基于折射率匹配方法的球床三维重构  

A 3D-reconstruction research on the visual liquid-pebble bed

作　　者：林大富[1,2] 刘峰瑞 陈兴伟 严睿[1] 梅牡丹[1] 张洁[1] 邹杨[1] 

机构地区：[1]中国科学院上海应用物理研究所,嘉定园区上海201800 [2]中国科学院大学,北京100049

出　　处：《核技术》2017年第10期87-94,共8页Nuclear Techniques

基　　金：中国科学院战略性先导科技专项(No.XDA02001002);中国科学院前沿科学重点研究项目(No.QYZDY-SSW-JSC016)资助~~

摘　　要：固态钍基熔盐堆(Thorium-based Molten Salt Reactor with Solid Fuel,TMSR-SF)是第四代核反应堆堆型之一,它融合了高温气冷堆的石墨基质包覆颗粒燃料球技术和熔盐堆的高温熔盐冷却剂技术。堆芯的物理设计和几何设计依赖于燃料球在堆芯中的堆积因子,为研究球床堆堆芯模型内燃料球的堆积三维结构,本文提出基于折射率匹配的方法对球床进行三维重构的方案,并通过初步的模拟实验对程序进行验证,旨在探索该方法在球床三维重构中的可行性。针对三维重构中的一系列关键问题进行阐释,并提出相应的解决方案;同时给出了三维重构方案的完整流程,并计算出了衡量三维重构精确度的度量值:直径重叠量。最后,搭建了一个小型规则排布的球床实验装置,通过折射率匹配技术开展球床可视化实验以探索该方案在球床三维重构中的精确度,并说明该方法的可行性。试验结果表明,颗粒间平均重叠量为1.43 mm,重构精度有待提高,重构方法有待改进。Background： Thorium-based molten salt reactor with solid fuel （TMSR-SF） is one type of the fourth nuclear power plant which combines high-temperature graphite-matrix coated-particle pebble fuel for high- temperature gas-cooled reactors and liquid salts developed for the molten salt reactors. The design of TMSR-SF requires detailed understanding of the packing structure of the pebble bed in reactor core. Purpose： This article is aimed to explore the effectiveness of refractive index matched scanning technique （RIMS） in the 3D-reconstruction of reactor core. Methods： The cross sections of the pebble bed are imaged by a charge-coupled device （CCD）, then the threshold transformation, filter transformation and Hough transformation are used to process the images, and the coordinates of points on the spheres＇ edge are extracted. Then an algorithm is used to acquire the relative center coordinates of each sphere. Results： The result shows that excluding irrelevant distractors can improve the accuracy of the 3D-reconstruction, and creating region of interest （ROI） to make threshold transformation is a good method to enhance circles＇ edges, and when the circles in the images distort, minimum bounding rectangle （MBR） functions ismore effective than Hough circle transformation. Conclusion： Our scheme of reconstruction can reconstruct the 3D packing structure of the pebble bed with the mean distance-overlapped which is 1.43 mm, and this precision needs to be improved later.

关 键 词：折射率匹配 图像处理 可视化液体球床 三维重构 规则球床 

分 类 号：TL99[核科学技术—核技术及应用]