【摘要】 基于微液层蒸干的临界触发机理,构建了偏离泡核沸腾(DNB)型的临界预测模型。通过对临界点处的汽块进行受力平衡分析,基于优化后的侧面提升力系数CL,确定了汽块滑移速度、微液层液膜厚度等参数,实现对均匀加热下DNB型临界热流密度的理论预测。采用2种加热长度下矩形窄缝通道内的临界热流密度实验数据对该模型进行了验证。结果表明:模型所预测矩形窄缝通道内的临界热流密度值与实验结果的偏差均在±15%之内,该模型的预测精度高于Bowring公式和Bettis公式的预测精度。更多还原

【Abstract】 Based on liquid sublayer dryout mechanism, a critical heat flux(CHF) model has been developed for the prediction of DNB-type CHF. In the model, the forces exerted on the vapor blanket are analyzed to calculate the boiling crisis parameters including vapor blanket velocity, sublayer thickness with modified lift force coefficient. The predictions of present CHF model are verified by CHF experimental results, which are obtained in two narrow rectangular test sections with different heating length. The deviations between the CHF predictions and CHF experiment results are within ±15% error band, which show more reasonable accuracy than using Bowring correlation and Bettis correlation.更多还原