核反应堆冷却介质驱动电机通风结构内流体特性分析

Analysis of Fluid Characteristics in Ventilation Structure of the Nuclear Reactor Cooling Medium Drive Motor

核反应堆冷却介质驱动电机是高温气冷堆一回路中的关键设备,作用是将氦气作为冷却介质驱动其在系统中交换热量,为研究冷却介质的流体特性与其在电机内的流体场分布对电机温升甚至整个系统的影响。以一台4 500 k W驱动电机为例,考虑以氦气为冷却介质的风磨损耗公式不同于传统公式,对风磨损耗进行重新计算;通过建立该电机通风系统的3D流体场计算模型,基于流体力学原理,采用有限元法得到通风系统内的流体分布;最后,为更好的研究氦气的流体特性,以空气作为对比对象,分析流体性质差异对电机气隙、转子轴向流速和通风沟径向风速分布的影响;结果表明:在相同条件下,氦冷时流体域内各区域流速低于空冷9.4%,有助于减小风磨损耗对电机温升的影响。

The nuclear reactor cooling medium drive motoris thecritical equipmentin the primary circuit of hightemperature gas cooled reactors. Role of the helium gas as cooling medium drive system for the exchange of heat,In order to study the influence of characteristics of cooling medium and the fluid field distribution upon temperature rise and system stability in the motor. A 4 500 k W driving motor as the research object,considered the loss formula that helium as the coolant is different from the traditional formula,calculated the windage loss by using numerical method. Fluid field analysis model of the coolingsystem was established. Based on the principle of fluid force,the finite element method was used to obtain the distribution of fluid in the ventilation system; Finally,in order to study the characteristics of helium better,took air as a comparison object,analyzed on influence of fluid property difference upon the wind velocity distribution in the air gap, the rotor axial and radial direction of the ventilation. The results of analysis shows that under the same conditions,the inlet-velocity of fluid region using helium cooling is lower 30% than that of using air cooling,which helps to reduce temperature rise of motor caused by windage loss.