Development of validation technology for detailed two-phase flow simulation codes to optimize innovative reactor design, 4; Development of a measurement technique for liquid film thickness in R134a-ethanol two-phase flow simulating high-temperature and high-pressure environments

Mori, Shoji*; Zhang, H.*; Umehara, Yutaro*; Horiguchi, Naoki   ; Yoshida, Hiroyuki  

To ensure nuclear safety, understanding of liquid film behavior of annular flow like flow near fuel rods in BWRs is important. It is hard to experimentally obtain thin liquid behavior in BWRs because of technical limits under the high pressure and temperature, 7MPa and 285C, and to understand the behavior sufficiently. Therefore, in this study, liquid film behavior under the actual condition was reproduced using ethanol-HFC134a system at 0.7MPa and 40C such as a university laboratory, which has almost same physical properties with the actual water-vapor system. In addition, the liquid film behavior was measured using the constant electric current method, and the measurable range and accuracy of the method were examined.