Characteristics and Identification of Super-Effective Thermal Fire- Extinguishing Agents

摘要

This report summarizes the findings of a three-year investigation designed to assess the potential for fire-extinguishing agents that act primarily by thermal means to replace the chemically active halons whose production has been banned due to their deleterious effects on stratospheric ozone. The project had four major components: 1) Extensive searches of thermodynamic databases maintained by NIST were carried out to identify% chemical compounds that are predicted to extract large amounts of heat from a combustion zone, 2) two liquids that were identified as being particularly interesting during the database search, were tested experimentally for their extinguishing effectiveness, 3) detailed chemical- kinetic modeling and experimental studies of extinguishing volume fractions in simple flame systems were used to improve the understanding of the effects of thermal agents on diffusion flames, and 4) empirical heat transfer correlations for spray cooling of a surface were used to estimate the efficiencies of surface cooling by thermal agents. The fluorinated ether methoxy-nonafluorobutane was identified as a potential replacement. It was also noted that agents released as liquids seem to be more effective than predicted based simply on their ability to absorb heat. Recommendations for additional studies are provided.