|
Project title and report nr
|
Description
|
|
Quantification the influence of air on the capacity of large diameter water pipelines and developing provisional guidelines for effective de-aeration
The results are discussed in the following reports:
Volume 1: WRC nr 1177/01/03
Volume 2: WRC nr 1177/02/03
|
The contents of Volume 1 comprises:
•Introduction
•Influence of air on pipelines
•Field investigations
•Experimental work
•Numerical modeling of air release from pipelines (CFD)
•Effective de-aeration of pipelines
•Further developments
Volume 2, includes the following sections:
•Introduction
•Intrusion of air into pipelines
•The consequences of air in pipelines
•Hydraulic transport of air
•Air valves
•Implementation of a new pipeline
•Sizing and positioning of air valves
•Typical installation details of air valves
•User comments
|
|
Review of factors that influence the energy loss in pipelines and the procedures to evaluate the hydraulic performance for different internal conditions
WRC nr 1269/01/06
|
The geographically mismatch of the water demand centres and the water resources necessitate the transport of water over long distances and high elevation differences. On average water is transported about
350 km in South Africa (Basson, Van Niekerk & Van Rooyen, 1997). High energy costs and the increasing demand require that the water transfer infrastructure should function optimally. Since the
1930’s various researchers contributed to the identification and development of factors and relationships to quantify the energy loss in pipelines, which led by 1958 to the development of pressures, head
losses and discharge relationships (Chadwick and Morfett, 1999) for the design and evaluation of pipes and pipe systems.
There are various factors that influence the hydraulic capacity and
pipeline designers need to take all of these into consideration during the design. For instance the estimation of roughness parameter for a pipeline has a significant effect on the hydraulic
capacity and operational costs. An underestimation of this parameter can be catastrophic when the required demand cannot be met. The better quantification and identification of these factors
required investigation, reviewing the available literature, conducting experimental investigations, perform field investigations and develop software that will assist designers in evaluating a pipeline
system over its full life cycle.
The aims of the study were:
•The quantification of the factors influencing the friction loss in pipelines.
•Establish the relationship between water quality,
operating conditions and the hydraulic performance of different liner systems and pipe materials.
•Development of selection criteria for liner systems and pipe material.
•Quantify the economic influence of increasing friction losses in a pipe system.
•Development of a computer model to evaluate whether to replace, refurbish or extend existing infrastructure components.
•Establish the effectiveness of different pipe rehabilitation options on the friction loss characteristics and liner integrity.
|
|
The potential application of Genetic Algorithms in the water industry
WRC nr 1144/01/01
|
The past decade marks the development of computational capacity that far exceeds the capacity of the “instructor” to define options to be evaluated when optimisation has to be achieved.
The
Government’s objective to provide “water for all” made it essential that the limited capital has to be employed to provide the maximum benefit. The optimal decision in terms of expansion, addition or
rehabilitation of water supply systems has to review the conflicting demands and select a cost effective and efficient solution.
Within the context of water supply, there are numerous variables
that can influence the selection and hence the final cost of system improvements.
These variables include:
•The high variance in rainfall and runoff,
•the availability of alternative water supply,
•the demand pattern variability,
•the operational ability of the system,
•the maintenance requirements,
•the running cost-especially power cost and
•the affordability and willingness to pay for services.
The determination of the optimal selection of system components requires techniques that can
be employed to assist the decision-maker in finding the appropriate solution within the environment of all the possible solutions (Solution space).
The aim of this study was to evaluate the application of genetic algorithms in the optimisation of different components of water supply projects, viz:
•pump selection and scheduling
•optimal pipeline diameter selection
•valves and surge alleviating devices selection
•management of water supply projects
•alterations and extensions required in the upgrading of the capacity of
water supply infrastructure.
|
|
Application and conceptual development of genetic algorithms for optimization in the water industry
WRC nr 1388/01/05
|
This study evaluated the application of genetic algorithms in the optimisation of different components of water supply projects and conceptually developed the procedures for the implementation thereof.
Based on the available literature study, as well as the feedback from water supply authorities, the need for the application of GAs as an optimisation technique in the water industry was
defined. The potential applications of GAs in the water industry in South Africa are:
- Hydrology and water resources assessment,
- Network optimisation,
- Optimisation of rehabilitation,
extension and upgrading of distribution networks during the planning and design phase,
- Operation and maintenance scheduling
This study objective was to provide the conceptual development of
procedures to implement GAs as an optimisation technique for water resources assessment and network optimisation.
|
|
Grouted linings for renovating steel pipelines
|
Research currently in progress
|
