表面微结构组合设计及水润滑摩擦学机理与试验研究

The reliability design of the overcurrent components of nuclear power generation equipment under extreme conditions is the basic research content of scientific research and engineering application. For the water lubricated tilting pad thrust bearing that mainly used for the nuclear main pump of the third generation as the research object, this project will conduct the problem of friction and wear and service reliability under the conditions of starting and stopping and boundary lubrication, which centers two scientific issues, “Multi field coupling lubrication model of surface texture and its drag reduction and bearing mechanism” and “The evolution law between shape and performance and the design method of parameter matching of composite texture under water lubrication”, to make a combinatorial design of surface microstructures and to research the tribological mechanism and experimental study of water lubrication. The study contents are as followings: study on multi field coupling lubrication model and performance law of micro texture, standard experiment and model modification of water lubrication tribological properties of micro texture, study on the mechanism of lubrication and drag reduction and test of the textured thrust pad. The expected results including: multi field coupling lubrication model of texture considering elastic deformation and interface slip effect, the evolution law between shape and performance and the design method of parameter matching of composite texture under water lubrication, the lubrication, drag reduction and bearing mechanism of textured thrust pad at low speed. The research results will provide a theoretical and technical basis for the design of the combined texture and the reliability design of the water lubricated bearing of the nuclear main pump.

极端工况下核能发电装备过流部件的可靠性设计是面向科学研究和工程应用的基础研究内容。本项目以第三代核主泵为主要应用背景，以水润滑可倾瓦推力轴承为研究对象，针对水润滑轴承在启停和边界润滑条件下存在的摩擦磨损和服役可靠性问题，围绕“表面织构的多场耦合润滑模型及减阻与承载机理”和“组合织构在水润滑条件下的形性演化规律及参数匹配设计方法”两个科学问题，开展表面微结构组合设计及水润滑摩擦学机理与试验研究。研究内容包括：微观织构的多场耦合润滑模型及性能规律研究；微观织构的水润滑摩擦学性能标准实验及模型修正；织构化推力可倾瓦试验及润滑减阻机理研究。预期成果包括：考虑弹性变形和界面滑移效应的织构多场耦合润滑模型；表面织构的形性演化规律及参数匹配设计方法；织构化推力瓦在低速下的润滑、减阻和承载机理。研究成果将为组合织构的设计及核主泵水润滑轴承可靠性设计提供理论和技术基础。

本项目针对水润滑推力轴承在启停和边界润滑条件下存在的摩擦磨损和服役可靠性问题。采用Comsol软件研究了不同类型织构下的轴承油膜压力、表面流速和油膜厚度等润滑性能。结果表明，混合织构与单一圆形织构下的轴承性能基本相同；瓦块外径方向的流速远远大于内径方向的流速。针对具有相同问题的机械密封，建立了摩擦学与动力学耦合的数学模型和螺旋槽机械密封瞬态启动过程润滑特性模型，研究了润滑状态转变过程。针对三种石墨材料进行了光滑平面及织构化界面的亲水性测试和水介质边界润滑性能试验。结果表明，随着载荷、线速度和配副的不同，摩擦系数在0.02-0.06范围内；织构的深度要浅且材料要耐磨。同时，以人字形织构为例研究了激光加工织构的工艺过程和最优参数；拓展研究了石墨材料在高温下与和WC-Ni配副的摩擦学性能。针对平衡梁可倾瓦推力轴承，建立了以支点膜厚为特征的瓦块膜厚方程，研究大尺寸平衡梁轴承在安装倾斜时的承载规律和精度。为了有效的设计和进行轴承试验，在织构化巴氏合金推力瓦块上，验证了超声测试技术进行可倾瓦轴承动态油膜厚度测试的可行性；研究了弹性支撑技术应用在大尺寸转子系统的轴承设计中并实现轴承摩擦学和润滑性能优化的可行性。自主设计和制造了织构化石墨轴承试验的小型试验台，其目的用于研究织构化轴承惰转运行时间、启停摩擦磨损情况以及稳定运行下的承载能力。