Расчетная оценка геометрических параметров спринклерных установок водяного пожаротушения высотных стеллажей

Abstract

Рассмотрены вопросы, связанные с применением спринклерных автоматических установок водяного пожаротушения стеллажей. Проанализированы соответствующие нормативные документы. Описаны варианты решения задач определения расхода воды из оросителя, координат места его установки, а также углов распыла огнетушащего вещества и наклона оси оросителя. Приведены примеры расчета геометрических параметров спринклерных автоматических установок водяного пожаротушения стеллажей. Fires at objects whith high-rack storage of combustible materials are particularly dangerous because of the rapid spread of the flame vertically, the risk of collapse of the racks and the damaging effects of high temperature on structural elements of the building. The main method of extinguishing such fires at the initial stage is the use of automatic sprinkler fire extinguishing systems (AUP). The requirements for AUP parameters (types of detectors and sprinklers, their characteristics and distances) depending on the height of the room and storage are currently set out in two normative documents: the set of rules (SP 241.1311500.2015) and the organization standard (VNPB 40-16). Unlike the SP, where there is provided only the supply of a fire extinguishing substance (FES) - water vertically down with high-flow sprinklers of type SOBR (ESFR) and there are no requirements for the type of fire detectors, VNPB provides the use of different types of detectors (aspiration, smoke, heat), forced start-up of AUP sprinklers, which reduces the time of free fire development and the supply of FES by a flow shaper with the spray angle ≈ 600 at an angle  to the vertical both to the horizontal and lateral surfaces of the racks. This article discusses the issues of determining the parameters of automatic sprinkler systems for water fire extinguishing of racks. Variants of solving synthesis problems are given - the choice of the places for installing sprinklers depending on the height and width of the racks, their axis of inclination, and also the spray angle. To solve these problems, the computer program called struja.exe was created, a series of calculations on which showed a negligible effect of aerodynamic drag due to relatively small distances. Examples are given. Thus, the features of the sprinkler AUP for the protection of rooms with high-rack storage and the task of determining its geometric parameters are considered. In this case, forced activation of the sprinkler follows in order to avoid a delay in the start of extinguishing. In the future, it is also desirable to conduct additional field experiments with sprinkler water supply and also (if possible) evaluate the effect of ascending flows of combustion products on the water flow from the sprinkler.