油气润滑滑动轴承输运特性及润滑技术研究

发布时间：2018-07-25 06:45

【摘要】：滑动轴承是燃气轮机、汽轮机、齿轮箱等旋转机械中的重要组成部分,具有工作平稳、承载能力高、摩擦系数低、吸振性好、工作可靠等突出优点。现代工程技术发展的趋势是加大轴承的承载能力和提高轴承的转速,这就会造成滑动轴承内的润滑油温度急剧升高,导致润滑油的粘度降低甚至失去润滑能力。油气润滑在滚动轴承、开式齿轮、火车轮缘、链条传动等方面的应用及研究已经证明,油气润滑的润滑冷却效果好,适用于极端工况和高温、有污染的工作环境。但在传统的滑动轴承上,油气润滑的应用面临轴承温升高、换热效率低等始终没有克服的难题,没能体现出在其它领域获得的优势。本文以油气润滑技术在滑动轴承中的应用为研究对象,针对现有滑动轴承油气润滑冷却效果不理想的问题,对油气润滑输运特性及润滑技术进行了详细的理论分析和试验研究。论文主要研究内容如下:1.分析了在滑动轴承上应用油气润滑技术的障碍,确定了油气润滑技术在滑动轴承上应用的技术途径,建立了描述油气润滑滑动轴承流场以及气液两相流模型的数学模型。2.试验研究了水平油气输送管内两相流的流动特性,分析了供油量、气体体积流量对管内油气两相流的流型和压降的影响,获得了管内流动的油气两相流压力损失关联式。通过数值模拟得到了水平油气输送管内详细的油气两相流输运特性,计算结果与试验值吻合良好。3.建立了油气两相流体喷射冷却旋转发热圆柱体的计算模型并进行了数值模拟研究,获得了圆柱体各个区域以及整体平均努赛尔数随油气两相流喷射距离、射流雷诺数和圆柱体转速变化的规律,研究了供气压力、喷射距离对流体喷射速度的影响规律。4.研究了载荷、转速等因素对轴瓦温升的影响和轴承内两相流的温度场、压力场分布规律,对比分析了油气润滑与注油润滑普通轴瓦平均对流传热系数随摩擦功率的变化关系,得到了不同空气流量对油气润滑平均对流传热系数的影响规律。5.对轴与部分轴瓦摩擦副进行了浸油润滑与油气润滑的对比试验研究,并以油气润滑部分轴瓦试件的温升和摩擦因数为判别指标,进行了供油量、供气量等性能参数和喷嘴位置、喷嘴类型等结构参数对润滑性能影响的试验研究,给出了温升的主要影响因素。6.进行了新型滑动轴承油润滑与油气润滑温升、摩擦力矩、摩擦因数等静特性参数的对比试验研究,并以温升、摩擦力矩及摩擦因数为判别指标,进行了载荷、供油量、供气量和轴承结构等因素的正交试验研究,获得了滑动轴承油气润滑特性的主要影响因素。
[Abstract]:Sliding bearing is an important part of gas turbine, steam turbine, gearbox and other rotating machinery. It has many outstanding advantages, such as stable work, high bearing capacity, low friction coefficient, good vibration absorption and reliable operation. The trend of the development of modern engineering technology is to increase bearing capacity and speed of bearing, which will cause the temperature of lubricating oil in sliding bearing to rise sharply, and the viscosity of lubricating oil will decrease or even lose its lubricating ability. The application and research of oil and gas lubrication in rolling bearing, open gear, train flange and chain drive have proved that the lubricating and cooling effect of oil and gas lubrication is good, suitable for extreme working conditions, high temperature and polluted working environment. However, in the traditional sliding bearing, the application of oil and gas lubrication is faced with the problem that the bearing temperature rises and the heat transfer efficiency is low, which can not reflect the advantages obtained in other fields. This paper takes the application of oil and gas lubrication technology in sliding bearing as the research object, aiming at the problem that the cooling effect of oil and gas lubrication of existing sliding bearing is not ideal, this paper makes a detailed theoretical analysis and experimental study on the oil and gas lubrication transport characteristics and lubrication technology. The main contents of this paper are as follows: 1: 1. This paper analyzes the obstacles of applying oil and gas lubrication technology to sliding bearings, determines the technical ways of applying oil and gas lubrication technology to sliding bearings, and establishes a mathematical model .2. which describes the flow field of oil and gas lubricated sliding bearings and the gas-liquid two phase flow model. The flow characteristics of two-phase flow in horizontal oil and gas conveying pipe are studied experimentally. The effects of oil supply and gas volume flow on the flow pattern and pressure drop of the two-phase flow in the pipe are analyzed, and the pressure loss correlation formula of the two-phase flow in the pipe is obtained. Through numerical simulation, the detailed characteristics of oil and gas two-phase flow in horizontal oil and gas pipeline are obtained, and the calculated results are in good agreement with the experimental data. In this paper, the computational model of the swirling heating cylinder for injection cooling of oil-gas two-phase fluid is established, and the numerical simulation is carried out. The average Nussel number of each region of the cylinder and the whole Nussel number are obtained with the injection distance of the oil-gas two-phase flow. The variation of jet Reynolds number and cylinder speed is studied. The influence of gas supply pressure and injection distance on the jet velocity is studied. The influence of load and rotational speed on the temperature rise of bearing and the distribution of temperature field and pressure field of two-phase flow in bearing are studied. The relationship between the average convection heat transfer coefficient of oil and gas lubrication and oil injection lubrication with friction power is compared and analyzed. The influence of different air flow rate on the average convection heat transfer coefficient of oil and gas lubrication is obtained. In this paper, a comparative test of oil-immersed lubrication and oil-gas lubrication is carried out on the friction pairs of shaft and partial bearing. Based on the temperature rise and friction coefficient of oil and gas lubricating parts, the performance parameters such as oil supply, gas supply and nozzle position are carried out. The influence of nozzle type and other structural parameters on lubricating performance is studied. The main influencing factors of temperature rise are given. A comparative experimental study on the static characteristic parameters, such as temperature rise, friction torque, friction coefficient of new type sliding bearing oil lubrication and oil and gas lubrication, has been carried out, and the load and fuel supply have been carried out with temperature rise, friction moment and friction coefficient as the discriminant index. The main influencing factors of oil and gas lubrication characteristics of sliding bearings were obtained by orthogonal test of air supply and bearing structure.
【学位授予单位】：哈尔滨工程大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TH133.31

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