Water Supply Networks as Cyber-physical Systems and Controllability Analysis

Cyber-physical systems (CPS) is a system of systems which consists of many subsystems that can stand alone in an individual manner and can be taken as a typical complex network. CPS can be applied in the critical infrastructures such as water supply networks, energy supply systems, and so on. In this paper, we analyze the structure of modern city water supply networks from the view of CPS theory. we use complex network theory to build an undirected and unweighted complex network model for the water supply networks to investigate the structural properties, and present the structure of the water supply networks and detect communities by a spectral analysis of the Laplacian matrix. Then, we analyze the structure and controllability of water supply networks by the structural controllability method. The results show the feasibility and effectiveness of the proposed complex network model. © 2014 Chinese Association of Automation.

Iodization of Village Water Supply in the Control of Endemic Iodine Deficiency in Rural Sarawak, Malaysia

A simple water iodizing system, which incorporates the Venturi principle in combination with the controlled release mechanism of a silicone-sodium iodide elastomer, for the iodization of rural piped-water supply in the control of endemic iodine deficiency has been developed and its effectiveness evaluated in three Iban longhouse villages in the iodinedeficient district of Lubok Antu, Sarawak. Urines were collected for iodine assays from women aged 15-40 years before and at 6 and 12 months after the connection of the iodinating device; goiter assessment was performed on the women at the start and end of the 1-year study. Water samples were collected for iodine assays at 2-weekly intervals. In all three villages, significant and sustained increases in median urinary iodine excretions,reaching levels recommended for an iodine-suffcient population, were observed; goitre prevalences were reduced in all the villages (by 22.6% to 35.8%). The iodine levels in the water ranged from 34 μg/l to 212 μg/L. In the control village, median urinary iodine excretions remained essentially unchanged but a small increase in goiter prevalence was observed. The iodized water was well received by the villagers and no adverse effects of water iodization were observed. The system functioned unattended throughout the one year period. The cost of providing supplemental iodine via the iodizing device is approximately 60 cents (U.S.) per family per year which is affordable by either the Government or the villagers. It is concluded that the iodizing system offers a new cost-effective strategy for the control of endemic iodine deficiency in Sarawak and may have applications in other areas with similar water sources

Study on the Elman Neural Network Operation Control Strategy of the Central Air Conditioning Chilled Water System

The stable operation of the central air conditioning water system always is a major difficulty for the control profession. Paper focus on the water system with multi variable, strong coupling, nonlinear, large time delay characteristics, presented use feed forward coupling compensation method, to eliminate the coupling effect between temperature and pressure. In this paper, the Elman neural network controller is designed for the first time, and the simulation results show that the response time of Elman neural network controller is shorter, the system is more stable and the overshoot is small.

Model predictive control for water management and energy security in arid/semiarid regions

This paper aims to develop a realistic operational optimal management of a water supply system in an arid/semiarid region under climate change conditions.The developed model considers the dynamic variation of water demand,rainfall,weather,and seasonal change in electricity price.It is mathematically developed as a multi-constraint non-linear programming model based on model predictive control principles.The model optimises the quantities of water supplied by each source every month and improves the energy efficiency in a water supply system with multiple types of sources.The effectiveness of the developed MPC model is verified by applying it to a case study and comparing the results with those obtained with an open loop model.Results showed that using the MPC model leads to a 4.16%increase in the water supply cost compared to the open loop model.However,when considering uncertainties in predicting water demands,aquifer recharges,rainfall,and evaporation rate,the MPC model was better than the open loop model.Indeed,the MPC model could meet the water demand at any period due to its predictability of variations,which was not the case with the open loop model.Moreover,a sensitivity analysis is conducted to verify the capacity of the developed model to deal with some phenomena due to climatic changes,such as in rainfall.

