组合管中段塞流耗散机理研究
发布时间：2018-08-28 07:47
【摘要】：柱状气液旋流分离器入口整流管主要通过扩径、下倾等几何结构的变化将段塞来流转化为分层流动来消除液塞对分离器旋流段的冲击,改善分离效果。本文对不同结构入口整流管段塞流动参数的沿程变化进行了针对性的模拟与实验研究。借助于Fluent模拟器的自定义接口(udf)利用一维稳态段塞流动模型定义瞬态的段塞流动初始条件并基于VOF多相流模型发展了一种段塞流动模拟的方法,对入口整流管中的液塞耗散规律进行了模拟研究。结果表明这一方法较好地模拟了柱状气液旋流分离器入口整流管中的液塞耗散过程。由模拟结果可以看出在一定范围内下倾角度θ与扩径比K的增大都有助于增强下倾管中的液塞耗散效果,其中扩径比K的增大对液塞耗散效果的增强作用占主要地位;在螺旋曲率D较大时(实际应用中较大)由于离心力的作用较小螺旋下倾管内的耗散规律与下倾直管基本相同,在相同耗散距离下螺旋下倾管出口持液率波动曲线更加平滑,整流效果较好;段塞流动入口会对旋流段的流场造成强烈冲击;下倾角度的增加会在很大程度上抑制气相空间的液相携带,同时提高了气相空间切向速度,这都有利于提高分离效果;但下倾角度的增加液加剧了气液界面气液两相的混合,实际应用中会造成采出液强烈的二次乳化。实验研究了段塞流特征参数在入口整流管中的沿程变化规律,整流管入口与下倾管入口的压力波动规律受立管段的影响随折算速度的变化表现出各异的规律;我们发现在立管段会发生液塞长度LS的增加,在立管顶部达到最大值,进入下倾管后,可以近似认为液塞长度LS的减小呈现出线性关系;液塞速度US在立管段会减小,在立管顶部达到最小值,进入下倾管后,可以近似认为液塞速度US的增加呈现出线性关系;本结构下倾管中的段塞流动与充分发展段塞流动不同之处在于液膜区较薄,液塞持液率明显较低且形状不规则,液塞区与液膜区在沿下倾管流动过程中会得到一定程度的恢复,液塞持液率明显升高。实验研究了整流管几何结构(下倾角度θ、扩径比K、缓冲长度LK)对液塞耗散效果的影响,扩径比K是影响段塞流耗散效果最为重要的一个参数,扩径比K的增大可以有效地促使液塞在较短的下倾距离上很快地耗散,容易发生液塞耗散的区域集中于流型图中段塞流区域的左上角和右下角;下倾角度θ的增大有利于液塞的耗散,随着下倾角度θ的增加,下倾管中的液塞速度US呈现出增大的趋势;在倾斜角度θ较大时液塞长度LS的减小受倾斜角度θ的影响较小,在倾斜角度θ=-21°~-40°范围内液塞耗散速度基本相同;在倾斜角度θ范围为-21°~-40°时随着倾斜角度θ的增加,气液界面趋于平滑;扩径位置对整流效果的影响较小,缓冲长度LK的改变对提高液塞耗散效果的作用不明显。
[Abstract]:The inlet rectifier of the columnar gas-liquid swirl separator transforms the slug flow into a stratified flow by changing the geometric structure such as expanding diameter and downward inclination to eliminate the impact of the slug on the cyclone section of the separator and improve the separation effect. In this paper, the flow parameters of slug in the inlet rectifier of different structures are simulated and experimentally studied. With the help of (udf), a custom interface of Fluent simulator, a method for simulating slug flow is developed by using one-dimensional steady slug flow model to define the initial conditions of transient slug flow and based on VOF multiphase flow model. The dissipation law of liquid plug in inlet rectifier pipe is simulated and studied. The results show that this method can well simulate the slug dissipation process in the inlet rectifier of the columnar gas-liquid cyclone separator. From the simulation results, it can be seen that the increase of the downdip angle 胃 and the expanding diameter ratio K in a certain range is helpful to enhance the liquid slug dissipation effect in the downdip pipe, in which the increasing of the diffusing diameter ratio K plays an important role in enhancing the liquid slug dissipation effect. When the spiral curvature D is larger (in practical application), the dissipation law in the downdip pipe is basically the same as that in the downdip pipe because of the smaller centrifugal force, and the fluctuation curve of the liquid holdup at the outlet of the helical downdip tube is smoother at the same dissipation distance. The rectifying effect is good, the slug inlet will have a strong impact on the flow field of the swirl section, and the increase of the downdip angle will greatly inhibit the liquid phase transport in the gas phase space, and increase the tangential velocity of the gas phase space at the same time. All of these are helpful to improve the separation effect, but the increase of downdip angle intensifies the gas-liquid two-phase mixing at the gas-liquid interface, which will result in the strong secondary emulsification of the produced liquid in practical application. The characteristic parameters of slug flow in the inlet rectifier are studied experimentally. The pressure fluctuation law of the inlet of the rectifier tube and the inlet of the downdip tube is different from the change of the conversion velocity by the influence of the vertical pipe section. We find that the length of liquid slug LS increases in the vertical section and reaches the maximum at the top of the riser. After entering the downdip pipe, it can be approximately assumed that the decrease of the length of liquid plug LS shows a linear relationship, and the liquid plug velocity US will decrease in the vertical section. At the top of the riser, the minimum value is reached, and after entering the downdip pipe, it can be approximately assumed that the increase of the slug velocity US shows a linear relationship, and the difference between the slug flow in the downdip pipe and the fully developed slug flow is that the liquid film area is relatively thin. The liquid holdup of the plug is obviously lower and the shape is irregular. The liquid slug area and the liquid film area will recover to a certain extent during the flow along the downdip pipe, and the liquid slug holdup will increase obviously. The effect of the geometry of rectifier tube (dip angle 胃, radius ratio K, buffer length LK) on the dissipation effect of liquid slug is studied experimentally. The ratio K is the most important parameter affecting the effect of slug flow dissipation. The increase of K can effectively cause the liquid plug to dissipate rapidly at a short downdip distance, and the area prone to liquid slug dissipation is concentrated in the upper left and lower right corner of the slug area in the flow pattern diagram. The increase of down dip angle 胃 is beneficial to the dissipation of liquid plug. With the increase of down dip angle 胃, the US of liquid plug velocity in downdip pipe tends to increase, and the decrease of liquid plug length LS is less affected by inclination angle 胃 when the inclination angle 胃 is larger. In the range of inclination angle 胃 -21 掳-40 掳, the dissipation velocity of liquid plug is basically the same, when the angle 胃 is -21 掳-40 掳, the gas-liquid interface tends to smooth with the increase of inclination angle 胃, and the influence of the expanding position on the effect of rectifier is small. The change of buffer length LK has no obvious effect on improving the dissipation of liquid plug.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE832
