基于供排水量平衡的管网入流入渗评估及其影响因素分析
Assessment of Water Inflow and Infiltration in Pipe Network Based on Water Supply and Drainage Balance and Analysis of Its Influencing Factors

针对污水管网的入流入渗问题，以供排水量平衡方法为基础，提出了入流入渗水量估算与影响因素分析的方法。以苏州市中心区某泵站片区为案例区域，通过用水量与实际污水流量的对比估算入流入渗水量，得到该片区2021年总体入流入渗率(占泵站总水量的比例)为32.7%。针对非降雨期间，以天为单位分析，得到案例区泵站液位下降1.0 m时入流入渗率上升约8%；河道水位上升0.10 m时入流入渗率上升约14%。针对降雨期间，以场次降雨为单位，共选取12场降雨进行分析，得到案例区平均每10 mm降雨带来的入流入渗水量约为泵站日均流量的0.20倍；降雨入流比例与泵站液位成负相关关系，在大雨条件(或累积降雨量40~60 mm)下的入流比例高于小雨、中雨或长期连续降雨。该结果可为当地的“厂站网”一体化控制提供依据，以通过合理的液位控制减少管网的入流入渗水量；针对降雨入流的分析结果可为管网的雨季调控措施提供参考。
Aiming at the problem of inflow and infiltration of sewage pipe network, based on the balance method of water supply and discharge, a method for estimation of inflow and infiltration and analysis of influencing factors is proposed. Taking a pump station area in the central area of Suzhou as a case area, the inflow and infiltration water volume are estimated by comparing the water consumption with the actual sewage flow, and the overall inflow and infiltration rate (accounting for the proportion of the total water volume of the pump station) of this area in 2021 is 32.7%. For the non-rainfall period, taking the day as the unit of analysis, it is obtained that when the liquid level of the pump station in the case area decreases by 1.0 m, the infiltration rate increases by about 8%; when the river water level rises by 0.10 m, the infiltration rate increases by about 14%. During the rainfall period, a total of 12 rainfall events were selected for analysis, and it was found that the average inflow and seepage volume per 10 mm rainfall in the case area was about 0.20 times of the daily average flow of the pump station; the proportion of rainfall inflow is negatively correlated with the liquid level of the pump station. Under heavy rain conditions (or cumulative rainfall of 40~60 mm), the proportion of rainfall inflow is higher than that of light rain, moderate rain or long-term continuous rainfall. The results can provide a basis for the local “plant-station-network” integrated control, so as to reduce the inflow and infiltration of the pipe network through reasonable liquid level control; the analysis results of rainfall inflow can provide reference for the rainy season regulation measures of pipe network.