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

• Published in: Nuclear science and techniques 2006, Vol.17 (4), p.252-256
• Main Authors: WU, Ge-Ping, QIU, Sui-Zheng, SU, Guang-Hui, JIA, Dou-Nan, LU, Dong-Hua
• Format: Article
• Language: English
• Subjects: Dryout point; Flow boiling; Narrow annular channel; O359; TL33; 临界热通量; 核沸腾; 流动沸腾; 狭窄环形通道
• ISSN: 1001-8042; 2210-3147
• DOI: 10.1016/S1001-8042(06)60047-X

An experimental research on the dryout point of flow boiling in narrow annular channels under low mass flux with 1.55 mm and 1.05 mm annular gap, respectively, is conducted. Distilled water is used as working fluid and the range of pressure is limited within 2.0-4.0 MPa and that of mass flux is 26.0-69.0 kg·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 qo/qi.