Xie Qiyuan

Experimental Analysis on False Alarms of Fire Detectors by Cooking Fumes

Experiments were conducted to analyze the response of ionization and photoelectric detectors to the two typical Chinese cooking fumes simulated in the FE/DE. Four real fire smokes were also carried out for comparison with the nuisance cooking fumes. The outputs of the ionization and photoelectric detector, CO, CO2 and humidity were recorded throughout the six experiments and were compared. The results of these experiments show that the smoke detectors, especially the ionization detector, are sensitive to cooking fumes and nuisance alarms are easy to happen. It is also indicated that CO and CO2 concentration in the cooking fumes varied much less than those in the four real fire sources. The feasibility of reducing false alarms in kitchen through the use of multi-criteria algorithm, which combines the CO or CO2 with smoke, is discussed as well.

Full-Scale Study on Breakage Behavior of 6mm Thick Toughened Glass in Fires

The objective of this work is to investigate the crack and fallout of 6 mm thick toughened glass in enclosure fires. Full-scale experiments are carried out in the ISO 9705 fire test room using pool fires with different pan sizes. The time-dependent temperature differences between the exposed and shaded regions of glazing edges at typical positions are monitored. The experimental results illustrate that compared with the floated glass with the same thickness, the toughened glass will crack and fall out at larger temperature differences. Here it is suggested that the critical breakage temperature difference for the 6 mm thick toughened glass is about 330-380 deg C. However, the whole piece of toughened glass would turn into many small fragments when the window glazing breaks. In this case, the pool fire is enhanced strongly since a relatively large vent forms in the window glazing. In addition, the full-scale experimental results also indicate that horizontally partitioning windows with frames may be helpful to prevent the whole large and tall toughened glass from falling out completely in fires. Language: en