Gas-dynamic features of explosive combustion of liquefied natural gas vapors

Purpose. The growth of the liquefied natural gas (LNG) market in the Russian Federation requires the development of economically justified fire safety measures. Based on the detailed physical and chemical analysis and experimental studies of combustion of LNG main combustible components, a differential methodology for determining the explosion pressure during emergency releases of LNG into open space was previously proposed. However, the publication did not imply a detailed gas-dynamic analysis of various mixed compositions combustion of main LNG combustible compositions. In this paper, the Reynolds number is calculated for various LNG compositions, and experimental studies on the flame front turbulization of various mixed compositions of methane-propane-butane-air are also conducted. Methods. To achieve the set goal, the similarity criterion was used – the Reynolds number, comparison methods, analysis of literature and experimental data were applied. Flame front turbulization was experimentally created, explosion pressure at different methane-propane-butane-air ratios was measured, and maximum explosion pressure values were analyzed. Findings. As a result of theoretical and experimental studies a linear nature of the explosion pressure change was revealed for LNG various model compositions mixed with air at the occurrence of gas-dynamic disturbances of the flame front, which confirms the previously proposed methodology for determining the explosion pressure of LNG vapors in open space, based on the percentage contribution of the main combustible components. Research application field. The obtained results allow determining the explosion pressure based on the percentage of the LNG main combustible components, taking into account the flame front turbulization . Conclusions. The linear dependence of the change in explosion pressure of liquefied natural gas taking into account the flame front turbulization was theoretically and experimentally confirmed.