垂直上升圆环形通道内超临界压力水的传热特性

Heat Transfer Characteristics of Supercritical Pressure Water in Vertical Upward Annular Channels

在压力P=23～28 MPa、质量流速G=350～1000 kg/(m2.s)、外壁面热流密度q=200～1000 kW/m2的试验参数范围内,对垂直上升圆环形通道内超临界压力水的传热特性进行试验研究。分析q、P、G、螺旋绕丝对传热特性的影响,比较有、无绕丝结构时出现的两种传热恶化。试验结果表明:提高G或降低q都可以强化超临界水的传热;在不同的传热类型下,P对传热特性有不同的影响;螺旋绕丝具有很好的局部强化传热作用,并且可以推迟在高热流密度、低质量流速下发生的传热恶化。

Within the range of pressure from 23 to 28 MPa, mass flux from 350 to 1000 kg/（m2.s）, and outside wall heat flux from 200 to 1000 kW/m：, experimental investigation was conducted on the heat transfer characteristics of supercritical pressure water in vertical upward annular channels. The effects of heat flux, pressure, mass flux and spiral spacer on heat transfer were analyzed, and two types of heat transfer deterioration occurred in the experiments were compared. The experimental results show that the heat transfer of water can be enhanced by increasing the mass flux or decreasing the wall heat flux. The effect of pressure on heat transfer is not uniform and depends on heat transfer form. It was found that the spiral spacer not only enhances the heat transfer of water, but also delays the heat transfer deterioration which occurs in high heat flux and low mass flux conditions.