Setting up the Goal of Eliminating Outbreaks of Blue-green Alga, Innovating the Idea of Controlling the Taihu Lake, and Ensuring the Safety of Water Supply in the Taihu Lake

Since the water supply crisis in the Taihu Lake on May 29,2007,the control of the Taihu Lake has achieved remarkable results,and the eutrophication has been greatly reduced.Existing problems are as follows:outbreaks of blue-green alga still appear seriously every year,and there is no goal to eliminate outbreaks of blue-green alga;the load into the lake greatly exceeds the environmental capacity;reed wetlands are greatly reduced;there is still the possibility of a water supply crisis;the research of eliminating outbreak of blue-green alga is weak.In this paper,the experience of controlling the Taihu Lake is summarized,and the ultimate goals of eliminating eutrophication and outbreaks of blue-green alga and restoring wetlands and biodiversity are proposed.Control measures are proposed,such as deepening the promotion of the lake chief system,establishing the lake chief system in an all-round way,and increasing applied scientific and technological efforts and capital investment.The necessity and possibility of further controlling the Taihu Lake to eliminate outbreaks of blue-green alga should be recognized.Relying on controlling eutrophication alone cannot eliminate outbreaks of blue-green alga.The point that phosphorus control is the key to eliminate outbreaks of blue-green alga is not suitable for the Taihu Lake.The integration ideas of"three types"of technologies should be innovated.The first one is"double reduction and double increase"measures to eliminate eutrophication,of which"double reduction"is to reduce external point sources and non-point sources and internal blue-green alga in sediment;for external sources,the treatment standard of sewage plants should be paid special attention to.The second one is"double algae removal"measures to salvage blue-green alga,suppresses and kills algae.The blue-green alga on the surface,middle and bottom of water should be thoroughly salvaged and eliminated from various water areas.The third one is"double restoration"measures to restore wetlands and biodiversity.The area of wetlands should be restored to the area from the 1960s to the 1970s before outbreaks of blue-green alga,and vegetation coverage reaches 25%-30%.The Taihu Lake is controlled in different waters to ensure water supply safety in water sources.Five suggestions are proposed,such as revising the"Overall Plan for the Comprehensive Treatment of Water Environment in the Taihu Lake Basin"again,incorporating the goal of eliminating outbreaks of blue-green alga in the plan,setting up this research topic,greatly improving sewage treatment standards in local legislation.

Research and application of GIS information system of Pipeline Network of Oil Field Water

Pipeline network of oil fi eld water is established on the basis of GIS geographic information and SCADA platform, and monitorthe running state of water supply system in oil fi eld mining area in real time through data acquisition, instrument measurement and control,wireless network, water quantity, water pressure and other on-line monitoring equipment. The water supply system is formed, and the informationof mass water supply system is analyzed and processed in a timely manner. The system manages the entire production, management and serviceprocesses of the water supply system in a dynamic manner in order to ensure water supply safety management, and realize the modernization,intelligence and information mode operation of the water supply system in the mining area.

Control of Water Supply in Pipe Networks Nonlinear Case

The paper deals with control of supply in pipe networks based on so-called Dynamic Virtual Distortion Method. Making use of the analytical network model of this installation and using presented below, the so-called Virtual Distortion Method （VDM）, the control of water supply can be performed. Minimization of supply pressure in inlets to the network, subject to inequality constraints imposed on outlet pressure （in chosen nodes） is discussed. Taking advantage of pre-computed influence vectors, the real-time control strategy can be realised with small computational effort and therefore, can be managed with use of hardware-based controllers. Non-linear constitutive relation （water flow vs. pressure head） has been assumed.

Analysis of the Effect of Quality Control Circle on the Central Sterile Supply Department

Objective:To analyze the effect of quality control circle on the central sterile supply department(CSSD).Methods:The control group and the observation group each consisted of 180 instruments received by the sterilization supply center from January to March 2023 and 11 CSSD staff.The control group underwent routine management while quality control circle was implemented in the observation group.The quality of work,disinfection and sterilization qualification rates,disinfection and sterilization of various instruments,cleaning indicators,and management satisfaction of both groups were compared.Results:The observation group scored higher in terms of work quality,the qualification rate of disinfection and sterilization in each link,the disinfection and sterilization of instruments,and cleaning indicators compared to the control group.Besides,the management satisfaction of the observation group was higher than that of the control group(P<0.05).Conclusion:A quality control circle ensures the quality of work,improves the cleaning,disinfection,and sterilization of instruments of the CSSD,and improves the management satisfaction of the CSSD staff.

