Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
Efficiency of gravity assisted heat pipe (thermosyphon) is studied. Tests were performed for a known geometry of a heat pipe 550 mm long, 22 mm outer diameter and wall thickness of 1 mm. Goal of present research is to determine the influence of phase change process (boiling, condensation) occurring inside the heat pipe for variety of working conditions. The study was conducted for the following refrigerants filling the interior of the heat pipe: R134a, R404A, R407C, and R410A. Different amounts of working fluids are considered. Numerical CFD simulation was performed for one case for validation and better understanding of two-phase processes occurring inside thermosyphon. Efficiency and effectiveness of the heat pipe was calculated on the basis of obtained experimental research data.