闸阀启闭过程磨损机理及流场模拟分析

发布时间：2018-07-05 01:35

本文选题：闸阀 + 流体动力学　；参考：《哈尔滨工程大学》2011年硕士论文

【摘要】：闸阀是油气田井口装置的主要控制部件之一,其性能的优劣直接关系到井口装置的可靠性及钻采施工的安全性。井口闸阀在高温高压工况下,启闭过程存在振动、噪声和内外泄漏,阀板、阀座和阀体内壁出现不同程度的磨损和腐蚀,以及阀板孔扩大、阀座磨损和应力裂纹,个别闸阀出现阀体刺穿现象。本文依据Hutchings摩擦学的磨损理论,结合闸阀实际工况,分析了携带悬浮固体颗粒流体对金属表面的冲蚀机理及金属在H2S、CO2环境中的腐蚀机理,得出了以冲蚀磨损为主的多种磨损与腐蚀磨损的综合作用是导致闸阀快速磨损主要原因的结论。建立了连续、不可压缩、常粘管内流体动力学的质量守恒方程和动量守恒方程,以及闸阀流道的几何模型。在此基础上应用流体动力学数值模拟计算软件FLUENT,采用基于雷诺平均法的标准k-ε两方程涡粘模型,对模型施加了符合实际工况的边界条件进行数值模拟计算。得到了闸阀内部的速度场和压力场,并与理论计算进行了比较,验证了数值模拟计算的结论。最后对闸阀内部流场特性与闸阀快速磨损机理进行分析,得出了小开度下的局部高速低压是闸阀快速磨损的根本原因。在此基础上,提出了闸阀的结构改进方案,并对改进后的流场进行了数值模拟计算,计算结果证明结构改进可以一定程度上减小过流截面的速度以及流体对闸阀的直接冲击。
[Abstract]:The gate valve is one of the main control components of the wellhead device of the oil and gas field . The performance of the gate valve is directly related to the reliability of the wellhead device and the safety of the drilling and mining construction . The wellhead gate valve has vibration , noise and internal and external leakage during the opening and closing process under the condition of high temperature and high pressure , and the valve plate , the valve seat and the inner wall of the valve body have different degrees of wear and corrosion , and the valve plate hole is enlarged , the valve seat wears and the stress crack , and the individual gate valve has a valve body puncture phenomenon .

In this paper , based on the wear theory of tribology and the actual working condition of gate valve , the mechanism of erosion and the corrosion mechanism of metal in H2S and CO2 environment are analyzed .

This paper establishes the mass conservation equation and momentum conservation equation and the momentum conservation equation , and the geometric model of gate valve flow channel based on the Reynolds average method . The velocity field and pressure field in the gate valve are obtained . The numerical simulation results are verified by comparison with the theoretical calculation .

At last , the characteristics of the internal flow field of gate valve and the mechanism of fast wear of gate valve are analyzed , and the root cause of rapid wear of gate valve is obtained . On this basis , the structure improvement scheme of gate valve is put forward , and the improved flow field is calculated . The results show that the structure improvement can reduce the velocity of the cross section and the direct impact of fluid to gate valve .
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH134

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