Experimental research on dryout point of flow boiling in narrow annular channels

Experimental research on dryout point of flow boiling in narrow annular channels 1 corresp first-author E-mail: gpwu@mailst.xjtu.edu.cn E-mail: gpwu@mailst.xjtu.edu.cn gpwu@mailst.xjtu.edu.cn 1 1 1 2 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 Reactor Engineering Research Division, Nuclear Power Institute of China, Chengdu 610041, China Reactor Engineering Research Division, Nuclear Power Institute of China, Chengdu 610041, China An experimental research on the dryout point of flow boiling in narrow annular channels under low mass flux with 1.55mm and 1.05mm annular gap, respectively, is conducted. Distilled water is used as working fluid and the range of pressure is limited within 2.0~4.0MPa and that of mass flux is 26.0~69.0kg·m -2 ·s -1 . The relation of critical heat flux (CHF) and critical qualities with mass flux and pressure are revealed. It is found that the critical qualities decrease with the increasing mass flux and increase with the increasing inlet qualities in externally heated annuli. Under the same conditions, critical qualities in the outer tube are always larger than those in the inner tube. The appearance of dryout point in bilaterally heated narrow annuli can be judged according to the ratio of q o / q i . Narrow annular channel Flow boiling Dryout point References Okawa T , Kotani A , Kataoka I . Prediction of dryout heat flux in vertical round tubes with uniform and non-uniform heating , The 10th International Topic Meeting on Nuclear Reactor Thermal Hydraulics , October 2003 , Seoul, Korea . Prediction of dryout heat flux in vertical round tubes with uniform and non-uniform heating Wang B X , Zhang J T , Peng X F , International Journal of Heat and Mass Transfer , 2000 , 43 : 1897 - 1903 . International Journal of Heat and Mass Transfer Knudsen J G , Katz D L . Fluid dynamics and heat transfer . New York : McGraw-Hill , 1958 : 186 - 195 . Fluid dynamics and heat transfer Collier J G , Thome J R . Convective boiling and condensation . Oxford : Oxford University Press , 1994 : 329 - 367 . Convective boiling and condensation 10.1016/S1001-8042(06)60047-X TL33,O359 2005-12-05 2006-08-20 2021-01-19 2006 Nuclear Science and Techniques 04 17