Potential scale of the use of hydrogen as a fuel can have not only a positive effect on the eсology, but also negative consequences in the form of emergency situations with the release of significant volumes of hydrogen and combustion of its mixtures with air with a possible transition to detonation.
In the experiments conducted recently at the FGBU VNIIPO EMERCOM of Russia with hydrogen-air mixtures with the volume up to 100 m3, a noticeable acceleration of the flame front was found during the combustion of such volumes of gas mixtures. Therefore, the studies were continued with the volumes of mixtures significantly larger, up to 300 m3.
The experiments were carried out on a landfill stand equipped with a system for remote refueling of rubber balloon probes with hydrogen, air, or oxygen. Transparent rubber shells (probe balls) with a wall thickness of 0.05 mm (50 microns) were filled with a hydrogen-air mixture with a hydrogen concentration of 32–39 volume %. Ignition of combustible mixtures was carried out by means of an electric spark with an energy of 1 J or a standard igniter with an energy of 25 J, as well as an electric detonator with an energy of 1200 J. Visible combustion rate of the hydrogen-air mixture was measured using a photo recorder and high-speed video recording. The pressure in the blast wave was recorded by knife-type sensors with piezoelectric elements.
The volume of hydrogen-air mixture can be estimated from the above empirical dependence. In the presence of a strong ignition source and obstacles that intensify the combustion process, a significant increase in the combustion rate up to detonation is possible.
2. Makeev V.I., Chuguev A.P., Lagozin A.Yu., Sychev A.N. Estimation of hydrogen explosive-fire-hazardous mass during liquid hydrogen evaporation in the open space. Aktualnye problemy pozharnoy bezopasnosti: materialy XXVII Mezhdunar. nauch.-prakt. konf., posvyashchennoy 25-letiyu MChS Rossii (Actual Problems of Fire Safety: materials of the Twenty-Seventh International Scientific-Practical Conference, Dedicated to the 25th Anniversary of the EMERCOM of Russia). In 3 parts. Pt. 2. Moscow: VNIIPO MChS Rossii, 2015. pp. 119–122. (In Russ.).
3. Chuguev A.P., Mordvinova A.V., Sychev A.N., Fedorinov M.V. Analytical Review of Fire Safety Equipment for Operations with Liquefied Combustible Gases. Aktualnye voprosy pozharnoy bezopasnosti = Current Fire Safety Issues. 2020. № 3 (5). pp. 25–29. (In Russ.).
4. SP 162.1330610.2014. Safety requirements for the production, storage, transportation and use of the liquid hydrogen. Available at: https://docs.cntd.ru/document/1200124842 (accessed: August 30, 2021). (In Russ.).
5. Kazhikin A. Hydrogen heart of «Energy». Available at: https://communa.ru/nauka_i_obrazovanie/vodorodnoe_serdtse_-energii/ (accessed: August 30, 2021). (In Russ.).
6. The Tu-155 is the only Soviet hydrogen-powered aircraft. Available at: https://zen.yandex.ru/media/they/tu155--edinstvennyi-sovetskii-samolet-na-vodorode-5cc16142bdd0e700b379016c (accessed: August 30, 2021). (In Russ.).
7. Decree of the Government of the Russian Federation of September 6, 2021 № 2471-r. Available at: http://static.government.ru/media/files/SdfpUMpB9jGNAzoJoEIcd4oXGyvhA3Xj.pdf (accessed: August 30, 2021). (In Russ.).
8. Shchelkin K.I., Troshin Ya.K. Gas dynamics of combustion. Мoscow: Izd-vo Akademii nauk SSSR, 1963. 256 p. (In Russ.).
9. Zeldovich Ya.B., Barenblatt G.I., Librovich V.B., Makhviladze G.M. Mathematical theory of combustion and explosion. Мoscow: Nauka, 1980. 478 p. (In Russ.).
10. Miroshnikov S.N. Gas explosions in the open space: abstract of the thesis … Candidate of Physical and Mathematical Sciences. Мoscow, 1980. 22 p. (In Russ.).
11. Bull D.C. Concentration limits to the initiation of unconfined detonation in fuel/air mixtures. Transactions of the Institution of Chemical Engineers. 1979. Vol. 57. № 4. pp. 219–227.
12. Marshall V. Main hazards of chemical production. Moscow: Mir, 1989. 671 p. (In Russ.).