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Analysis of the Influence of Construction Insulation Systems on Public Safety in China

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ABSTRACT

With the Government of China’s proposed Energy Efficiency Regulations (GB40411-2007), the implementation of external insulation systems will be mandatory in China. The frequent external insulation system fires cause huge numbers of casualties and extensive property damage and have rapidly become a new hot issue in construction evacuation safety in China. This study attempts to reconstruct an actual fire scene and propose a quantitative risk assessment method for upward insulation system fires using thermal analysis tests and large eddy simulations (using the Fire Dynamics Simulator (FDS) software). Firstly, the pyrolysis and combustion characteristics of Extruded polystyrene board (XPS panel), such as ignition temperature, combustion heat, limiting oxygen index, thermogravimetric analysis and thermal radiation analysis were studied experimentally. Based on these experimental data, large eddy simulation was then applied to reconstruct insulation system fires. The results show that upward insulation system fires could be accurately reconstructed by using thermal analysis test and large eddy simulation. The spread of insulation material system fires in the vertical direction is faster than that in the horizontal direction. Moreover, we also find that there is a possibility of flashover in enclosures caused by insulation system fires as the smoke temperature exceeds 600 °C. The simulation methods and experimental results obtained in this paper could provide valuable references for fire evacuation, hazard assessment and fire resistant construction design studies.

No MeSH data available.


Surface temperatures in the experiment and LES simulation.
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ijerph-13-00861-f007: Surface temperatures in the experiment and LES simulation.

Mentions: The upward flame spread along the XPS panel is presented in Figure 6a, from which we can see that the flame spreads along the XPS panel following a ribbon burn pattern. Due to the fact the flame convection directly heats the XPS panel during the fire spread process, the flame spread in the vertical direction is faster than that in the horizontal direction. The flame spread simulated by FDS version 6.0 is presented in Figure 6b. Comparing these two figures, we can see that the simulated burning patterns and flame spread are similar to those in the fire experiment. Figure 7 presents the surface temperatures in the experiment and Large eddy simulation (LES simulation). From this figure, we can see that the simulated surface temperature basically coincides with the experimental data and that the simulated temperature is higher and more sensitive than the experimental data as a result of using thermocouples which may be not sensitive enough. Meanwhile, the weight sensor recorded the mass loss rate of XPS panels during the whole experiment process. By analyzing this data, we find that the mean mass lose rate is 1.5 g/s during the period between the XPS ignition and flame spreading all over surface. Thus the mean heat release rate in this period is:(8)Q=φ×m×ΔHwhere is combustion efficiency, LIU Wanfu has given a suggested value 0.67 for XPS panel’s combustion efficiency [25]. Thus the mean heat release rate is Q = 0.67 × 1.5 × 45.20 kW which well agrees with the simulated data values of 40.2 kW. When the flame spreads all over surface, the XPS panel is burning violently and dripping appears frequently. At this time, the mass lose rate recorded by the balance has no reference value.


Analysis of the Influence of Construction Insulation Systems on Public Safety in China
Surface temperatures in the experiment and LES simulation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036694&req=5

ijerph-13-00861-f007: Surface temperatures in the experiment and LES simulation.
Mentions: The upward flame spread along the XPS panel is presented in Figure 6a, from which we can see that the flame spreads along the XPS panel following a ribbon burn pattern. Due to the fact the flame convection directly heats the XPS panel during the fire spread process, the flame spread in the vertical direction is faster than that in the horizontal direction. The flame spread simulated by FDS version 6.0 is presented in Figure 6b. Comparing these two figures, we can see that the simulated burning patterns and flame spread are similar to those in the fire experiment. Figure 7 presents the surface temperatures in the experiment and Large eddy simulation (LES simulation). From this figure, we can see that the simulated surface temperature basically coincides with the experimental data and that the simulated temperature is higher and more sensitive than the experimental data as a result of using thermocouples which may be not sensitive enough. Meanwhile, the weight sensor recorded the mass loss rate of XPS panels during the whole experiment process. By analyzing this data, we find that the mean mass lose rate is 1.5 g/s during the period between the XPS ignition and flame spreading all over surface. Thus the mean heat release rate in this period is:(8)Q=φ×m×ΔHwhere is combustion efficiency, LIU Wanfu has given a suggested value 0.67 for XPS panel’s combustion efficiency [25]. Thus the mean heat release rate is Q = 0.67 × 1.5 × 45.20 kW which well agrees with the simulated data values of 40.2 kW. When the flame spreads all over surface, the XPS panel is burning violently and dripping appears frequently. At this time, the mass lose rate recorded by the balance has no reference value.

View Article: PubMed Central - PubMed

ABSTRACT

With the Government of China’s proposed Energy Efficiency Regulations (GB40411-2007), the implementation of external insulation systems will be mandatory in China. The frequent external insulation system fires cause huge numbers of casualties and extensive property damage and have rapidly become a new hot issue in construction evacuation safety in China. This study attempts to reconstruct an actual fire scene and propose a quantitative risk assessment method for upward insulation system fires using thermal analysis tests and large eddy simulations (using the Fire Dynamics Simulator (FDS) software). Firstly, the pyrolysis and combustion characteristics of Extruded polystyrene board (XPS panel), such as ignition temperature, combustion heat, limiting oxygen index, thermogravimetric analysis and thermal radiation analysis were studied experimentally. Based on these experimental data, large eddy simulation was then applied to reconstruct insulation system fires. The results show that upward insulation system fires could be accurately reconstructed by using thermal analysis test and large eddy simulation. The spread of insulation material system fires in the vertical direction is faster than that in the horizontal direction. Moreover, we also find that there is a possibility of flashover in enclosures caused by insulation system fires as the smoke temperature exceeds 600 °C. The simulation methods and experimental results obtained in this paper could provide valuable references for fire evacuation, hazard assessment and fire resistant construction design studies.

No MeSH data available.