AI Article Synopsis
- A series of fire experiments were conducted using a 1/10 scale model tunnel with a lateral open shaft to study the effects of a mechanical exhaust system on temperature changes during a fire.
- The research revealed important correlations between smoke extraction rates and ceiling temperatures, with variations observed in temperature distribution near the fire source based on induced longitudinal velocity.
- Findings led to the development of a modified model for maximum excess temperature and a simplified model for ceiling temperature decay, which are significant for improving fire safety measures in mountain tunnels.
Article 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 δ. It is 0.85 (0.71) for the induced dimensionless longitudinal velocity [Formula: see text] [Formula: see text], 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 [Formula: see text] upstream and downstream of the fire source are proportional to [Formula: see text]([Formula: see text]) for [Formula: see text][Formula: see text]. The research results have certain guiding significance for the arrangement of fire protection, fire monitoring and early warning devices in mountain tunnels.
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| http://dx.doi.org/10.1038/s41598-024-79576-9 | DOI Listing |
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11695599 | PMC |
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