Selection of Water Transmission Method and Analysis of Pipe Network Zoning in Municipal Water Supply and Drainage Design

With the acceleration of urbanization,the demand for water supply and drainage pipe networks has increased significantly.In the planning of urban construction,it is necessary to optimize the design of the water supply and drainage system pipe network to effectively save energy while providing residents with more accessible water resources.Therefore,the municipal water supply and drainage system and the water transmission methods should be designed according to the geographical conditions of the city.In this paper,we mainly analyze the design of municipal water supply and drainage systems and the selection of water transmission methods.Besides,the optimization of the water supply and drainage network zoning process and pipe network maintenance is also discussed,so as to provide a reference for municipal water supply and drainage work.

Simultaneous synthesis of heat-integrated water networks by a nonlinear program:Considering the wastewater regeneration reuse

Heat-integrated water network synthesis(HIWNS)has received considerable attention for the advantages of reducing water and energy consumptions.HIWNS is effective in water and energy sustainability.Mixed integer non-linear programming(MINLP)is usually applied in HIWNS.In this work,a novel nonlinear programming(NLP)was proposed for HIWNS by considering wastewater reuse and wastewater regeneration reuse.Integer variables are changed to non-linear equation by the methods for identifying stream roles and denoting the existence of process matches.The model is tested by examples with single and multiple regeneration unit problems.The testing results showed that the NLP is an alternative method for HIWNS with wastewater reuse and regeneration reuse.

Application of Dynamic Programming Method in Optimization of Water Distribution Pipe Network

With a water-supply network by dynamic programming. The minimal as an example, the network was optimized annual discounted costs were taken as an objective function and node pressure etc. as constraint conditions. The alternative pipe diameters were optimized as per enumeration method and the group allowing objective function with the least values would be the optimized one. It is proved the optimized pipe network reduced by 11.49% in terms of cost and the optimized ben- efits proved much significant.

Optimal operation of water distribution networks under local pipe failures

The optimal operation of water distribution networks under local pipe failures, such as water main breaks, was proposed. Based on a hydraulic analysis and a simulation of water distribution networks, a macroscopic model for a network under a local pipe failure was established by the statistical regression. After the operation objectives under a local pipe failure were determined, the optimal operation model was developed and solved by the genetic algorithm. The program was developed and examined by a city distribution network. The optimal operation alternative shows that the electricity cost is saved approximately 11%, the income of the water corporation is increased approximately 5%, and the pressure in the water distribution network is distributed evenly to ensure the network safe operation. Therefore, the proposed method for optimal operation under local pipe failure is feasible and cost-effective.

Impact of the Condition of Drinking Water Supply Networks on the Quality of Water Intended for Consumption: The Case of the Network in the Commune of Daloa (Central West of Côte d’Ivoire)

The potability of drinking water depends not only on the source and the treatment system, but also on the quality of the waterworks. In fact, the quality of drinking water is considerably degraded by the dilapidated state and lack of maintenance of drinking water networks. In Côte d’Ivoire, the majority of drinking water networks in the various towns are ageing. In Daloa, despite the efforts made by the company in charge of water treatment and distribution to make the water drinkable, the water at consumers’ taps is often colored, has an unpleasant aftertaste and settles after collection. As a result, people are concerned about the potability of tap water, and some are turning to alternative sources of drinking water of unknown quality. In order to determine the factors responsible for the deterioration in water color and taste, as well as the sectors of the network most affected, a diagnosis of the network’s equipment was carried out. Water samples taken from the network were analyzed for color and turbidity. The diagnosis revealed that most of the equipment (suction pads, valves, drains and fire hydrants) is outdated and irregularly maintained. Analyses show that the water is more colored in cast-iron and PVC pipes than in asbestos cement pipes. Coloration values in the network range from 0 to 27 UVC for asbestos cement pipes, from 15 to 56 UCV for ductile iron pipes, and from 11 to 102 UCV for PVC pipes. On the over hand, turbidity values vary from 8.02 to 3.32 NTU for ductile cast iron pipes, 8.51 to 16.98 NTU for asbestos cement pipes and 0.9 to 6.98 NTU for PVC pipes. Old cast-iron pipes release ferric ions on contact with water, degrading their color. Old cast-iron pipes release ferric ions into the water, degrading its color. The high color values observed in the vicinity of drains are thought to be due to irregular maintenance of the network. In fact, after network maintenance, a reduction rate ranging from 2% to 73% is observed for turbidity, while for color, the rate varies from 5% to 72%. In short, the network’s obsolescence and irregular maintenance contribute significantly to the deterioration of water quality.

