Modeling the effects of high radiative heat fluxes on intumescent material decomposition
- 作者：Di Blasi ; Colomba
- 关键词：Intumescent material ; Decomposition ; Modeling
- 刊名：Journal of Analytical and Applied Pyrolysis
- 出版年：2004
- 期刊代码：46_01652370
- 类别：ch
- 出版时间：June, 2004
- 卷：71
- 期：2
- 页码：721-737
- 文件大小：258 K
摘要
The thermal response of a composite system consisting of a substrate (steel) and an intumescent coating is investigated by means of a mathematical model, including multi-step reaction kinetics and transport phenomena. Apart from the quantitative prediction of the time history of the substrate temperature under severe heating, the model is used to reproduce the application of widely variable radiative heat fluxes (20–200kW/m2). The substrate heating rate always presents two local maxima, separated by a delay caused by coating degradation and swelling. The maxima occur when the activity of chemical reactions is small and correspond to low (conductive heat transfer through the virgin coating) and high (radiative heat transfer through the highly porous char) temperatures, respectively. The occurrence time and the magnitude of the low-temperature maximum are essentially determined by the physico-chemical properties of the system. On the contrary, those of the high-temperature maximum and, at a lower extent, the delay in temperature rise are also affected by the intensity of the external radiative heat flux.