The Effect of Water Vapor on the Flammability of Fluorinated Refrigerants

Published

March 24, 2025

Author(s)

Gregory Linteris, Michael Hegetschweiler, Valeri Babushok

Abstract

Possible replacements for the refrigerant R-134a have been proposed in previous work based on their flammability behavior in standard tests of the Heating, Ventilation, Air-Conditioning, and Refrigeration industry. The present work extends that behavior to more extreme conditions of temperature and humidity based on estimates of the overall reaction rate of the mixtures obtained from perfectly-stirred reactor PSR model simulations. The PSR simulations were found to predict the flammability conditions of the standard test well. For initial temperatures of 23 ℃ to 60 ℃ and water vapor volume fraction in the oxidizer of 0 % to 10 %, the effect of humidity on the overall reaction rate is predicted to be much larger than the effect of temperature, with an increase in the overall reaction rate up to about 2.5 to 9 times with most moist flames as compared to dry.

Proceedings Title

14th U.S. National Combustion Meeting

Conference Dates

March 16-19, 2025

Conference Location

Boston, MA, US

Conference Title

14th U.S. National Combustion Meeting Organized by the Eastern States Section of the Combustion Institute

Pub Type

Conferences

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Keywords

Refrigerant Flammability, hydrofluorocarbons, hydrofluoroolefins

Citation

Linteris, G. , Hegetschweiler, M. and Babushok, V. (2025), The Effect of Water Vapor on the Flammability of Fluorinated Refrigerants, 14th U.S. National Combustion Meeting , Boston, MA, US, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959519 (Accessed November 23, 2025)