【摘要】 为研究螺旋管内汽水两相流干涸特性,在较宽的流动参数范围内(系统压力P=2～7 MPa,质量流速G=150～700 kg/(m~2·s),热流密度q=75～350 k W/m~2)对一立式螺旋管(内径15. 26 mm,螺旋直径350 mm,螺旋升角10°)进行了试验,分析了管内流动沸腾传热系数和壁面温度的变化特征,获得了压力、质量流速、热流密度3个流动参数对临界干度的影响规律,并将现有文献中的临界干度预测关系式与试验结果进行了对比,推荐了适用于该工况范围的关系式。更多还原

【Abstract】 In order to study the dryout characteristics of steam-water flow in a vertical helically coiled tube with inner diameter of 15. 26 mm,coil diameter of 350 mm and helix angle of 10,experiments were performed on the tube at a system pressure of 2 ～ 7 MPa,mass velocity of 150 ～ 700 kg/( m~2·s) and wall heat flux of 75 ～ 350 kW/m~2. The boiling heat transfer coefficient of flow in the tube and change characteristics of wall surface temperature were analyzed,and the influence rules of three flow parameters,namely,system pressure,mass velocity and wall heat flux,on the critical quality were obtained. Several available dryout correlations in existing literature were compared with experimental results,and the correlation applicable to the range of operating conditions in this paper was recommended.更多还原