轴流式血泵轴承基于血液损伤的温度场分析

Blood damage-based temperature field analysis of axial flow blood pump bearing

为研究血泵轴承在工作过程中的温升对血液的影响,通过在流式细胞仪中对红细胞进行死亡率分析计算和脆性试验,得到红细胞损伤机理,确定血液损伤临界值;对血泵轴承摩擦接触面进行热流密度计算,利用WORKBENCH分别对血泵轴承与导轮整体进行仿真。通过分析血泵轴承的温度场,得到不同摩擦系数及转速下的温升情况。实验结果显示,红细胞的死亡率随着温度的升高而增大,温度达到47℃时红细胞死亡数量已超过一半。仿真结果表明,温升情况与材料选择有一定关联,每种材料轴承的温升都是随着转速和摩擦系数的增大而上升,可以通过降低转速,或减小轴与轴套接触面的表面粗糙度的方法来降低温升,使轴承温度始终低于血液损伤临界值。

In order to study the effects of temperature rise of blood pump bearing on the blood during the working process,a red blood cell damage mechanism is obtained by analyzing the mortality rate and testing the brittleness of red blood cells in flow cytometry,thereby determining the critical value of blood damage.The bearing friction contact surface is used to calculate the heat flux density,andWORKBENCH is used to simulate the whole of the blood pump bearing and the guide wheel.By analyzing the temperature field of the blood pump bearing,the temperature rises at different friction coefficients and rotational speeds are obtained.The experimental results show that the mortality rate of red blood cells rises with the increase of temperature,and that the number of red blood cell deaths has exceeded half when the temperature reaches 47°C.The simulation results reveal that the temperature rise is related to the material selection,and the temperature rise of each material bearing is increased with the increase of rotational speed and friction coefficient.Therefore,the temperature rise can be reduced by reducing rotational speed or reducing the surface roughness of the contact surface between the shaft and the sleeve,so as to ensure the temperature of bearing is always lower than the critical value of blood damage.