Experimental study on the maximum temperature rise of the ceiling with dual fire sources at different transverse positions in a tunnel
YUAN Heyong
WU Zhihui
Abstract：To analyze the maximum temperature rise of the ceiling in a natural ventilation tunnel with two fire sources,a total of 75 sets of dual fire source fire tests are conducted in a tunnel model(scaled at 1:10 compared to the actual tunnel)under three influencing factors:fire source edge length,distance between fire sources,and lateral position of fire sources.These results are compared against 9 sets of single fire source fire tests to examine the impact of the three factors on the maximum temperature rise of the ceiling.The results indicate that:when the distance between dual fire sources is the same,a larger fire source edge length leads to a greater maximum temperature rise of the ceiling;the distance between fire sources and their lateral position significantly affect the maximum temperature rise of the ceiling;when the fire source edge length and distance between dual fire sources are the same,the maximum temperature rise of the ceiling is greatest when the fire source is positioned against the wall;during single fire source combustion,as the fire source gradually moves away from the side wall,the maximum temperature rise of the ceiling first decreases and then increases;when the distance between dual fire sources is relatively large,the maximum temperature rise of the ceiling continuously decreases as the fire source moves away from the side wall;when the fire source edge lengths are the same,as the distance between dual fire sources increases,the maximum temperature rise of the ceiling when the fire sources are in the same position generally shows a decreasing trend.By combining the Alpert ceiling maximum temperature rise prediction model with the Zukoski mirror effect,a relatively accurate prediction of the maximum temperature rise of the ceiling can be made when a single fire source is positioned against the wall;the normalized maximum temperature rise of the ceiling for dual fire sources located at different transverse positions in the tunnel decreases with the increase of the dimensionless distance between fire sources.
Keywords：safety engineeringdual fire sourcestunnel transverse positiondistance between fire sourcesmaximum temperature rise of the ceiling
Publication Date：2024-12-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：8( 119-125,142 )