Study of fire characteristics affected by sealing in the cable compartment of a utility tunnel

Sealing shaft vents is an effective method of controlling fires in utility tunnels. A sealing strategy was scientifically developed in order to investigate the impact of varying sealing ratios on cable fires in utility tunnel shaft vents. In this paper, cable compartment fires with different sealing ratios were simulated by using Fire Dynamics Software (FDS). And the influence of the sealing strategy on the temperature, smoke dispersion and flow field characteristics of the cable compartment ceiling were analyzed. The results showed that the degree of the shaft sealing significantly impacts the temperature gradient and smoke dispersal patterns within the utility tunnel. When the sealing rate exceeds 75%, due to the accumulation of high-temperature smoke in utility tunnels and the continuous consumption of oxygen, fires are more prone to self-extinguishment. A ceiling temperature prediction model was developed that provides reasonable predictions for fire scenarios considering different sealing ratios. Under different sealing conditions, high concentrations of smoke may accumulate in utility tunnels, which should be considered in firefighting and rescue operations. Practical Application This study provides valuable insights into the practical implications of controlling and mitigating the impact of fires in the cable compartment of utility tunnel. By understanding the sealing effect role of cable compartment of utility tunnel and providing a quantitative tool for smoke spread law assessment, this study contributes to the enhancement of safety measures and the protection of lives in utility tunnels during fire incidents.