Extended experimental studies of water curtains effectiveness to broaden the scope of their application

Анализ основных ранее выполненных научных и экспериментальных исследований, а также нормативных документов показал необходимость, во-первых, актуализации отдельных требований нормативных документов в области применения водяных завес и, во-вторых, уточнения области их применения. На основании анализа нормативных документов, научно-технической литературы, опыта реализации водяных завес на объектах защиты различных классов функциональной пожарной опасности и с целью расширения области их применения проведены натурные укрупненные исследования на стенде, имитирующем реальное помещение, в следующих направлениях: - определение влияние высоты установки оросителей и их геометрического расположения относительно друг друга на экранирующую способность водяной завесы; - определение влияния зоны, свободной от пожарной нагрузки, на эффективность водяной завесы; - исследование эффективности применения водяных завес с организацией подачи водяных струй с уровня пола; - исследование параметров водяных завес, используемых в качестве противопожарных преград в технологических проемах и транспортных галереях, в частности при комбинированном применении водяных завес и систем дымоудаления. A methodology has been developed and large-scale studies of the effectiveness of water curtains and water irrigation have been carried out. As a result there have been obtained data for changes, additions and adjustments to separate requirements of regulatory documents on fire safety. The most effective sprinklers tested to prevent the spread of fire through a water curtain and reduce the intensity of heat flow are the products “ZAVESA K-48” (Chang Der) and “ZVN- 5” (PA “Spetsavtomatika” Biysk). When studying the optimal conditions for the arrangement of sprinklers relative to each other, during the tests there is observed the intersection of sprinkler plots that causes the efficiency decrease of individual sprinkler and, in general, the increase of the consumption characteristics of the entire curtain. Therefore, the number of sprinklers, taking into account the irrigation plot, should be determined in the process of preliminary tests. For example, according to the experiment results during the tests, the sprinklers were located on a water line relative to each other in a staggered order at a distance of 1 m. Analysis of the results of experiments to determine the level of heat flux reduction by height when the sprinklers are located at floor level and the supply of water curtain from the bottom upwards leads to the conclusion that, firstly, with this method of arrangement of sprinklers efficiency of heat flux intensity reduction increases and, secondly, the height of the fire load, as well as the installation location and tactical characteristics of the curtain itself have a significant impact on heat flux reduction. When determining the minimum distances of the water curtain from the zone free from the fire load in the premises, it was found that the greatest decrease in the intensity of thermal radiation is recorded at the height of the installation of a water pipe with sprinklers 7.5 m. In some cases, while reducing the intensity of heat flows, it is not possible to exclude penetration of combustion products into the protected volume behind the water curtain, because when the sprayers are located at the ceiling of the building, due to the ejecting ability, the curtain will accumulate smoke in the upper part of the smoke tank and lower it down, initiating its breakthrough into the velocity redistribution zone. Thus, the combustion products are redirected to the neutral zone below the safety mark (1,7 m). The test results obtained with the combined use of water curtains and smoke removal indicate the effectiveness of the joint operation of these systems. Their simultaneous use makes it possible not only to reduce the intensity of heat flows, but also to prevent the flow of the smoke reservoir into the safety zone.