In the present study, a test facility, called WAFT [1], has been set up to study liquid flooding phenomena on a heated large flat plate with the counter-current air-water flow. The various thermal hydraulic working condition parameters, especially, temperature and velocity of water, air and oil media, could be obtained by adjust the control devices, such as, heater, valve and frequency regulator. Because of transparent organic glass slab in the test section, the dynamic behavior of water film flow in the different locations of test area can be clearly observed by virtue of high-speed video camera, such as wave pattern change, film rupture, droplet splash and dry spot occurrence. During the test, a series of tests were performed under the conditions of steel plate heat flux 25 kw/m2, the water film with mass flow rate 0.1 and 0.6 kg/s.m and the temperature 70 and 92 °C, the velocity of air entrance ranging from 6.0 to 11.50 m/s and the inlet air temperature of 45 and 60 °C, respectively. According to the acquisition data, a modified Wallis liquid flooding predicted relation was proposed considering the influence factor of temperature from large steel plates, air and water film, i.e., the effect of water film evaporation. The results indicate that the mass flow rate of water film and inlet air velocity have a great effect on the emergence of liquid flooding.
展开▼
机译：在本研究中，已经建立了一个名为WAFT [1]的测试设备，以研究带有逆流空气-水流的加热的大平板上的液泛现象。通过调节加热器，阀门和频率调节器等控制装置，可以获得各种热工工况参数，尤其是水，空气和油介质的温度和速度。由于测试部分使用透明的有机玻璃板，因此可以通过高速摄像机清楚地观察到测试区域不同位置的水膜流动的动态行为，例如波型变化，膜破裂，液滴飞溅和出现干斑。在测试过程中，在以下条件下进行了一系列测试：钢板热通量25 kw / m2，质量流量为0.1和0.6 kg / sm的水膜，温度为70和92°C，空气进入的速度范围从6.0到11.50 m / s，进气温度分别为45和60°C。根据采集的数据，提出了一种改进的Wallis液驱预测关系式，其中考虑了大型钢板，空气和水膜的温度影响因素，即水膜蒸发的影响。结果表明，水膜的质量流量和进气速度对液驱的产生有很大的影响。
展开▼
