螺杆泵丁腈基定子橡胶磨粒侵蚀行为研究

发布时间：2018-05-19 09:48

本文选题：橡胶定子 + 金属转子　；参考：《沈阳工业大学》2017年硕士论文

【摘要】：在螺杆泵的运行初期,为了保证容积效率,橡胶定子与金属转子之间设置为过盈配合,两者之间形成较大的挤压。在运行过程中,金属转子携带含砂原油介质与橡胶定子发生磨损行为。随着橡胶定子的磨损,定子与转子之间的过盈量逐渐减小,并向间隙配合过渡。在间隙配合下,砂粒的切削作用使橡胶定子磨损,容积效率降低。当橡胶磨损达到一定程度,排量达不到使用要求时,导致螺杆泵报废。在过盈配合——间隙配合——螺杆泵报废的过程,其使用寿命与橡胶定子的耐磨性能息息相关。现阶段,人们已开展了橡胶密封件的二体磨损、三体磨粒磨损以及橡胶密封件配方的研制等工作,取得了很多研究成果,但还没有基于螺杆泵失效过程开展橡胶定子磨粒侵蚀的研究。为此,本文利用自行研制的磨损间隙调整式环块摩擦磨损试验机,在不同过盈配合和间隙配合下研究丁腈基定子橡胶的磨粒侵蚀行为,分析不同过盈量、间隙量以及不同形状砂粒对橡胶侵蚀磨损的影响,并观测橡胶磨痕表面的形貌。结果表明:干摩擦下随着过盈量的增加,丁腈橡胶的摩擦温度和磨损量不断增大,摩擦扭矩达到稳定时所需的时间先增加后降低,在0.6mm时达到峰值。过盈量较小时,摩擦力比较平缓;而在大过盈时摩擦力急剧上升。其原因在于大过盈量下橡胶表面接触压力大,产生的摩擦热使橡胶软化,发生粘着磨损,并出现胶合现象。在含砂原油介质中,随着过盈量的增大,丁腈橡胶的摩擦力和磨损量均先降低后趋于平稳。原油中的砂粒对橡胶表面产生犁削作用,在表面形成划痕和凹坑。间隙配合条件下,随着间隙量的增加,丁腈橡胶的摩擦力和磨损量曲线先急剧降低后趋于稳定。随着原油中砂粒尺寸的增大,砂粒与橡胶表面的接触面积增大,丁腈橡胶的摩擦力、磨损量均不断增大。在间隙配合下,含尖形砂粒原油介质下橡胶的磨损量大于圆形砂粒原油介质,其原因在于尖形砂粒有多个切削刃,更容易被压入橡胶表面,对橡胶表面的切削作用明显。本论文的研究不仅对橡胶磨损理论的发展有重要的研究价值,也对提高潜油螺杆泵等液体混输设备的有效寿命具有实际意义。
[Abstract]:In the initial stage of the screw pump, in order to ensure the volumetric efficiency, the interference fit between the rubber stator and the metal rotor was set, and a large extrusion was formed between the two. During operation, the metal rotor carries sand-bearing crude oil medium and rubber stator wear behavior. With the wear of the rubber stator, the interference between the stator and the rotor decreases gradually and transitions to the clearance fit. With the clearance fit, the cutting action of sand particles makes the rubber stator wear and reduce the volumetric efficiency. When rubber wear up to a certain extent, displacement can not reach the requirements, leading to screw pump scrap. The service life of interference fit-clearance fit-screw pump is closely related to the wear resistance of rubber stator. At this stage, people have carried out the work of two-body wear, three-body abrasive wear and the development of rubber seal formula, and obtained a lot of research results. However, there is no research on abrasion erosion of rubber stator based on the failure process of screw pump. In this paper, the abrasive erosion behavior of butadiene-based stator rubber was studied by using a self-developed friction and wear tester with adjustable wear gap and different interference fit and clearance fit, and the different interference amounts were analyzed. The effects of clearance amount and sand particles of different shapes on the erosive wear of rubber were investigated and the surface morphology of rubber abrasions was observed. The results show that the friction temperature and wear amount of nitrile rubber increase with the increase of interference under dry friction. The time required for friction torque to reach stability first increases and then decreases, and reaches the peak value at 0.6mm. When the interference is small, the friction force is more gentle, while the friction force increases sharply when the interference is large. The reason lies in the high contact pressure of rubber surface under large interference, the friction heat produced makes rubber soften, the adhesive wear occurs, and the phenomenon of adhesion occurs. In the medium containing sand crude oil, the friction force and wear rate of NBR decrease first and then tend to steady with the increase of interference. Sand in crude oil ploughs the rubber surface, forming scratches and pits on the surface. Under the condition of gap fit, the friction and wear curves of NBR decreased sharply and then tended to stabilize with the increase of clearance. With the increase of grain size in crude oil, the contact area between sand and rubber surface increases, and the friction and wear of NBR increase. The wear rate of rubber in the oil medium containing sharp sand grain is larger than that in the oil medium containing circular sand grain under the condition of clearance coordination. The reason is that there are many cutting edges in the sharp sand grain, so it is easier to be pressed into the rubber surface, and the cutting effect on the rubber surface is obvious. The research in this paper is not only of great value to the development of rubber wear theory, but also of practical significance to improve the effective life of submersible screw pump and other liquid mixing equipment.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE933.3;TQ336.5

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