An investigation of flow characteristics and critical heat flux in vertical upward round tube

An investigation of flow characteristics and critical heat flux in vertical upward round tube 1 first-author 1 corresp E-mail: szqiu@mailst.xjtu.edu.cn E-mail: szqiu@mailst.xjtu.edu.cn szqiu@mailst.xjtu.edu.cn 1 State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China Prediction of critical heat flux (CHF) in annular flow is important for the safety of once-through steam generator and the reactor core under accident conditions. The dryout in annular flow occurs at the point where the film is depleted due to entrainment, deposition, and evaporation. The film thickness, film mass flow rate along axial distribution, and CHF are calculated in vertical upward round tube on the basis of a separated flow model of annular flow. The theoretical CHF values are higher than those derived from experimental data, with error being within 30%. Annular flow Critical heat flux Dryout Entrainment Deposition References Butterwort D , Hewitt G F . Two-phase flow and heat transfer , Oxford University Press , 1977 Two-phase flow and heat transfer Isbin H S , Vanerwater R , Fauske H K , et al . J Heat Transfer , 1961 , 83 ( 5 ): 149 - 157 J Heat Transfer Hewitt G F , Hall-Taylor N S . Annular two-phase flow , Pergamon Press , New York , 1970 Annular two-phase flow Ishii M , Mishima K . Int J Heat Mass Transfer , 1989 , 32 ( 10 ): 1835 - 1846 Int J Heat Mass Transfer Tomio Okawa , Tsutoshi Kitahara , Kenji Yoshida , et al . International Heat and Mass Transfer , 2002 , 45 : 87 - 98 International Heat and Mass Transfer Kataoka I , Ishii M , Nakayama A . Int J Heat Mass Transfer , 2000 , 43 : 1573 - 1589 Int J Heat Mass Transfer Paleev I I , Filippovich B S . Int J Heat Mass Transfer , 1966 , 9 : 1089 - 1093 Int J Heat Mass Transfer Henstock W H , Hanratty T J . AICHE , 1976 , 22 : 990 - 1000 AICHE Ren Ling . Experimental research of dryout in vertical upward round tube, Master Thesis , China Institute of Atomic Energy , July 2003 Experimental research of dryout in vertical upward round tube, Master Thesis 10.1016/S1001-8042(06)60033-X TL33 2005-12-16 2006-06-20 2021-01-19 2006 Nuclear Science and Techniques 03 17