本文编号：2208749
[Abstract]:The inlet rectifier of the columnar gas-liquid swirl separator transforms the slug flow into a stratified flow by changing the geometric structure such as expanding diameter and downward inclination to eliminate the impact of the slug on the cyclone section of the separator and improve the separation effect. In this paper, the flow parameters of slug in the inlet rectifier of different structures are simulated and experimentally studied. With the help of (udf), a custom interface of Fluent simulator, a method for simulating slug flow is developed by using one-dimensional steady slug flow model to define the initial conditions of transient slug flow and based on VOF multiphase flow model. The dissipation law of liquid plug in inlet rectifier pipe is simulated and studied. The results show that this method can well simulate the slug dissipation process in the inlet rectifier of the columnar gas-liquid cyclone separator. From the simulation results, it can be seen that the increase of the downdip angle 胃 and the expanding diameter ratio K in a certain range is helpful to enhance the liquid slug dissipation effect in the downdip pipe, in which the increasing of the diffusing diameter ratio K plays an important role in enhancing the liquid slug dissipation effect. When the spiral curvature D is larger (in practical application), the dissipation law in the downdip pipe is basically the same as that in the downdip pipe because of the smaller centrifugal force, and the fluctuation curve of the liquid holdup at the outlet of the helical downdip tube is smoother at the same dissipation distance. The rectifying effect is good, the slug inlet will have a strong impact on the flow field of the swirl section, and the increase of the downdip angle will greatly inhibit the liquid phase transport in the gas phase space, and increase the tangential velocity of the gas phase space at the same time. All of these are helpful to improve the separation effect, but the increase of downdip angle intensifies the gas-liquid two-phase mixing at the gas-liquid interface, which will result in the strong secondary emulsification of the produced liquid in practical application. The characteristic parameters of slug flow in the inlet rectifier are studied experimentally. The pressure fluctuation law of the inlet of the rectifier tube and the inlet of the downdip tube is different from the change of the conversion velocity by the influence of the vertical pipe section. We find that the length of liquid slug LS increases in the vertical section and reaches the maximum at the top of the riser. After entering the downdip pipe, it can be approximately assumed that the decrease of the length of liquid plug LS shows a linear relationship, and the liquid plug velocity US will decrease in the vertical section. At the top of the riser, the minimum value is reached, and after entering the downdip pipe, it can be approximately assumed that the increase of the slug velocity US shows a linear relationship, and the difference between the slug flow in the downdip pipe and the fully developed slug flow is that the liquid film area is relatively thin. The liquid holdup of the plug is obviously lower and the shape is irregular. The liquid slug area and the liquid film area will recover to a certain extent during the flow along the downdip pipe, and the liquid slug holdup will increase obviously. The effect of the geometry of rectifier tube (dip angle 胃, radius ratio K, buffer length LK) on the dissipation effect of liquid slug is studied experimentally. The ratio K is the most important parameter affecting the effect of slug flow dissipation. The increase of K can effectively cause the liquid plug to dissipate rapidly at a short downdip distance, and the area prone to liquid slug dissipation is concentrated in the upper left and lower right corner of the slug area in the flow pattern diagram. The increase of down dip angle 胃 is beneficial to the dissipation of liquid plug. With the increase of down dip angle 胃, the US of liquid plug velocity in downdip pipe tends to increase, and the decrease of liquid plug length LS is less affected by inclination angle 胃 when the inclination angle 胃 is larger. In the range of inclination angle 胃 -21 掳-40 掳, the dissipation velocity of liquid plug is basically the same, when the angle 胃 is -21 掳-40 掳, the gas-liquid interface tends to smooth with the increase of inclination angle 胃, and the influence of the expanding position on the effect of rectifier is small. The change of buffer length LK has no obvious effect on improving the dissipation of liquid plug.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE832
【参考文献】
相关期刊论文 前2条
1 王鑫,郭烈锦;水平管气液段塞流流量瞬变特性模拟研究[J];工程热物理学报;2004年05期
2 曹学文,林宗虎,黄庆宣,寇杰;新型管柱式气液旋流分离器[J];天然气工业;2002年02期
相关博士学位论文 前1条
1 罗小明;气液两相和油气水三相段塞流流动特性研究[D];中国石油大学;2007年
，本文编号：2208749
本文链接：https://www.wllwen.com/kejilunwen/shiyounenyuanlunwen/2208749.html
