建筑倾斜外立面火溢流沿程温度分布研究

消防科学与技术 ›› 2022, Vol. 41 ›› Issue (3): 330-333.

建筑倾斜外立面火溢流沿程温度分布研究

张孝春1，程章昆1，吴斌斌2，陈钦佩3

（1.广东工业大学环境科学与工程学院，广东广州 510006；2.广东省建筑科学研究院集团股份有限公司，广东广州 510500；3.应急管理部天津消防研究所，天津 300381）

出版日期:2022-03-15 发布日期:2022-03-15
作者简介:张孝春（1987-），男，山东济南人，广东工业大学安全工程系副主任，副教授，主要从事火灾动力学理论与防治基础、安全评估等研究，广东省广州市广州大学城外环西路100号广东工业大学工学三号馆，510006。
基金资助:
广东省重点领域研发计划项目(2019B111102002)；国家自然科学基金（51506032）；广东省自然科学基金（2019A1515011846）

Study on longitudinal temperature distribution of spill fire plumes along sloped facade wall of building fires

ZHANG Xiao-chun1, CHENG Zhang-kun1, WU Bin-bin2, CHEN Qin-pei3

(1. School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou Guangdong 510006, China; 2. Guangdong Provincial Academy of Building Research Group Co., Ltd., Guangzhou Guangdong 510500, China; 3. Tianjin Fire Science and Technology Research Institute of MEM, Tianjin 300381, China)

Online:2022-03-15 Published:2022-03-15

摘要/Abstract

摘要： 建筑火灾是火灾科学领域的重要研究方向之一，外立面火溢流温度分布对于建筑火灾风险评估与建筑防火设计具有重要意义。虽然已有众多学者对竖直外立面火溢流温度分布特性进行了研究，但是对倾斜外立面火溢流沿程温度分布特性的研究还较少。因此，本文对建筑倾斜外立面火溢流沿程温度分布特性进行了研究，以求建立适用于倾斜外立面火溢流沿程温度分布的预测公式。基于弗洛德相似原理，在网格独立性验证和实验数据对比验证的基础上，利用FDS建立了1∶2的中尺寸燃烧室开展相关研究。燃烧室尺寸为3.78 m2.36 m1.6 m，在燃烧室上方设置一角度可变的混凝土板（长2.36 m，高7.55 m），用以模拟建筑的外立面。研究中设计了4种矩形开口尺寸（0.52 m×0.65 m、0.78 m×0.52 m、0.78 m×0.65 m、0.78 m×0.78 m）、4种外立面倾角（0?、10?、15?、20?），并为每个开口尺寸分别设计了4种火源功率，共计64种模拟工况。通过分析FDS数值模拟的结果发现：（1）在开口尺寸和火源功率一定的情况下，在相同测点处竖直外立面（θ=0?）的温度要明显小于倾斜外立面（θ＞0?）的温度；（2）当外立面倾角θ=20?时，在羽流区相同温度测点处测得的温度是4种倾角中最高的；（3）当外立面倾角θ＜20?时，外立面相同测点处的温度随着外立面倾角θ的增大而逐渐增大；（4）在开口尺寸和外立面倾角一定的情况下，随着火源功率的上升，外立面火溢流的最高温度变化不大。为进一步研究倾斜外立面上火溢流沿程温度分布特性，用1+sinθ对经典理论中的Z-Zn进行修正后发现，同一尺寸和火源功率下不同外立面倾角的火溢流温度数据具有更好的聚拢效果。基于此，在0<θ<20?的范围内建立了倾斜外立面沿程温度预测公式。本文研究结果是基于外立面倾角处于0?~20?区间完成的，对于外立面倾角大于20?时外立面火溢流沿程温度分布是否符合这个规律还有待研究。

关键词: 建筑火灾；倾斜外立面；数值模拟；温度分布

Abstract: Building fire is one of the most important research fields in fire science, and the temperature distribution of the spill plume along the facade is very important for the risk assessment and prevention design of the building. Although many scholars have studied the vertical temperature distribution of spill plumes on vertical facade, there are few studies on temperature distribution along sloped facade. This paper aims to reveal the characteristics of longitudinal temperature distribution of spill plumes along the sloped facade in building fire, and establishes a predicted correlation for the temperature distribution along sloped facade. Based on Froude similarity theory, a 1∶2 medium-scale-combustion chamber was built in the FDS to carry out numerical simulation research. The validation of the numerical model was confirmed through mesh sensitivity test and the comparison with experimental data. The dimensions of the combustion chamber were 3.78 m2.36 m1.6 m. A variable-angle concrete slab (2.36 m in length and 7.55 m in height) was installed above the opening of the combustion chamber to simulate the facade of the building. To investigate the temperature distribution of spill plumes along sloped facade wall, a total of 64 scenarios were considered with 4 different dimensions of rectangular openings(0.52 m0.65 m, 0.78 m0.52 m, 0.78 m0.65 m, 0.78 m0.78 m), 4 different facade wall angles (0°,10°,15°,20°) and 4 different heat release rates respectively. It is found that: (1) When the dimension of the openings and the heat release rates are constant, the temperature along the sloped facade (θ＞0°) is significantly higher than that along the vertical facade at the same measurement point (θ=0°). (2) When the angle of facade wall is set as 20°, the temperature at the same measurement point in the plume region is the highest among the four designed angles. (3) When the angle of facade wall is less than 20°, the temperature at the same measurement point gradually increases with the angle of the facade θ. (4) When the dimension of the openings and the angle of facade are the constant, with the increase of heat release rates, the maximum temperatures of the spill plume is almost constant. For further research on spill fire plume temperature distribution characteristics of sloped facade, the Z-Zn in classical theory is modified by 1+sinθ. It is found that the spill plume temperatures of the same opening dimension and heat release rate with different angles of facade wall collapse well. Based on these results, a predicted correlation of the temperature along the sloped facade is established, whose facade wall angles are in the range of 0<θ<20°.The results in this paper are based on the sloped angle between 0° and 20°. It needs to be further studied that whether the temperature distribution of spill plume conforms to this law when the sloped angle is greater than 20°.

Key words: building fire; sloped facade wall; numerical simulation; temperature distribution

张孝春1，程章昆1，吴斌斌2，陈钦佩3. 建筑倾斜外立面火溢流沿程温度分布研究[J]. 消防科学与技术, 2022, 41(3): 330-333.

ZHANG Xiao-chun1, CHENG Zhang-kun1, WU Bin-bin2, CHEN Qin-pei3. Study on longitudinal temperature distribution of spill fire plumes along sloped facade wall of building fires[J]. Fire Science and Technology, 2022, 41(3): 330-333.