Experimental and theoretical study on ceiling temperature distributions in mountain tunnel with a lateral open shaft
Abstract A series of fire experiments in a 1/10 scale model tunnel with a lateral open shaft were conducted. Analysis was performed to explore the maximum excess temperature and longitudinal temperature decay under the influence of a mechanical exhaust system with a lateral open shaft. Three differe...
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Nature Portfolio
2025-01-01
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| Online Access: | https://doi.org/10.1038/s41598-024-79576-9 |
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| author | Yuchun Zhang Xinyu Liu Rui Tan Wei Hou Longfei Chen Shaoshuai Xing Zhisheng Li Yunhai Guo Xiaoqing Han |
| author_facet | Yuchun Zhang Xinyu Liu Rui Tan Wei Hou Longfei Chen Shaoshuai Xing Zhisheng Li Yunhai Guo Xiaoqing Han |
| author_sort | Yuchun Zhang |
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| description | Abstract A series of fire experiments in a 1/10 scale model tunnel with a lateral open shaft were conducted. Analysis was performed to explore the maximum excess temperature and longitudinal temperature decay under the influence of a mechanical exhaust system with a lateral open shaft. Three different pool sizes and numerous extraction rates were considered. The experimental results yielded intriguing insights into the correlations between the rate of smoke extraction and the ceiling temperature. The variations in the temperature distribution of ceiling smoke upstream and downstream the fire source is different under the induced longitudinal velocity, especially for the near the fire source area. An analysis of the maximum excess temperature was conducted by inducing the heat loss coefficient $$\delta$$ . It is 0.85 (0.71) for the induced dimensionless longitudinal velocity $${\lambda V_{s} }^{\prime} \le 0.19$$ $$\left( {\left( {\lambda V_{s} } \right){\prime}> 0.19} \right)$$ , which indicates the effect of a large velocity on the smoke heat loss. Then, a modified model of the maximum excess temperature was given for a tunnel utilizing lateral open shaft smoke extraction. In addition, a simple model was proposed to capture ceiling temperature decay, where the decay coefficients $$k_{i}$$ upstream and downstream of the fire source are proportional to $$1/Q^{^{\prime}1/3}$$ ( $$V_{in}{\prime} /Q^{^{\prime}1/3}$$ ) for $$( {\lambda V_{s} })^ {\prime} \le 0.19$$ $$\left( {\left( {\lambda V_{s} } \right){\prime}> 0.19} \right)$$ . The research results have certain guiding significance for the arrangement of fire protection, fire monitoring and early warning devices in mountain tunnels. |
| format | Article |
| id | doaj-art-65338a36d2554a4f9c25795c827658d8 |
| institution | Kabale University |
| issn | 2045-2322 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj-art-65338a36d2554a4f9c25795c827658d82025-01-05T12:20:03ZengNature PortfolioScientific Reports2045-23222025-01-0115111510.1038/s41598-024-79576-9Experimental and theoretical study on ceiling temperature distributions in mountain tunnel with a lateral open shaftYuchun Zhang0Xinyu Liu1Rui Tan2Wei Hou3Longfei Chen4Shaoshuai Xing5Zhisheng Li6Yunhai Guo7Xiaoqing Han8Department of Fire Protection Engineering, Southwest Jiaotong UniversitySchool of Mining and Geomatics Engineering, Hebei University of EngineeringSchool of Mining and Geomatics Engineering, Hebei University of EngineeringSchool of Mining and Geomatics Engineering, Hebei University of EngineeringDepartment of Fire Protection Engineering, Southwest Jiaotong UniversityDepartment of Fire Protection Engineering, Southwest Jiaotong UniversitySchool of Mining and Geomatics Engineering, Hebei University of EngineeringJizhong Energy Fengfeng Group Co., LtdJizhong Energy Fengfeng Group Co., LtdAbstract A series of fire experiments in a 1/10 scale model tunnel with a lateral open shaft were conducted. Analysis was performed to explore the maximum excess temperature and longitudinal temperature decay under the influence of a mechanical exhaust system with a lateral open shaft. Three different pool sizes and numerous extraction rates were considered. The experimental results yielded intriguing insights into the correlations between the rate of smoke extraction and the ceiling temperature. The variations in the temperature distribution of ceiling smoke upstream and downstream the fire source is different under the induced longitudinal velocity, especially for the near the fire source area. An analysis of the maximum excess temperature was conducted by inducing the heat loss coefficient $$\delta$$ . It is 0.85 (0.71) for the induced dimensionless longitudinal velocity $${\lambda V_{s} }^{\prime} \le 0.19$$ $$\left( {\left( {\lambda V_{s} } \right){\prime}> 0.19} \right)$$ , which indicates the effect of a large velocity on the smoke heat loss. Then, a modified model of the maximum excess temperature was given for a tunnel utilizing lateral open shaft smoke extraction. In addition, a simple model was proposed to capture ceiling temperature decay, where the decay coefficients $$k_{i}$$ upstream and downstream of the fire source are proportional to $$1/Q^{^{\prime}1/3}$$ ( $$V_{in}{\prime} /Q^{^{\prime}1/3}$$ ) for $$( {\lambda V_{s} })^ {\prime} \le 0.19$$ $$\left( {\left( {\lambda V_{s} } \right){\prime}> 0.19} \right)$$ . The research results have certain guiding significance for the arrangement of fire protection, fire monitoring and early warning devices in mountain tunnels.https://doi.org/10.1038/s41598-024-79576-9Mechanical exhaustMountain tunnel fireLateral open shaftMaximum excess temperatureLongitudinal decay |
| spellingShingle | Yuchun Zhang Xinyu Liu Rui Tan Wei Hou Longfei Chen Shaoshuai Xing Zhisheng Li Yunhai Guo Xiaoqing Han Experimental and theoretical study on ceiling temperature distributions in mountain tunnel with a lateral open shaft Scientific Reports Mechanical exhaust Mountain tunnel fire Lateral open shaft Maximum excess temperature Longitudinal decay |
| title | Experimental and theoretical study on ceiling temperature distributions in mountain tunnel with a lateral open shaft |
| title_full | Experimental and theoretical study on ceiling temperature distributions in mountain tunnel with a lateral open shaft |
| title_fullStr | Experimental and theoretical study on ceiling temperature distributions in mountain tunnel with a lateral open shaft |
| title_full_unstemmed | Experimental and theoretical study on ceiling temperature distributions in mountain tunnel with a lateral open shaft |
| title_short | Experimental and theoretical study on ceiling temperature distributions in mountain tunnel with a lateral open shaft |
| title_sort | experimental and theoretical study on ceiling temperature distributions in mountain tunnel with a lateral open shaft |
| topic | Mechanical exhaust Mountain tunnel fire Lateral open shaft Maximum excess temperature Longitudinal decay |
| url | https://doi.org/10.1038/s41598-024-79576-9 |
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