基于有限元分析的三片式硬密封球阀结构优化与研究

发布时间：2018-11-23 10:09

【摘要】：球阀是流体管路的控制装置。球阀的结构比较简单,密封性较好,相同公称尺寸的阀类,球阀所占的体积较小,质量较轻和材料消耗较少,因而球阀广泛的应用在发电厂、建筑行业等行业中。尤其是在西方工业发达的国家,球阀的使用更加广泛,其可靠性及其他性能指标均达到较高水平,球阀的种类和数量不断扩大。在球阀耐高温、耐高压、大口径、高密封性等方面有了很大的发展。随着金属材料的发展及技术的进步,球阀的使用寿命大大提升。目前,西方国家的研究正在向着球阀优良的调节性能和一阀多用的方向发展。目前三片式硬密封球阀在使用过程中,往往出现阀杆疲劳磨损、密封性失效、球阀的启闭扭矩过大等问题。为了探究阀杆失效原因,减小球阀启闭扭矩,改善球阀密封性能,本文以作者在某实习企业生产的三片式硬密封球阀为研究对象,对球阀的结构特点和密封原理进行了详细分析;并以有限元法为基础,使用Solid works软件建立了三片式硬密封固定球阀各部件三维模型及总装模型,对球体与阀杆接触部位运用ANSYS有限元软件进行应力分析,确定出应力集中的位置;然后通过优化三片式硬密封球阀启闭装置,可减小球阀阀杆与球体的接触应力,避免了应力集中的现象;最后对选定的三片式硬密封固定球阀启闭装置进行密封性能分析与优化,通过增大原设计压力角,使摩擦转矩减小,可提高密封性能。课题的研究结果为企业改进球阀性能、开发新产品提供了重要的理论参考依据。
[Abstract]:Ball valve is the control device of fluid pipeline. The structure of ball valve is simple, the sealing property is better, the valve of same nominal size occupies small volume, lighter mass and less material consumption, so ball valve is widely used in power plant, construction industry and other industries. Especially in the developed countries in the west, the ball valve is more widely used, its reliability and other performance indexes reach a higher level, and the variety and quantity of ball valve are expanding. In ball valve high-temperature resistance, high-pressure, large-caliber, high-tightness and so on has a great development. With the development of metal material and the progress of technology, the service life of ball valve is greatly improved. At present, the research in western countries is developing towards the good regulating performance of ball valve and the multi-use of one valve. At present, there are many problems such as fatigue wear of valve stem, failure of sealing property and excessive opening and closing torque of ball valve in the process of using three-piece hard sealing ball valve. In order to investigate the failure reason of valve stem, reduce the opening and closing torque of ball valve, and improve the sealing performance of ball valve, this paper takes the three-piece hard seal ball valve produced by the author in a practical enterprise as the research object. The structure characteristics and sealing principle of ball valve are analyzed in detail. Based on the finite element method (FEM), the three dimensional model and the assembly model of the three piece hard seal fixed ball valve are established by using Solid works software. The stress analysis of the contact part between the ball and the valve stem is carried out by using the ANSYS finite element software. Determine the location of stress concentration; Then the contact stress between the valve stem and the ball can be reduced by optimizing the opening and closing device of the three-piece hard sealing ball valve, and the phenomenon of stress concentration can be avoided. Finally, the sealing performance of the three-piece hard seal fixed ball valve is analyzed and optimized. The friction torque can be reduced by increasing the original design pressure angle, and the sealing performance can be improved. The research results provide an important theoretical basis for enterprises to improve the performance of ball valves and develop new products.
【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】：TH134

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