An analysis of the explosion limits of hydrogen-oxygen mixtures

In this study, the essential factors governing the Z-shaped explosion limits of hydrogen-oxygen mixtures are studied using eigenvalue analysis. In particular, it is demonstrated that the wall destruction of H and HO2 is essential for the occurrence of the first and third limits, while that of O, OH, and H2O2 play secondary, quantitative roles for such limits. By performing quasi-steady-state analysis, an approximate, cubic equation for the explosion limits is obtained, from which explicit expressions governing the various explosion limits including the state of the loss of non-monotonicity are derived and discussed.