环形燃料元件几何尺寸对其热工性能的影响研究  

Study on the influence of geometric size of annular fuel element on thermal performance

作　　者：向钊才 曾付林 赵鹏程[1] XIANG Zhaocai;ZENG Fulin;ZHAO Pengcheng(School of Nuclear Science and Technology,University of South China,Hengyang 421001,China)

机构地区：[1]南华大学核科学技术学院,衡阳421001

出　　处：《核技术》2023年第1期90-99,共10页Nuclear Techniques

基　　金：国家自然科学基金(No.11905101)资助。

摘　　要：针对环形燃料元件,基于欧洲铅冷系统反应堆ELSY选取环形燃料元件参数,建立环形燃料元件导热模型,设定环形燃料元件的初始参数并利用MATLAB编制环形燃料元件导热计算程序,通过制定的三个评估标准研究环形燃料流量分配比、内外包壳厚度、内外气隙厚度和芯块厚度对环形燃料元件热工性能的影响并进行几何尺寸修正。研究结果表明:适当增大流量分配比、减小内包壳厚度、增大外包壳厚度、减小内外气隙间距和减小芯块厚度可改善元件的热工性能;设定流量分配比为1、内包壳厚度0.06 cm修正为0.04 cm、外包壳厚度0.06 cm修正为0.07 cm、内外气隙间距0.035 cm修正为0.015 cm、芯块厚度修正为0.05 cm,进行这些几何尺寸修正后,芯块的最高温度下降了90 K(8.6%),绝热面位置偏离芯块几何中心不足2μm,内外通道冷却剂出口温差不足2 K,环形燃料元件热工性能得到了明显提高。[Background]Compared with conventional rod-type nuclear fuel,annular fuel has higher power density and better heat transfer efficiency,which can significantly improve the safety and economy of the reactor.[Purpose]This study aims to investigate the effect of ring fuel element geometry on the thermal performance and to correct the initial parameters.[Methods]The initial parameters of the ring fuel element were set and the thermal conductivity calculation program of the ring fuel element was prepared.The effects of the ring fuel flow distribution ratio,inner and outer cladding thickness,inner and outer air gap thickness and core block thickness on the thermal performance of the ring fuel element were investigated by three evaluation criteria developed and geometric corrections are made.[Results]Appropriately increasing the flow distribution ratio,decreasing the inner casing thickness,increasing the outer casing thickness,decreasing the inner and outer air gap spacing and decreasing the core block thickness can improve the thermal performance of the components;setting the flow distribution ratio to 1,the inner casing thickness 0.06 cm is amended to 0.04 cm,the outer casing thickness 0.06 cm is amended to 0.07 cm,the inner and outer air gap spacing 0.035 cm.The thickness of core block is amended to 0.5 cm.[Conclusions]Thermal performance of annular fuel elements is significantly improved after appropriate geometry correction is made.

关 键 词：环形燃料元件 热工性能 几何尺寸修正 导热模型 流量分配比 

分 类 号：TL433[核科学技术—核技术及应用]