Influence of 2,3,3,3-tetrafluoropropene (HFO-1234yf) addition on laminar burning velocities of CH4–air and DME–air mixtures

Abstract

This study experimentally and numerically determined the laminar burning velocities (LBVs) of methane–air and dimethyl ether–air flames with the addition of CH2CFCF3 (HFO-1234yf) to assess its suppression capability. Experiments were conducted using an optically tracked, constant-volume combustion vessel at 0.1 MPa and 298 K. The experimental data on the laminar burning velocities were compared with the numerical predictions obtained using a recently developed kinetic model for describing CH2CFCF3 combustion. Good agreement between the modeling results and predictions was observed for the stoichiometric and rich flames (ϕ = 1.3), whereas for the lean conditions (ϕ = 0.6), the modeling results had relatively large over predictions (by up to 44%) on the suppression effectiveness of CH2CFCF3 for high agent volume fractions. The measurement results indicated that the LBV reductions caused by the addition of CH2CFCF3 to CH4–air and DME–air flames were nearly equivalent to those of CF3Br under rich conditions. For the lean mixtures, CH2CFCF3 caused a significant increase (by up to 180%) in burning velocity for all test concentrations. The modeling of flame propagation using a detailed model was performed to interpret the switch in the relative performance of CH2CFCF3 with the mixture's stoichiometry.