In this paper, new measurements of frost nucleation time and growth rate on a small 0.3m by 0.3m microchannel heat exchanger are presented. During the data reduction, fin surface temperature, uniform air temperature distribution, air lift and drag effects, and air velocity distribution were carefully evaluated and taken into consideration. The microchannel fin surface temperature, entering air face velocity, relative humidity and the amount of water retained within the fins were varied in a parametric fashion in order to identify the predominant factors affecting the frosting performance. Results show that the water retention and air face velocity do not have a significant impact on the frosting cycle while surface temperature and air relative humidity affect the frosting time considerably. Digital videos of frost formation confirmed that frost does not nucleate from large water droplets within the fins but mainly from the leading edges at the front of the fins.
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机译：在本文中，提出了在0.3m x 0.3m的小型微通道换热器上霜冻成核时间和生长速率的新测量方法。在数据缩减过程中，仔细评估并考虑了散热片表面温度，均匀的空气温度分布，空气升力和阻力效应以及空气速度分布。为了确定影响结霜性能的主要因素，微通道散热片的表面温度，进入的空气面速度，相对湿度和散热片中残留的水量都以参数方式进行了更改。结果表明，保水量和空气面速度对结霜周期没有显着影响，而表面温度和空气相对湿度对结霜时间影响很大。结霜的数字视频证实，霜不是从鳍片内的大水滴中成核，而是主要从鳍片前缘形成核。
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