compressible energy equation is recovered by an energy distribution function. The energy distribution function is then coupled to the density distribution function via the thermal equation of state. In order to obtain an adjustable specific-heat ratio, a constant related to the specific-heat ratio is introduced into the equilibrium energy distribution function. Two different coupled double-distribution-function lattice Boltzmann models are also proposed in the paper. Numerical simulations are performed for the Riemann problem, the double-Mach-reflection problem, and the Couette flow with a range of specific-heat ratios and Prandtl numbers. The numerical results are found to be in excellent agreement with analytical and/or other solutions.

关键词： NUMERICAL-SIMULATION STRONG SHOCKS flowS MODEL SCHEMES CONNECTION

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A New Measuring Method of Oil‐water‐gas Three Phase flowrate by Using of Heat Transfer and Fluid Dynamics

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AIP Conference Proceedings 2007年第1期914卷 221-225页

作者： Hongwei Liao Siyi Zhou Lei Liu Fangde Zhou Key State Laboratory of Multiphase Flow In Power engineering Xian Jiaotong University Xian. China

It is so difficult to measure individual flowrates of oil‐water‐gas three phase on‐line that very few real three phase flowmeters have been developed in the world. This paper presents a new measuring method of oil‐water‐gas three phase flowrate by using of heat transfer and fluid dynamics. A cylindrical cyclone is used to separating the most of natural gas from oil‐water‐gas three phase mixture. A flow mixer is used to homogenize oil and gas flow in a short distance for measurement of bulk flow velocity. A venture‐tube is used to measure overall flowrate of three phase mixture. An inverse‐U tube is used to measure gas fraction. The heat transfer way is used to measure water fraction. No radiation method is used. So this kind of flowmeter is much more safety, and has much more accuracy. Many room and field experiments have been done. The test results done by the Test Institute of Petroleum Industry of Daqing Oil Field Construction & Design Research Institute were quite well. This kind of three phase flowmeter has been widely used in many oil fields.

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Measurement of current distributions in a PEM fuel cell with interdigitated flow Fields

Measurement of current distributions in a PEM fuel cell with...

引用

7th Symposium Devoted to Proton Exchange Membrane Fuel Cells - 212th ECS Meeting

作者： Zhang, G.S. Ma, B. Shang, D.H. Guo, L.J. Sun, H. Liu, H.T. State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an Shaanxi 710049 China Department of Mechanical and Aerospace Engineering University of Miami Coral Gables FL 33124 United States Electrochemical Society

ISBN: (纸本)9781566775823

Current distributions in a PEM fuel cell with interdigitated flow fields were measured with the current distribution measurement gasket technique. The measurement results showed that current density distribution in a fuel cell with interdigitated flow fields is much more uniform than those observed in a fuel cell with serpentine flow fields, especially at low reactant gas flows. The more uniform current distribution can be attributed to more uniform flow distribution over the flow fields. Measurement results also showed that interdigitated flow fields have very good water removal capability and no flooding phenomena were observed at high humidification temperatures;while at low humidification temperatures, the effect of drying is more severe than that found in serpentine flow fields. © The Electrochemical Society.

关键词： Proton exchange membrane fuel cells (PEMFC)

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Design of High-Order Difference Scheme and Analysis of Solution Characteristics - Part II: A Kind of Third-Order Difference Scheme and New Scheme Design Theory

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Numerical Heat Transfer: Part B -- Fundamentals 2007年第3期52卷 271-295页

作者： Jin, W. W. Tao, W. Q. wqtao@*** State Key Laboratory of Multiphase Flow in Power Engineering School of Energy &Power Engineering Xi''an Jiaotong University Xi''an People''s Republic of China

In this Part II, on the basis of the general style design of second-order difference scheme and the analysis of the absolutely stable scheme proposed in Part I, the companion article, the general design method of any high-order difference scheme is proposed. Based on this method, a new kind of third-order difference scheme including 17 different variants is constructed, which uses the same grid points as existing second-order difference schemes but is different from them in that the grids are chosen symmetrically from two sides of the interface. Because they have the same matrix style created by the same grid plots of the discretization equation, these third-order schemes require the same CPU time and memory as the second-order schemes; however, this kind of symmetrical third-order difference scheme will keep the consistency between the false diffusion and the stability, and the stability of the scheme is better than that of the existing biased second-order scheme. Further research shows that under the conditions of matrix style and computer memory, the scheme constituted by symmetrically numbered grids from two sides of the interface with odd order of accuracy can maintain consistency between numerical accuracy and stability better than any kind of scheme designed according to the 'upwind' idea. Based on this understanding, a new scheme design theory called symmetric and odd-order accuracy scheme design theory is proposed. [ABSTRACT FROM AUTHOR]

关键词： power (Mechanics) NUMERICAL analysis HEAT transfer multiphase flow NUMERICAL calculations

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Experimental study on optical properties of the collector

引用

International Solar Energy Society Solar World Congress 2007, ISES 2007

作者： Wang, Juan Zhao, Liang Li, Huashan School of Science Xi'an Jiaotong University P.O. Box 2264 Xi'an 710049 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

ISBN: (纸本)9781622765447

Solar collector is one of the most important parts of solar chimney power plant. It plays an important role in improving the efficiency and saving the cost of the whole system. In this paper, several transparent materials which could be used as the collector were chosen to study the optical properties. The materials include polymethyl methacrylate (PMMA), polycarbonate (PC), perspex (PS) and ordinary glass. Firstly, an experiment device was designed with the collector angles varying from 15° to 60°. Secondly, different thickness of glass and different slope angles of the collector of these materials mentioned above on transmittance was compared. The effect of pollutions caused by the natural environment such as dust, rain and aging on these materials was considered in the experiment. Based on the experimental results, a conclusion was made that PMMA has the highest transmittance among the four materials without considering other factors.

关键词： Optical properties

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