顶部开口的城市公路隧道自然通风现场实测与潜力预测

Field measurement and theoretical prediction on natural ventilation urban vehicular tunnels with roof openings

本文采用单点测试和连续测试2种方法,针对3条自然通风和2条机械通风公路隧道使用TSI7575-X型空气品质仪和KIMO-VT200型风速测试仪开展现场实测,获取隧道内温度、风速、CO和CO2浓度分布状况,并采用实测结果与已有的理论模型进行对比验证。结果表明:活塞风存在于所有隧道内,但机械通风隧道的活塞效应优于自然通风隧道;从入口到出口,所有隧道的温度、CO和CO2浓度均上升;隧道内风速主要依赖于车速(vt)和开口率(Rf),最大CO浓度随车速的降低和隧道长度的延长而增大,但受开口率的影响较小;CO的安全浓度标准依赖于人员暴露时间,在20 km/h和1 700辆/h车道条件下,所允许的隧道长度可达到3 000 m。

Three naturally ventilated and two mechanically ventilated urban vehicular tunnels were investigated using TSI7575-X and KIMO-VT200 for continuous and single-point measurements during congested periods. The theoretical model was validated by comparing the air velocities,CO and CO2 concentrations with that of the field measurement. Results showed that piston winds existed in every tunnel but the piston effect in mechanically ventilated tunnels was more apparent compared with that in naturally ventilated tunnels. All temperature as well as CO and CO2 concentrations increased from inlets to outlets.Furthermore,the air velocities depended largely on the vehicle speed（ vt） and the opening area ratio（Rf）. The maximum CO concentrations increased with the decrease in vtand the increase in tunnel length（L） but were minimally affected by Rf. The safety standards for CO concentration depended on exposure time. The allowed tunnel length could be up to 3 000 m at 20 km/h and 1 700 veh/h.