The Comparison of Thermal Performance on a Two-Phase Closed Thermosyphon Using Metal Oxide Nanofluids

Nanofluids are stable suspensions of nano solid particles in a conventional fluid. They have great potential in heat transfer enhancement and can be used in thermal equipment such as thermosyphons as the heat transfer media. A two-phase closed thermosyphon is a device for heat transfer; it consists of an evacuated-closed tube filled with a certain amount of a stable working fluid. In this paper, after preparing two kind nanofluids “Al2O3/Water” and “CuO/Water” in different volume percent (1%~3%) the role of using these nanofluids instead of pure water as the heat transfer media are investigated. Experimental results shows that nanofluid can significant improve efficiency of two-phase closed thermosyphon. For filling ratio of 45%, using the “Al2O3/Water” and “CuO/Water” nanofluid instead of water in the system, resulted in 14.7% and 13.4% gain in the efficiency. For both nanofluids maximum efficiency of two-phase closed thermosyphon tacked place at 35% filling ratio and 3 volume percent.