低温环境下水滴在冷表面结冰过程的实验研究

Experimental Study on Freezing Process of Water Droplet on Cold Surface at Low Ambient Temperatures

本文研究了环境温度的变化和实验表面改变对水滴结冰过程的影响。在温度可调的低温环境测试箱中搭建了观测水滴结冰的实验装置。用气压控制器控制液滴发生装置内的压强并使其产生水滴,通过相机记录水滴在冷表面上的结冰过程。实验结果表明:实验板表面的导热系数对水滴的结冰时间影响较大,环境温度为-22. 0℃时,红铜表面的结冰时间为3. 8 s,不锈钢表面的结冰时间为5. 0 s,均小于玻璃表面上的结冰时间15. 2 s;水滴在不同实验表面上结冰时均会产生凸起,但仅在玻璃表面上会发生明显的凸起塌陷现象。

The present study measured the effects of the ambient temperature and substrate surface on the freezing process of a water droplet. We built the experimental setup for the measurement of the droplet freezing process in a low-temperature test chamber. An air pressure controller was used to control the pressure inside the droplet generator to produce water droplets. Then,a camera recorded the details of the droplet freezing process. The results showed that the heat conductivity coefficient of the substrate surface had a significant influence on the freezing time. When the ambient temperature was-22. 0 ℃,the freezing time of the droplets on red copper was 3. 8 s and the freezing time of droplets on stainless steel was 5. 0 s,both of which were less than the 15. 2 s measured for the glass surface. In addition,despite the appearance of protrusions during the water droplet freezing process in all the cases,the collapsing bulge phenomenon happened only in the glass surface case.