Evaluation of steam-water annular flow characteristics under BWR operating conditions based on experiments with simulant fluids

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

Due to the operating conditions of BWRs (285C and 7 MPa), the direct visualization and detailed liquid film measurement of steam-water annular flow in BWRs have been highly challenging. This study addresses this limitation by developing a novel HFC134a-ethanol annular flow system at lower temperature and pressure (40C and 0.7 MPa), simulating the steam-water annular flow under BWR conditions. The experiments of HFC134a-ethanol upward annular flow were conducted in a 5 mm inner diameter tube using the constant electric current method, and we obtained the flow characteristics including base, average, and maximum film thickness and the height of disturbance wave.