Abstract
Fires at residential buildings are extinguished by both compact and sprayed jets of water. The result of fire suppression at facilities using compact jets of water is the increased consumption of water, which leads to collapse of the structures at a building. The application of water firehoses without fire-rescue vehicles is also impossible. Water that is sprayed to the droplets of small size makes it possible to extinguish a flame mainly by the dilution of a gas combustible medium with water vapor, formed during evaporation of droplets. The effectiveness of fire extinguishing with finely-dispersed water is affected by a diameter of the droplets or dispersion. It is proposed, to suppress developed fires at facilities, to apply the installation of fire extinguishing with finely-dispersed water of the pulse-periodic action. We have tested the designed installation for fire extinguishing. Based on the research results, we obtained parameters for the operation of the installation, such as the velocity of the shock wave, which amounted to 1,667–1,724 m/s. It was established that one detonation cycle uses about 30 mg/cycle of combustible mixture. Detonation cycle frequency is greater than 20 Hz. The estimated total power of the installation is 50 kW. According to results of the study, we found that the transition of combustion into detonation occurs at the expense of compression and heating of the combustible mixture. The established parameters for the operation of the installation make it possible to disperse water jets in the installation's barrel by a flow of detonation products. The resulting dispersion of a finely-dispersed water jet by the method of trapping the droplets of water is within 60‒100 µm. Based on the results of our study, it was established that an optimum water feed to the installation is 0.5‒1 l/s, which depends on the area of a fire. This means that during operation water consumption to suppress a fire would equal 1,800 l, which would enable the removal of heat from a fire site at about 4 GJ/h; the area of a fire in this case would make up 125 m 2 .
Highlights
At present, personnel of the fire-rescue units (FRU) use water when extinguishing 90 % of fires
When FRU put out the fires at residential buildings [1, 2], water is fed to the center of a fire using the B firehoses by sprayed jets
The result of extinguishing a fire is that the amount of water consumed by firehoses reaches 2.7 to 3.7 l/s; in this case, about 4‒6 % is delivered to the center of the fire
Summary
Personnel of the fire-rescue units (FRU) use water when extinguishing 90 % of fires. When FRU put out the fires at residential buildings [1, 2], water is fed to the center of a fire using the B firehoses by sprayed jets. The most promising direction for extinguishing fires in residential buildings is the use of technical means, which enable the formation of finely dispersed water jets. These tools enhance the efficiency of water use with a corresponding decrease in water consumption [5]. This is achieved because when employing finely-dispersed water, a cooling surface grows, depending on the dispersity, from 0.18 l/m2 to 0.017 l/m2. The relevance of our work is explained by the need for the further development of technical means capable of receiving and delivering finely-dispersed water to the center of a fire, in order to improve efficiency of fire extinguishing at buildings and facilities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
