Critical Conditions of Chain Thermal Explosion

This paper reports results of experimental investigation of the critical conditions of chain thermal explosion of hydrogen–air and methane–air mixtures are introduced. The observed regularities, including the difference in critical conditions between the ignition and explosion of these combustibles, are explained by considering the chemical mechanisms of oxidation of hydrogen and methane in the context of the nonlinear theory of nonisothermal chain processes. Examples of regularities of combustion processes at atmospheric pressure are given that cannot be described without considering the leading role of the competition between the branching and termination of reaction chains. It is shown that in solving the equations used to describe combustion processes, neglect of the variation in the heat effects of reactions with temperature can lead to large errors.