基于CFD的铅基快堆单盒燃料组件堵流事故分析

Analysis of Blockage Accident of Lead-Based Fast Reactor Single-Box Fuel Assembly Based on CFD

铅基快堆在运行过程中产生的腐蚀产物有可能会在堆内沉积,导致堵流事故的发生。基于计算流体力学(CFD)软件Ansys Fluent分析了不同堵块面积、堵块厚度、堵块类型以及堵块位置对堵流事故中传热以及流场性质的影响规律。结果显示,堵块面积的增加会增加回流区域面积,使得温度回落更慢,传热恶化显著;堵块厚度的增加将导致冷却剂和包壳最高温度上升,极易导致包壳损坏;多孔介质堵块内冷却剂以较低流速通过,缓解了堵块造成的影响,其危害小于实心堵块;堵流发生在组件活性区中部与发生在活性区出、入口相比所造成的局部温升更加明显,危害更大。

The corrosion products produced during the operation of the lead-based reactor may be deposited in the reactor,resulting in the occurrence of flow plugging accident.Based on the computational fluid dynamics software Ansys Fluent,the effects of different blockage area,thickness,type and position on the deterioration of heat transfer and the properties of flow field in current plugging accident are analyzed.The results show that the increasing of blockage area will increase the reflux area,which makes the temperature fall more slowly and the heat transfer worsen obviously;the increasing of the blockage thickness will lead to the increasing of the maximum temperature of coolant and cladding,which can easily lead to cladding damage;the coolant in the porous medium blockage passes at a lower flow rate,which alleviates the influence of blockage and does less harm than the solid blockage.The local warming caused by the blockage located in the middle of the active area is more obvious and more harmful than that caused by the blockage in the entrance and exit of the active area.