超临界水冷堆水棒导热性能研究

Study on Heat Conduction Performance of Water-rod in SCWR

在热谱超临界水冷堆设计中,工质在堆芯内剧烈的密度变化使堆芯轴向方向慢化不均匀,需要引入水棒结构减小这种影响。为描述超临界水冷堆堆芯热工水力现象和中子慢化性能,更好地实现超临界水冷堆的设计,需要研究水棒导热性能的影响。针对特定的超临界水冷堆组件,选取不同水棒中间材料的热导率,编制程序对堆芯燃料、冷却剂、慢化剂进行联合求解,计算得出各种工况下的温度分布,并进行对比分析。结果表明,燃料通道和水棒内工质随着流动的方向其温度都是呈现不断升高的趋势;不合理的材料选取,可能出现慢化剂与冷却剂反向传热的现象;在水棒材料选取时,应尽量选择热导率比较小的材料。

In the design of thermal spectrum supercritical water cooled reactor（SCWR）,water-rod was introduced to decrease the axial uneven moderation caused by severe density change of water in reactor core.A study on heat conduction performance of water-rod is necessary to realize thermal-hydraulic influence and moderated property of core,and to design SCWR better.For certain assembly,different thermal conductivity of water-rod middle material was chosen,program to associated-calculate the fuel rod,coolant and moderator were made,the temperature distributions of different cases were obtained.The comparison results indicate that the temperature of both coolant and moderator have an increased tendency in flowing direction;unreasonable material selection will cause reverse heat transfer between moderator and coolant;the material with low thermal conductivity is better when selecting water-rod material.