DISTRIBUTION OF THERMAL BALANCE DURING FIRES IN CLOSED ROOMS

The methodology of determining the thermal balance during fires in closed room was developed. Thermal balance during a fire is primarily influenced by the temperature of the seat of fire. This temperature depends on the burning rate of combustion products, the area of the fire and its duration and the mass of gas in the volume of the room. The lower calorific value also has a significant effect on the of thermal balance. The value of the heat flow, which passes into the walls of the room at all stages of the fire, was estimated. Analytic expression for determining the heat absorption coefficient depending on the duration of free burning was obtained. The results of research show that the heat absorption coefficient φ is not a constant value – during the fire it changes its value and reaches a maximum (no more than 0.5). Increasing of the volume of the room leads to increasing of the heat loss (more heat goes into the environment), which reduces the thermal load on the building structures.