Development of nontoxic heat transport fluids for habitat two-phase thermal control systems

The goal of this project was to develop suitable nontoxic two-phase heat transport fluids for manned spacecraft habitats. To meet the NASA two-phase fluid design criteria, the fluids must be nontoxic, nonflammable and thermally stable. They must also have suitable vapor pressure, melting point and other thermophysical property characteristics to maximize thermal performance and minimize system mass. An innovative computational chemistry approach, combined with extensive thermophysical, toxicity, flammability, and thermal stability testing, was used on this effort to identify, screen, and test candidate heat transport fluids. Several fluids were found that have suitable characteristics for use in manned spacecraft habitats. These fluids can be used in single-phase or two-phase pumped loop systems, heat pipes, or heat pumps