控制棒驱动机构传热特性数值研究
Numerical Study on Heat Transfer Characteristics of Control Rod Drive Mechanism

控制棒驱动机构(CRDM, Control Rod Drive Mechanism)是控制反应堆正常安全运行的重要设备。反应堆运行时，受反应堆冷却剂的热虹吸和磁扼线圈通电产生热量的作用，驱动机构在较高的温度下运行，如果磁扼线圈等部件的温度长时间超过其允许的使用温度，会严重影响这些部件的工作寿命，甚至造成失效，影响反应堆的正常运行，因此需要对CRDM进行冷却。文章针对单根控制棒驱动机构，进行计算流体力学(CFD, Computational Fluid Dynamics)数值模拟，在自然对流工况下，对CRDM的传热特性进行了研究，得到CRDM整体和各个关键部位的温度分布情况，并针对不同输入参数对磁扼线圈温度影响进行了敏感性分析，发现线圈发热量和导热系数对线圈的平均温度影响较大，线圈发热量增加68%，提升线圈平均温度提高26%。线圈导热系数提高17.75倍，线圈平均温度减小25%。
Control rod drive mechanism (CRDM) is an important equipment to control the normal and safe operation of the reactor. During the operation of the reactor, due to the thermal siphon of the reactor coolant and the heat generated by the magnetic yoke coil, the CRDM needs to operate at higher temperatures. If their temperature exceeds the allowable temperature for a long time, it will seriously affect the working life of these components, even cause failure, and affect the normal opera-tion of the reactor. So it is necessary to study the heat transfer characteristics of CRDM. In this paper, aiming at the single CRDM, the CFD numerical simulation is carried out, and the temperature distribution of the whole and each key part of CRDM is obtained. The sensitivity analysis of the influence of different input parameters on the temperature of magnetic yoke coil is carried out. It is found that the calorific value and thermal conductivity of the coil have great influence on the average temperature of the magnetic coil. The heating capacity of the coil increased by 68%, and the average temperature of the lifting coil increased by 26%. The thermal conductivity of the coil is increased by 17.75 times, and the average temperature of the coil is reduced by 25%.