Influence of the temperature of inflow air on the vertical temperature distribution of window spill fire plume

Abstract

The temperature of inflow air through a window is important for the vertical temperature calculation of window spilled flame, which is believed to be the usual fire cause of façade fire. However, the temperature of inflow air differs from a large window height. With an aim to clarify the effects of the inflow air on the vertical temperature of window spilled fire plume, a series of fire plume tests performed a 1.35 m × 1.35 m × 1.35 m fire compartment. The window opening size varied from 0.91 m (Height) × 0.41 m (Width) to 0.91 m (Height) × 0.91 m (Width). The heat release rate (HRR) changed from 300 kW to 900 kW. The temperature distribution of window opening is recorded by a thermocouple tree with a distance of 5 cm and window spill flame is got via 196 thermocouples with a distance of 10 cm. It is found the big disagreement between experimental tests and calculated values using the ambient temperature as the temperature of inflow air. To improve the results, the ambient temperature is replaced by the average temperature in the calculation, interestingly, the agreement of above results are increased by 21.0%, 29.0%, 21.0%, 29.2% and 23.0%, respectively. The temperature of inlet air through window opening should be carefully considered when the Yokoi correlation is used in the large-scale scene. It provides an insight for the understanding of discontinuity resulting from the scale effects.