供水管网的单向冲洗研究

管网冲洗的目的主要是去除附着在管道内壁上的生物膜、部分管垢及沉积物。传统冲洗方法打开消火栓是无序的，没有采取关闭阀门等措施控制流向，因此冲洗效果不明显。单向冲洗方法通过关闭阀门和调整打开的消火栓个数来控制水的流向和流速（〉1．8m／s），各冲洗区域互不影响，克服了传统冲洗方法的弊端，能够有效改善管网水水质。对某小区供水管网进行单向冲洗的结果表明，经过单向冲洗后管网水中的细菌总数与浊度明显降低，余氯与Langelier指数在短期内（1周）有下降的趋势，但当管道内壁状况稳定后，这两项指标与冲洗前相比变化不大。

Study on Unidirectional Flushing of Water Distribution System

The objectives of flushing water distribution system include removal of biofilm, scale and sediment in the pipe.In conventional flushing,the process of opening hydrants is nonsequential,valve closure is not used for controlling the flow direction,so the conventional flushing is not effective.In unidirectional flushing,water flow direction and velocity(>1.8 m/s) are controlled by closing appropriate valves and regulating the opened hydrants without influence between flushing areas,which can overcome the disadvantages of conventional flushing and effectively improve the water quality in water distribution system.The result of the unidirectional flushing shows that HPC and turbidity are obviously decreased.Residual chlorine and Langelier index are reduced in short time(a week),but will increase and almost equal to that before flushing when the situation of pipe inner wall is stabilized.