CRITICAL ANALYSIS OF METHODS FOR CALCULATING EXTINGUISHING AGENTS SUPPLY TO LONG-DISTANCE PUMPING OPERATIONS

При тушении сложных и масштабных пожаров, как правило, возникает необходимость подачи огнетушащих веществ (ОТВ) на большие расстояния. Наиболее экономичным и рациональным способом развертывания магистральных насосно-рукавных линий является способ подачи вперекачку. При расчетах пользуются формулами справочников руководителя тушения пожаров. Проведен анализ влияния значений гидравлического сопротивления рукавов, указанных в справочниках, на длину рукавных линий. Показано, что при расчетах они дают заниженные значения расстояний, на которые подаются ОТВ. Предложено выполнить исследования по определению величин гидравлического сопротивления для современных типов пожарных рукавов. When extinguishing complex, protracted fires there is used a large number of vehicles and, very often, there is a shortage of water. Water is supplied from water sources located at a great distance from the fire site. In this case, there are used three schemes of water delivery: by delivery, pumping from pump to pump of fire trucks, pumping with the use of intermediate tanks (tanker trucks, various kinds of tanks). The first two schemes are costly due to the use of a large number of vehicles. The third scheme has a number of advantages: it reduces the use of tank trucks, which are scarce in fire extinguishing, and simplifies the management of the pumping process. But, before laying the main pressure fire hoses from the water source to the fire site, it is necessary to perform the calculation of this line. It includes determination of the type and quantity of necessary fire-technical equipment, assessment of the impact of the terrain on the conditions of fire hoses laying, etc. When making such calculations, the ratios from the fire manager’s handbooks are used. The article gives examples of discrepancy between the performed calculations and real examples of laying pump-hose lines. Such comparison is made on the example of using the complex of equipment «Geyser 10000» when laying a hose-pipe line with the length of 10 km and using PANRC when supplying water at a distance of more than 1 km. Analysis of the results of such comparison showed that calculated values of the length of pump-hose lines are considerably less than the real result of assembling such a line. It is established that the main reason for such discrepancy is outdated data on the value of hydraulic resistance of fire hoses. Reference literature provides values of hydraulic resistance for fire hoses made of materials and technologies of the 50s–70s. Modern fire hoses are made of polymeric materials. For these, hydraulic resistance data are not available for some hose diameters. It is recommended to revise the reference data on hydraulic resistance of fire hoses.