三偏心蝶阀的力矩计算及结构优化

发布时间：2018-11-25 08:56

【摘要】：三偏心金属密封蝶阀因其温度压力适用范围广,可实现“零泄漏”密封,近年来得到迅猛发展。但是三偏心蝶阀的启闭运动是一个复杂的三维空间运动轨迹,要求蝶板与阀座在开启与关闭过程中无干涉,密封比压分布相对均匀。迄今为止国内尚未对其进行系统的研究及合理规范的设计计算,致使三偏心蝶阀的发展及应用受到一定程度的限制。本文阐述了三偏心蝶阀的结构,推导出沿蝶板厚度任意截面的几何方程并对其性质进行了分析。结果表明,沿蝶板厚度的平行截面轮廓线为标准的椭圆形,进而推导出了蝶板几个主要截面几何参数之间的关系。本文对三偏心蝶阀蝶板在关闭瞬间和开启瞬间分别做了受力分析,并推导出在这两种工况下摩擦力矩和阀杆扭矩的计算公式。本文对三偏心蝶阀蝶板密封面的摩擦力矩的计算公式作了推导并进行了定性的分析。结果表明,三偏心蝶阀的轴向偏心距对蝶阀的摩擦力矩影响不大,几乎成水平直线;径向偏心距与摩擦力矩近似成正比;角偏心与摩擦力矩近似成反比。本文还对三偏心蝶阀的阀杆扭矩公式作了推导并进行了计算验证。结果表明,径向偏心距与阀杆扭矩近似成正比,而轴向偏心和角偏心对阀杆扭矩的影响不大。
[Abstract]:Three-eccentric metal seal butterfly valve has been developed rapidly in recent years because of its wide application range of temperature and pressure and the realization of "zero leakage" seal. But the opening and closing motion of the three-eccentric butterfly valve is a complicated three-dimensional movement track, which requires that the butterfly plate and the valve seat have no interference in the process of opening and closing, and the distribution of the sealing specific pressure is relatively uniform. Up to now, there is no systematic research and reasonable standard design and calculation, which limits the development and application of tri-eccentric butterfly valve to a certain extent. In this paper, the structure of three-eccentric butterfly valve is described, the geometric equation of arbitrary section along the thickness of butterfly plate is derived and its properties are analyzed. The results show that the parallel section contour along the thickness of the butterfly plate is a standard ellipse, and the relationship between several main section geometric parameters of the butterfly plate is deduced. In this paper, the forces on the butterfly plate of the three-eccentric butterfly valve are analyzed at the closing moment and the opening moment, respectively, and the formulas for calculating the friction torque and the valve stem torque under these two conditions are derived. In this paper, the formula for calculating friction moment of butterfly plate sealing surface of tri-eccentric butterfly valve is deduced and qualitatively analyzed. The results show that the axial eccentricity of the three-eccentric butterfly valve has little effect on the friction torque of the butterfly valve and almost becomes a horizontal straight line; the radial eccentricity is approximately proportional to the friction moment; and the angular eccentricity is approximately inversely proportional to the friction moment. The formula of valve stem torque of three eccentric butterfly valve is deduced and verified. The results show that radial eccentricity is approximately proportional to stem torque, while axial eccentricity and angular eccentricity have little effect on stem torque.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH134

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