Site Selection of Waste Slag Yard and Design of Protective Measures in Water Supply Project of Drawing from the Songhua River in Central Cities of Jilin

Water supply project of drawing from the Songhua River in central cities of Jilin is taken as research object.On the basis of analyzing project characteristics and natural conditions of the project area,site selection of waste slag yard of water diversion project and design of water and soil conservation measures are discussed.Rationality of site selection of waste slag yard and pertinence of prevention and control measures of water and soil loss in waste slag yard are analyzed,and comprehensive utilization of waste slag in large-scale production and construction projects is explored.

Predictive Zone Control of Pressure Management for Water Supply Network Systems

In this paper we address the problem of pressure management in water supply system （WSS） network. The model-based predictive control （MPC） strategies have some important features to deal with WSS. By hydraulic analysis of WSS, the predictive model is derived from the dynamic model and static model of WSS. Through WSS, the consumers＇ demands are required to be met at all times according to some operational constraints that must be satisfied. The constraints of flow through actuators, the water level of reservoirs and the consumer areas＇ pressure demand are determined by a specific system. In this work, we develop a constrained MPC controller that considers the zone control of the pressure outputs and incorporates steady state economic targets in the control cost function. The designed management strategies are applied to a case study and simulation results, covering different aspects, are provided. The output nodal pressure can be controlled in the desired zone by optimal scheduling the actuators of the WSS. If the variation range of reservoir＇s water level is broader, the rate of flow through the actuators is gentle, and vice versa.

基于主动水蓄冷的冷水机组节能优化策略研究

针对目前空调行业中应用蓄冷技术进行经济性优化过程中能耗普遍增加的问题,提出一种以保持冷水机组高能效运行为核心的节能优化运行策略,该策略通过小型蓄冷罐储存和释放冷量,主动调控冷水主机的负荷率,保持冷水主机长时间处于高效运行状态以实现节能。以一座医院的中央空调系统的运行数据为数据来源,建立空调系统物理模型进行模拟,得到冷水主机在不同环境条件下的性能曲线,用于准确描述每时刻冷水主机的高效运行状态。在最大冷负荷为9979 kW的供冷季典型日,相比于无主动水蓄冷的常规冷水机组运行策略,可节省日用电量2777 kW·h,占当日中央空调系统用电量的6.0%,并在整个供冷季节省中央空调系统用电量2.35%,节省冷水主机用电量4.45%。

基于水资源供需关系的江河源头优先保护区划分方法研究——以广东省漠阳江流域为例

江河源头保护对区域水安全具有重要意义,如何提取江河源头的关键信息并构建评估体系,是水生态环境分区管控体系研究的重点与难点之一。深入剖析水循环、生态系统服务理论中江河源头与人类活动的供需关系,将生态系统服务评估方法整合应用到水生态环境分区管控中,提出基于水资源供需关系的江河源头优先保护区划分方法,并以漠阳江流域为案例开展研究,评估识别其江河源头优先保护区。结果表明:1)基于生态系统服务供需与流转格局、水资源供给服务功能量核算、重要性指数计算及分级等研究方法,采用ArcGIS软件空间叠加运算功能,按行政村(社区)统计水资源自盈余量(SWS)、水资源供给服务路径长(TL)指标,通过SWS、TL可以精准刻画流域内的水资源供需及流转格局,基于SWS、TL加权计算的江河源头保护重要性指数可以有效表征流域内各地区差异。2)对漠阳江流域评估分析,按重要性指数将流域分为极重要区、较重要区、一般重要区、生态发展区、城市开发区5级,面积占比分别为17.8%、36.9%、36.6%、7.2%、1.5%。极重要区主要包括漠阳江从源头至大河水库段集水区、天露山西部降雨高值区等区域,较重要区包括极重要区外围连片山区、潭水河上游连片山区,一般重要区大部分是平原地带的农业区,生态发展区包括上游、中游大型城镇以及下游阳江市主城区周边大型城镇,城市开发区为下游阳江市主城区。划分的5级分区在水资源供给、开发利用等方面的统计指标均呈较好的梯度分布,构建了全流域的上游水资源供给与下游水资源利用的水生态环境分区管控格局。3)建议将漠阳江流域连片极重要区划为江河源头优先保护区,加强水源涵养林建设,并重点保护百涌自然保护区等生物多样性关键区,加大重点保护植物、特有植物、重点保护动物及其栖息地的保护修复力度。

