供水管网水力与水质特性研究

发布时间：2018-11-03 08:25

【摘要】：给水管网在整个供水系统中占有重要地位，对水质安全有非常关键的作用。近年来给水管网的二次污染问题吸引了人们越来越多的关注，人们因此提出了水质的生物稳定性概念。控制给水管网内的细菌再生长对提高水质的生物稳定性作用极大。给水管网内壁上的生物膜中的微生物可能随着管段内水体水力条件的变化而进入到水体，因此，生物膜有如一个在管网中能够缓慢释放微生物的容器。本文以一座示范性工程管网展开研究，从软件建模开始，为了有更好的水力模型作为水质研究的基础，针对目前供水管网水压及流量监测点不足的状况，提出了一种基于广义伪逆解的供水管网水力状况实时模拟方法。该方法利用管网SCADA系统提供的少量水压及流量监测值作为欠定非线性水力方程组的输入量，节点流量作为方程的输出量，利用广义伪逆矩阵解，通过迭代法构造搜索向量，得出非线性水力方程组的解，即节点需水量。在此基础上，，计算出管网中未被监测的节点水压和管道流量。将该方法应用于我国南方某乡镇供水管网水力状态的实时模拟，结果表明，节点水压与实际值吻合较好，该方法可用于供水管网监测点不足时节点水压的的实时模拟。为了能更准确地反映真实情况下给水管网水中的微生物与余氯的相互作用，在探究给水管网中生物膜对水质的影响实验时采用旧的球墨铸铁管与自来水接触，水样经过加氯等处理后进行微生物实验。实验结果较好地反映了余氯量与微生物量的关系，在与实际管网水质检验结果对比后，有一定的相关性，能够结合起来反映出给水管网在一年四季中随着温度的变化，水质的变化情况。实验还考虑了pH的影响，结果证明，随着pH值的降低，给水管网中的微生物含量逐渐减少。该实验还反映出，春季是管网中微生物生长较活跃的季节，应该加强水质安全防范措施。在延时的管网水力模型清晰的情况下，掌握给水管网中水质微生物指标与余氯指标的关系，借助软件的模拟结果，能够让我们在整个管网的层面上认识到水质的微生物指标情况，对加强给水管网水质管理与加强防范措施有较大的帮助。
[Abstract]:Water supply network plays an important role in the whole water supply system and plays a key role in water quality safety. In recent years, people pay more and more attention to the problem of secondary pollution of water supply network, so people put forward the concept of biological stability of water quality. Controlling bacterial regrowth in water supply networks plays a significant role in improving the biological stability of water quality. The microbes in the biofilm on the inner wall of the water supply network may enter the water body with the change of the hydraulic conditions of the water in the pipe section. Therefore, the biofilm is like a vessel which can release microorganism slowly in the pipe network. In this paper, a model engineering pipe network is studied. Starting from the software modeling, in order to have a better hydraulic model as the basis of water quality research, this paper aims at the shortage of water pressure and discharge monitoring points in the water supply network. A real-time simulation method for hydraulic condition of water supply network based on generalized pseudo-inverse solution is presented. In this method, a small amount of water pressure and flow monitoring value provided by SCADA system of pipe network are used as the input of underdetermined nonlinear hydraulic equations, the node flow is taken as the output of the equation, and the generalized pseudo-inverse matrix solution is used to construct the search vector by iterative method. The solution of nonlinear hydraulic equations, that is, node water demand, is obtained. On this basis, the unmonitored node water pressure and pipe flow in the pipe network are calculated. The method is applied to the real-time simulation of the hydraulic state of a township water supply network in southern China. The results show that the node water pressure is in good agreement with the actual value, and this method can be used to simulate the water pressure of the node when the monitoring points of the water supply network are insufficient. In order to more accurately reflect the interaction between microorganisms and residual chlorine in the water supply network under real conditions, the influence of biofilm on water quality in the water supply network was investigated by using old ductile iron pipe and tap water. Water samples were treated with chlorine and microbiological experiments were carried out. The experimental results reflect the relationship between residual chlorine content and microbial biomass. Compared with the actual water quality test results, there is a certain correlation, which can be combined to reflect the variation of water supply network with temperature in the four seasons of the year. Changes in water quality The effect of pH is also considered in the experiment. The results show that the microbial content in water supply network decreases gradually with the decrease of pH value. The experiment also shows that spring is the most active season for the growth of microbes in pipe networks, and water quality safety precautions should be strengthened. Under the condition that the hydraulic model of the delayed pipe network is clear, the relationship between the microbial index of water quality and the residual chlorine index in the water supply network is grasped, and the simulation results of the software are used. It can make us realize the microbial index of water quality on the whole pipe network level, which is helpful to strengthen water quality management and preventive measures of water supply network.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU991.3

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