Development of computer code for water-steam flow in steam generator and simulation of flow instabilities

Yoshikawa, Ryuji  ; Ohshima, Hiroyuki

The feasibility assessment of steam generator with straight heat transfer tube is being carried out. In this study, the computer code for water-steam flow in SG was developed. The drift-flux model and semi-implicit method were used. The total flow rate and temperature of flow into the inlet plenum, and the pressure of outlet plenum were given as boundary conditions. The flow instability experiments with two parallel channels were simulated. The capability of computer code on predictions of flow oscillation and stable boundary was confirmed. The sensitivity analysis was also carried out to quantify the impact of each parameter on oscillation period and the stable boundary. It can be expected to improve the accuracy of the computer code by using appropriate drift velocity and two-phase frictional multiplier correlations.