Kui Chang

Water distribution network real-time simulation based on SCADA system using OPC communication

Hydraulic simulation models of water distribution networks (WDN) are routinely used for operational investigations and network design purposes. However, their full potential is often never realized because in the majority of cases, they have been calibrated with data collected manually from the field during a single historic time period and reflects the network operational conditions that were prevalent at that time. They were then applied as part of a reactive investigation. An urban water distribution network real time simulation system based on SCADA system using OPC (object linking and Embedding(OLE) for Process control) communication was built in this paper. In order to make real-time simulation of water distribution network, the real-time data was collected every 15 minutes, the real time data were received and sent into water distribution network simulation model by OPC communication of SCADA system. The real-time data included total head of reservoir, flow rate, pressure, pump operation information. The real-time simulation system can give timely warning of changes for normal network operation, providing capacity to minimize customer impact and comparing the simulation results with the real-time data collected. The real time simulation system of urban water distribution network solved the problem of data input and user interaction compare to traditional network model. It offers a way for the development of intelligent water network.

The water distribution network digital management platform in Harbin, China

Water distribution network rehabilitation project is based on the digital analysis platform. The platform is built on the basis of microscope model in water distribution network. The water distribution network can be simulated under all kinds of scenarios, and the state-of-art can be shown in many ways by the digital analysis platform. It is very useful for the switch between the new and the old water sources, and for optimal control of water network. The digital analysis system for water distribution network has been successfully applied in the switch of water sources in a metropolis in north-eastern China. In conclusion, the digital platform is a powerful tool to realize the digital water distribution network. And it also provides effective guarantee for scientific control, operation, management and improvement of water distribution network.

Subatmospheric pressure protection for large diameter long distance pipeline system: A case study

Typical surge analysis of long distance pipelines involve pump power failure and startup at lift stations discharging into force mains. Utilities have several options for protecting pipeline systems from the effects of transients and surges. But how to select an effective surge protection strategy to design the system to withstand the stresses of transients is still a great challenge, especially for a high-lift, multiple peaks long distance system. This paper describes unique considerations that should be addressed when performing hydraulic transient analysis and recommending surge protection for water supply systems. Hydropneumatic tanks, surge tanks, vacuum breaker valves, surge-anticipator valves (SAV), surge relief valve (SRV), or both of them combined, and air valves will be discussed. Recent project examples and the effect of these new devices on surge protection in China will be presented.

STUDY ON RESIDUAL CHLORINE CONTROL OF WATER DISTRIBUTION SYSTEMS WITH MULTIPLE WATER SOURCES

A best chlorine injection schedule for each source and booster station in a distribution system is studied and a multiple object optimal operation model of water distribution system(WDS) considering residual chlorine is also presented. The optimal scheduling of water distribution system is composed of two parts, the hydraulic and the water quality optimal control, and water quality optimal control is based on the hydraulic optimal control. As an important component of water quality optimal control, the residual chlorine control is selected as one of the objective functions of the optimal scheduling of water distribution system. A new multiple objects optimal operation model of WDSs is developed. The objective functions include minimum of residual chlorine and minimum costs of WDSs operation. The decision variables include the demand, pressure and residual chlorine at each water source, nodal demand, nodal pressure, and nodal residual chlorine. The hydraulic and the water quality model are solved by EPANET. The multiple objects optimal operation model of WDS is solved by the non-dominated sorting genetic algorithm (NSGA-II). Adaptive penalty functions are also applied in the process of model solved As a case study, the multiple objectives optimal operation model is applied in a large scale WDS. The WDS ’s total demand is about 1,320,000 m 3 /d, and is composed of 9 water plants, 32 water sources, and 468 wells. The result shows that the optimization of chlorine of each water source makes the distribution of nodal chlorine more reasonable and the concentration of nodal residual chlorine was reduced.

Research on Water Quality Comprehensive Evaluation Index for Water Supply Network Using SOM

A water quality comprehensive evaluation was taken for the water in water supply network. It was on the basis of water supply network microcosmic model. The water quality indicators, by which the state of water quality was expressed, were chosen as the input vector for the comprehensive evaluation model. The self-organizing feature map and k-means arithmetic were taken in the model. As a result, a comprehensive water quality evaluation method was proposed for the defects of single indicator grade evaluation. And the objective water quality evaluation model of water supply water network was taken. Compared with the single-evaluation indicators, SOM can take into account the single water quality monitoring data and the overall data, and reflect the water quality distributing in the water supply network objectively.

