摘要
特征线方法通过在计算区域密置特征线来计算角通量,对于计算区域的材料分布和几何结构没有要求,因此特征线方法的几何处理能力受制于几何描述模块对于各种几何区域的描述能力。基于体素构造(CSG)方法,开发了三维特征线程序MOCP的几何描述模块。该几何描述模块可描述随机分布的球床。针对球形燃料的网格划分方式进行了研究,临界球的计算结果表明,当径向网格超过30层时,keff的相对误差小于0.1%。通过对几何描述方式的改进大幅提高了三维特征线追踪的效率,并且实现了在各种形状边界上的特征线布置。
In MOC(method of characteristics),angular flux is calculated by sweeping over all the tracks densely arranged in the district.The sweeping process is independent of material distribution and geometry.As a result,the capability of treating different kinds of geometry structures of MOC is limited by the capability of geometry modeling modular.The geometry modular of the code MOCP(method of characteristics for high temperature pebble-bed reactor)was developed based on CSG(constructive solid geometry)method.The geometry modular of MOCP is capable of describing the stochastic distributed pebble-bed.The meshing method of spherical fuel was studied.The result shows that relative error of keffof a critical sphere is less than 0.1% when the critical sphere is divided into more than 30 layers.Furthermore,the 3D ray tracing efficiency isgreatly improved by optimizing the geometry tree and MOCP is able to arrange track on the different shapes of the geometries including cube,cylinder and sphere.
引文
[1]ASKEW J R.A characteristics formulation of the neutron transport equation in complicated geometries[R].Winfrith:United Kingdom Atomic Energy Authority,1972.
[2]李富,魏春琳,周旭华,等.模块式高温气冷堆的物理特性[C]∥第十二届反应堆数值计算与粒子输运学术会议暨2008年反应堆物理会议.合肥:中国科学院等离子体物理研究所,2008.
[3]LI Fu,GUO Jian,GUO Jiong.Preliminary study on applying the method of characteristics to pebble-bed HTR[C]∥International Topical Meeting on High Temperature Reactor Technology(HTR).United States:American Nuclear Society,2016.
[4]ZHANG Z,DONG Y,LI F,et al.The Shandong Shidao Bay 200 MWe High-temperature Gas-cooled Reactor Pebble-bed Module(HTRPM)Demonstration Power Plant:An engineering and technological innovation[J].Engineering,2016,2(1):112-118.
[5]陈其昌,吴宏春,曹良志.基于AutoCAD二次开发实现中子输运方程特征线法求解[J].原子能科学技术,2009,43(3):257-262.CHEN Qichang,WU Hongchun,CAO Liangzhi.Realization of method of characteristics based on customization of AutoCAD[J].Atomic Energy Science and Technology,2009,43(3):257-262(in Chinese).
[6]柴晓明.求解三维中子输运问题的特征线方法研究[D].北京:清华大学,2010.
[7]LIU Z,WU H,CAO L,et al.A new threedimensional method of characteristics for the neutron transport calculation[J].Annals of Nuclear Energy,2011,38(2):447-454.
[8]张知竹,李庆,王侃.GPU加速三维特征线方法的研究[J].核动力工程,2013,34(增刊1):18-23.ZHANG Zhizhu,LI Qing,WANG Kan.Study on acceleration of three-dimensional method of characteristics by GPU[J].Nuclear Power Engineering,2013,34(S1):18-23(in Chinese).
[9]BOYD W,SHANER S,LI L,et al.The OpenMOC method of characteristics neutral particle transport code[J].Annals of Nuclear Energy,2014,68:43-52.
[10]Handbook of nuclear engineering[M].[S.l.]:Springer Science&Business Media,2010.
[11]KOCHUNAS B M.A hybrid parallel algorithm for the 3-D method of characteristics solution of the Boltzmann transport equation on high performance compute clusters[J].Information Technology Journal,2013.http:∥trove.nla.gov.au/version/206636557.
[12]严蔚敏,吴伟民.数据结构:C语言版[M].北京:清华大学出版社有限公司,2002.
[13]施工.高等反应堆物理讲义[M].北京:清华大学,2014.
[14]CARLSON B G.Tables of equal weight quadrature EQ N over the unit sphere,LA-4734[R].USA:Los Alamos Scientific Laboratory of the University of California,1971.