气井气液两相管流压降计算模型评价与优选

目前工程上常用的气液两相管流压降计算模型建立的基础不同,其适用条件均具有一定的局限性。特别是含水气井,不同气水比时,气井井底流压计算结果差异大,影响气井生产动态分析和优化的准确性。鉴于此,文中整理了国内外102组气井生产实测数据,对8种常用气液两相管流压降模型进行评价与优选。结果表明:气水比大于2 441 m~3/m~3时,Hagedorn-Brown模型和Gray模型计算结果与实测数据最吻合,平均相对误差最小;气水比小于2 441 m~3/m~3时,Beggs-Brill模型计算结果与实测数据最吻合,平均相对误差最小。因此,气水比大于2 441 m~3/m~3的气井推荐使用Hagedorn-Brown模型或Gray模型计算,气水比小于2 441 m~3/m~3的气井推荐使用Beggs-Brill模型计算。     

油品脱水用碟式离心机的流场及分离性能

研究对象为油品脱水用碟式离心机，通过CFD模拟研究了碟式离心机碟片上螺旋型筋条对碟片间两相三维流动的影响规律。结果表明，同一径向位置上，相邻两碟片间液流的周向速度在平行于转轴的面内呈抛物线分布，接触碟片表面处流体跟随碟片旋转，远离碟片处流体的周向速度大于碟片的周向速度；螺旋型筋条能够有效地减小这种滞后性，而且能够有效地减小碟片间流动的湍流强度；不同碟片间的分散相体积分数分布不一，顶层和底层中的高，中间层内的低；同一碟片间，中性进料孔和定距筋条附近有水相浓集现象。螺旋型筋条能够有效地提高分散相分布的均匀性和分离效率，研究发现，螺旋型筋条的碟片结构能使碟式离心机实现航空煤油的高精度分离。     

Pressure Data Analysis in Two Phase Naturally Fractured Reservoirs With a Pseudo Steady State Flow Regime Using the TDS Technique

The matrix-to-fracture interporosity parameter (λ), and fracture storativity (ω) are subject to changes during the life of an oil field. This depends entirely on the nature of saturation condition both in fractures and matrix blocks. Failure to consider two-phase flow parameters will result in inaccurate estimation of reservoir parameters. Because of the high amount of this type of behavior in many reservoirs worldwide, developing appropriate method is very important. A new procedure is presented for analyzing transient test in naturally fractured reservoirs with pseudo steady state two-phase (oil and water) flow using direct synthesis technique (TDS) to determining reservoir parameters. TDS is a modern technique that utilizes the characteristic lines and points found on the pressure and pressure derivative log-log plot. These points and lines are then used with appropriate equations to solve directly for desired reservoir parameters. The proposed methodology is successfully verified by its application to field simulated pressure data and a step-by-step procedure for calculating these parameters is included.     

Numerical Analysis of Two-Phase Electrophoresis

Numerical modeling results for electrophoresis in aqueous two-phase systems are shown to agree with experimental results in both batch and flow devices. A previously discovered polarization effect due to the phase partitioning is further investigated. Numerical and experimental results indicate that this polarization effect is not always significant since it is small for systems with equilibrium partition coefficients near 1 and since its influence diminishes with increasing electric field strength and electrophoresis time. The numerical models should prove useful for optimizing two-phase electrophoretic separations aimed at either concentrating solutes near the interface or directing them across it.     

Local Measurement of Gas-Liquid Bubbly Flow with a Double-Sensor Probe

A double-sensor probe was used to measure local interfacial parameters of a gas-liquid bubbly flow in a horizontal tube. The parameters included void fraction, interfacial concentration, bubble size distribution, bubble frequency and bubble interface velocity. The authors paid special attention to the probe design and construction for minimizing measurement errors. Measures were also taken in the design of sensor ends for preventing corrosions in the flow. This is an effort to improve the current double-sensor probe technique to meet the ever-increasing needs to local varameter measurements in gas-liquid two-phase flows.     

超微粉碎-微波双水相萃取红花龙胆中环烯醚萜苷类

以红花龙胆全草为原料,采用超微粉碎和微波控温辅助双水相法提取了其中的环烯醚萜苷类。通过单因素实验和正交实验确定了最佳提取工艺;考察了所得环烯醚萜苷类的总抗氧化作用及其清除1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的能力。结果表明,最佳提取工艺为:在30.0 g〔无水乙醇7.8 g(质量分数26%),磷酸氢二钾(K2HPO4)3.0 g (质量分数10%)〕乙醇/K2HPO4双水相体系中,红花龙胆干粉粒度为400目,微波温度(70±1)℃,微波时间110 s,红花龙胆干粉加入量3.5 g,得率为5.48%,相比传统提取工艺热回流得率(3.61%)显著提高。此法能抑制试材内源性水解酶活性且中和植酸(红花龙胆中的酸性物质)来降低溶出环烯醚萜苷类发生聚合反应的几率,有效解决了红花龙胆中环烯醚萜苷类需富集才能检测到的问题;总环烯醚萜苷类的抗氧化能力在0.2～0.6 g/L内强于2,6-二叔丁基-4-甲基苯酚(BHT),对DPPH·的清除能力在0.2～1.0 g/L内强于BHT。     

低温高速动静压轴承气液两相润滑氧介质物性参数获取

研究了高速涡轮泵动静压轴承的液氧润滑介质物性情况,获取了氧介质在单相及两相下的物性参数.研究结果表明:对于单相(液相或气相)氧介质,在一定的压力和温度下可建立其密度和粘度随压力和温度的变化关系或直接查表获得；对于两相氧介质,其物性参数的荻取可以采用两相均质混合模型方法进行计算.计算结果表明在液氧不断汽化并最终转变为气态...     

用相指示器函数方法(分散元概率密度函数)推导及验证湍流稀两相流动的欧拉-欧拉模型

A statistical formalism overcoming some conceptual and practical difficulties arising in existing two-phase flow (2PHF) mathematical modelling has been applied to propose a model for dilute 2PHF turbulent flows.Phase interaction terms with a clear physical meaning enter the equations and the formalism provides some guidelines for the avoidance of closure assumptions or the rational approximation of these terms. Continuous phase averaged continuity, momentum, turbulent kinetic energy and turbulence dissipation rate equations have been rigorously and systematically obtained in a single step. These equations display a structure similar to that for single-phase flows.It is also assumed that dispersed phase dynamics is well described by a probability density function (pdf) equation and Eulerian continuity, momentum and fluctuating kinetic energy equations for the dispersed phase are deduced.An extension of the standard k-c turbulence model for the continuous phase is used. A gradient transport model is adopted for the dispersed phase fluctuating fluxes of momentum and kinetic energy at the non-colliding, large inertia limit. This model is then used to predict the behaviour of three axisymmetric turbulent jets of air laden with solid particles varying in size and concentration. Qualitative and quantitative numerical predictions compare reasonably well with the three different sets of experimental results, studying the influence of particle size, loading ratio and flow confinement velocity.