Influence of cable inclination angle and longitudinal ventilation on temperature distribution during cable fire in utility tunnel

Abstract

Cable fire in utility tunnel commonly cause severe economic lost. This work experimentally investigates influence of cable inclination angle and longitudinal ventilation on temperature distribution during cable fire in utility tunnel. The position of the maximum ceiling temperature is located near the fire source. The position of the maximum ceiling temperature shifts with the increase of the wind speed. When the wind speed is less than 0.45 m/s, the maximum ceiling temperature increases with the increase of wind speed. When the wind speed is greater than 0.45 m/s, the conclusion is opposite. The dimensionless temperature rise and the longitudinal distance accord well with the attenuation law of power-exponential function. In the area between the cable bearer and the fan, larger wind speed corresponds to faster decay of the dimensionless temperature rise. In the area between the cable bearer and the outlet, the conclusion is opposite. The position of the maximum ceiling temperature is independent of the cable inclination angle. When the cable inclination angle is less than 15°, the maximum ceiling temperature increases with the increase of the cable inclination angle. When the cable inclination angle is greater than 15°, the conclusion is opposite.

Keywords

• Utility tunnel
• Cable inclination angle
• Longitudinal ventilation
• Temperature distribution