A flammability limit model for hydrogen-air-diluent mixtures based on heat transfer characteristics in flame propagation

Flammability Limits of Combustible Gases at Elevated Temperatures and Pressures: Recent Advances and Future Perspectives

“…Shih 200 and Ha et al 201 pointed out that the conduction of heat loss from the reaction zone to the postreaction zone should be considered. Jeon et al 31 developed a CFT model that can predict the lower flammability limit of gas mixtures by considering the heat loss mechanism during flame propagation. The model takes into account thermal conduction losses through equations.…”

“…where c is the coefficient obtained from the experimental measurement, c = 0.0854. Catoire et al 196 proposed an equation for estimating the lower flammability limit of pure combustible gases in the 25− Table 5 58 Babrauskas, 155 Bodurtha, 156 and Vanderstraeten et al 82 instead of relying on the theory of combustible ignition, flame propagation, and flame extinction, they both build black box models by fitting experimental data heat balance theory CAFT method Benedetto, 157 Mashuga et al, 158 Shebeko et al, 159 Rowley et al, 160 Vidal et al, 161,162 Qin et al, 163 Chen et al, 164,165 Shu et al, 166,167 Li et al, 168 Hu et al, 169 Palucis et al, 170 Wu et al, 171 Bounaceur et al, 172 Wan et al, 173−176 and Mendiburu et al 177−180 this method is unsuitable for estimating the upper limits of flammability because it is difficult to calculate the heat capacity of unburned fuel precisely CFT method Zhao et al, 181 Liaw et al, 182 Kim et al, 30 and Jeon et al 31 flame propagation and heat dissipation theory burn rate method Law et al, 183 Wang et al, 184 where X is the mole fraction of fuel in the corresponding stoichiometric fuel/air mixture, n is the number of carbon atoms in the molecule, and T is the temperature (K).…”

“…Jeon et al developed a CFT model that can predict the lower flammability limit of gas mixtures by considering the heat loss mechanism during flame propagation. The model takes into account thermal conduction losses through equations.…”

“…The flammability limits of many flammable gases have been evaluated at ambient temperature and pressure. , However, the flammability limits are affected by the initial temperature, initial pressure, inert medium or impurity gas, , explosion container and shape, ignition energy and position, turbulent flow state, and other environmental factors operating methods. , Many processes are run at elevated temperatures and pressures in current industries, such as the air injection process, − high-temperature reaction process in the chemical industry, − fuel cell or internal combustion engine, waste gas treatment in the metallurgical industry, core melting accidents of nuclear power plants, , and fire accidents. Existing studies have shown that many factors must be considered at high temperatures and pressures, resulting in difficulties in experiments and measurements.…”

Simulation of a Hydrogen-Air Diffusion Flame under Consideration of Component-Specific Diffusivities

“…analyzed the combustion characteristics and obtain critical parameters and determine an optimal operation modus also experimentell. Focusing on the flammability limit of hydrogen Joongoo et al were able to determine the risk of a hydrogen flame by developing and validating a model for various hydrogen-air mixtures [14].…”