Abstract:

The influence of N₂ mass fraction, coolant mass flux and mixture mass flux on condensation heat transfer in the horizontal rectangular channel have been investigated, with the mixture mass flux ranging from 38 kg·m^-2·s^-1 to 132 kg·m^-2·s^-1. The results show that when the steam flows at high speed, the deterioration of noncondensable gas on the condensation heat transfer is relatively decreased, 8% noncondensable gas results in the reduction of 26.4% in condensation heat transfer coefficient. The condensation heat transfer coefficient increases with the increase of the mixture mass flux and decreases with the increase of the coolant mass flux. Moreover, the variations of the condensation heat transfer along the mixture flow direction are also obtained, the results show that the local condensation heat transfer coefficient decreases along the mixture flow direction.

Key words: rectangular, channel noncondensable, gas condensation

摘要：

对质量流量为38～132 kg·m^-2·s^-1的蒸汽/氮气混合气在水平矩形通道内的凝结换热过程进行了实验研究，研究了氮气含量、混合气质量流量以及冷水质量流量对蒸汽凝结换热的影响。结果表明：在蒸汽流速较高时，不凝气对蒸汽凝结换热的削弱相对较少——8%的不凝气使汽侧凝结传热系数平均下降了26.4%；蒸汽的凝结传热系数随着混合气质量流量的增加而增加、随着冷水流量的增加而下降；此外，通过研究还发现，沿着混合气流动方向，蒸汽凝结传热系数逐渐减小。

关键词: 矩形通道, 不凝气, 蒸汽凝结