It is shown that the experimental studies of flame propagation speed, the maximum pressure of the explosion of hydrogen-air mixtures were carried out in free space under the influence of slowing down and accelerating factors, such as power and type of ignition source, the effect of flame acceleration in the pipe, the effect of obstacles on the flame propagation path, the volume and composition of the combustible mixture when the content of the oxidizing agent or phlegmatizer changes in it.
The dependence was established allowing to estimate the volume of a hydrogen-air mixture, during the combustion of which one can expect the burning speed that is close to the speed of sound in the initial mixture, and at which the transition of deflagration combustion to detonation is possible. When phlegmatizing hydrogen-air and oxygen-hydrogen mixtures with inert gases, such as nitrogen for example, the effect of reducing the burning speed and explosion pressure is achieved. The processes and conditions for the transition of deflagration combustion to detonation of free volumes of hydrogen-air mixtures and mixtures enriched and depleted of oxygen, depending on the power of the ignition source, volume, composition of the mixture and its turbulence, were studied.
It is noted that as the content of the inert gas in the mixture increases, these indicators decrease, and the profile of the pressure wave changes qualitatively. Turbulization of hydrogen-air and hydrogen-oxygen mixtures with dilution using nitrogen to certain limits by turbulators leads to an increase in the values of the apparent burning speed and the maximum speed of explosion burning, up to the transition to detonation. Irrigation of combustible mixtures with atomized water leads to the same effect.
2. Vogman L.P., Bolodyan I.A., Britikov D.A. On the Issue of Differentiation of Modes for Deflagration Combustion and Explosion. Bezopasnost Truda v Promyshlennosti = Occupational Safety in Industry. 2020. № 12. pp. 32–37. (In Russ.). DOI: 10.24000/0409-2961-2020-12-32-37
3. Vogman L.P., Bolodyan I.A., Prostov E.N., Britikov D.A. Localization and Reduction of Accident Consequences during Deflagration and Explosion. Pozharnaya bezopasnost = Fire Safety. 2021. № 1 (102). pp. 42–46. (In Russ.). DOI: 10.37657/vniipo.pb.2021.90.78.004
4. Marshall V. Main hazards of chemical production. Moscow: Mir, 1989. 671 p. (In Russ.).
5. Makeev V.I., Gostintsev Yu.A., Strogonov V.V., Bokhon Yu.A., Chernushkin Yu.N., Kulikov V.N. Burning and detonation of hydrogen-air mixtures in free volumes. Fizika goreniya i vzryva = Physics of burning and explosion. 1983. Vol. 19. № 5. pp. 16–18. (In Russ.).
6. Rozlovskiy A.I. Fundamentals of explosion safety when working with combustible gases and vapors. Moscow: Khimiya, 1980. 376 p. (In Russ.).
7. Troshin Ya.K., Shchelkin K.I. The structure of the front of spherical flames and the instability of normal burning. Izvestiya Akademii nauk SSSR. Otdelenie tekhnicheskikh nauk = Proceedings of the Academy of Sciences of the USSR. Department of technical sciences. 1955. № 9. pp. 160–166. (In Russ.).
8. Becker T., Ebert F. Vergleich zwischen experiment und theories der explosion grober, freier gaswolken. Chemie Ingenieur Technik. 1985. Vol. 57. № 1. pp. 42–45.
9. Chuguev A.P., Bolodyan I.A., Nekrasov V.P., Fedorinov M.V., Sychev A.N. Explosive Combustion of Hydrogen-Air Mixtures Large Volumes in the Open Atmosphere. Bezopasnost Truda v Promyshlennosti = Occupational Safety in Industry. 2021. № 12. pp. 24–28. (In Russ.). DOI: 10.24000/0409-2961-2021-12-24-28
10. Zeldovich Ya.B., Rozlovskiy A.I. On the сonditions for the occurrence of normal burning instability. Doklady Akademii nauk = Reports of the Academy of Sciences. 1947. Vol. LVII. № 4. pp. 365–368. (In Russ.).
11. Azatyan V.V. Chain reactions of burning, explosion, and detonation in gases. Chemical control methods. Moscow: Rossiyskaya akademiya nauk, 2020. 360 p. (In Russ.).
12. Shirvill L.C., Roberts T.A., Royle M., Willoughby D.B., Gautier T. Safety studies on high-pressure hydrogen vehicle refuelling stations: Releases into a simulated high-pressure dispensing area. International Journal of Hydrogen Energy. 2012. Vol. 37. Iss. 8. pp. 6949–6964. DOI: 10.1016/j.ijhydene.2012.01.030