Effectiveness of urban distributed runoff model for discharge and water depth calculation in urban drainage pipe networks

Effective urban land-use re-planning and the strategic arrangement of drainage pipe networks can significantly enhance urban flood defense capacity.Aimed at reducing the potential risks of urban flooding,this paper presents a straightforward and efficient approach to an urban distributed runoff model(UDRM).The model is developed to quantify the discharge and water depth within urban drainage pipe networks under varying rainfall intensities and land-use scenarios.The Nash efficiency coefficient of UDRM exceeds 0.9,which indicates its high computational efficiency and potential benefit in predicting urban flooding.The prediction of drainage conditions under both current and re-planned land-use types is achieved by adopting different flood recurrence intervals.The findings reveal that the re-planned land-use strategies could effectively diminish flood risk upstream of the drainage pipe network across 20-year and 50-year flood recurrence intervals.However,in the case of extreme rainfall events(a 100-year flood recurrence),the re-planned land-use approach fell short of fulfilling the requirements necessary for flood disaster mitigation.In these instances,the adoption of larger-diameter drainage pipes becomes an essential requisite to satisfy drainage needs.Accordingly,the proposed UDRM effectively combines land-use information with pipeline data to give practical suggestions for pipeline modification and land-use optimization to combat urban floods.Therefore,this methodology warrants further promotion in the field of urban re-planning.

Design of Water Network with Multiple Contaminants and Zero Discharge

The paper presents a procedure to design water network. First of all, water reuse system, water regeneration reuse system (including regeneration recycle) and wastewater treatment system are designed separately. But the interaction between different parts demands that each part is designed iteratively to optimize the whole water network. Therefore, on the basis of the separated design a water netvrork superstructure including reuse, regeneration and wastewater treatment is established from the system engineering point of view. And a multi-objective adaptive simulated annealing genetic algorithm is adopted to simultaneously integrate the overall water netvrork to balance the economic and environmental effects. The algorithm overcomes the defect of local optimum of simulated annealing (SA), avoids the pre-maturation of genetic algorithm (GA) and finds a set of solutions (pareto front) in acceptable computer time. Prom the pareto front, a point with minimum fresh water consumption will be extended to zero discharge as our ultimate goal.

Variable Chlorine Decay Rate Modeling of the Matsapha Town Water Network Using EPANET Program

A variable chlorine decay rate modeling of the Matsapha town water network was developed based on initial chlorine dosages. The model was adequately described by a second order rate function of the chlorine decay rate with respect to the initial chlorine dose applied. Simulations of chlorine residuals within the Matsapha water distribution network were run using the EPANET 2.0 program at different initial chlorine dosages and using the variable decay rate as described by the second order model. The measurement results indicated that the use of constant decay rate tended to underestimate chlorine residuals leading to potentially excess dosages with the associated chemical cost and side effects. The error between the two rate models varied between 0% and 15%. It is suggested that the use of water quality simulation programs such as EPANET be enhanced through the extension programs that accommodate variable rate modeling of chlorine residuals within distribution systems.

A heuristic design method for batch water-using networks of multiple contaminants with regeneration unit

This work develops a heuristic method for the design of batch water-using networks of multiple contaminants with regeneration unit based on the concepts of concentration potential. A water-using network involving regeneration unit can be formed by adding the regenerated stream(s) into the network involving reuse only. In the design procedure of the network operated in a single batch mode, time is take n as the primary factor a nd con centration potentials as the secondary one. For the networks operated in a repeated mode, the design procedure is similar to that for continuous processes, besides designing the storage tanks with the rules proposed. Continuous regeneration unit is selected in this work. With the proposed method, the network structure corresponding to the minimum freshwater consumption can be obtained. It is shown that the method proposed in this article is simple, effective and has clear engineering meaning.

