Chemistry of Destroying of Organophosphorus Compounds in Flame and Mechanism of Their Action as Fire Suppressants

摘要

The structure of atmospheric lean (phi=0.8) and rich (phi=1.2) CH4/ O2/Ar and C3H8/O2/Ar flames doped with trimethylphosphate (TMP) was studied by molecular beam mass spectrometry (MBMS) and modeling. Methodic difficulties of MBMS measurement of the structure of atmospheric flames were analyzed and recommendations were elaborated. An influence of TMP additive on the structure of atmospheric flames was demonstrated. A strong influence of equivalence ratio of a flame on the concentration of PO, PO2, HOPO, HOPO2 and OP(OH)3 has been observed. The influence of TMP additive on concentration of H, OH, CH3 was investigated. TMP loading dependencies of burning velocity of a stoichiometric CH4/air and C3H8/air flames were measured and simulated. TMP and triethylphosphate loading dependence of normalized extinction strain rate of opposed-jet CH4/O2/N2 flame was measured. Both OPC demonstrated close fire suppression effectiveness. Comparison of the experimental data with results of modeling on flame structure and burning velocity made it possible to reveal essential drawbacks of our kinetic model proposed early and noticeably refine it. The published models of Glaude et al. and Babushok and Tsang were tested by comparing measured and simulated concentrations of phosphorus containing flame species. In order to make the mechanism to predict better both the flame structure and burning velocity rate constants of eight the most important reactions from Twarowski mechanism have been modified. The possible reasons of the failure of the models to predict the structure of the rich flames were analyzed and perspectives of future research were discussed.