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Research on the Temperature Distribution Characteristics of Tunnel Fire Based on Distributed Optical Fiber Monitoring
(1. State Key Laboratory of Road Engineering Safety and Health in Cold and High-Altitude Regions of CCCC First Highway Consultants Co., Ltd., Xi′an 710065; 2. Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071;3. University of Chinese Academy of Sciences, Beijing 100049; 4. Xiangyang Auto Vocational and Technical College,Xiangyang 441021)
Abstract In order to verify the test result of distributed optical fiber monitoring technology in highway tunnel fire, research was conducted on the fire location and fire scale prediction method based on optical fiber monitoring reults, scale physical model test and Pyrosim dynamic simulation were carried out for tunnel fire under natural ventilation, and the formula was proposed for the highest temperature rise of crown and the the longitudinal temperature attenuation pattern of tunnels in case of tunnel fire under natural ventilation. The results show that the crown temperature curve based on distributed optical fiber monitoring is consistent with the thermocouple monitoring curve, and close to the curve obtained by numerical simulation. Distributed optical fiber wide area intensive monitoring is more suitable for early detection of tunnel fire temperature distribution characteristics. Under the natural ventilation, the longitudinal temperature attenuation pattern of the crown is basically a power exponential function in case of tunnel fire, and the temperature tends to be stable after a certain distance from the fire source. The distributed optical fiber is used for long-distance full coverage monitoring without blind area along the tunnel. Combining the formula for the highest temperature rise of the crown and the formula for the longitudinal temperature attenuation pattern, and based on the mutual evidence and inspection between the highly intensive optical fiber measurement results, the vertical and horizontal positions of the fire source can be accurately located, the fire power can be predicted, and the fire scale can be determined.
Abstract：
In order to verify the test result of distributed optical fiber monitoring technology in highway tunnel fire, research was conducted on the fire location and fire scale prediction method based on optical fiber monitoring reults, scale physical model test and Pyrosim dynamic simulation were carried out for tunnel fire under natural ventilation, and the formula was proposed for the highest temperature rise of crown and the the longitudinal temperature attenuation pattern of tunnels in case of tunnel fire under natural ventilation. The results show that the crown temperature curve based on distributed optical fiber monitoring is consistent with the thermocouple monitoring curve, and close to the curve obtained by numerical simulation. Distributed optical fiber wide area intensive monitoring is more suitable for early detection of tunnel fire temperature distribution characteristics. Under the natural ventilation, the longitudinal temperature attenuation pattern of the crown is basically a power exponential function in case of tunnel fire, and the temperature tends to be stable after a certain distance from the fire source. The distributed optical fiber is used for long-distance full coverage monitoring without blind area along the tunnel. Combining the formula for the highest temperature rise of the crown and the formula for the longitudinal temperature attenuation pattern, and based on the mutual evidence and inspection between the highly intensive optical fiber measurement results, the vertical and horizontal positions of the fire source can be accurately located, the fire power can be predicted, and the fire scale can be determined.
LI Zhen1 LENG Xianlun2,
3 YIN Qiuyu4
.Research on the Temperature Distribution Characteristics of Tunnel Fire Based on Distributed Optical Fiber Monitoring[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(6): 132-139
2022, Vol. 59 