Balanyuk V. Scientific basis for reducing the environmental impact of fires at their initial stage by the action of shock waves

On the basis of the analysis of the characteristics of the existing fire extinguishing agents, the scientific basis for reducing the negative impact of fires on the environment was created, taking into account the features and regularities of the factors affecting the effectiveness of the combustion of combustible environments at the initial stage of the development of fires with shock waves, including their combined application with environmentally acceptable gas and aerosol fire substances. It has been experimentally established that a series of 3 shock waves at a frequency of 8 - 12 Hz provide an increase the fire-extinguishing efficiency of extinguish ants with volumetric effect up to 20% in the experimental chamber compared with the action of a single shock wave. It was discovered the effect of synergy between the components of the combined fire extinguishing system, which manifests itself in reducing the extinguish ant concentration of СО2 to 4.8%, and nitrogen to the concentration of 10.2% under the condition of the influence of the single and triple shock waves series with the specified frequency, which lies down to reduction of their fire-extinguishing concentrations up to 7 times in comparison with their individual values. It was scientifically substantiated schematic decisions and parameters and created the technical means that implement the technology of ceasefire at the initial stage of the development by using shock waves or their combinations with environmentally acceptable extinguishants of volumetric action, which prevents the spread of combustion and reduce environmental pollution. Shock wave generators can be both present in the device and installed separately and be used together with separately installed shock wave generators. At the same time, the duration of emissions and the volume of harmful substances to the environment as a result of fires are significantly reduced, which leads to an increase in the efficiency of ensuring the environmental safety of the population and territories of Ukraine. The conducted field tests showed predictably high extinguishing efficiency of developed fire extinguishers aerosol generators, autonomous aerosol combustion and fire fighting combustion units, as well as combined fire extinguishing and fire prevention devices. At the same time, the extinguishing concentration of fire extinguishing components with combined action in large-sized premises reduces up to 3 times for fire extinguishers and for gas extinguishing substances (СО2, N2) up to 6 times in comparison with their individual values under the influence on the environment of series of shock waves with the capacity up to 2500 Pa and a frequency of about 10 Hz. The results of the dissertation research are the scientific basis for reducing the harmful effects on the environment of combustion products and extinguishant substances by significant increasing the efficiency of extinguishant aerosol and gases and reducing the fire extinction time under the action of shock waves. It was found that mentioned quench method would reduce the emission of greenhouse gases - carbon dioxide up to 3 times compared with its individual extinguishing concentration, and in combination with extinguishant aerosols and shock waves up to 6 times.