Virtual reality simulation system for water supply and distribution network

One of the challenges of Virtual Reality (VR) technology is implementing its effective integration with application models to provide feasible information in real time. This paper will investigate VR simulation systems in Water Distribution Networks (WDN). A framework of a VR simulation system for WDN was proposed and a prototype was developed to provide an intuitive user interface offering real-time simulation and interaction through multi-sensory channels. This enables data processing, visualisation, scene roaming, hydraulic and water quality calculation and network analysis. The hydraulic and water quality models are combined into the VR simulation system; dynamic hydraulic and water quality information is expressed visually and managed interactively in the three dimensional virtual environment. The proposed VR simulation framework and developed system were evaluated in a case study which demonstrated its effectiveness as a tool to enhance understanding and operational efficiency in the WDN.

WATER DISTRIBUTION NETWORK RESIDUAL CHLORINE MODELING BASED ON THE SYNERGY OF CHLORINE AND CHLORINE DIOXIDE

The kinetics and mechanisms of chlorine dioxide and chlorine in water distribution network is described, and a multi-species network water quality model is built in this paper. Experiment was composed of two parts, static test and dynamic test. The cast iron pipe, steel pipe, and PVC pipe were selected to carry out static experiments. In order to study the kinetic and mechanism of the combination disinfection of chlorine dioxide and chlorine, the reaction was under the condition of different chlorine dioxide and chlorine dosing ratio and different chlorination method. Dynamic experiments carried out in the cast iron pipe in different chlorine dioxide and chlorine dosing ratio and different flow conditions to study the kinetic and mechanism of the combination disinfection of chlorine dioxide and chlorine .A multi-species network water quality model using EPANET-MSX toolkit is built based on kinetic and mechanism of the combination disinfection of chlorine dioxide and chlorine. The concentration of residual chlorine (Cl2), chlorine dioxide (ClO2), chlorite in the bulk water and biofilm was taken as the main parameters. And the model was calibrated by the experiment data. The water quality model application in a large water distribution network, of which the total demand is 800,000 m 3 /d in China. The results show that the combination of chlorine dioxide and chlorine disinfection can reduce the chlorine and chlorine dioxide disinfection by-product and residual chlorine concentration distribution was more reasonable.

RESEARCH ON LEAKAGE CONTROL OF WATER DISTRIBUTION NETWORK BASED ON PRESSURE-DRIVEN DEMAND MODEL

In order to achieve the control of network leakage, and establish leakage control model, Embedding pressure-driven node flow hydraulic model into leakage control model was developed leakage control model based on pressure-driven node flow was formulated. Taking the total loss as the objective function, the optimal valve setting was solved by genetic algorithm. Reducing leakage can be achieved by reconfiguring valve operation to the biggest extent under the precondition of normal water supply.

Research on water quality comprehensive evaluation of water supply network using SOM

water quality comprehensive evaluation of water supply network was present in this paper. It is on the basis of microcosmic model in water supply network. The water quality indicators, by which the states of water quality are expressed, are selected as the input vector for the comprehensive evaluation model. The Self-Organizing Feature Map (SOM) and K-Means arithmetic are adopted in the model. Since there are some problems using single indicator grade evaluation method, thus a comprehensive water quality evaluation method is proposed in this paper. The objective water quality evaluation model of water supply network is developed. In comparison to the single-evaluation indicator, both the single water quality monitoring data and the overall data are all considered in the model using SOM, which reflect the water quality distribution in the water supply network objectively.

Establishment of the Scheduling Training System of Water Distribution Network Using Virtual Reality

A water distribution network model which was based on virtual reality was constructed and the state-of-art was simulated in a 3D scene. It works with a clear sense. The water network engineering database was built firstly in this paper to keep the precision of the 3D model. The water network model was constructed after the 3D models of the valves and pipes were made. The model was driven by the Vega and the simulation of the state-of-art was taken by the VC++MFC and EPANET software package. In conclusion, all kinds of data for water distribution network could be shown in the VR based simulation of the water distribution network directly. The topology linkage of the water network and the state-of-art analysis can be realized. The system overcomes the limitation of the traditional GIS system, and the simulation is exact and believable.