Performance Study Of A Thrust Loading Device For A Nuclear Reactor Coolant Pump Bearing Test Rig

In a nuclear reactor cooling cycle system,the main pump bearing is the key rotary parts in the system,the bearing performance of which is directly related to the stable operation of the cooling cycle system.In order to simulate the full condition axial loading test,a high-load high-speed two-way thrust loading test rig was designed.The axial loading device is the core part of the test bed,and its bearing performance is very important for the normal operation of the whole system.Because of the big size,large load of the device,the speed is relatively high,the equipment are prone to cause oil film failure,wear and tear,even burning tile,which will lead to the system abnormal operation or shutdown.In this article,taking the loading device of a nuclear pump bearing test rig as the research object,the flow field characteristics,oil film bearing capacity and its influencing factors were studied,analysis of thermal-fluid-structural coupling deformation and structural improvement were conducted.The main research contents are as follows:1.The three-dimensional oil film numerical analysis model was established based on the N-S equation,the effects of pressure and velocity distribution on oil film flow field under different operating conditions were researched.The effects of rotational speed,inlet oil pressure and viscosity-temperature effect on the bearing performance of oil film were studied.2.The thermal-fluid-structural coupling model of the thrust loading device was constructed,the elastic deformation,the thermal deformation and the thermal deformation of the thrust plate were solved based on the fluid-solid-heat coupling model,and the influencing factor of oil film failure were investigated.3.Based on the analysis of the oil film bearing capacity and the analysis of the thermal performance coupled deformation,the structural improvement of the prototype loading device was put forward.Four kinds of improvement schemes were proposed and analyzed:(1)The annular single oil chamber was changed into the fan-shaped three oil chamber;(2)The annular single oil chamber was moved inward by 2 mm and 6 mm;(3)Change The depth of the oil chamber was adjusted;(4)The thrust plate thickness was altered.The feasibility of the above four kinds of improvement schemes were analyzed by numerical calculation.4.The most realistic improvement scheme the fan-shaped three oil chamber was selected,the improved structure was manufactured and a new loading test was carried out to validate the feasibility of this improvement and the applicability of the numerical method.The research provides an important reference and basis for the design and application of the maincore pump bearing loading device.