基于矩形窄缝通道实验数据的DNB机理模型评价

DNB Mechanistic Model Assessment Based on Experimental Data in Narrow Rectangular Channel

偏离泡核沸腾(DNB)对于压水堆安全具有重要意义。已有机理模型能否适用于矩形窄缝通道缺乏足够的实验验证。本文基于矩形窄缝通道实验数据,对微液层蒸干模型和汽泡壅塞模型两类DNB机理模型进行了计算评价。结果显示:汽泡壅塞模型适用范围较微液层蒸干模型宽;部分热工参数对模型计算性能有系统性影响。随空泡份额的增大,各模型的计算性能均变差,可能是通道几何差异所致。

The departure from nucleate boiling（DNB） is important concerning about the safety of a PWR.Lacking assessment by experimental data points,it＇s doubtful whether the existing models can be used in narrow rectangular channels or not.Based on experimental data points in narrow rectangular channels,two kinds of classical DNB models,which include liquid sublayer dryout model（LSDM） and bubble crowding model（BCM）,were assessed.The results show that the BCM has much wider application range than the LSDM.Several thermal parameters show systematical influences on the calculated results by the models.The performances of all the models deteriorate as the void fraction increases.The reason may be attributed to the geometrical differences between a circular tube and narrow rectangular channel.