Estimation of building ventilation on the heat release rate of fire in a room

Abstract

Ventilation to the scene of afire in buildings is inevitable. The inflow of fresh air from outdoors may accelerate combustion and cause serious losses of property. However, the extent of this influence on fire remains unknown. The heat release rate (HRR) is an important factor that influences disaster intensity. In this study, the mass loss method was used to calculate the HRR of a combustible by testing the mass of the burning material mass with ventilation. We selected a full-scale room to determine the influence of ventilation. Different factors that affect HRR, such as inlet velocity, jet range, and air change rate (ACH), were considered.Preliminary results suggested that the HRR of a fire would not change significantly under different ACH conditions with indirect air supply. When the distance of the air supply was shorter than 1.5m, a maximum difference of 1.8 times was found between indirect and direct air supply. The HRR with direct air supply is the function of air velocity and jet range. This function was used to quantify the effect of direct air supply on HRR.