静压干气密封微尺度气膜特性的研究

发布时间：2018-04-30 00:30

本文选题：静压干气密封 + 有限差分法　；参考：《兰州理工大学》2014年硕士论文

【摘要】：干气密封是目前迅速发展的新颖密封类型,被广泛应用于高速回转设备随着工程应用的发展,干气密封开始应用于低速设备,如反应釜轴端密封,然而,高速动压效应理论已不能适用于低速充气式静压润滑理论,迫切需要建立静压干气密封润滑理论来指导工程应用。在工程应用中静压干气密封常常会因气膜厚度的过大或过小,出现泄漏量过大或动静环碰磨的现象,这就需要对气膜厚度进行计算并加以控制。主要研究内容和结论如下： (1)以雷诺方程为核心,进一步推导了静压干气密封气膜润滑控制方程。 (2)采用有限差分法来求解节流孔式静压干气密封气膜雷诺方程；用VB编写了求解静压干气密封气膜雷诺方程的计算程序。 (3)在编写的VB程序中调用MATLAB程序绘制气膜压力分布图。 (4)在流量平衡原理的基础上提出了变步长的逐步逼近的迭代算法。结果表明,气膜径向压力从节流孔向静环内径和外径方向呈近似抛物线状逐渐下降,极大压力出现在节流孔处,极大值为3.567MPa,极小值为0.212MPa；随气膜厚度的增大端面气膜开启力减小；在工况一定的情况下,气膜刚度随着气膜厚度的增大逐渐减小。为了保证计算的准确性,将VB软件计算的径向压力分布,开启力、气膜刚度、泄漏量的计算值与文献值进行了对比,进一步进行了对泄漏量的试验验证,结果表明静压干气密封内,理论计算的泄漏量实测的泄漏量之间相对误差在最大值7.46%,相对误差最小值为1.30%。与实际情况有一定的偏差。泄漏量随着节流孔直径的增大而不断上升。虽然为了降低泄露量可以选择更小的节流孔直径,但是太小的节流孔直径使得加工难度系数大,所以选择合理的节流孔直径对静压干气密封的泄露量有很重要的意义,从而验证了文章VB数值软件计算的准确性。综上所述,为静压干气密封的设计和使用提供了理论基础,对静压干气密封的安全性,可靠性具有非常重要的工程应用价值。
[Abstract]:Dry gas seal is a new type of seal developed rapidly at present. It is widely used in high speed rotary equipment. With the development of engineering application, dry gas seal has been applied to low-speed equipment, such as shaft end seal of reactor, however, The theory of high speed dynamic pressure effect can not be applied to the theory of low speed pneumatic hydrostatic lubrication. It is urgent to establish the theory of hydrostatic dry gas seal lubrication to guide the engineering application. In engineering application, hydrostatic dry gas seal often appears the phenomenon of excessive leakage or static ring rubbing due to the excessive or too small film thickness, which needs to be calculated and controlled. The main contents and conclusions are as follows: 1) the governing equation of hydrostatic dry gas seal film lubrication is derived with Reynolds equation as the core. The finite difference method is used to solve the gas film Reynolds equation of the hydrostatic dry gas seal with orifice, and the program of solving the Reynolds equation of the gas film of the hydrostatic dry gas seal is compiled by VB. In VB program, MATLAB program is used to draw film pressure distribution map. 4) based on the principle of traffic balance, an iterative algorithm of stepwise approximation with variable step size is proposed. The results show that the radial pressure of the gas film decreases gradually from the orifice to the direction of the inner and outer diameter of the static ring, and the maximum pressure appears at the orifice with the maximum value of 3.567 MPa and the minimum value of 0.212 MPA, and the opening force decreases with the increase of the thickness of the film. The film stiffness decreases with the increase of film thickness. In order to ensure the accuracy of the calculation, the calculated values of radial pressure distribution, opening force, film stiffness and leakage volume calculated by VB software are compared with those of the literature. The results show that the relative error of the measured leakage is 7.46 and the minimum relative error is 1.30 in the hydrostatic dry gas seal. There is a certain deviation from the actual situation. The leakage increases with the increase of orifice diameter. Although smaller throttle diameter can be chosen to reduce leakage, but too small throttle diameter makes machining difficulty coefficient large, so choosing reasonable throttle diameter is of great significance to leakage amount of hydrostatic dry gas seal. Thus, the accuracy of the calculation of VB numerical software is verified. To sum up, it provides a theoretical basis for the design and application of hydrostatic dry gas seal, and has very important engineering application value for the safety and reliability of hydrostatic dry gas seal.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB42

【参考文献】

中国期刊全文数据库前10条

1 薛龙,郭德申;真空平衡型气体静压止推轴承刚度分析[J];北京石油化工学院学报;2000年01期

2 郑书飞;蒋书运;;一类改进的气体静压轴承压力场分布有限差分算法(英文)[J];Journal of Southeast University(English Edition);2009年04期

3 王婧;张力;邓达强;陈卫军;徐宗俊;;准气体动力循环Power MEMS气体静压轴承[J];重庆大学学报(自然科学版);2007年07期

4 杜建军,姚英学,崔洋,刘暾;气体静压轴颈-止推串接型轴承静特性的分析[J];航空精密制造技术;2005年02期

5 包钢,樊蕾,李军,王祖温;圆盘多供气孔气体静压止推轴承的有限元分析[J];机床与液压;2003年02期

6 史玉峰,靳奉祥;MATLAB与Visual Basic相结合及其在测绘数据处理中的应用[J];计算机工程与应用;2002年22期

7 孙西芝,陈时锦,程凯;空气静压导轨静态性能的解析计算及分析[J];机械设计与制造;2005年01期

8 李雷磊;;化工高压设备静压干气密封特性研究[J];科技信息;2011年19期

9 杜建军,刘暾,姚英学;狭缝节流气体静压轴颈-止推轴承静态特性分析[J];摩擦学学报;2002年01期

10 杜建军,姚英学,高栋,刘暾;气体静压轴颈-止推串接型轴承涡流力矩的有限元分析[J];润滑与密封;2005年03期