风井送排风对近接隧道污染物窜流影响

INFLUENCE OF VENTILATION SHAFT ON SERIES-FLOW IN SERIAL TUNNELS WITH SHORT BREAK

基于射流扩散理论,构建带风井近接隧道在四种送排风方式下的窜流比模型。计算表明,利用风井送排风可有效抑制近接隧道的污染物窜流现象,其效果受风井送排风量、上下游隧道需风量、隧道洞间距等因素的共同影响。就抑制窜流而言,在下游隧道设置排风竖井是效率最低的措施;当上游隧道需风量较小时,上游排风方式的抑制窜流效果最佳;当上下游隧道需风量接近或下游隧道需风量较小时,下游送风方式的抑制效率最高。

Series-flow models of four supply and exhaust modes for serial tunnels with short break are established base on jet diffusion theory. The results shows： the series-flow of pollution can be suppressed by the supply and exhaust shaft effectively, the efficiency depends on the air volume of shaft, required air volume of upstream and downstream tunnels, and distance between upstream and downstream tunnels. For suppressing the series-flow, setting exhaust shaft in the downstream tunnel shows the lowest efficiency; when the required air volume of upstream tunnel is smaller, setting exhaust shaft in the upstream tunnel shows the highest efficiency; when the required air volume of upstream tunnel is similar to that of downstream tunnel or the required air volume of upstream tunnel is larger, setting supply shaft in the downstream tunnel shows the highest efficiency.