【作者】 王和顺；

【导师】 陈次昌；

【作者基本信息】 西南交通大学 ， 机械设计及理论， 2006， 博士

【摘要】 以提高干气密封运行稳定性为目标。从密封启、停端面脱开；端面槽形改善；建立适当的密封监控系统，这三个方面来进行研究，对应不同的角度提出了多种措施，以达到提高干气密封运行稳定性的目的。 首先，以干气密封启动过程中端面开启力的变化为主要研究对象，对端面在启动和停车过程中的接触情况进行了分析。指出在启、停过程中因转速相对较低，开启力不足以将端面脱开，所以两密封端面处于直接接触状态，端面间摩擦、磨损较严重，对密封性能极为不利。为了消除启、停过程中端面的直接接触，首次提出了启、停端面脱开的概念，并以四川日机密封研究所设计生产的B823d型，单端面干气密封为例，对启、停端面脱开的可行方案进行研究，提出了三种方案，对比分析了它们的优缺点。 其次，用FLUENT对干气密封流体动压的产生、压力分布、承载能力进行了分析计算。指出流场压力分布的特征是：在槽台交界处，气膜压力产生较大变化，即在气体流入的槽台交界处，压力减小，产生局部负压（相对）；气体流出的槽台交界处，压力增大，产生流体动压，而不同的进、出口压差和螺旋角大小，会导致上述两个压力分布区域，沿槽形方向移动，范围大小也将随之变化。 在对密封端面流场进行计算分析的基础上，提出优化槽形，以增大流体动压效应。通过对压缩机用干气密封端面槽形参数进行优化，并将优化后槽与原槽形密封端面开启力、气膜刚度作了对比分析，肯定了槽的优化对密封气膜刚度的提升。 再次，以干气密封端面间隙测量为主要研究内容，在对传统测量方法充分调研的基础上，提出了用CCD来进行端面测量的新方法。该方法的重点是如何提高普通CCD的测量精度，主要理论依据是CCD像素等距错排。通过综合分析各列（行）CCD像元感光情况来获得精确度更高的测量值。以线阵CCD为例，将N个像元间距为H的线阵CCD器件并排组合在一起，并沿像元线性分布方向以距离为H₁=H／N依次均匀错开排列。多个线阵CCD的感光电信号经多通道A／D同步采集，保存到存储器中指定位置。然后，通过对所有CCD测量数据的分析计算来获得精确的测量值。用双线阵CCD错排和单线阵CCD更多还原

【Abstract】 For the purpose of higher stability, face opening at dry gas seal starting and stopping; groove shape reform and proper monitoring system set up are investigated. Several methods are proposed from different point of view to enhance dry gas seal working stability.Firstly, touch status at seal starting and stopping is analyzed through detailed study on face opening force at seal startup. Because too low rotate speed at seal starting and stopping, there’s no enough opening force to open seal’s face, so the two faces of the seal will directly touched, Result in badly friction and wear, it’s too disadvantage to seal. Face opening concept is proposed to avoid face directly touch. Three possible projects of face opening are researched based on the type of B823d, their advantage and disadvantage is analyzed contrastively.Secondly, Numerical calculating use FLUENT is carried out, emphases on hydrodynamic pressure’s forming, distributing, and carrying capacity. Characteristic of fluid field pressure distributing is: at the intersection of groove and stage, there’s clear change of film pressure, at the place gas flow into, pressure will depressed, negative pressure (relatively) zone formed; at the place gas flow out, pressure will increased, hydrodynamic pressure is formed. The two type of pressure distributing zone will displace and reformed with different screw-angle and different press difference of import and export.After sufficiency study of seal face fluid field, reforming groove shape is proposed to gain higher hydrodynamic domino offect. Through optimize the parameters of dry gas seal used by compress machine, and then the optimized seal groove shape and primary groove shape seal is analyzed contrastively, emphases on film stiffness and opening force, result shows: gas film stiffness and opening force will improve by optimizing groove shape, higher stability is gained.Thirdly, the new method by use CCD measure face clearance is proposed through sufficiency study of traditional measurement methods. The key of the new method is how to improve common CCD’s measurement precision, base theoretical更多还原