Justification of the smoke consumption removed from the floor corridors during a fire in high-rise buildings
Authors: Есин Владимир Михайлович , Калмыков Сергей Петрович 
Published: September 2022

Статистические данные показывают, что причиной гибели людей при пожарах в 80 % случаев являются дым и отравление токсичными продуктами горения. Система противодымной защиты - одна из подсистем активной противопожарной защиты зданий и сооружений. Область применения и состав систем регламентируются действующими нормативными документами. Одной из задач системы противодымной защиты является предотвращение выхода дыма из коридора в лестничную клетку и создание незадымленной зоны в нижней части коридора. Параметры вентиляционного оборудования систем противодымной защиты определяются расчетом. В настоящее время расчеты проводятся по методикам ВНИИПО или АВОК.

Statistics show that 80 % of deaths in fires are caused by smoke and poisoning by toxic combustion products. The smoke protection system is one of the subsystems of active fire protection of buildings and structures. The scope and structure of the systems are regulated by the current regulatory documents. One of the tasks of the smoke protection system is to prevent smoke from escaping from the corridor to the stairwell and to create a smoke-free zone in the lower part of the corridor. The parameters of the ventilation equipment of smoke control systems are determined by calculation. At present, calculations are carried out according to the methods of FGBU VNIIPO EMERCOM of Russia or ABOK. Purposes. To confirm the smoke-free (smoky) nature of the protected spaces and to determine the optimal parameters of operation of the smoke exhaust system from the corridors, based on numerical experiments it is necessary to evaluate the operation of the exhaust smoke ventilation of the corridors at various values of the determining parameters. Research methods. The field (differential) model was used for calculations since the floor of the building equipped with a smoke ventilation system has a complex geometric shape. There was used the Fire Dynamics Simulator software package which implements the field model of a fire in a room during the numerical simulation. Results and discussion. The least value of smoke spreading in the corridor and the absence of smoke in the stairwell of type H2 is observed in the variant of ensuring the air flow rate through the open door from the stairwell to the corridor equal to 2,1 m/s and the flow rate of the removed combustion products equal to 2,31 kg/s. A similar picture is observed in all considered options, both with opened and not opened glazing of the opening of the fire seat room and with different distances between the fire seat room and the staircase. Conclusions. The conducted numerical experiments show and confirm the assumption about the violation of the balance of the costs of smoke removal from the corridor and the support of the stairwell. The consequence of this is the low efficiency of these systems which entails smoke in the protected volumes. The results of calculations allow identifying the variant of operation of the smoke exhaust system from the corridors and the backwater system in the H2 type stairwell with the highest efficiency. This is the option when the air flow rate through the doorway is 2,1 m/s, and the smoke exhaust flow rate corresponds to the air flow rate from the staircase to the corridor. To carry out practical calculations including according to existing methods for the effective operation of the smoke exhaust system from the corridors and the backwater system in the H2 type stairwell, it is necessary to take inflow and smoke exhaust costs corresponding to the “Recommendations for the calculation of ventilation systems for smoke protection of residential buildings with increased number of storeys”.