天山胜利隧道内置高位水池的消防供水系统设计研究

为解决10 km甚至20 km以上的高寒高海拔超长公路隧道消防供水系统设计中洞外设置供水系统被冻结、洞内管网严重超压等难题,通过对乌尉高速天山胜利隧道消防设计的难点,以及常规的隧道外常高压供水系统及稳高压供水系统在该隧道中难以实施等问题展开深入研究,提出天山胜利隧道内设置高位消防水池及将隧道内消防管网进行分区供水的设计方案并详细论述。对于10 km甚至20 km以上的高寒高海拔超长公路隧道消防供水系统的设计:1)隧道消防给水宜采用高位消防水池供水的常高压供水系统;2)常规的隧道外常高压供水系统及稳高压供水系统在高寒高海拔超长公路隧道中无法实施,可考虑隧道内置高位消防水池的设计;3)隧道内置高位消防水池的数量、设置间距、设置高度等应根据隧道的长度、纵坡等综合考虑并进行水力计算后确定;4)隧道内置高位消防水池的常高压供水系统能解决这类隧道消防供水系统设计中管网严重超压的难题,具有供水安全可靠、施工难度较小、经济、环保等优点。

废水处理中水质监测参数的实时预测研究

针对污水处理厂生化池中参数监测智能化水平不高、人力耗费较大的问题,提出基于麻雀算法-长短期记忆神经网络(Sparrow Search Algorithm-Long Short Term Memory Network,SSA-LSTM)的水质参数预测模型。以污水处理过程中好氧区溶解氧(Dissolved Oxygen,DO)、好氧区混合液悬浮固体(Mixed Liquid Suspended Solids,MLSS)质量浓度、缺氧区DO、缺氧区氧化还原电位(Oxidation-Reduction Potential,ORP)、厌氧区DO和厌氧区ORP 6个关键指标为数据样本,进行实例研究。将SSA-LSTM的预测结果与长短期记忆神经网络(Long Short-Term Memory Network,LSTM)、粒子群算法(Particle Swarm optimization-Long Short Term Memory Network,PSO-LSTM)、深度森林以及支持向量机进行对比分析,结果显示:SSA-LSTM在6个参数上的均方误差(EMSE)和决定系数(R2)均表现出更好的预测性,预测精度最高。

污水管道水位流速检测装置设计

在线实时监测市政污水管道内污水的水位和流速能帮助市政管理部门精准掌握污水流动情况,及时了解管道出现的问题,提高工作效率。该文依据绕流理论设计并制作了一种基于浮球的水位和流速检测装置,通过测量浮球随水位变化的相对位移实现水位测量;通过测量流体对浮球的推力实现流速测量。装置的GSM/GPRS模块接收水位和流速的检测数据并传输至远程监控端,实现远程在线监测。在明渠标准实验台对该检测装置的水位和流速测量值进行标定和精度实验,实验结果表明:测量水位的偏差在±3 mm内,误差不大于其满量程的0.5%;流速测量偏差值在±0.04m/s内,误差不大于其满量程的5%。将该检测装置安装在实际的污水管道内,对污水水位和流速进行了为期三个月的实验监测,检测值的远程传输结果符合预期。

西北地区某市地下水供水管网黄水产生原因分析与控制技术中试研究

随着供水管道使用年限的增加,管网逐渐老化,管网化学稳定性问题日益突出。为解决西北地区某市高碱度地下水供水管网黄水问题,保障用水安全,开展了黄水产生原因分析与控制技术中试研究。一方面,监测黄水形成过程中水质特点和规律,对铸铁管腐蚀管垢成分进行分析,探明黄水形成原因。另一方面,搭建管网中试系统,研究了余氯、碱度、缓蚀剂对管网铁释放的影响。结果表明:黄水形成存在周期性规律,形成原因为水力冲刷增强导致管垢中的铁释放到水体中,水体存在一定的腐蚀性也会影响铁释放。管垢主要成分为Fe3O4和α-FeOOH,但不同管垢层形貌特征及化学组成存在差异。建议该地区管网余氯浓度控制在0.4 mg/L左右,余氯较高或较低均会促进铁释放。综合考虑效果和经济性,应对突发性黄水问题时,建议优先采用0.5 mg/L(以P计)的三聚磷酸钠作为缓蚀剂投加控制黄水现象。每吨水需增加药剂成本约为0.018元。

基于WaterGEMS的供水管网建模及爆管分析研究

利用WaterGEMS建模软件及某市高新区自来水公司收集到相关数据,研究分析城市供水管网爆管事故,利用黄金分割法研究漏失水量,通过建模与计算机技术相结合进行动态分析,比较建立管网微观模型能够较好预测出供水管网发生爆管事故位置及漏失水量.

