준-밀폐형 2상자연순환회로 내에서의 팽창탱크 연결관의 유동저항에 따른 유동 불안정 현상의 변화

Abstract

In the present experimental study, the flow instabilities in a semi-closed two-phase natural circulation loop were examined. Heat flux, heater-inlet subcooling, and flow restrictions at the expansion-tank-line were taken as the controlling parameters. Excursive Instability was not observed when the flow restriction at the expansion-tank-line is very high. Six circulation modes were identified ; The single-phase natural circulation, periodic circulations (A), (B), (C), and (D), and the two-phase continuous circulation. Parametric study shows that the increase of the expansion-tank-line restriction and the decrease of the inlet subcooling broaden the range of the stable(continuous) two-phase circulation mode.