Automated mobile water leakage assessment system

Erwee, Jurie Johannes (2016-12)

Thesis (MEng)--Stellenbosch University, 2016.

Thesis

ENGLISH ABSTRACT: Despite humanity’s absolute reliance on the increasingly scarce resource of potable water, 25.4% of South Africa’s water is lost due to leaks in the distribution network before it reaches the consumer. This figure is even worse in many developing countries. Because developing countries generally have a lack of technical skills, active leakage management techniques are not implemented, resulting in a large number of leaks being undetected. Current leak detection and assessment solutions are not well suited to the conditions of developing countries, due to the substantial cost thereof and the lacking practitioner skills. The work presented in this thesis describes the development of a mobile platform that automatically assesses a section of the Water Distribution System (WDS) to identify and characterise leaks, and transmits the data to an online platform for storage and further analysis. The approach taken is to measure the resulting flow rates at discrete pressure levels that the proposed system applies to the assessed section of the WDS. According to the Fixed And Variable Area Discharge (FAVAD) equation, this relationship can be used to give an indication of the size and type of apparent leaks, since round holes, longitudinal cracks, and circumferential cracks behave differently. The proposed mobile platform connects via a fire hydrant to a section of the WDS, which is isolated by shutting its mains and service valves, and executes the test at a push of a button, making it suitable for low-skilled operators. Once the test is completed, the results are transmitted to an online platform, where it can be analysed further and viewed by a water distributor or expert. The thesis presents the design and test procedures of control circuitry and software that are developed specifically with mobility and automation in mind. The consistency and accuracy of the system’s results are experimentally tested on three different leak types and three different pipe materials, namely polyvinyl chloride, high density polyethylene, and polypropylene, since these pipes are commonly used on municipal WDSs. The flow rate for the round holes were found to be more consistent than the flow rate of the longitudinal cracks. The results also showed that leakages are easily effected by small imperfections caused by leak manufacturing. The tests verified the system’s ability to detect and characterise the leaks in terms of the FAVAD equation with detected results corresponding to theoretically predicted values. The research objective of developing an automated mobile platform that assess leaks and transmit the results to an online analysis platform, was achieved. If the solution is deployed, it will enable water distributors to implement active leakage control and prioritise refurbishment projects.

AFRIKAANSE OPSOMMING: Tenspyte van die mensdom se totale afhanklikheid van al skaarser drinkbarewaterbronne, word 25.4% van Suid-Afrika se water weens lekkasies in die verspreidingsnetwerk verlore, voordat dit die verbruiker bereik. In meeste ontwikkelende lande is hierdie persentasie selfs erger. Weens ontwikkelende lande se tekort aan tegniesevaardighede word aktiewe lekkasiebestuur nie toegepas nie. Gevolglik is daar ’n groot aantal onopegespoorde lekkasies. Huidige waterlekkasiebespeur- en -assesseringsoplossings is nie gepas vir die toestand van ontwikkelende lande nie, weens die koste verbonde en die tekort aan praktisynvaardighede. Die werk wat in hierdie tesis voorgehou word beskryf die ontwikkeling van ’n mobiele platform wat outomaties ’n gedeelte van die waterverspreidingsnetwerk assesseer om lekkasies te identifiseer en te karakteriseer, waarna die resultate na ’n aanlynplatform versend word vir verdere analiese en berging. ’n Benadering is geneem waar die gevolglike vloei gemeet word by diskrete drukvlakke wat die voorgestelde stelsel op die geassesseerde deel van die waterverspreidingsnetwerk uitoefen. Volgens die vaste-en-veranderlike-area-deurstroming-vergelyking (VEVAD) kan hierdie verhouding die oënskynlike lek se grootte en tiepe aandui, aangesien ronde gate, longitudinale krake, en omtrekkrake verskillend optree. Die voorgestelde mobiele platform konnekteer deur ’n brandkraan aan ’n gedeelte van die waterverspreidingsnetwerk, wat geïsoleer is deur die toemaak van die hoofleiding- en dienskrane, en met die druk van ’n knoppie word die toets uitgevoer, wat dit gepas maak vir ’n ongeskoolde operateur. Sodra die toets voltooi is word die resultate na ’n aanlynplatform versend waar dit verder geanaliseer word en vertoon word vir waterverspreiders of kenners. Hierdie tesis bied die ontwerp en toetsprosedures van die beheerelektronika en sagteware, wat spesifiek met mobiliteit en outomatisering in gedagte ontwikkel is. Die konsekwentheid en akkuraatheid van die stelsel se resultate is eksperimenteel getoets op drie verskillende lektiepes en drie verskillende pypmateriale, naamlik polivinielchloried, hoëdigtheidpoliëtileen, en polipropileen aangesien dit algemeen deur munisipalewaterverspreiders gebruik word. Daar was gevind dat die vloeitempo van die ronde gate meer konsekwent is as die vloeitempo van die longitudinale krake. Die resultate toon ook dat lekkasies maklik deur klein onvolmaakthede, wat veroorsaak is deur lekvervaardiging, affekteer word. Die toetse verifieer die stelsel se vermoë om lekkasies te bespeur en te karakteriseer in terme van die VAVAD vergelyking, aangesien die toetsresultate in lyn is met die teoreties bepaalde waardes. Die navorsingdoelstelling om ’n ge-outomatiseerde mobiele platform te ontwikkel wat lekkasies assesseer en die resultate na ’n aanlynplatform versend, was bereik. Indien die oplossing ontplooi word, sal dit waterverspreiders in staat stel om aktiewe lekkasiebestuur te implementeer en opknappingprojekte te prioritiseer.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/100335
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