超临界水冷堆类四边形子通道亚临界水的传热试验研究

Experimental Investigation on Heat Transfer Characteristics of Subcritical Pressure Water Flowing in Subchannel with Square Distribution in SCWR

在压力为11～19 MPa,质量流速为700～1300 kg/（m^2·s）,热流密度为200～600 k W/m^2的工况范围内,对超临界水冷堆（SCWR）堆芯棒直径为8 mm,栅距比为1.2的类四边形子通道的传热特性进行试验研究。结果表明：热流密度对类四边形子通道管管内的传热特性的影响显著,热流密度越高,传热恶化越容易发生;在较低的质量流速下,传热恶化发生可能性较大,质量流速较高时,对传热特性影响较小;压力对类四边形管管内传热特性的影响明显,压力越高,传热恶化现象越易发生,且临界干度值越低,传热恶化所覆盖的焓值区域越大。

Within the pressure range from 11 to 19 MPa, mass velocity from 700 to 1300 kg/（m^2·s）, and inner wall heat flux from 200 to 1000 kW/m^2, experiments were performed to investigate the heat transfer characteristics of water flowing in subchannel with square distribution in SCWR. The subchannel was formed according to the fuel rods of the diameter 8 mm, and the pitch-to-diameter ratio was 1.2. The results show that the heat transfer characteristics of subcritical pressure water flowing in the subchannel with square distribution are significantly affected by the inner wall heat flux. Heat transfer deterioration more likely happens with higher inner wall heat flux. Heat transfer deterioration is more likely happened under low mass velocity, while it has little influence on the heat transfer characteristics at high mass velocity. The pressure has significant effects on the heat transfer characteristics. The higher pressure, the more likely the heat transfer deterioration occurred. The lower critical steam quality and the widely enthalpy region where heat transfer deterioration happen.