6500HP型压裂泵柱塞密封结构与性能研究

发布时间：2018-03-09 22:09

本文选题：压裂泵　切入点：柱塞密封　出处：《兰州理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国页岩气主要分布在山区,山区地形复杂,同时作业面积狭小,控制开采设备的数量和占地面积显得尤其重要,用大功率的压裂设备代替目前小功率的压裂设备可以做到减少压裂设备的数量。随着压裂设备的功率增大,对柱塞的密封提出了更高的要求。柱塞的密封结构在防止压裂液泄漏,提高压裂泵容积效率以及保证压裂设备正常运转中起到重要作用。本文对6500HP型压裂泵柱塞密封结构进行设计,并对密封圈的材料、形状进行选型,进而应用有限元对6500HP型压裂泵柱塞密封圈在工作状态下进行仿真,模拟柱塞密封圈的密封性能。在分析过程中对密封圈的几何非线性、材料非线性以及状态非线性加以考虑,研究柱塞密封效果的相关影响因素,研究了机械滞后生热以及摩擦生热对密封圈温度场的影响,对柱塞密封圈进行热应力耦合分析。对柱塞的密封间隙进行研究,研究内容与所得结论如下:1、对橡胶密封圈的结构进行理论分析和建模。通过对V型密封圈结构进行改进设计,运用橡胶的结构非线性理论和材料的超弹性理对柱塞密封圈建立了有限元模型,并对其进行研究分析。研究结果表明:V型密封圈唇部夹角处以及下唇部接近柱塞外侧部分最容易发生失效,其中柱塞与密封圈相对运动的过程中发生摩擦,由于摩擦的存在,使得柱塞密封圈的寿命减少,同时压裂泵内压裂液的工作压力以及柱塞与密封圈之间的摩擦系数对压裂泵柱塞密封效果也有重要影响。2、对柱塞密封圈温度场进行分析。运用传热学理论,对柱塞密封圈的热源进行分析。在压裂泵工作过程中,柱塞与密封圈相对滑动,滑动过程中密封圈热量来源主要有两块:第一块是柱塞与密封圈之间的滑动摩擦产生的热量,这部分热量主要集中在活塞和密封圈接触的部分,使密封圈内唇温度身高;第二块是由于密封圈工作过程中,橡胶材料的机械滞后因素生成的热量。通过V型圈的结构可以看出,唇部橡胶材料少于背部,机械滞后现象主要发生在密封圈背部靠近中心的位置。在滑动摩擦和机械滞后两种因素作用下使得柱塞密封圈的局部温度升高,同时由于压裂液温度的升高以及压裂液工作压力的增大也会造成柱塞密封圈的温度升高。3、对密封圈的温度-结构进行耦合分析。通过将密封圈工作过程中密封圈的温度升高造成密封圈内部应力变化的结果反馈到结构分析中的应力场,反馈结果显示:在环境温度较低时,橡胶热胀冷缩,造成密封材料的弹性下降,随着密封圈弹性的下降会导致密封效果不佳,密封不严,因此泄漏量会随之增加,由于密封圈弹性下降可能造成密封圈局部发生龟裂现象,龟裂发生后,使得密封圈的弹性无法恢复;高温也容易使橡胶密封圈氧化,引起密封圈老化、变形,使得密封圈的张力,弹性以及硬度都会有很大程度的降低。4、对柱塞密封间隙进行建模。通过对柱塞密封圈密封间隙的仿真,分析间隙大小、入口压力、泄漏量三者之间存在的关联,并借助于仿真分析后,获得研究结果为:当入口压力和间隙大小不断扩大时,泄漏量也会同步发生增大现象,并及即便间隙出现细微的变动,泄漏量也会引发巨大变化。
[Abstract]:Shale gas in China are mainly distributed in the mountainous area, mountainous terrain, while the operation area is small, the number of devices and control mining area is particularly important, fracturing equipment with high power to replace the current fracturing equipment small power can reduce the number of fracturing equipment. With the increase of power fracturing equipment, put forward higher requirements on the plunger seal. The sealing structure of the plunger in the fracturing fluid to prevent leakage, improve the volumetric efficiency and ensure the fracturing pump plays an important role in the normal operation of fracturing equipment. In this paper, the 6500HP type fracturing pump plunger seal structure was designed, and the seal material selection, shape, and then the application of finite element of 6500HP sealing ring fracturing pump plunger is simulated in the working state, the sealing performance of the sealing ring of the plunger. Simulation in the analysis process of the sealing ring with geometric nonlinearity, material nonlinearity The nonlinear state and related factors into consideration, the sealing effect of the plunger, studied the influence of mechanical hysteresis heat and friction heat on the temperature field of the sealing ring, sealing ring of the piston thermal stress coupled analysis. Research on the plunger seal gap, research contents and conclusions are as follows: 1. Theoretical analysis and modeling of the structure of rubber sealing ring. The sealing ring structure to improve the design of V type, using the structure of rubber material nonlinear theory and super elastic sealing ring on the plunger and a finite element model was established and analyzed. The results show that the V type seal lip angle and lower lip close to the plunger the lateral part of the most prone to failure, the friction piston and seals the relative motion of the process, due to the existence of friction, reduce the life of plunger seals, and fracturing pump In the fracturing fluid working pressure and the friction coefficient between the plunger and the seal ring sealing effect of plunger has important effect on.2, piston seal temperature field is analyzed. The theory of heat transfer, the heat source of piston seal were analyzed. In the process of fracturing pump, the plunger and the seal ring relative slip. In the process of sliding ring heat sources are mainly two: the first one is sliding friction of the plunger and the seal between the heat generated, the heat is mainly concentrated on the piston and the sealing ring contact part, the seal lip temperature within the circle of the second block is high; because the sealing process, rubber machinery the heat produced by lag factors. Structure of V ring can be seen, the lip rubber material is less than the back, mechanical hysteresis phenomenon occurs in the sealing ring back near the center. The sliding friction and machine The local temperature lag two factors under the action of the piston seal increases, while temperature increases due to increase of fracturing fluid and fracturing fluid pressure can cause the piston seal temperature.3, coupling analysis of sealing ring temperature structure. The sealing ring of the sealing ring temperature increase caused by the sealing ring of the internal stress of the feedback to the structure analysis of the stress field, feedback the results show that: in the low temperature, thermal expansion and contraction of rubber sealing material, resulting in decreased elasticity, with decreasing elastic sealing ring will lead to poor sealing effect, the seal is not strict, so the leakage volume will increase the elastic sealing ring, sealing ring may lead to the decrease in local cracking, cracking, the sealing ring can not restore the elasticity; high temperature is also easy to make rubber seals caused by oxidation,. Sealing ring aging, deformation, making ring tension, elasticity and hardness will greatly reduce.4, seal clearance on the plunger is modeled. Through the simulation of the plunger sealing ring seal gap analysis, the size of the gap between the entrance pressure, leakage of the three related, and with the help of simulation analysis the results obtained, as the entrance pressure and the gap size continues to expand, the leakage will occur simultaneously to increase the phenomenon, and even subtle changes in the gap, leakage will lead to great changes.

【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE934.2

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