智能变压供水系统在某园区淡旺季中的应用

针对某旅游园区供水系统在淡旺季和人流量变化中的需求差异,提出了一种基于物联网和自适应控制的智能供水系统设计方案。原系统仅根据预测供水需量及系统压力,在每日不同时段进行变频设置控制,不能根据实际需求量实现动态调节。为了实现供水模式根据实际用水流量的智能控制,系统通过无线传感器网络和云平台实时监控供水压力和流量,并结合历史数据进行优化配置。经测试,该方案能有效稳定供水压力和流量,显著提升供水系统的灵活性和节能效果。总结了系统设计、施工、调试及运行效能分析的经验,以为类似工程提供一定参考。

城市给排水系统防漏与堵漏技术研究及实践

广州市作为中国南方的重要城市,其给排水系统的运行状况直接关系到城市的正常运转和居民的生活质量。本文以广州市为例,深入分析了其给排水系统面临的渗漏与堵塞问题,通过具体的数据和案例分析,探讨了问题的成因、影响及解决方案。通过引入智能监测系统、应用新型环保材料、加强施工质量控制和运维管理等多方面措施,提出了提升广州市给排水系统运行效率和安全性的综合策略。

Online differential pressure reset method with adaptive adjustment algorithm for variable chilled water flow control in central air-conditioning systems

Central air-conditioning systems predominantly operate under partial load conditions.The optimization of a differential pressure setpoint in the chilled water system of a central air-conditioning system leads to a more energy-efficient operation.Determining the differential pressure adjustment value based on the terminal user's real-time demand is one of the critical issues to be addressed during the optimal control process.Furthermore,the online application of the differential pressure setpoint optimization method needs to be considered,along with the stability of the system.This paper proposes a variable differential pressure reset method with an adaptive adjustment algorithm based on the Mamdani fuzzy model.The proposed method was compared with differential pressure reset methods with reference to the chilled water differential temperature,outdoor temperature,and linear model based on the adjustment algorithm.The energy-saving potential,temperature control effect,and avoidance of the most unfavorable thermodynamic loop effects of the four methods were investigated experimentally.The results indicated that,while satisfying the terminal user's energy supply demand and ensuring the avoidance of the most unfavorable thermodynamic loop,the proposed adaptive adjustment algorithm also decreased the differential pressure setpoint value by 25.1%—59.1%and achieved energy savings of 10.6%-45.0%.By monitoring the valve position and supply air temperature of each terminal user,the proposed method exhibited suitable online adaptability and could be flexibly applied to buildings with random load changes.

控制性供水湖泊旱限水位确定方法——以洱海为例

旱限水位作为干旱预警以及工程抗预案的重要指标和依据,对科学指导湖泊开展抗旱调度具有重要的作用。本文针对控制性供水湖泊的特征,在充分考虑湖泊自身生态健康稳定的同时,结合湖泊兴利调节逆序递推计算,提出了一种控制性供水湖泊旱限水位计算方法,以洱海为例,验证了该方法的合理性。结果表明:通过设定旱限水位,在考虑湖泊最小生态需求的基础上,通过在干旱前期预留水量,可有效缓解干旱年份的湖泊周边地区的严重缺水情况;在设置旱限水位后,连旱最不利年份下洱海环湖供水缺水量减少1023万m^(3),引洱入宾农业灌溉用水减少1016万m^(3),环湖城市供水、引洱入宾灌溉严重缺水月数分别减少11、10个,低于最低生态水位月数减少15个。本研究为水旱灾害防御部门制定湖泊旱限水位、指导湖泊开展抗旱调度提供了一套通用算法,能够为干旱防御决策提供科学依据和技术支撑。

