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| Study on the effect of makeup air supplementation on fire smoke control in subway tunnel |
| LEI Wenjun1,GUO Lili1,ZHAO Xuming1,TAI Chuanmin1,QI Yue2
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(1.School of Thermal Engineering, Shandong Jianzhu University, Jinan 250101, Shandong, China;
2.Integrated Equipment Industry Group Enterprise,Yantai 264002, Shandong, China)
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Abstract To address the issues of excessive air volume and insufficient targeting effectiveness in traditional subway tunnel make-up air systems, a novel composite ventilation method was proposed. This approach integrated side-supply in the breathing zone with bottom-supply ventilation based on occupant evacuation behavior patterns, with the objective of investigating its effectiveness in controlling smoke dispersion in evacuation passages.A physical model of a metro tunnel section was constructed using numerical simulation. Comparative analysis was conducted on the distribution patterns of CO concentration, temperature, and visibility in evacuation pathways under four distinct ventilation conditions: natural air replenishment, breathing-zone lateral air supply, bottom air supply, and combined ventilation modes.The study found that natural make-up air had the worst effect on controlling fire smoke in the evacuation channel, with visibility, CO concentration, and temperature all failing to meet personnel evacuation requirements.Breathing zone side-feeding make-up air could control the CO concentration in the evacuation channel below 62 mg/m3, but the mixing of make-up air and smoke caused the average temperature in the evacuation channel to reach 227 °C, which did not satisfy the requirements for safe personnel evacuation.For bottom make-up air, the average temperature in the evacuation channel exceeded 300 °C, and the average CO concentration was 100 mg/m3, both higher than the safety parameters required for personnel evacuation.When the combined make-up air of breathing zone side-feeding and bottom-feeding was applied, with the air volume ratio of side-feeding to bottom-feeding being 6:1 and the corresponding wind speeds being 1.8 m/s and 0.3 m/s respectively, the CO concentration in the evacuation channel was 34.6 mg/m3, the temperature was 59.2 °C, and the visibility was 18.6 m—all meeting the standards for safe personnel evacuation.The combined make-up air method of side-feeding in the breathing zone and bottom-feeding can effectively control fire smoke in metro tunnel evacuation channels, providing a theoretical basis for precise make-up air design in underground spaces aimed at ensuring personnel safety.
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Received: 03 January 2025
Published: 03 June 2025
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