推力瓦几何参数对核主泵推力轴承油系统特性的影响

Effect of thrust pad geometric parameters on characteristics of thrust bearing oil system for nuclear coolant pump

针对某核主泵的双向推力轴承在试验过程中出现上部推力瓦温度过高的问题,在不改变油系统、推力轴承结构尺寸及推力瓦数量的条件下,在推力瓦侧面开设不同尺寸的凹槽以控制瓦间流动.经过多方案优选设计出一种改进型推力瓦,以期通过优化推力瓦几何参数解决上部推力瓦温度过高的问题.基于流场数值模拟方法对油系统瓦间流场进行了深入分析,通过对比改进前后2种瓦的瓦间流动分布定性分析推力瓦几何参数对双向推力轴承油系统流动及冷却性能的影响,表明优化后的改进型推力瓦在相同运行条件下大大减轻了油流对冲及阻塞的现象,消除了不合理的回流,增大了进入流道的冷油流量,从而提高了油系统的冷却效果,使得上部推力瓦温度明显降低并达到了设计要求.同时证明了推力瓦几何参数是影响推力轴承油系统特性的重要因素.研究结果能为探究推力瓦几何参数对油系统特性的影响,以及类似轴承系统的推力瓦几何参数优化提供参考.

To solve the problem that the temperature of the upper thrust pad is too high in the test process of the bidirectional thrust bearing of a nuclear coolant pump,without changing the structure size of the oil system and the thrust bearing,and the number of thrust pad,design grooves with diffe-rent sizes were designed on the side of the thrust pads to control the flow.An improved thrust pad was designed through multi-scheme optimization in order to solve the problem of high temperature of the upper thrust pad by optimizing the geometric parameters of the thrust pad.Based on the numerical simulation method,the flow field of the oil system was deeply analyzed.By comparing the flow field of two kinds of thrust pads,the influence of geometric parameters of the thrust pad on the flow and cooling performance of the bidirectional thrust bearing oil system was analyzed qualitatively,the influence of dynamic and cooling performance shows that under the same operation conditions,the optimized thrust pad greatly reduces the oil flow hedging and blockage,eliminates the unreasonable backflow,and increases the cold oil flow into the channel.Thus the cooling effect of the oil system is improved,and the temperature of the upper thrust pad is obviously reduced,which meets the design requirements.And it is proved that the geometric parameters of thrust pad are the important factors affecting the characteristics of thrust bearing oil system.The results can provide a reference for exploring the influence of thrust pad geometry parameters on oil system characteristics and optimization of thrust pad geometry parameters similar to bearing system.