关于单立管系统通气流量影响因素的试验研究

Influence Factors of Air Flow for Single Stack Drainage System

在34层高的试验塔上,采用定流量测试法,分别测试PVC-U普通单立管系统、PVCU特殊配件单立管系统(光壁管+旋流三通)以及PVC-U特殊单立管系统(螺旋管+旋流三通)管顶通气流量与系统最大负压。结合通气流量随排水量以及系统最大负压的变化情况进一步分析单立管系统管顶通气流量的影响因素。结果表明:系统最大负压是影响通气流量的主要因素,其主要受水膜气水界面切应力和自由水滴的共同作用;在管顶通气条件相同的情况下,通气流量的大小是系统最大负压和水舌阻力共同作用的结果。

The maximum negative pressure and the air flow of three different PVC-U drainage systems including conventional single stack drainage system, single stack drainage single stack system with inner smooth pipe and cyclone tee, and special stack drainage system with spiral pipe and cyclone tee were investigated using constant flow generator on a 34-floor tower. The influence factors of the air flow for single stack drainage systems were analyzed based on the changes of air flow with the changes of drainage volume and the maximum negative pressure. The results showed that the maximum negative pressure was an important factor influencing the air flow, which was caused by the friction at the inner annulus surface and free water droplet in the air core. Moreover, the air flow was influenced by the maximum negative pressure and the nappe resistance under the same ventilation conditions.