Abstract:

Galinstan, a room temperature liquid metal, combines both the features of liquid and metal. Utilizing the oscillating motion of the mixed working fluids of liquid metal and surfactant solution, a high thermal conductivity mixed liquid metal self-dispersed micro-nano droplets in the oscillating heat pipe (OHP) was formed with high heat transfer performance. 6-turn flat plate oscillating heat pipe with Galinstan and surfactant as the working fluids was investigated visually and experimentally under different liquid metal filling ratios and heat input in this work. The results demonstrated that liquid metal was driven to oscillate with the pressure difference induced by phase change of working fluids and broke up into spherical droplets. It was hard for the droplets to coalescence because of exited surfactant solutions. There were nano-particles with the diameter of 410—520nm, left in the surfactant solutions after the oscillation of liquid metal. When the filling ratios of liquid metal was 20%—25%, the high viscosity and mass of liquid metal spherical droplets hindered the oscillating motion of the mixed working fluids easily and thus increased the thermal resistance of the oscillating heat pipe. When the filling ratios was 5%—10%, the mixed working fluids coupled the high thermal conductivity of the liquid metal and the heat transfer performance was improved effectively and the thermal resistance was reduced by 11.21% at most when the liquid metal filling ratio was 5%.

Key words: oscillating heat pipes, liquid metal, micro-nano droplets, surfactant, heat transfer performance

摘要：

利用室温液态金属和表面活性剂溶液混合工质的振荡运动，在脉动热管中形成液态金属微纳液滴分散的高热导率混合流体并提高其传热性能。本文将液态金属表面活性剂混合工质引入六弯管板式脉动热管中，在不同液态金属填充量和加热功率下开展可视化和传热性能实验。实验结果表明，液态金属在表面活性剂混合工质中通过振荡自分散成球形液滴且相互之间不易发生合并，并在表面活性剂工质中留下粒径在410~520nm的纳米颗粒。传热性能方面，液态金属填充量在20%~25%时，液态金属球形液滴的黏度高、质量大，会阻碍混合工质的振荡运动从而降低脉动热管的传热性能，填充量在5%~10%时，混合工质耦合了液态金属的高热导率特性，有效提高传热性能，热阻最多降低11.21%。

关键词: 脉动热管, 液态金属, 微纳液滴, 表面活性剂, 传热性能