Investigating the effect of temperature, pressure, and inert gas on the flammability range of ethane/oxygen mixtures

Abstract

The flammability limit is a critical parameter used to evaluate the risk of explosions from flammable gases and design appropriate explosion-proof measures. This study employs a combined approach of theoretical analysis and experimental determination to investigate the impact of temperature, pressure, and inert gas on the FL of ethane/oxygen mixtures in an environment of elevated temperatures and pressures. The findings demonstrate that the flammability range of ethane/oxygen mixtures progressively widens at elevated temperature and pressure conditions. At high pressures, the upper flammability limit (UFL) of ethane displays a quadratic-linear relationship with temperature, with a turning point at 200 °C. The impact of temperature and pressure on explosion risk is primarily achieved through their effect on the UFL. A new inerting capacity of added diluting gas, δ, is defined for inert gas, revealing that the inerting effect of diluting gas is enhanced under the influence of temperature or pressure. However, the inerting effect of nitrogen weakens as the initial pressure increases, while it strengthens as the initial temperature increases. The inerting effect of water vapor in the system of ethane/oxygen/nitrogen is superior to that of nitrogen. The combustion reaction kinetics of ethane and nitrogen near the UFL is influenced by high temperature, high pressure, and water vapor. The coupling effect of high initial temperature and pressure on the inerting effect of the two inert gases is less pronounced than that of single factors.