摘要
油气井地面装置中,天然气中含有泥砂,管道输送介质为气-固两相流,节流阀内部在气-固两相流(特别是其中的砂粒)持续冲击和切削作用下会产生冲蚀破坏。以锥形节流阀和楔形节流阀为基础研究对象,提出3种改进的结构形式:圆台状阀芯锥形节流阀、圆台状阀芯楔形节流阀、三段式阀芯楔形节流阀。以规格为DN 50 mm的上述5种节流阀为例,采用Pro/E 5.0软件建立几何模型,应用ANSYS Fluent 14.5软件进行建模分析,天然气作为连续相,砂粒作为离散相,连续相采用RNG k-ε湍流模型,离散相采用离散相模型,冲蚀速率模型采用ANSYS Fluent14.5中定义的冲蚀速率公式。得到如下结论:在气-固两相流条件下,节流阀内部的冲蚀破坏不可避免。节流阀内部产生冲蚀破坏的位置为阀芯的迎流壁面处、阀芯与节流孔交接处以及出口管段内壁面处,软件模拟结果与现场冲蚀失效情况一致。3种改进后的阀芯结构在一定程度上均改变了砂粒的运动轨迹,减小了对出口管段内壁面的冲蚀,对节流阀冲蚀控制的主要区域起到一定的保护作用。除采取改进阀芯结构的方法外,还可以通过采用耐冲蚀材料、涂层保护、加装硬质合金套、加装防冲刺短节等措施减缓节流阀内部的冲蚀破坏。
In the oil and gas well surface equipment,natural gas contains mud and sand,and the pipeline transport medium is gas-solid two-phase flow. Inside the throttle valve,erosion damage will occur under the continuous impact and cutting action of the gas-solid two-phase flow( especially the sand particles therein). Based on conical throttle valve and wedge throttle valve,three improved structural forms are proposed:conical throttle valve of round table valve core,wedge throttle valve of round table valve core and wedge throttle valve of three section valve core. Taking the abovementioned five types of throttle valves with a size of DN50 mm as examples,a geometric model was established using Pro/E 5. 0 software,and modeling analysis was performed using ANSYS Fluent 14. 5 software. Natural gas is used as the continuous phase,sand is used as the discrete phase,RNG k-ε turbulence model is used for the continuous phase,discrete phase model is used for the discrete phase,and erosion rate formula defined in ANSYS Fluent 14. 5 is used for erosion rate model.The conclusions are as follows: Under the condition of gas-solid two-phase flow,erosion damage inside throttle valve is unavoidable. The locations of erosion damage inside the throttle valve are the facing wall of the valve core,the junction of the valve core and the throttle hole,and the inner wall surface of the outlet pipe section. The software simulation results are consistent with the field erosion failure. To some extent,the three modified valve core structures have changed the movement track of sand particles,reduced the erosion of the inner wall of the outlet pipe section,and played a certain protective role in the main area of throttle valve erosion control. In addition to adopting methods to improve the structure of the valve core,the erosion damage inside the throttle can also be slowed down by adopting measures such as erosion-resistant materials,coating protection,installation of hard alloy sleeves,and installation of anti-sprint short joints.
作者
钱东良
田辉芳
QIAN Dongliang;TIAN Huifang
出处
《煤气与热力》
2020年第4期J0024-J0031,J0045,J0046,共10页
Gas & Heat
关键词
油气井地面装置
节流阀
气-固两相流
含砂天然气
冲蚀速率
oil and gas well surface equipment
throttle valve
gas-solid two-phase flow
sandy natural gas
erosion rate
