Investigation of thermal conductivity of nanofluids with liquid gallium as a base fluid for nuclear applications

Abstract

Nanofluids (nanoparticle colloidal suspensions) are nanotechnology-based fluids engineered for enhancing thermal conductivity by dispersing and stably suspending nanoparticles in traditional heat transfer fluids. The small thermal conductivity of water or other organic fluids as base fluids would lower their effectiveness as a cooling fluid. Such concept of nanofluids can be extended to even liquid metals such as sodium, lead and lead-bismuth, as well as gallium being considered as potential coolants in Fast Reactor. Among them, the gallium is the naturally existing liquid having the lowest melting point (∼30 oC) and has no explosive reaction with water. However, the liquid metal has relatively lower thermal conductivity compared to other liquid metals. If nanoparticles were dispersed well in liquid gallium, nanofluids with liquid gallium as a base fluid having the highest conductivity are expected to be an idealistic and a promising way for making a highly conductive coolant for nuclear applications without the safety concern.