液压油污染度在线监测系统研制及实验研究

油液污染是液压系统最主要的故障根源,而现有的油液污染检测设备价格昂贵、检测周期长、对操作环境要求严格.该文以特制滤膜为敏感元件,恒功率淤积法为技术原理,结合计算机技术在测量与监测方面的应用,研制出一套基于MCGS工控组态软件的液压油污染度在线监测系统,并完成了对在线监测系统的实验研究.实验研究结果表明,系统监测结果准确可靠,满足了鉴定油液污染等级的要求,可用于油液污染度的现场在线监测,具有一定的推广应用价值.     

淤积原理在液压系统在线污染监测中的应用

采用淤积原理的在线污染监测方法，通过检测流过滤膜某一固定体积时的压差来测量液压系统的油液污染度。研制出在线监测装置，采用电磁铁推动活塞吸油和获得压降，步进电机带动自制金属滤膜旋转实现过滤与反向冲洗功能，利用虚拟仪器软件LabVIEW设计监控平台，并对在线污染监测方法进行了理论分析与实验研究。实验结果表明，在线污染监测方法能给出ISO、NAS与SAE油液污染等级，可满足生产现场的在线监测要求。     

一种基于滤膜堵塞的在线油液污染测试系统

开发一种在线油液污染检测系统,该系统以滤膜作为传感元件,通过专门设计的配重系统实现恒压测试,可实现在线自动清洗、自动取样、自动检测,避免了二次污染和人工干涉对检测结果的影响,为故障诊断提供了可靠的数据.     

一种油液污染自动检测技术的研究

以滤膜堵塞法原理为基础,研制开发了"油液污染自动检测系统",对实现油液的在线实时检测,促进我国设备监测与故障诊断以及主动维修决策技术的发展有重大意义.     

液压油多参量品质诊断研究

提出了一种油液多参量诊断方法,研究了污染因素对液压油介电常数、黏度和密度的影响,得出40 ℃下3个参数的使用阈值,并采用信息融合技术建立了油液综合品质诊断模型。试验结果表明,介电常数、黏度、密度随温度变化规律明显,3个指标可从不同方面反映出液压油含水率、酸值的变化,可作为液压油失效的判断依据。油液污染因素与多个参数关系的研究可保证监测信息的全面性和可靠性,为液压油品质的多参量在线监测以及液压系统中机械元件的故障诊断提供了实验研究基础。     

基于滤膜堵塞型的油液污染检测系统的设计

针对基于滤膜堵塞检测法的污染检测仪存在的测试范围不够宽、集成度不高、自动化程度低等问题,利用计算机及机电一体化技术,设计一种基于滤膜堵塞原理的在线油液污染度检测系统。该系统包含负压取样、恒压测试、滤膜反冲洗、PLC控制及ARM处理器等装置,能够实现在线自动取样和检测,且检测结果具有较好的可靠性。     

SGA2723矿用汽车液压系统油液污染度的在线检测系统的研究

通过现场设备跟踪试验分析了液压系统污染源及种类,通过对有关油液污染控制理论和在线监测方法的深入研究和分析,采用光散型自动颗粒计数器结合虚拟仪器在测控系统中的应用,自行开发了一套基于虚拟仪器的油液污染在线监测系统。     

光纤传感器在线油液监测系统的研究

在分析了油液污染产生的原因及其对机械设备的危害的基础上，利用油液中悬浮颗粒对光线的吸收，结合光纤传感系统的优点设计了油液光纤监测传感器。实验结果表明，该系统可以在一定程度上检测油液的污染度，在机械设备的实时在线监测中具有一定的应用价值。     

在线监测液压系统油液污染度的一种方法

针对液压系统油液中,固体杂质、水等污染物的存在而导致液压元件失效的问题,设计了液压油污染度的在线监测装置,通过找出影响液压油电导率变化的因素,监测液压油电导率的变化,实现了对油液中固体杂质含量和水含量的在线监测,为系统的主动维修提供了可靠数据。     

船舶柴油机在线油液监测传感器的安装设计

论述常见的在线水分/黏度/磨损颗粒量传感器的选取及设计安装.针对船舶柴油机干式和湿式润滑系统的特点,提出不同的在线油液监测传感器的设计安装方法,并进行试验研究.结果表明,按该方法设计安装的柴油机在线油液监测传感器测试稳定性好,不仅满足油液在线监测的取样要求,且大大降低了传感器加工安装的难度.     

