Abstract
<jats:p>Одним из перспективных способов тушения полярных жидкостей может быть использование самовспенивающейся газоаэрозоленаполненной пены (СГП), подаваемой в слой горючей полярной жидкости в виде затопленной струи. Определены зависимости, по которым можно рассчитать характеристики распределения пенообразователя в затопленной струе, и проанализированы методы оценки времени разрушения пенообразователя, содержащегося в СГП, подаваемой в слой полярной жидкости в виде затопленной струи.</jats:p> <jats:p>When extinguishing polar flammable liquids stored in tanks, alcohol-resistant foam concentrates are typically used, and the foam is applied only onto the surface. It is promising to extend the subsurface application of self-foaming gas-aerosol foam (SGF), supplied as a submerged turbulent jet, to the extinguishing of polar flammable liquids by employing the theory of jet flows. To achieve this, the fundamental relationships for calculating the parameters of a SGF turbulent jet must be determined. Solving the equations governing an axisymmetric turbulent jet, both in integral form and as partial differential equations of motion, yields formulas for calculating the ejection rate of the polar liquid into the jet and the foam concentrate concentration distribution across the jet cross-section. The polar liquid entrained into the jet dilutes SGF concentrate nearly tenfold and begins to destroy it. The rate of foam destruction depends on the nature of the interaction between the foam concentrate and the polar liquid, whether diffusion- or chemically-driven. For example, under diffusion-driven destruction with ethyl alcohol, the time for the foam to lose its insulating properties is approximately 800 seconds, which is almost half the extinguishing time. However, given the high delivery rate of the submerged SGF jet (9 s to penetrate the liquid layer, and 40 s total discharge time from the nozzle), it can be expected that the foam's fire-extinguishing properties are maintained even with vigorous mixing of the foam concentrate and the polar liquid. This is confirmed by fire tests involving AI-95 gasoline containing oxygenates in a 5,000 m3 tank.</jats:p>