Experimental and numerical evaluation of flame temperature reduction in propane (R-290)–argon mixtures for safer refrigerant design

The scientific community is paying close attention to environmentally suitable substitutes for traditional high-global warming potential refrigerants. Propane (R290) has emerged as a viable natural refrigerant due to its outstanding thermodynamic performance and low ozone depletion potential. However, in case of unintentional leakage and ignition, its extreme flammability presents significant safety risks. In order to reduce this danger, the current work uses both experimental observations and COMSOL multiphysics numerical simulations to examine how argon (Ar) dilution affects propane's flame temperature characteristics. Argon, an inert noble gas, is introduced into propane—argon mixture in concentrations ranging from 0% to 30% to assess its flame-suppressing capability. The primary objective of this study is to analyze how maximum flame temperature changes as the fuel mixture's argon increases. By contrasting simulated temperature distributions with experimentally obtained flame temperatures under controlled combustion conditions, the numerical model is verified. The findings show that increasing the argon content from 0% to 30% causes peak flame temperature to drop significantly, from 2236 to 1791 K in experimental observations and from 2410 to 2156 K in numerical calculations. This reduction is attributed to the dilution effect, reduced reactant concentration, and the thermal inertness of argon, which absorbs heat without participating in chemical reactions. The findings indicate that argon effectively suppresses propane flame intensity and lowers combustion temperatures. This study highlights potential of propane–argon blends as safer, low-GWP refrigerant alternatives and provides valuable insights for development of fire-risk-reduced refrigerant mixtures for future refrigeration and air-conditioning applications.