液压油污染实验与在线监测模型

液压油污染物主要包括水和固体颗粒等。介绍了水污染液压油衰变模型(S-B模型)和固体颗粒污染液压油衰变模型(G-S)模型,以这两个模型为基础,建立了衰变液压油含水率在线监测模型和固体颗粒质量分数在线监测模型,并对其进行了实验验证。结果表明:两个模型能较好地实现衰变液压油含水率和铁粉质量分数的在线监测,有利于降低煤矿维修成本和保证液压系统正常运转。     

一种油液污染在线监测方法的研究

本文推导了滤网前后压差与被堵塞网孔数、电磁铁功率以及油液粘度之间的函数关系式,通过测滤网前后的压差,从而可间接测量出油液的污染等级,并给出了在线监测系统原理图。     

某型装备液压系统便携式故障检测仪设计

 为解决某型装备液压系统野外无法现场快速诊断故障、严重影响战备训练的问题,设计了该便携式故障检测仪,主要由液压油污染度、液压流量、液压控制器等检测单元和液压油在线循环过滤系统组成。以激光光阻法颗粒计数传感器为基础,研制了液压油污染度检测仪;针对污染度高的液压油采用离心分离技术,减少污染磨损,提高液压系统可靠性和寿命;采用超声波时差法检测技术,实现了对液压系统状态参数的非介入式检测。实验结果表明,该检测仪能够完成对液压系统的准确有效检测。     

Active control of hydraulic oil contamination to extend the service life of aviation hydraulic system

The hydraulic system is the control center of aircraft, the performance of which is critically dependent on the purity of the oil that flows through it. Contamination of hydraulic system oil has been known to be the primary cause of catastrophic failure and accidents. A review of literature in the area of hydraulic oil contamination reveals three facts: (i) there is a dearth of effective methods to prevent intrusion of external contaminants into the hydraulic oil, (ii) there are no effective purification methods for liquid and gaseous contaminants of oil, and (iii) there is an absence of real-time monitoring for major contaminants. This work systematically reviews the hazards, sources, and removal methods of major contaminants, especially of gaseous contaminants. An active method to control oil contamination is proposed instead of the existing passive maintenance techniques that are ridden with problems. In a case study of aviation hydraulic system, our active control system comprises (i) a closed hydraulic circuit and a closed oil tank to prevent the intrusion of external contaminants, (ii) a vacuum centrifuge to efficiently remove contaminants without creating consumption costs, and (iii) monitoring devices installed to actively monitor the contaminant content in oil during operation. The results from the purification experiments and three-dimensional modeling indicate that the active control of hydraulic oil contamination can effectively remove 98.4% solid contaminants and reduce the water content below 50 ppm, and in particular reduce the gas content below 2%. It is obvious that this method can improve the continuous operation capability of aviation hydraulic systems and extend the intermaintenance period of aircrafts by reducing the contaminant content in oil.     

Reliability optimization design of hydraulic system considering oil contamination

This paper presents a reliability optimization design method for a hydraulic system that considers oil contamination. The proposed method applies the quantitative relationship between oil contamination and system reliability to the reliability design of a hydraulic system, while considering the performance, layout, and other design factors. A global reliability model of the hydraulic system is constructed based on the oil contamination control model. Further studies aiming at an optimization design model of the hydraulic system is established where the cost is the objective function, reliability index, size and structure range, performance requirements are constraints, structure size and oil change period are design variables. For illustration, a case study on the reliability optimization design of the oil supply point branch of the static pressure bracket of a certain type of heavy CNC horizontal lathe is considered.

     

某型坦克液压助力装置油液监测研究

随着液压助力系统在新装备中的应用,液压油的污染问题逐步成为装备油液监测与分析的重要内容。通过液压油的污染监测可以反映液压系统的磨损状态和污染情况,论文采集了7辆使用了不同摩托小时的某型坦克液压助力系统的油液,应用光谱仪和便携式油质分析仪(portable oil diagnostic system,PODS)进行了颗粒浓度的分析与比较。结果发现Fe元素(来自油缸-活塞摩擦副)的含量基本随着使用时间的增加而逐渐增加,外来污染如硅元素的含量则与装备本身的日常维护好坏关系密切。总体看来光谱分析和污染度分析可以反映该系统的磨损程度和污染程度,可为装备在用油的使用维护与更换提供数据和技术支持。     

Practical contaminant analysis of lubricating oil in a steam turbine-generator

In order to identify the level of contamination of lubricating oil in a turbine-generator at a local power plant, contaminant analysis was conducted. The contaminant analysis was also used to assess the condition of tribo-components such as bearings, gears and bearing deflectors. Oil samples were taken and the debris in the used lubricating oil were analysed off-line to provide information for the construction of an on-line monitoring system. Statistical analysis of debris was also carried out to determine the quantitative trend of oil contamination. The on-line contaminant monitoring system was then developed with the capabilities to provide an early warning of excessive oil contamination and to detect any impending failures of tribo-components. Guidelines necessary for maintenance engineers such as preset warning level and a trip level (automatic shutdown) of contamination were established. In the system, a device utilizing a filter blockage principle was employed to measure the contamination level. The on-line system developed was installed and field tested in a turbine-generator at a local power plant. During the two year period of investigation, the lubricating system and related tribo-components were revealed to be in normal condition.