Full-scale tests on smoke temperature distribution in long-large subway tunnels with longitudinal mechanical ventilation: Fid-Bau Portal

Full-scale tests on smoke temperature distribution in long-large subway tunnels with longitudinal mechanical ventilation

Shi, Congling / Li, Jian / Xu, Xuan

Abstract

Highlight • Study fire behaviors in long-large subway tunnel through full-scale tests. • Divides fire downstream space into three zones: Zone I, Zone II and Zone III. • Proves ceiling temperature rise at both Zone II and III are exponential functions. • Propose a method to compute ceiling smoke temperature distribution. • Proposed theoretical method shows a good match with full-scale tests.

Abstract Long-large subway tunnel accommodates the requirements of high-speed operation of trains, but also poses challenges on smoke control in case of tunnel fire. In conjunction with full-scale fire tests and theoretical analysis, this paper studies the fire behaviors of long-large subway tunnel by focusing on maximum ceiling smoke temperature rise, and smoke temperature rise distribution. The space downstream of fire source are divided into three zones, namely, inclined plume zone (Zone I), smoke entrainment zone (Zone II) and smoke column zone (Zone III). This paper proves that ceiling smoke temperature rise (CSTR) distribution at both Zone II and Zone III are exponential functions, but with different exponents. This paper proposes a method to compute the above exponents for Zone II and Zone III respectively. Full-scale tests verify that the proposed theoretical prediction method could predict the CSTR distribution with a relative error within 20%. Particularly, the proposed method is compared with several current computation methods, and is found has better correlation with the test data. Moreover, the measured maximum CSTR is found to be between the results of Kurioka’s model and Li Ingason’s model, and is closer with the later.