石油化工泵用机械密封的可靠性参数估计

石油化工泵用机械密封的失效分为早期失效、偶然失效和耗损失效三种,其失效模式符合威布尔分布.给出了机械密封失效模式的威布尔表达式,介绍了采用矩估计法、极大似然估计法和线性回归分析法对机械密封可靠性数据进行参数估计的实用方法,提出了机械密封可靠度及寿命的计算方法.     

Influence analysis of secondary O-ring seals in dynamic behavior of spiral groove gas face seals

The current research on secondary O-ring seals used in mechanical seals has begun to focus on their dynamic properties. However, detailed analysis of the dynamic properties of O-ring seals in spiral groove gas face seals is lacking. In particular a transient study and a difference analysis of steady-state and transient performance are imperative. In this paper, a case study is performed to gauge the effect of secondary O-ring seals on the dynamic behavior (steady-state performance and transient performance) of face seals. A numerical finite element method (FEM) model is developed for the dynamic analysis of spiral groove gas face seals with a flexibly mounted stator in the axial and angular modes. The rotor tilt angle, static stator tilt angle and O-ring damping are selected to investigate the effect of O-ring seals on face seals during stable running operation. The results show that the angular factor can be ignored to save time in the simulation under small damping or undamped conditions. However, large O-ring damping has an enormous effect on the angular phase difference of mated rings, affecting the steady-state performance of face seals and largely increasing the possibility of face contact that reduces the service life of face seals. A pressure drop fluctuation is carried out to analyze the effect of O-ring seals on the transient performance of face seals. The results show that face seals could remain stable without support stiffness and O-ring damping during normal stable operation but may enter a large-leakage state when confronting instantaneous fluctuations. The oscillation-amplitude shortening effect of O-ring damping on the axial mode is much greater than that on the angular modes and O-ring damping prefers to cater for axial motion at the cost of angular motion. This research proposes a detailed dynamic-property study of O-ring seals in spiral groove gas face seals, to assist in the design of face seals.     

变工况机械密封端面运动实验分析

通过采用螺旋增压辅助手段开发的抗变机械密封和普通机械密封对比实验，探讨了热油泵机械密封在工况变化时动环开启失效机制，分析了相同压力和相同温度、相同温度和不同压力、相同压力和不同温度3种情况下机械密封对比实验结果。结果表明：普通热油泵机械密封在工况变化时会因闪蒸而开启失效，而抗变机械密封采用螺旋辅助增压手段提高密封出口端压力．有效改变汽化半径，使密封端面处于全液相状况．从而具备较强的抗变工况能力。     

基于专家经验法的机械密封基本事件失效概率分析方法

该文针对在缺失大量失效统计数据时获得机械密封失效概率非常困难的状况,采用专家经验法对机械密封发生失效的基本事件进行定性判断,并采用模糊集理论,对专家给出的机械密封失效基本事件的失效概率进行定量分析,综合判断机械密封失效的基本事件的发生概率,获得基于专家经验法分析机械密封基本事件失效发生的概率值,指导机械密封的故障诊断,获得机械密封可靠性评估的基础数据。同时该方法可为研究机械密封可靠性提供一种研究思路。     

浅析新型机械密封在矿用潜水泥浆泵中的研究和应用

本文对新型机械密封在矿用潜水泥浆泵中的应用进行了较全面的阐述,介绍了机械密封的工作原理、结构型式、性能特性、发展趋势,分析了密封端面开槽技术的应用,并运用先进的CFD软件对密封端面进行了仿真,为泵用机械密封的研究和发展有着重要意义。     

机械密封的功率消耗试验及测量方法

随着机械密封应用的普及、机械密封的失效已成为石油化工等部门的回转机械（离心泵等）工作不可靠的重要因素,机械密封的端面摩擦不但直接消耗能源,而且,因端面摩擦过度而引起的密封失效泄漏所造成的损失则更大。本文在试验的基础上,研究了机械密封消耗的构成,介绍机械密封摩擦功率的测量方法,对机械密封不同工况不功率消耗的变化进行了分析,提出了降低机械密封功率消耗和改善密封功能,提高机械密封的工作可靠性的途径。     

Parametric study on balance ratio of mechanical face seal in steam environment

An experimental study on friction and wear of carbon-graphite mechanical face seal, used in rotary joints of paper industries, has been presented. Experimental setup has been designed and developed to simulate the actual industrial environment faced by mechanical seal. Actual mechanical face seals (same material, surface roughness and dimensions) have been used to explore the effect of operating environments, steam pressures, speeds and balance ratios on the wear rates and friction losses. An experimental parametric study on four balance ratio conditions with constant speed and variable steam pressures has been performed, which has shown that a substantial reduction in frictional torques and wear rates is achievable with low balance ratios. The photomicrographs of seal wear and list of weight loss data have been reported in the present paper. The measured frictional torque data are also plotted against the balance ratios and finally the required balance ratio condition, to achieve an approximately 2 year's service life of mechanical seal, has been proposed.     

新型上游泵送密封在污水泵上的开发应用

针对污水泵现场工况条件及原用普通接触式机械密封存在的问题，开发设计出适用于污水泵的零泄漏上游泵送机械密封。工业应用结果表明，开发的集装式上游泵送机械密封可实现含固体颗粒介质的零泄漏。且具有使用寿命长、抗干扰能力强、运行费用低、安装维修方便等系列优点。     

上游泵送机械密封在液化汽泵上的应用研究

针对液化汽泵现场工况条件,分析了泵用普通接触式密封存在的问题,开发设计出适用液化汽泵的零逸出上游泵送机械密封,工业应用结果表明,上游泵送机械密封可实现易挥发性介质的零逸出,且具有使用寿命长,运行费用低,安全可靠等优点。     

流体密封技术

流体密封作为一门新兴的工程技术学科正越来越受到各行业的关注。本文对流体密封的定义、作用、重要性、分类、涉及的主要学科、主要应用领域以及最新进展作一简单介绍，并阐述了高速透平压缩机轴封经历的四个发展阶段：迷宫密封、浮环密封、机械密封、干气密封。干气密封是最先进的轴端密封形式，已在炼油、化工等行业高速透平压缩机上得到越来越广泛的应用。