An Evaluation of Halides and Other Substances as Potential Heat Pipe Fluids

Heat pipe technologies are classified on the basis of the operational temperature range. In the intermediate temperature range of 400 -700 K, heat pipe fluids are not currently available. A survey is undertaken to ide ntify potential heat pipe fluids in this range. Some of the metallic halides and other substances appear to have many of the desirable characteristics of heat pipe fluids, but thermodynamic and thermophysical properties of these substances are difficult to find or non -existent. From the available data, a list of candidate fluids is chosen for experimental studies to determine chemical compatibility with potential envelope and wick metals. Water is explored as an intermediate temperature fluid to test it s up per operational temperature limit. Life test data are non -existent.