延长油田某注水示范区地面系统优化改造

延长油田地处鄂尔多斯盆地,属低产、低渗透油藏,注水开发是持续稳产的主要方式。为提高注水开发水平与效果,建立注水示范区,从地下、地上同步调整优化,注水地面系统是否高效、是否适用直接影响着注水开发目标能否实现。为提升示范区注水地面系统适应性,通过注水管网优化改造、注水工艺优化、污水处理站水质提升三方面开展地面系统优化改造,通过管网切割重整、配水间改注水站,实现整体降压、局部增压,注水干线辐射半径小于等于4 km,注水干线流速小于等于1.5 m/s,单井支管流速小于等于1.0 m/s;同时配套单干管、短支线,流动洗井车洗井工艺,完善主要水处理工艺,补齐装置短板,优化药剂投加。改造后,管网效率由43%提高至79%,水质达标率由70%提高至95%,解决了以往注水系统效率低、压损大、能耗高、注不进水、注不够水、水质差的问题。

叠压供水系统对市政管网的影响分析

叠压供水充分利用管网余压进行变频恒压供水,具有节能、供水水质稳定等优点。然而叠压供水系统直接与市政管网相连,启动时会引起接入点及管网上下游的流量和压力波动,对市政管网输送水量变化和压力变化带来影响。以江苏省JT城区的市政管网为研究对象,采用EPANET软件执行延时模拟、HAMMER软件执行瞬时模拟,分析叠压供水系统对市政管网的影响程度和规律,并确定了两个评价指标:最低市政供水压力要求和系统接入点运行压降要求。结果表明,叠压供水系统对市政管网的影响与小区入住率、用水时段、叠压数量等因素有关;小区附近叠压供水系统数量越少、分布越稀疏,多叠压供水系统运行时接入点压降就越小。当实际应用中影响超出安全范围时,建议通过优化控制方式和供水方式缓解影响,保障供水安全。

基于中压变流器的半导体器件结温耦合计算方法研究

随着工业生产需求的变流器功率逐渐增大,水冷变流器的应用日益增多。器件结温作为变流器的核心应用参数受到了广泛的关注和研究。本文从水冷变流器实际工程应用出发,对变流器半导体器件结温计算过程进行了逐步分析,应用仿真软件对半导体器件、散热器的热物性参数进行了细致分析,提出了一种管网流量计算方法,简化了水冷变流器“负载-流量-结温”计算的过程,有效提高了工程设计效率。

基于BiLSTM深度学习模型的污水处理厂水质预测

针对污水处理厂部分水质指标难以实时测定的问题,本研究利用BiLSTM神经网络建立软测量模型,获取预测数据。实验表明,该模型对出水COD与出水TN的预测均有较高的准确度。预测数据可为污水处理厂运营者的维护与管理提供科学依据,并且可以提前预知水质异常等状况。

城市集中供热水处理专家帮助系统的开发

随着智能城市的不断发展,专家帮助系统在人们的生活中发挥着至关重要的作用。针对热电联产机组和热水管网水处理经常出现的一些故障进行分析,将热源厂水处理中常出现的设备故障问题及其解决方案制作成数据库和专家知识库,在windows环境下,将数据库与Visual Basic6.0软件对接,开发出供水管网故障诊断专家帮助系统软件。主要功能有查询数据库中的供热管网故障类型、解决方案、即时更新数据库内容。

基于制浆全过程关键污染指标分析的“降污减排”策略研究

造纸行业废水是工业废水的主要来源之一,在国内外都是工业源重点调查行业。减少清水用量与增加生产体系浆水利用率是近年来实现降污减排主流策略,但生产过程浆体系污染物定量、迁移方向以及水循环节点常规污染物指标特征尚不明确。本文选取广西某制浆企业为例,通过检测该企业制浆全过程制浆体系、循环用水节点常规污染指标,结合数据绘制制浆体系的常规污染指标迁移图,分析生产用水循环管理系统,从用水结构优化探索源头减排新策略。