Numerical Investigation of the Chemical Effect and Inhibition Effect Improvement of C3H2F3Br (2-BTP) Using the Perfectly Stirred Reactor Model

The overall chemical rate and chemical effect of CF3Br, 2-BTP and 2-BTP/CO2 with hydrocarbon flames are calculated using the perfectly stirred reactor (PSR) model. The chemical effects of CF3Br with CH4/air flames always inhibit combustion. The chemical saturation concentration of CF3Br in stoichiometric and lean (phi = 0.6) CH4/air flames at 298 K and 1 bar is roughly 2.5% and 0.8%, respectively. The overall chemical rate of 2-BTP with moist C3H8/air flames is always less than the uninhibited condition and fluctuates with sub-inerting agent additions. The net chemical effect variation of 2-BTP is more complicated than experimented and calculated flame speeds with 2-BTP added to lean hydrocarbon flames. There are negative chemical effects (chemical combustion effects) with certain sub-inerting 2-BTP concentrations (0.015 Xa 0.034), which result in the experimented unwanted combustion enhancement in lean moist C3H8/air flames. CO2 can obviously improve the inhibition effect of 2-BTP in lean moist C3H8/air flames, driving negative chemical effects (enhance combustion) into positive chemical effects (inhibit combustion) with lean moist C3H8/air flames. No enhanced combustion would occur with the blends (2-BTP/CO2) when CO2 addition is larger than 4% in phi = 0.6 moist C3H8/air flames at 298 K and 1 bar.