作者：
XUE YangXIONG Fu-ruiSUN Jian-qiaoDepartment of Mechanics
Tianjin UniversityTianjin300350China Science and Technology on Reactor System Design Technology LaboratoryNuclear Power Institute of ChinaChengdu 610041China School of EngineeringUniversity of CaliforniaMercedCA 95343USA
Large eddy simulation(LES) of the swirling flow in the rod bundle subchannels with spacer grids are presented. According to the rod bundle flow benchmark experiment, the 5×5 rod bundle with a split-type spacer gr...
详细信息
Natural convective heat transfer in enclosures is widely researched in extensive range of engineering application such as passive residual heat removal system (PRHRS) in nuclear plant, solar collectors and cooling of ...
详细信息
ISBN:
(纸本)9781510811843
Natural convective heat transfer in enclosures is widely researched in extensive range of engineering application such as passive residual heat removal system (PRHRS) in nuclear plant, solar collectors and cooling of electronic equipment. After Fukushima incident, the application and researching of PRHRS have been gaining more and more attention. It still has no proper calculating tools to analyze natural convective heat transfer with large L/D ratio and high Rayleigh number in PRHRS. In this paper, based on some former natural convective heat transfer experiments, numerical simulations and scale analysis, the single phase natural convective heat transfer correlation from the vertical tube have been developed. Transient single phase natural convection heat transfer along vertical tube in a cylindrical enclosure has been investigated for water with widely used computational fluid dynamic (CFD) engineering program ANSYS CFX-12. The influence brought by different geometry of tube and mesh scales has been evaluated by the results of former experiments. The ratio of tube length to diameter is a dimensionless factor affects heat transfer rate. The evaluation of thermal stratification to natural convective heat transfer in enclosure has been studied. Numerical simulation covers large L/D and high Rayleigh number natural convection: 108RaL14. Based on the scale analysis of natural convection cylindrical boundary equations the new dimensionless group has been put forward contains L/D factor. The new natural convective heat transfer along the vertical single tube model has been build according to the former experiments1 results. After combining numerical simulation results, the new model covers the higher Rayleigh number range of natural convection.
In NPP, the digital control system which integrated software and hardware are increasingly used to improve dependability and introduce new functionality. Traditional safety analysis can get a good result when handling...
详细信息
The digitalized Instrumentation and Control (I&C) system of Nuclear power plants can provide many advantages. However, digital control systems induce new failure modes that differ from those of analog control syst...
详细信息
There are two ways in the development of CHF correlation in rod bundles: one is based on round tube CHF correlations, considering the effects of spacers and CHF promoters, effects of cold walls, etc. The other one is ...
详细信息
ISBN:
(纸本)9781510811843
There are two ways in the development of CHF correlation in rod bundles: one is based on round tube CHF correlations, considering the effects of spacers and CHF promoters, effects of cold walls, etc. The other one is to develop the correlation directly using the rod bundles CHF experimental data which includes two methods: me minimum DNBR point method and the BO point method. In this study, the local thermal-hydraulic parameters at DNB occurrence point of each set of bundle CHF data were obtained by using the subchannel code ATHAS. Both of the minimum DNBR point and the BO point methods were then applied to develop a new CHF correlation for rod bundles. The so-called "three-step method" was used to determine the shape of me correlation and the non-linear regression analysis method was applied to determine the coefficients of the correlation. Based on the large database of CHF tests, a new CHF correlation named the ACC correlation has been developed. The analysis and assessment results indicate that me ACC correlation can fit the experimental data well with high prediction accuracy and correct parametric trends. Compared with the minimum DNBR point method, me BO point method is recommended to predict me risk of DNB because it is more reasonable and conservative with better predication rate. Coupled with subchannel code ATHAS, this correlation can simulate the thermalhydraulics performances of rod bundles exactly.
Spacer grid is an important component in PWR fuel assemblies for its significant influence on thermal-hydraulic characteristics of the reactor core. In this study, single-phase CFD technology is used to study the flow...
详细信息
The SGTR studies correspond to the double-ended guillotine rupture of a steam generator tube, which allows unimped blowdown from both ends of the severed tube. Occurrence of the SGTR a ccident leads to an inc rease in...
详细信息
暂无评论