滴状冷凝强化传热管制备及性能研究

Preparation and Performance Study of Enhanced Dropwise Condensation Heat-transfer Tubes

采用涂覆-热处理法制备了二甲基硅油膜、硅橡胶膜、纳米白炭黑-硅橡胶膜滴状冷凝强化传热管。研究了二甲基硅油、107硅橡胶、纳米Si O2在铸膜液中浓度对热通量、总传热系数、冷凝传热系数及表面传热温差等的影响,并用傅里叶红外光谱和接触角对本实验所制备的传热管表面进行了分析。结果表明：实验所制得的4种类型的传热管均可以实现滴状冷凝现象;与相应的膜状冷凝相比,纳米白炭黑-硅橡胶膜的冷凝传热系数提高了3.1~3.3倍,传热效果最好;二甲基硅油膜强化传热管的传热效果次之,与相应的膜状冷凝相比,其冷凝传热系数提高了1.9~2.1倍;两种膜的表面温差分别约为相应膜状冷凝的1.3~1.4倍和1.2~1.3倍。

The coating-heat treatment method was adopted to prepare enhanced dropwise condensation heat- transfer tubes which coated with dimethicone film, silicone rubber film and Nano silica-silicone rubber film re- spectively; and the concentration influence of the dimethicone, 107 silicone rubber and Nano silica in the casting solution on the heat flux, heat transfer coefficient, total heat transfer coefficient and surface temperature difference was investigated; meanwhile, having the prepared tubes＇ surface analyzed with FT-IR and contact angle shows that the four heat-transfer tubes prepared in the experiment can realize dropwise condensaion; compared to the filmwise condensation, the condensation coefficient of Nano silica-silicone rubber film can be increased by 3.1- 3.3 times together with the best heat transfer effect ; and the heat transfer effect of the tube with Nano silica-silicone film takes the second place together with improved condensation coefficient by 1.9 - 2.1 times ; and as for the surface temperature difference, these two films stays at 1.3 - 1.4 times and 1.2 - 1.3 times of the corresponding filmwise condensation, respectively.