Subcooled boiling bubble condensation experiments were conducted in a vertical-upward annular channel by using water as the testing fluid at atmosphere pressure. The test runs comprised of bulk liquid temperatures, velocities and wall heat fluxes ranging from 75.0 degrees Celsius to 98.0 degrees Celsius, 0.25 m/s to 1.0 m/s and 150 kW/m2 to 200 kW/m2 respectively. A particle/droplet image analysis system was employed to capture the flow channel at four locations downstream of heated section for a total of 13 test conditions. The bubble Sauter-mean diameter was obtained in the range of 0.1 mm to 0.9 mm. It is also found that bubble sizes increase with the increase of liquid temperature or the decrease of liquid velocity. The condensation Nusselt number was calculated to be in the range of 10-4 to 10-1, which is much smaller than the typical range of 100 to102. This might due to the existence of non-condensable gas in the bubble.
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机译：在大气压下，以水为测试液，在垂直向上的环形通道中进行过冷沸腾冷凝实验。该测试包括散装液体温度，速度和壁热通量，范围分别为75.0摄氏度至98.0摄氏度，0.25 m / s至1.0 m / s和150 kW / m2至200 kW / m2。使用颗粒/液滴图像分析系统在加热段下游的四个位置捕获流道，总共进行了13个测试条件。获得的气泡索特平均直径在0.1mm至0.9mm的范围内。还发现气泡尺寸随着液体温度的升高或液体速度的降低而增加。计算得出的缩合努塞尔数在10-4至10-1的范围内，比典型的100-102的范围小得多。这可能是由于气泡中存在不可凝气体所致。
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