竖直及倾斜环隙流道内自然对流沸腾临界热负荷

Critical Heat Flux During Natural Convective Boiling in Vertical and Inclined Narrow Annuli

以水为工质 ,在常压下对垂直和倾斜环隙流道内的自然对流沸腾临界热负荷进行了实验研究和理论分析 ,得到了计及进出口局部阻力的计算公式 ,讨论了流道几何尺寸、几何形状、倾角、压力和进出口局部阻力等因素对临界热负荷的影响 ,最后提出了一个新的 ,可用于计算竖直环隙、圆管及长方形流道内自然对流沸腾临界热负荷的半经验公式 ,其计算精度和适用范围较现有的计算公式有显著提高 ,原则上不受H/De 值大小的限制。

The critical heat flux during natural convective boiling in vertical and inclined narrow annuli,which was submerged in saturated water and the inner tube was used as heating surface,was investigated under atmospheric pressure with both ends open. A theoretical formula based on homogeneous flow model of vapor and liquid mixture was derived. The effects of gap size,shape, inclination angle, pressure and form losses of two ends of annuli were discussed. At the end, a new semi empirical correlation was also derived which can accurately predict the CHF of vertical annuli, circle tube and rectangular channel in a very wide range of parameters.