关键词: 公路隧道, 集中排烟, 排烟道风压, 沿程阻力系数, 现场测试

Abstract: To investigate the pressure distribution laws and alongrange resistance in the exhaust flue under the centralized smoke exhaust mode, the wind speed and static pressure in the exhaust flue of the Meizizhou Yangtze river tunnel are experimentally tested in the field and the alongrange resistance in the exhaust flue is analyzed. The results reveal the following. (1) The negative pressure formed after the wind flow enters the exhaust flue gradually decreases and reaches the maximum absolute value at the end of the exhaust flue. (2) The wind pressure and air volume matched by fans at both ends are related to the length of the exhaust flue pipeline at both ends, and the wind pressure matched by the fans is lower when the exhaust valve is opened near the fans. (3) The alongrange resistance coefficient in the exhaust flue under the various modes of exhaust valve opening ranges from 0.01 to 0.03 with an average value of 0.018. The results reveal that the length of the pipeline should be comprehensively considered when selecting a fan, and the most unfavorable pipeline length is the distance between the two ends of the work shaft when the open smoke exhaust valve is located at one end of the work shaft. Furthermore, improving the quality of smoke exhaust valves at both ends of the flue during construction to reduce wind leakage effectively lowers the resistance along both ends of the flue.

Key words: highway tunnel, centralized smoke exhaust, wind pressure of smoke exhaust flue, alongrange drag coefficient, field test