Концентрационные пределы распространения пламени сжиженного природного газа

Abstract

Concentration limits of flame propagation are the fundamental indicator in determining fire and explosion hazard of combustible gases. Correct determination of this parameter allows to assess the possibility of ignition of gas-air mixture. The issues of determining the concentration limits of flame propagation are represented by a large number of experimental and theoretical studies. Despite this, in the literature these indicators for the same combustible mixture differ markedly from each other. This fact is explained by different experimental conditions, as well as different approaches to analyzing the research results. Inaccuracies may arise due to the exclusively thermal approach to determining ignition limits. Although the chain-thermal theory of flame propagation is currently developed. In addition, when determining the concentration limits of flame propagation for mixed compositions, the effect of the mixture components on each other cannot be neglected. In practice, the mixture of hydrocarbons is the liquefied natural gas. Its intensive development in Russia requires a qualitative assessment of the explosion and fire hazard, in particular, the flammability limits indicators. Currently, the concentration limits of flame propagation of the liquefied natural gas vapors are determined by methane. Therefore, the application of the existing approach introduces significant errors in the determination of these indicators. On the basis of the conducted experiments, the legitimacy of applying Le Chatelier's rule for technical calculations of the concentration limits of flame propagation of a mixture of the liquefied natural gas vapors with air was established. This allows to use a differentiated approach in calculations for different compositions of the liquefied natural gas.