The Study On Fire Performance Of Computer Monitors

With the development of science and technology, computers are more and more widely used in our daily lives. These computers, which exist in offices, homes, internet bars and electrical reading rooms, not only make daily lives convenient, but also increase fire risk in these place.TG-DTA technique is used to study the pyrolysis of enclosure materials of computer monitor under different kinds of environment (Air and Nitrogen) and heating rates (10,30,50℃/min). It is found that the pyrolysis process in air can be divided into three stages, but there are only two stages when the pyrolysis process is taken in Nitrogent, lacking the last stage of oxidation and heat emission in air. Furthermore, with activation energy of each stage decreasing, it is gained that the stability of the enclosure materials is reducing as temperature is rising. In air, lower heating rate benefits pyrolysis when temperature is less than 415℃, and it is contrary when temperature is higher than 415℃. Lower heating rate always helps to the pyrolysis in Nitrogen.ISO 9705 Standard Room is used to full-scale experiment study of different types of computer monitors in confined space, and Heat Release Rate (HRR), Temperature at the centre of door, Temperature in Standard Combustion Room, Extinction Coefficient (EXT), soot concentration and yield rate are measured in it. Based on the study of the connection between HRR and ventilation factor, peak HRR with the ventilation area is zero is defined as Net Heat Release Rate, which expresses the peak HRR when the combustion happened in the closed room. Using the Net Release Rate, it is received that the connection between several parameters (such as EXT, soot concentration and yield rate) and ventilation factor. Moreover, on the basis of fire characteristic in defined space, the combustion process can be simply divided into two stages: ascending stage and descent stage, so the relation between several parameters and HRR are studied during these two stages.The study on the pyrolysis kinetics and full-scale experiments of computer monitors promotes the knowledge on pyrolysis process and the influences of outer factors to fire characteristic. The study also benefits the evaluation of fire risk of computer monitors and the avoidance of casualty and property loss in fire.