核动力蒸汽发生器三维热工水力分析程序STAF的发展与应用

Development and Application of Three-dimensional Nuclear Steam Generator Thermal-hydraulic Analysis Code STAF

蒸汽发生器(SG)作为核动力系统一、二次侧能量转换枢纽,保证其安全运行至关重要。为对标国外先进SG三维热工水力分析程序,西安交通大学核反应堆热工水力团队(NuTHeL)基于多孔介质方法和漂移流模型自主开发了SG三维热工分析程序——STAF系列。初始程序STAF1.0将SG一次侧简化为一维流动,与采用多孔介质模型的二次侧实现耦合换热。为实现蒸汽发生器一、二次侧全三维高精度耦合分析,团队基于局部精细化建模结合重叠网格方法,进一步开发了一、二次侧全三维耦合瞬态分析程序STAF-CT(STAF2.0)。近些年,团队基于开源CFD平台OpenFOAM开发了STAF3.0版本,在原有计算功能基础上实现了并行计算,大幅提高了计算效率。本文详细介绍STAF系列程序数学物理模型、开发验证过程,并重点介绍STAF系列程序在核工程领域典型应用,包括SG三维稳态及瞬态热工水力特性分析、带轴流式预热器强化换热、堵管运行、二次侧^(16)N迁移、腐蚀沉积和海洋条件下SG热工水力响应特性等。

To ensure the safe operation of the steam generator(SG)in the nuclear power system is of great importance.A number of three-dimensional thermal-hydraulic SG analysis codes have been developed which used for SG thermal safety analysis and design reference.In order to develop a domestic advanced SG analysis code,the NuTHeL of Xi’an Jiaotong University developed the three-dimensional SG thermal-hydraulic analysis code STAF based on the drift flux model and porous media.The initial program version was STAF1.0,which was characterized by simplifying the U-tube bundles of primary side into a one-dimensional flow,and thermal coupling with the secondary side(three-dimensional porous media model)was realized.The election of heat transfer model,resistance model,turbulence model and drift flux model has also been discussed.Combined with the FRIGG experiment data,the thermal-hydraulic calculation accuracy of STAF is better than the ATHOS code.For simulating the three-dimensional flow of U-tube bundles on primary side,the refined modeling combined with the porous media has been adopted in the STAF-CT(STAF2.0).The mesh of bundles on secondary side and primary side was overlapped,which was used for full three-dimensional thermal coupling between the primary and secondary sides.STAF-CT characterized by full three-dimensional thermal coupling between the primary and secondary sides,which could obtain more reliable distribution of thermal-hydraulic parameters compared with STAF1.0.The above two SG codes are both developed based on commercial CFD platform(ANSYS).In order to avoid the copyright restrictions,STAF3.0 version abandoned the commercial CFD platform,developed on the open source CFD platform OpenFOAM instead.The OpenFOAM does not possess all the physical models that STAF needed,extra models have been developed and implanted into OpenFOAM,all the functions of old versions(STAF-CT)were also retained and the computing results have been tested well.To take full advantage of the multi-core processor,the parallel function was also upgraded,which effectively improves the computing efficiency compared with serial computing.Finally,typical applications of the STAF series have been introduced,such as SG thermal-hydraulic analysis,enhanced heat transfer with axial economizer,tube plugging conditions,^(16)N migration in secondary side of the SG,corrosion deposits on tubes and marine conditions.The STAF series of programs have a wide range of functions and applications,and can provide important reference for the development of the SG three-dimensional thermal-hydraulic analysis program for advanced nuclear power systems,as well as provide tools to support new generation steam generator design optimization and safety analysis.