Model of Thermal Mechanism of Subclass A1 Fire Extinguishing with General Purpose Fire Extinguishing Powder in Non-Stationary Heat Exchange Conditions
https://doi.org/10.21122/2220-9506-2019-10-4-391-401
Abstract
The aim of the paper was to develop a model of thermal extinguishing mechanism using dry chemical powder taking into account the inertia of heat transfer to powder particles during unsteady heat exchange to identify the optimal conditions for extinguishing of A1 class fires with powders.
The method of experimental and mathematical modelling of fire extinguishing process using dry chemical powder with short-term effect on the fire was used to achieve the goal. The experimental dependences of the extinguishing time and unit consumption of the extinguishing powder on the intensity of the powder supply to the combustion zone in extinguishing of subclass A1 fire in same area and in a limited volume were obtained. The mathematical model of a thermal extinguishing mechanism using dry chemical powder has been developed, taking into account the inertia of heat transfer to powder particles during unsteady heat exchange.
Analysis of the regularities of extinguishing the subclass A1 fire using powder with a short feeding it into the fire indicates the presence of optimum values of unity consumption of powder on the fire from the intensity of feeding it into the fire. The presence of this optimum is due to the inertia of extinguishing the subclass A1 fire using powder due to the finiteness of the heat transfer time to the particles of the extinguishing powder and the limited time of interaction of particles with the combustible material.
The theoretical analysis of the fire extinguishing process over the area taking into account the inertia of heat transfer to the powder particles at non-stationary heat exchange are carried out. The results of the analysis are in qualitative agreement with the results of the experimental study of the regularities of extinguishing of model fire foci of subclass A1 with General-purpose fire extinguishing powder.
About the Author
A. I. KitsakBelarus
Address for correspondence: А.I. Kitsak – Research Institute of Fire Safety and Emergencies of the Ministry for Emergency Situations of the Republic of Belarus, Soltys str., 183a, Minsk 220046, Belarus e-mail: kitsak48@yandex.ru
References
1. Baratov A.N. Gorenie–Pozhar–Vzryv–Bezopasnost' [Combustion–Fire–Explosion–Safety]. Moskva, FGU VNIIPO MCHS ROSSII, 2003, 364 p.
2. Abduragimov I.M., Govorov V.Y., Makarov V.E. Fiziko-khimicheskie osnovy razvitiya i tusheniya pozharov [Physico-chemical basis for the development and extinguishing of fires]. Moskva, VIPSH MVD SSSR, 1980, 255 p.
3. Kireev A.A., Bondarenko S.N. [Investigation of reignition of wood treated with gelling extinguishing agents]. Problemy pozharnoj bezopasnosti [The problem of fire safety], 2009, vol. 25, pp. 65‒72 (in Russian).
4. Rashayan I.I. Fiziko-khimicheskie osnovy razvitiya i tusheniya pozhara [Physical and chemical bases of development and fire fighting]. Tolyatti, Tolyatti SU, 2013, 107 p.
5. Kitsak A.I. [Experimental evaluation of the fire extinguishing efficiency of fire of subclass A1 on the surface and in the bulk by general-purpose extinguishing powder with its short-term impact on the fire source]. Chrezvychajnye situatsii: preduprezhdenie i likvidatsiya. [Emergency situations: prevention and liquidation], 2019, vol. 45, no. 1, pp. 29‒41 (in Russian).
6. Korol’chenko D.A., Sharovarnikov A.F. [Extinguishing of a flame by dry chemical powder and aerosol compositions]. Pozharovzryvobezopasnost' [Fire and explosion safety], 2014, no. 8, pp. 63‒68 (in Russian).
7. Korol’chenko D.A., Sharovarnikov A. F. [Features of flame extinguishing by highly dispersed gas-aerosol systems]. Pozharovzryvobezopasnost' [Fire and explosion safety], 2014, vol. 23, no. 10, pp. 66‒72 (in Russian).
8. Korol’chenko D.A. [Analysis of the process of extinguishing a flame of flammable liquids by dispersed fire extinguishing agents and low expansion foam]. Pozharovzryvobezopasnost' [Fire and explosion safety], 2016, vol. 25, no. 2, pp. 52‒56 (in Russian).
9. Yakunin M.M. [The influence of relaxation processes on the transfer of heat generated by intense energy flows]. Fizika i khimiya obrabotki materialov [Physics and chemistry of materials processing], 2010, no. 3, pp. 27‒33 (in Russian).
10. Kitsak A.I. The dynamics of dry chemical powder particles towards the fi source during their pulse feeding into combustion zone. BITP, 2018, vol. 49, iss. 1, pp. 76‒85. DOI: 10.12845/bitp.49.1.2018.7
Review
For citations:
Kitsak A.I. Model of Thermal Mechanism of Subclass A1 Fire Extinguishing with General Purpose Fire Extinguishing Powder in Non-Stationary Heat Exchange Conditions. Devices and Methods of Measurements. 2019;10(4):391-401. (In Russ.) https://doi.org/10.21122/2220-9506-2019-10-4-391-401