| 大跨桥梁油罐车燃烧火灾模型计算方法研究 |
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| 引用本文： | 李雪红,杨星墀,徐秀丽,郭志明,唐贺强.大跨桥梁油罐车燃烧火灾模型计算方法研究[J].中国公路学报,2022,35(6):147-157. |
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| 作者姓名： | 李雪红 杨星墀 徐秀丽 郭志明 唐贺强 |
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| 作者单位： | 1. 南京工业大学 土木工程学院, 江苏 南京 211816;2. 南京市公共工程建设中心, 江苏 南京 210008;3. 中铁大桥勘测设计院集团有限公司, 湖北 武汉 430056 |
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| 基金项目： | 江苏省交通运输科技项目(2021QD06)；江苏省研究生科研创新计划项目(KYCX21_1153) |
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| 摘 要： | 桥梁上油罐车燃烧可分为油罐车火灾和燃油泄漏油池火灾2种,为了建立2种定量分析的火灾模型,基于火灾学原理,采用理论分析与FDS数值模拟相结合的方法,提出了考虑危化品种类、桥面风、油罐车尺寸等因素的油罐车火灾最大热释放速率定量计算方法;建立了燃烧油池最大直径、扩散时间以及直径扩大速度的求解方程,提出了可表征不同泄漏孔径下油池扩散、燃烧动态过程的数学模型,并通过前人的试验结果对模型的正确性进行了验证。通过对依托工程的分析,结果表明:油罐车火灾时,最大热释放速率与桥面风速正相关,但增长幅度逐渐减小,风速从4.96 m·s-1增至10.84 m·s-1时,最大热释放速率的变化范围为62.89~113.54 MW,随风速增加至10.84 m·s-1,燃烧时间逐渐变短,缩短至原来的57%,火焰高度逐渐降低,趋近于9.5 m(含油罐车高度);火焰核心区域随风速增大而增大,且向下风向倾斜。泄漏油池燃烧时,泄漏孔径的变化对热释放速率和油池扩散时间影响较小;泄漏速率比接近于泄漏孔半径的平方比,油池最大直径比、扩大速度比与泄漏孔半径比相当,燃烧时间随泄漏孔半径的增大而减小,减小速度变缓;随着燃烧油池直径增大,火焰高度增加,火焰核心区域增大;当扩散至最大直径时,其火焰的水平影响区域比油罐车燃烧更广,但燃烧时间更短。
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| 关 键 词： | 桥梁工程 火灾模型 理论分析 热释放速率 油罐车火灾 燃油泄漏油池火灾 燃油扩散 |
| 收稿时间： | 2021-12-16 |
Research on Calculation Method for Tank Truck Fire Model on Large-span Bridge |
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| LI Xue-hong,YANG Xing-chi,XU Xiu-li,GUO Zhi-ming,TANG He-qiang.Research on Calculation Method for Tank Truck Fire Model on Large-span Bridge[J].China Journal of Highway and Transport,2022,35(6):147-157. |
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| Authors: | LI Xue-hong YANG Xing-chi XU Xiu-li GUO Zhi-ming TANG He-qiang |
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| Affiliation: | 1. School of Civil Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China;2. Nanjing Public Engineering Construction Center, Nanjing 210008, Jiangsu, China;3. China Railway Major Bridge Reconnaissance & Design Institute Co. Ltd., Wuhan 430056, Hubei, China |
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| Abstract: | The combustion of tank trucks on bridges can be divided into tank truck fire and fuel leaking oil pool fire. A research method combining a theoretical analysis and FDS numerical simulation was developed based on the principles of fire science to establish two fire models for a quantitative analysis. A quantitative calculation method was then proposed for the maximum heat release rate of oil tanker fires by considering various factors such as the type of hazardous chemicals, bridge deck wind, and tank truck size., the equations for solving the maximum diameter, diffusion time, and diameter expansion rate of the burning oil pool were established. Subsequently, a mathematical model that can characterize the dynamic process of oil pool diffusion and combustion under different leakage apertures was proposed. The accuracy of the proposed model was verified using the experimental results in previous studies. Based on the analysis of supporting projects, the following observations were made. When the oil tanker burns, the maximum heat release rate is positively correlated with the wind speed of the bridge deck and the growth rate gradually decreases. When the wind speed increased from 4.96 m·s-1 to 10.84 m·s-1, the maximum heat release rate increased from 62.89 to 113.54 MW. As the wind speed increased to 10.84 m·s-1, the combustion time gradually shortened to 57% of the original, and the flame height gradually decreased, approaching 9.5m (including the height of the oil tanker). The core area of the flame also gradually increased with the increase in the wind speed and was inclined in the downwind direction. When the leaking oil pool burns, the change in the leak hole diameter had little effect on the heat release rate and diffusion time of the burning oil pool. Moreover, the leakage rate ratio was close to the square ratio of the leakage hole radius, the ratio of the maximum diameter of the oil pool and the expansion rate of the oil pool diameter were equivalent to the ratio of the leakage hole radius, and the combustion time decreased with the increase in the leak hole radius. The decreasing speed became slower as the diameter of the combustion oil pool increased, the flame height, and the core area of the flame also increased when the oil had spread to the maximum diameter. The horizontal influence area of the flame was also wider than that of tank truck fire, and the combustion time was shorter. |
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| Keywords: | bridge engineering fire model theoretical analysis heat release rate oil tank truck fire fuel leaking pool fire fuel diffusion |
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