为提升压水堆堆芯棒束通道热工水力计算的精度和效率,本文提出一种Picard算法和Krylov子空间算法相结合的全隐式Picard Krylov算法.利用Picard算法完成棒束子通道两流体方程组全隐式求解,并使用Krylov子空间方法提升Picard迭代计算效率.研究表明:全隐式Picard Krylov算法在压水堆子通道及棒束通道基准题稳态和瞬态计算中,数值结果与实验结果吻合较好,且相较于Picard算法稳态计算效率最高提升 89.7%,瞬态计算效率最高提升20.68%.相较于传统的算符分解及Picard迭代方法,全隐式Picard Krylov算法具有良好的计算精度和效率.
To improve the accuracy and efficiency of the thermal-hydraulic calculation of the rod bundle channel of a pressurized water reactor,this paper proposes a fully implicit Picard-Krylov algorithm that combines the Picard and Krylov subspace algorithms.The Picard algorithm is used to complete the fully implicit solution of the two-fluid equations of the rod bundle subchannels,and the Krylov subspace algorithm is used to improve the Picard iteration calculation efficiency.We found that the numerical results of the fully implicit Picard-Krylov algorithm are consist-ent with the experimental results in the benchmark based on NUPEC PWR subchannel and bundle tests.Compared with the Picard algorithm,the steady-state calculation efficiency increases by up to 89.7%,and the transient cal-culation efficiency increases by up to 20.68%.The fully implicit Picard-Krylov algorithm has higher calculation ac-curacy and efficiency than the traditional operator splitting and Picard iteration methods.