DEVELOPMENT OF LEAK RATE MODEL FOR HELIUM FLOW IN ELLIPTICALLY CONVERGING THROUGH WALL CRACK
Leak Before Break (LBB) analysis is widely used to demonstrate system safety of pressurized equipments in nuclear plants. Developing a precise leak rate model for helium flow in complex geometry cracks is a key point for LBB analysis in Very High Temperature gas-cooled Reactor (VHTR). A literature study was firstly carried out concentrating on leak rate models proposed or used in LBB analysis. Helium leak rate experiments named DEDIFAR have been performed using elliptically converging and diverging artificial cracks in order to study the effect of the crack length ratio of a real through wall crack. Computational Fluid Dynamics (CFD) calculations of DEDIFAR experiments are presented to analyze the distributions and tendencies of flow parameters in converging cracks. Then, a parametric study was completed to investigate crack geometry effect on mass flow rate. Based on the results of these studies, the effects of upstream pressure and convergence ratio (inside over outside crack lengths) on mass flow rate are analyzed. The results show that the pressure loss mainly concentrates around the smallest exit crack area, and that when the convergence ratio equals or exceeds 20, flow parameters inside the crack domain remain almost the same.
Sheng Zhou Zhengming Zhang Pierre Lamagnere Thierry Cadiou Jean-luc Berton Marc Grandotto-Biettoli
Institute of Nuclear and New Energy Technology Tsinghua University, Beijing 100084, P.R.China DEN/DER/SESI CEA Cadarache, 13108 Saint-Paul-Lez-Durance Cedex, France DEN/DTN/STPA CEA Cadarache, 13108 Saint-Paul-Lez-Durance Cedex, France DEN/DER/SSTH CEA Cadarache, 13108 Saint-Paul-Lez-Durance Cedex, France
国际会议
18th International Conference on Nuclear Engineering(第18届国际核能工程大会 ICONE 18)
西安
英文
1-6
2010-05-17（万方平台首次上网日期，不代表论文的发表时间）