Molten salt is a highly efficient heat transfer working fluid. It is widely used in central solar power

nuclear reactor

and heat treatment of metals. The startup process of gravity heat pipe with mixed nitrate as the working fluid was investigated experimentally by analyzing the startup characteristics

stability

and the influence of inclination angle on the startup behavior. The gravity heat pipe was fabricated with 316 L stainless steel

with outer diameter of 22 mm

thickness of 2 mm and total length of 980 mm. In order to explore the heat pipe start-up behavior of mixed nitrates

the experimental result with 40 g mixed nitrate working fluid is compared to that with 40 g naphthalene working fluid. The startup time of heat pipe with mixed nitrates is shorter than that with naphthalene and the heat pipe with mixed nitrates is superior to that with naphthalene in the stability. The boiling point of mixed nitrate is about 250℃. The startup characteristics at inclination angle of 50° are superior to those at 30°

70° and 90°. The experiment shows that it is feasible for using mixed nitrates as the working fluid of heat pipe.