地下调蓄隧道系统气团释放诱发的井喷特性研究

Characteristics of geysers induced by release of air pocket in storage tunnel system

地下调蓄隧道系统是解决城市调蓄能力不足和防止内涝的重要工程,井喷现象是系统内发生的一种严重水力事故,气团释放诱发的井喷特性研究对调蓄隧道系统的安全运行有着重要意义。该文采用实验和数值模拟相结合的方法,对气团运移及释放过程中的水气两相运动进行了深入研究,结果表明,气团释放诱发的井喷气泡形态类似于经典的泰勒气泡,但其上升速度显著大于泰勒气泡速度,且有加速上升的趋势;调蓄隧道系统中,气泡压力与水柱重力之间存在一个动态平衡过程,气泡压力水头与水柱高度差决定了井喷的强度,其大小随着井隧直径比的增大而快速减小,当井隧直径比等于0.8时,气泡压力水头与水柱高度差已接近于0,此时气团释放不会引发井喷。

The storage tunnel system is an important project to solve the shortage of urban storage capacity and prevent waterlogging,geyser phenomenon is a serious hydraulic accident occurring in the system,and the study on the characteristics of geyser is of great significance for the safe operation of the storage tunnel system.In this paper,the movements of water and gas in the release process of air pocket are studied,employing experiment and numerical simulation.The research results show that the bubble shape of geyser induced by the release of air pocket is similar with the traditional Taylor bubble,but the rising bubble velocity of geyser is significantly higher than that of Taylor bubble,and it has a trend of accelerated rising.There is a dynamic balance between bubble pressure and gravity of the upper water column in the storage tunnel system,and the difference value determines the geyser intensity.The difference value decreases rapidly with the increase in the diameter ratio of shaft and tunnel.When the diameter ratio is equal to 0.8,the difference value between bubble pressure head and water column height is close to 0,and the release of air pocket will not cause the geyser phenomenon.