低温圆截面直肋结霜工况下的传热研究

通过对低温圆截面直肋在自然对流下的结霜研究,得出肋片在低温下的结霜特点和传热特性。空气相对湿度对结霜起主导作用,同一空气相对湿度下,霜层主要参数都在相仿的数值范围内变化。肋基温度对霜层生长的影响较小,但仍存在一种随着肋基温度的降低,结霜厚度随之增加的微弱趋势。随着空气相对湿度的增加,霜层厚度增大,但通过霜层的热通量和传热比反而增大,霜层物性对霜层的传热起决定性影响。

A Study on Heat Transfer of Circular Cross-Section Fins With Cryogenic Fin Base-Temperature under Frosting Conditions

The characteristics of frost formation and heat transfer of fins with cryogenic fin base-temperature under natural convection were studied.The air relative humidity has significant effects on frost formation.The main parameters of frost layers change in the similar range with the same air relative humidity in experiments.Effects of fin base-temperature are weak on frost layer growth,but there is still a weak trend that the frost layer thickness increases with the decrease of fin base-temperature.With the increase of air relative humidity,the thickness of the frost layer increases,but the heat flux and heat transfer ratio of fins increase.The physical properties of frost layers play a decisive role in the heat transfer through frost layers.