变化条件下长江口防洪御潮及供水保障研究进展与展望

近一个世纪以来,全球气候变暖导致海平面持续上升,增加了整个长江口的水深,抬高了潮汐和风暴潮的基础水位,使得河口咸潮入侵,洪水和风暴潮发生的频率和强度增加。同时,由于长江流域水土保持和水库群建设,进入河口的泥沙量锐减,加剧了河口咸潮上溯,对区域人群生产生活产生一定影响。从全球气候变暖背景下长江口海平面上升和演变规律、长江口人类活动与气候变化影响下的动力要素变化、河口咸潮入侵时空分布和水盐交换机制及供水安全风险、海平面上升对海堤防洪御潮能力的影响、长江口地区防洪御潮韧性等5个方面总结归纳了现有研究成果,提出未来研究的方向,以期对保障河口地区水资源安全利用和防洪御潮能力提升提供参考。

基于集控中心的沙溪流域梯级水电站水调自动化系统建设研究

闽江主流沙溪流域集控中心建成后,必须构建基于集控中心的流域水调自动化系统,以集合全流域水情信息,从而加快流域梯级水电站水库调度的决策与响应速度,提高沙溪流域水电集群的综合效益。基于集控中心的沙溪流域梯级电站水调自动化系统建设包括架构“集控中心”、水调自动化系统建设模式、业务节点互联、水情测报系统站点布设、通信组网设计、洪水预报对象规划等,该方案可对水调系统全要素和水调全过程进行数字化映射、智慧化模拟,实现与水电站、设备、气象的同步仿真运行、虚实交互、迭代优化,支撑精准化决策,助力流域梯级水电站绿色高质量发展。

基于可控破坏的供用水系统极限调控理论框架

特大干旱作为一种极端气候现象,会导致严重的水资源短缺、经济社会损失和生态环境破坏。为抗旱减灾,应该在供水侧尽可能挖潜增供,在用水侧尽可能压缩减用,即供用水系统的极限调控。为了供用水系统的可持续,特大干旱条件下供用水系统的调控,既要挑战极限又要确保破坏可控。本研究在“概念内涵—理论框架—调控策略”的总体思路下,引入耗散结构理论和熵理论,分析了特大干旱条件下供用水系统特点,探讨可控破坏的概念、内涵及判别方法,创建特大干旱条件下基于可控破坏的供用水系统极限调控的理论框架,提出特大干旱条件下供用水系统的极限调控策略,为特大干旱应对提供理论指导和方法支持。

量化积分绩效分配模式在消毒供应中心工勤人员中的应用研究

目的探讨量化积分在消毒供应中心工勤人员绩效分配中的应用效果,为消毒供应中心提供一种有效的绩效分配方法。方法采用前-后对照研究方法,选取2020年1月至12月本院消毒供应中心绩效分配模式为对照组,选取2021年1月至12月本院消毒供应中心绩效分配模式为试验组。对照组采用按工勤人员工龄绩效分配模式,试验组采用量化积分绩效分配模式,即从技术层级、工作质量、工作效率、工作量方面实施量化绩效分配模式。比较改进前后两组工勤人员工作效率、工作质量缺陷发生率(包装器械缺失、器械种类错误、包装标识错误、收送物品错误、信息系统操作错误)、临床科室满意度情况。结果实施量化积分绩效分配模式后,试验组工勤人员工作效率和临床科室满意度均高于对照组,工作缺陷发生率低于对照组,两组比较,差异具有统计学意义(均P<0.05)。结论量化积分绩效分配模式在消毒供应中心工勤人员中的应用,能够提高工勤人员的工作能动性,提高工作效率和工作质量。