以氧化石墨烯分散液(浓度为0.5mg/m L)和正丁醇水溶液(质量分数为0.5%)的混合溶液(体积比2∶5)为工质,充液率为50%,对不同加热功率条件下环路脉动热管稳定运行的传热特性进行实验研究,并与正丁醇水溶液和去离子水的传热性能进行对比,分析了混合溶液在脉动热管稳定运行时冷热端温差和传热热阻的变化特点,探究了氧化石墨烯对自湿润流体传热性能的影响。研究结果表明:在自湿润流体中加入氧化石墨烯能够强化脉动热管的传热特性,但是和脉动热管的加热功率密切相关;在低加热功率下,氧化石墨烯对自湿润流体脉动热管的传热特性没有强化作用;随着加热功率的增加,强化作用明显增强,而当加热功率过大时,强化作用又会逐渐减弱。
This research investigated heat transfer characteristics of the steady operation processes of pulsating heat pipe (PHP) at various heating power. The working fluid was mixture of graphene oxide dispersion at concentration of 0.5mg/mL and n-butanol aqueous solution with mass fraction of 0.5%. The volume ratio of the mixture was 2 : 5 and filling ratio was 50%. Heat transfer performances were compared between mixed solution, n-butanol aqueous solution and deionized water. The effects of graphene oxide on the heat transfer performance of self-rewetting fluid were explored by analyzing the temperature difference and thermal resistance of PHP with the mixture. The results showed that graphene oxide could enhance the heat transfer characteristics of PHP when added in self-rewetting fluid, and heating power had important effects on the heat transfer enhancement. Graphene oxide had no effects on the heat transfer characteristics of PHP with self-rewetting fluid at low heating power. The strengthening effects increased significantly with increase of heating power, but the increase became less significant when heating power increased to a certain value.