竖直窄矩形流道液泛研究

Study of flooding in vertical narrow rectangular channels

为了研究窄小流道内气液两相逆向流动问题,以空气-水为工质,对竖直窄矩形流道内液泛过程及液泛特征点进行了实验研究和理论分析,并与传统流道液泛进行了比较.结果表明,竖直窄矩形流道内液泛起始点符合Wallis关系式,与传统流道液泛起始点以压差突变进行判断不同,窄矩形流道内液泛起始点的判断以有水被携带出流道为标志.窄矩形流道内完全携带点与水流量大小、实验段入口条件无关,只与气体流量大小有关;流向反转点与试验段壁面干燥程度有关,与水流量大小及气体入口条件无关.

In order to investigate the question of the countercurrent flow of a two-phase gas-liquid in a vertical narrow channel,this paper describes an experimental study on a flooding mechanism,the onset of flooding,and the pressure drop change in vertical narrow rectangular channels with air and water as the working fluids contrasted with those in conventional channels.The results show that the onset of flooding complies with the Wallis formula in vertical narrow rectangular channels.The onset of flooding in traditional channel can be judged by a sudden change of differential pressure,while in vertical narrow rectangular channel the onset of flooding can be judged by a sign of water taken out of the channel.The carryover is only related to air flow and not water flow and experimental section entry conditions.In addition,reversal of the flow direction is connected with a dry condition of the channel wall,but not water flow and air entry conditions.