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郭烈锦, Xuejun Chen, Liejin Guo*
International Journal of Multiphase Flow 25(1999)1053-1072,-0001,():
-1年11月30日
Experimental investigations on oil-air-water three-phase flow were carried out in two helically coiled tubes with inner diameter of 39mm and coil diameters of 265 and 522.5mm, respectively. The purpose of this work is to provide a basis for the invention and development of a new kind of separation technology for gas-oil-water mixtures with low oil fraction β≤30%. The flow patterns of oil-water two-phase flow and oil-air-water three-phase flow were directly observed in test sections made of plexiglass tubes. The flows observed in coiled tubes could be classified into more than four flow patterns and some flow regime maps were generated and delineated for these tubes. The present results were compared with some results in horizontal flow. The phase inversion characteristics in helically coiled tubes were also discussed. The frictional pressure drop of oil-air-water three-phase flow were measured. The effects of flow rates and liquid properties on pressure drop were examined. Based on the experimental data and analysis of the flow mechanism the criteria for the flow pattern transition boundaries between two different flow patterns were proposed in terms of dimensionless parameters. Correlations for the predictions of pressure drop were also obtained.
Oil-air-water three-phase flows, Flow patterns, Frictional pressure drop, Helically coiled tube
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郭烈锦, Liejin Guo*, Ziping Feng, Xuejun Chen
International Journal of Heat and Mass Transfer 44(2001)2601-2610,-0001,():
-1年11月30日
Fractional pressure drops of single-phase water and steam-water two-phase flows were studied in a pressure range of 3.0-3.5 Mpa. Two helical coiled tubes were employed as test sections and their four different helix axial inclinations were examined. It is found that helix axial angles have little influence on the single-phase Frictional pressure drop, while variation of the steam-water two-phase flow frictional pressure drop is enlarged to 70%. For single-phase flow, some previous correlations were quite accurate in predicting the frictional pressure drop for lower Reynolds number conditions, and a modified correlation was obtained from an enlarged Reynolds number range of the present test. For boiling two-phase flow, great deviation was found among the published few empirical equations and their capability of practical utilization is rather poor on account of their complication in structure. A new easily stipulated correlation is deducted from our present data.
Steam-water two-phase flow, Frictional pressure drop, Helical coiled tubes
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【期刊论文】Liquid-solid separation phenomena of two-phase turbulent flow in curved pipes
郭烈锦, Hui Gao, Liejin Guo*, Ximin Zhang
International Journal of Heat and Mass Transfer 45(2002)4995-5005,-0001,():
-1年11月30日
The present study is to contribute some knowledge of phase separation phenomena of liquid-solid two-phase turbulent flow in curved pipes and provide a basis for the invention and development of a new type of curved pipe separator. Firstly, the solid-liquid two-phase flows in two-dimensional (2D) curved channels were numerically simulated using a two-way coupling Euler-Lagrangian scheme. Phase distribution characteristics of 2D curved channel twophase flow were examined under conditions of different particle size, liquid flowrate and coil curvature. Based on the numerical results, the dynamic effects and contributions to phase separation of particle-subjected forces, including centrifugal force, drag force, pressure gradient force, gravity force, buoyancy force, virtual mass force and lift force, were exposed by kinematic and dynamic analysis alongparticle trajectories. Secondly, measurement of particle size and concentration profiles in helically coiled tube two-phase flow was conducted usinga nonintrusive Malvern 2600 particle sizer based on laser diffraction. Particle size and concentration distribution characteristics of helically coiled tube twophase flow and the effect of secondary flow on phase separation were analyzed based on experimental data.
Curved pipe, Phase separation, Turbulence, Liquid-solid two-phase flow, Numerical simulation
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郭烈锦, X.H. Hao, L.J. Guo*, X. Mao, X.M. Zhang, X.J. Chen
International Journal of Hydrogen Energy 28(2003)55-64,-0001,():
-1年11月30日
Thermochemical gasification of biomass has been identified as a possible system for producing renewable hydrogen. A continuous tubular supercritical water gasification system is under development that can be used for solution or slurry materials gasification without drying. A unique feature of this system is its ability to realize the overall high-pressure continuous reaction by operating the valves. By the use of this system, designed for temperatures up to 923.15K and pressures up to 35MPa, glucose, as a model compound of biomass, was gasified in supercritical water at a series of temperature and pressure during different resident times to form a product gas composed of H2, CO, CH4, CO2, and a small amount of C2H4 and C2H6. Glucose at low concentrations (ca. 0.1M) can be completely gasified in 923.15K, 25MPa, and 3.6min resident time and no char or tar was observed. Consequently, we adopted these conditions as baseline reaction conditions for the following glucose concentration, alkali addition and reactor tube diameter effect studies. The raw biomass feedstock of sawdust with some CMC was also gasified in this system, the gasification efficiency in excess of 95% was reached.
Hydrogen production, Biomass, Supercritical water
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郭烈锦, Lie-Jin Guo*, Guang-Jun Li, Xue-Jun Chen
International Journal of Heat and Mass Transfer 45(2002)1525-1534,-0001,():
-1年11月30日
A linear instability analysis was conducted firstly on the interface of a stratified gas-liquid two-phase flow in a circular piper employing a two-fluid model. The constitutive equations simulation technique was discussed, and the dispersive equation of interfacial waves was derived. The effects of flow rates of gas and liquid, liquid viscosity, surface tension and tube inclination on the stability of interface were investigated. A set of non-linear hyperbolic governing equations was deduced from the complete two-fluid model equation by omitting the effect of the surface tension and assuming a quasi-steady-state for the gas phase. Using characteristic line and finite difference, the propagation and growth of the interfacial disturbances were investigated in terms of gas and liquid superficial velocities. Then the results of the non-linear stability analysis were compared with those obtained by the linear stability analysis and experimental data. The non-linear stability analysis not only confirms the conclusions reached by the linear instability analysis, but also gives an insight into the growth and propagation of the interfacial disturbances on the interface of a gas-liquid two-phase flow.
Gas-liquid two-phase flow, Interfacial waves, Linear and non-linear stability analysis, Characteristic line, Numerical simulation
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