Effects of dynamic load on flow resistance, void fraction and heat transfer of steam-water two-phase flow in pipes
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摘要: 利用旋转平台对动载作用下单相水和沸腾两相流流动及传热特性进行了实验研究.通过改变旋转速度、入口温度、液体流量等参数,获得了静止和旋转2种状态下的单相水及沸腾两相流实验数据.对旋转状态下的管内两相流型进行可视化拍摄,得到了动载作用下的两相流型图.结果表明,过载方向与流动方向相反时,过载越大,管内压力和流阻越大,液相流量、空隙率和流体得热量越小.可见,动载阻碍流体向前流动,强化了管外散热,削弱了管内流体的相变换热能力.Abstract: An experimental investigation using a rotating platform was performed to obtain the flow and heat transfer characteristics of single-phase water and two-phase pipe boiling water under dynamic load in present work. By changing the parameters, such as rotation speed, inlet temperature, flow rate, and so on, the flow and heat transfer data of single-phase water and two-phase boiling water flow under static and dynamic conditions were obtained. The image of two-phase flow patterns under dynamic load was obtained with a video camera. The results show that as the direction of the dynamic load is opposite to the flow direction, the greater the dynamic load, the higher the outlet pressure in test section and the flow resistance, and the lower the liquid flow rate, the void fraction, and the heat gained by fluid. Therefore, the dynamic load will block the fluid flow, enhance heat dissipation toward the ambient environment and reduce the heat transfer to the two-phase boiling fluid.
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Key words:
- dynamic load /
- flow pattern /
- boiling heat transfer /
- experimental research /
- steam-water two-phase flow
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