氧化石墨烯/石蜡复合相变乳液的制备及对流传热特性

为提高石蜡相变乳液的传热性能,通过添加氧化石墨烯(GO),制备了GO/石蜡复合相变乳液并对其相关性能进行了表征。搭建了流动阻力、对流换热试验台,对比研究了石蜡相变乳液及GO/石蜡复合相变乳液的流动阻力特性和对流换热特性,试验结果表明,由于GO的亲水性,复合相变乳液都表现出较好的稳定性。当GO的质量分数为0.01％、0.02％、0.03％时,复合相变乳液的热导率分别增加了20.01％、30.50％、35.18％。添加GO使乳液的流动阻力略有增加,直管段最大增加了6.70%,90°弯管处最大增加了13.20%;对流传热系数随着GO浓度的增加而增大,当GO浓度为0.03％时,对流传热系数最大提高了43.90％。

Preparation and heat transfer characteristics of GO/paraffin composite phase change emulsions

To improve the heat transfer performance of paraffin phase change emulsion, GO/paraffin composite phase change emulsion was prepared by adding graphene oxide (GO) and its properties were characterized. The flow resistance and convection heat transfer test rig were set up, and the flow resistance characteristics and convective heat transfer characteristics of paraffin phase change emulsion and GO/paraffin composite phase change emulsion were comparatively studied. The results show that the composite phase change emulsion shows good stability due to the hydrophilicity of GO. When the mass fraction of GO is 0.01%, 0.02%, and 0.03%, the thermal conductivity of the composite phase change emulsion increases by 20.01%, 30.50%, and 35.18%, respectively. The flow resistance of the GO/paraffin composite phase change emulsion increases slightly compared to that of paraffin phase change emulsion. The straight pipe section increased by 6.70%, and the 90°elbow section increased by 13.20%.The convective heat transfer coefficient increases with the increase of GO concentration. The maximum convective heat transfer coefficient was increased by 43.90% at the GO addition amount of 0.03%.