中文摘要：

采用反映系统序列间正、负相关性的灰色关联度模型,对自然循环条件下影响窄通道过冷沸腾起始点（ONB点）发生的相关因素进行分析。结果表明：在所选参数范围内,加热功率与ONB点位置呈负相关性,质量流量和工质压力与ONB点位置呈正相关性,即加热功率增加ONB点提前出现,质量流量增加、工质压力提高ONB点推后出现;窄缝间隙与ONB起始热流密度呈弱正相关性,其增加会推迟ONB点的出现。

英文摘要：

Grey correlation degree calculation model which reflects the positive and negative relation of sequences is applied to calculate the relevant influence factors on ONB（Onset of Nucleate Boiling） in narrow channel under natural circulation.Results show that in the range of selected parameters： heating power shows a negative correlation with the distance between ONB and channel inlet,which proves that heating power promotes ONB occurrence;mass flow and pressure show positive correlation with the distance between ONB and channel inlet,which proves that these two factors postpone ONB occurrence.And a weak positive corre-lation exists between the narrow channel gap and inception heat flux at the location of ONB.The occurrence of ONB will be postponed as the value of channel gap becomes bigger.