【作者】 徐杰；

【导师】 刘振祥；

【作者基本信息】 东南大学 ， 动力工程（专业学位）， 2017， 硕士

【摘要】 在电厂生产运行中,润滑油的应用非常普遍,尤以汽轮机中的运用最为典型。润滑油在使用一段时间后粘度、水分等参量会偏离初始值,因此润滑油需要定期取样检测,但取样检测有局限性,若润滑油在检测周期内发生变质,将会严重影响汽轮机的运行质量与寿命。因此开发一套润滑油特性监测系统实时查看润滑油的性能指标就具有一定的工业价值。本文对影响润滑油性能的参量、常用润滑油检测方法以及离线式油液监测的现状进行了介绍,发现传统的油液检测方法只能检测油品的单一参数,而且离线式油液检测有局限性,从而确定了课题的研究方向,即通过润滑油各种参量的在线监测判断润滑油的性能状况。本文首先完成了系统总体架构的设计。之后根据系统功能的需要,选择了相应的嵌入式工控主板。为了实现工控主板的控制与通讯功能,完成了应用底板的设计,包括CAN驱动电路设计、电源模块设计、485通信电路设计等。根据需要监测的润滑油参数选择了一种能测量润滑油粘度、温度、介电常数、密度的传感器。完成了 CAN控制器的初始化,传感器模块的数据发送、接收程序设计。为了实现润滑油参量的实时查看,设计了一套在线监测系统。该系统能实时显示润滑油的粘度、温度、介电常数、密度数据和图像,并将参量的数据保存在内存中,以便进一步的研究与分析。在监测系统设计完成之后,搭建相应的实验平台,对在线监测系统的功能与精度进行测试,测试结果表明本套系统能够满足在线监测要求。之后对润滑油的参量进行实验研究,发现润滑油的粘度随温度的升高逐渐减小并通过保存在嵌入式主板中的数据拟合出相应的润滑油粘温关系公式。根据粘温公式以及油膜刚度、阻尼的计算公式得出不同温度下的油膜刚度与阻尼。同时也发现在温度不变的情况下润滑油介电常数随着水分、含铁量的增加不断增加,说明用介电常数作为评价润滑油衰变程度的综合指标是可行的。更多还原

【Abstract】 Lubricating Oil plays a significant role in the power plant,especially in the steam turbine.After a period of time,lubricating oil’viscosity,moisture and other parameters will deviate from the initial value.Therefore it is necessary to detect the lubricating oil termly.However,periodic detection has limitations.If lubricating oil deteriorates during the detection cycle,it will affect the steam turbine seriously.Therefore,it has a great value to develop an online monitoring system of lubricating oil’speciality.This paper introduces the parameters that affect the performance of lubricating oil,the lubricating oil detection methods which is commonly used and the status of off-line oil monitoring.The traditional oil detection method can only detect the single parameter of the lubricating oil,and the off-line oil detection has limitation,so it is necessary to estimate the lubricating oil’performance through the online monitoring system of lubricating oil’multi-parameters.Firstly,this paper completed the design of the overall system architecture.And then according to the needs of the system function,the corresponding embedded industrial motherboard was selected.In order to realize the control and communication function of the embedded industrial motherboard,the design of the carrier board was completed.The design of the carrier board includes that,CAN drive circuit design,power module design and 485 communication circuit design.According to the lubricating oil’parameters needed to be monitored,a sensor that can measure the viscosity,temperature,dielectric constant,and density is selected.And then,CAN controller initialization and the sensor module sending,receiving program design is accomplished.In order to view the parameters of the lubricanting oil in real time,an on-line monitoring system is designed.This system can display the multi-parameter data and images of the lubricating oil in real time,and can save the parameter data in the memory for further research and analysis.The corresponding experimental platform should be set up to test the online monitoring system.The test results reflect that this online monitoring system could meet the experimental requirements.After the test,the experimental study on the parameters of lubricating oil could be relizable.Through experimental studies,it could be found that,the viscosity decreases with the increase of the temperature,and the viscosity of the lubricating oil is in accordance with the Walther formula.According to the Walther formula and the calculation formula of oil film’stiffness and damp,the oil film’stiffness and damp could be calculated.And it could be found that,the dielectric constant increases with increasing moisture content and iron content.Therefore,using the dielectronic constant as the evaluation index of lubricating oil pollution is feasible.更多还原