安全弁における単相及び二相流の流出挙動

概要

論文の詳細を見る
The discharging flow rate from safety or relief valves is restricted with the minimum flow area between disk and seat. The flow rate is usually smaller than the calculation with the minimum flow area due to the vena contraction. The discharging flow rate of water was measured at different valve lifts and seat configurations. The water flow rate was affected with the lift and seat configuration due to the different formation of vena contraction. The air and air-water two-phase discharging flow rate were also measured and compared with the non-equilibrium or slip flow model. The air flow rate was affected not only with the vena contraction but also with the delay of expansion. The two-phase flow rate was affected with the slip velocity between air and water. It was suggested that the vena contraction of two-phase flow was mitigated with the oscillatory flow behavior. The two-phase discharging flow rate was well correlated with the simple pressure loss equation. The single and two-phase discharging behavior was carefully observed by using the transparent disk.