Water Supply Pipe Network Research Articles

Defects Diagnosis Technology of Water Supply Pipe's Network Using Pipe Endoscope Camera of High Resolution/High Pressure Resistance Performance

The size of pipe network accident caused by aging of water distribution system, rapid urbanization, abnormal climate or a disaster such as an earthquake is gradually becoming larger. Accordingly, it is required to improve the technology to maintain the water distribution system so that the related technologies can be scientifically and systematically applied. The paradigm of Korean water supply service is changing from supply era to maintenance era, and it is required to apply equipment and method to effectively check, diagnose and test the internal condition of the pipe without stopping water supply. If photographing and diagnosis of the burial environment around the water service pipeline and inside the pipe can be carried out without stopping water supply effectively utilizing the surrounding facilities such as straight piping and air valve to the maximum, decrepit pipe (defective pipe) improvement projects can be effectively carried out by making adequate decisions. Also, a systematic and more efficient water supply service maintenance system can be established by building a database of surrounding pipeline directly investigated and selecting priority of direct/indirect evaluation. This study has raised accuracy of a diagnosis by applying a camera capable of securing high resolution without generation of distortion in case of photographing the inside of a pipe, and suggested an application method of the pipe endoscope camera using an inspection hole inside a pipe.

Data Acquisition and Monitoring System for Water Supply Pipe Network Based on GPRS

It is the necessity of the modern city development to implement the informatization management of water supply pipe network. The paper introduces the design of a data acquisition and monitoring system for water supply pipe network based on GPRS. It presents the implement of the hardware and software design of the data acquisition and monitoring terminal which is based on the embedded technology and uC/OS-II operating system, as well as the software design of the monitor center. The communication protocol based on GPRS and Winsock network programming technology is provided. The various field data collected by the terminal are encapsulated and sent to the GPRS module by microprocessor serial port. Then, the GPRS module sends the data to the remote monitor center which realizes the functions such as data process, data storage and statistical analysis. The system works well in the laboratory environment.

Wireless Monitoring and Scheduling System of Urban Water Supply Network

Currently, data communications used in the monitoring and scheduling system of urban water supply network can be simply divided into wireless and wired. While the wireless data communications with network flexibility, less investment, easy maintenance, cost-effective advantages. Therefore, the wireless data communications has become a major data transmission in urban water supply scheduling. The wireless transmission of state parameters in urban water supply pipe network was studied in this paper. This paper presents a wireless monitoring and scheduling scheme based on the short message transmission technology in urban water supply network. It introduced the hardware components of the system, and wireless data transmission software.

A Spatial probabilistic model of pipeline failures

A spatial probabilistic model is developed and applied to predict failure patterns over a water supply pipe network. The Zalaegerszeg waterworks is used to illustrate the methodology. The ageing of water supply pipes is a worldwide concern; therefore it is of high interest to identify the best interventions in time and space. Two-part models can be used; one is an economic by formulating time horizon total costs. The other part forecasts the break patterns in time and space. Spatial modeling is necessary since elements of the cost function depend on the location of failures. A network based model is developed for the internal part of the Zalaegerszeg waterworks since the system is homogeneous in a sense that the environmental and network features do not exhibit significant correlation with the occurrence of failures. Network based failure probabilities are described by a space-time Poisson process where non-homogeneous Poisson process (NHPP) refers to time and a stochastic point process refers to space. To es timate the intensity the whole area is covered by a grid system of 250 × 250 meters with an average pipe length of 703 meter in a cell. Both the number of and the distance between failures prove the applicability of the Poisson process. It is shown how a simulation procedure can be applied to generate possible pipe failure patterns which - by combining with the spatial cost functions - leads to estimate total costs per selected time periods.

Colebrook-White Formula for Pipe Flows

Flow-resistance laws—as used, for example, in water-supply pipe networks—are formulas relating the volume flow rate, q, along a pipe to the pressure-head difference, t, between its ends, such that q=ψ(t), in which ψ is monotonic. The simple Hazen-Williams power law is often used, but in appropriate circumstances the more complicated Colebrook-White law (CW) may better represent aspects of the experimental data. Result 1, the first and easiest-to-state result in the paper, is that ϕCW, the inverse of ψCW, can be expressed in terms of the Lambert W-function (Corless et al. 1993). Result 2 summarizes one use of this, and of related results, in convex optimization problems describing equilibrium flows in pipe networks.

Optimal Location of Control Valves in Pipe Networks by Genetic Algorithm

This paper addresses the problem of appropriate location of control valves in a water supply pipe network and their settings via genetic algorithm (GA) to obtain maximum leakage reduction for given nodal demands and reservoir levels. Embedded in this optimization is the problem of determination of optimal control-valve settings in terms of minimization of system leakage for a given location of valves. It is shown through an example water distribution network that the optimally located valves are much more effective at producing maximum leakage reduction in the network. On the basis of multiple simulations of demand patterns, it was found that the expected value of leakage in a network provided with optimally placed control valves is practically independent of total demand. A study of the effect of varying demands on the optimal location of valves indicated distinct combinations of valve-locations for the different spatial patterns of nodal demands and for different total demands.

Braess's paradox and power-law nonlinearities in networks

AbstractWe study flows in physical networks with a potential function defined over the nodes and a flow defined over the arcs. The networks have the further property that the flow on an arc a is a given increasing function of the difference in potential between its initial and terminal node. An example is the equilibrium flow in water-supply pipe networks where the potential is the head and the Hazen-Williams rule gives the flow as a numerical factor ka times the head difference to a power s > 0 (and s ≅ 0.54). In the pipe-network problem with Hazen-Williams nonlinearities, having the same s > 0 on each arc, given the consumptions and supplies, the power usage is a decreasing function of the conductivity factors ka. There is also a converse to this. Approximately stated, it is: if every relationship between flow and head difference is not a power law, with the same s on each arc, given at least 6 pipes, one can arrange (lengths of) them so that Braess's paradox occurs, i.e. one can increase the conductivity of an individual pipe yet require more power to maintain the same consumptions.