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This diploma thesis focuses on the optimization of water supply system in the town of Počátky. It describes the process of creating a mathematical model needed for the hydraulic analysis, which was used to assess the water supply system Počátky. This thesis task is to apprise reader, with a basic distribution in the drinking water supply, how to proceed in collecting data on hydraulic analysis requirements and using tools and means used in hydraulic analysis. Conclusions are processed variants for possible optimization of water supply system Počátky.

Mathematical analyses indicated that significant possibilities exist for load shifting projects on a Large Potable Water Utility (LPWU) in South Africa. A primary concern remained, i.e. whether the load variation would have an effect on the water quality. Extensive simulation and testing were initiated in order to prove that the load shift will not affect the water quality. In South Africa, the highest standard for drinking water is the Blue Drop award. The LPWU has received this award multiple times and strives to maintain it. An investigation was launched to determine if this load shifting project would have an effect on the quality standards to which the utility holds (SANS 241 (2011)). The LPWU has over 3000 km of pipelines to supply potable water to the industrial heartland of the country as well as millions of domestic users. The LPWU network is the longest pumping network in the world and is still expanding. The investigation included a simulation of a pumping simulation package to determine how the system would react to the changes. In this simulation, the load reduction in terms of Mega litre per day (Ml/day) was established. Results were compared to the normal operating parameters of the Water Treatment Works (WTW). The mathematical analysis in this investigation concluded that an evening peak load shift of 24.5 MW is achievable. This dissertation will emphasise the necessity of a detailed investigation. The investigations and simulation will determine that the volume of water is well within the operating parameters of the WTW. Studies were done on each area of the plant. In-depth conversations with WTW personnel revealed that the reduction of the volume of water in question will not have an effect on the water quality. Further, it was established that it would be possible to use the sumps of the water treatment works to achieve the desired load shift. By using the sumps of the WTW, a load shift can be done without stopping any process in the WTW with the exception of disinfection at the Booster Pump Stations (BPS), where the balancing reservoirs were used as buffer capacity. The investigation shifted to establish whether stagnant water and a change in dosage would have an effect on the water quality in regard to the reduction and recovery load. As expected, the water never became stagnant at any moment due to the fact that only a small portion of the load was reduced. The water quality and dosage report of the water utility was used and compared to normal operations. The planned load shift had no effect on any aspects of the water quality. The project is feasible and will reach the set targets without affecting the water quality. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

Mathematical analyses indicated that significant possibilities exist for load shifting projects on a Large Potable Water Utility (LPWU) in South Africa. A primary concern remained, i.e. whether the load variation would have an effect on the water quality. Extensive simulation and testing were initiated in order to prove that the load shift will not affect the water quality. In South Africa, the highest standard for drinking water is the Blue Drop award. The LPWU has received this award multiple times and strives to maintain it. An investigation was launched to determine if this load shifting project would have an effect on the quality standards to which the utility holds (SANS 241 (2011)). The LPWU has over 3000 km of pipelines to supply potable water to the industrial heartland of the country as well as millions of domestic users. The LPWU network is the longest pumping network in the world and is still expanding. The investigation included a simulation of a pumping simulation package to determine how the system would react to the changes. In this simulation, the load reduction in terms of Mega litre per day (Ml/day) was established. Results were compared to the normal operating parameters of the Water Treatment Works (WTW). The mathematical analysis in this investigation concluded that an evening peak load shift of 24.5 MW is achievable. This dissertation will emphasise the necessity of a detailed investigation. The investigations and simulation will determine that the volume of water is well within the operating parameters of the WTW. Studies were done on each area of the plant. In-depth conversations with WTW personnel revealed that the reduction of the volume of water in question will not have an effect on the water quality. Further, it was established that it would be possible to use the sumps of the water treatment works to achieve the desired load shift. By using the sumps of the WTW, a load shift can be done without stopping any process in the WTW with the exception of disinfection at the Booster Pump Stations (BPS), where the balancing reservoirs were used as buffer capacity. The investigation shifted to establish whether stagnant water and a change in dosage would have an effect on the water quality in regard to the reduction and recovery load. As expected, the water never became stagnant at any moment due to the fact that only a small portion of the load was reduced. The water quality and dosage report of the water utility was used and compared to normal operations. The planned load shift had no effect on any aspects of the water quality. The project is feasible and will reach the set targets without affecting the water quality. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

Large scale nonlinear programming (NLP) has proven to be an effective framework for obtaining profit gains through optimal process design and operations in chemical engineering. While the classical SQP and Interior Point methods have been successfully applied to solve many optimization problems, the focus of both academia and industry on larger and more complicated problems requires further development of numerical algorithms which can provide improved computational efficiency. The primary purpose of this dissertation is to develop effective problem formulations and an advanced numerical algorithms for efficient solution of these challenging problems. As problem sizes increase, there is a need for tailored algorithms that can exploit problem specific structure. Furthermore, computer chip manufacturers are no longer focusing on increased clock-speeds, but rather on hyperthreading and multi-core architectures. Therefore, to see continued performance improvement, we must focus on algorithms that can exploit emerging parallel computing architectures. In this dissertation, we develop an advanced parallel solution strategy for nonlinear programming problems with block-angular structure. The effectiveness of this and modern off-the-shelf tools are demonstrated on a wide range of problem classes. Here, we treat optimal design, optimal operation, dynamic optimization, and parameter estimation. Two case studies (air separation units and heat-integrated columns) are investigated to deal with design under uncertainty with rigorous models. For optimal operation, this dissertation takes cryogenic air separation units as a primary case study and focuses on formulations for handling uncertain product demands, contractual constraints on customer satisfaction levels, and variable power pricing. Multiperiod formulations provide operating plans that consider inventory to meet customer demands and improve profits. In the area of dynamic optimization, optimal reference trajectories are determined for load changes in an air separation process. A multiscenario programming formulation is again used, this time with large-scale discretized dynamic models. Finally, to emphasize a different decomposition approach, we address a problem with significant spatial complexity. Unknown water demands within a large scale city-wide distribution network are estimated. This problem provides a different decomposition mechanism than the multiscenario or multiperiod problems; nevertheless, our parallel approach provides effective speedup.

In recent years, the increasing awareness of scarcity of water resources, indications of likely climate variability, and the increasing pressure to use available fresh water resources more efficiently have together reinforced the need to look at infrastructure solutions with due regard to environmental considerations and social impacts, present and future. There is a vital need to apply an integrated approach to catchment management to implement sustainable solutions to resolve issues such as water supply and sewerage, drainage and river flooding. Many potentials solutions are available to control water demand and manage flood problems. Greywater recycling and rainwater harvesting are novel technologies. However, their catchment scale impacts on hydraulic and hydrological flows are poorly understood. The research aim is to identify the hydrologic and hydraulic impacts of scaling up such technologies at catchment scale. For this particular study, a computer simulation model will be used to evaluate how increasing urbanisation, climate change and the implementation of greywater recycling and rainwater harvesting may alter the water balance within a representative catchment. To achieve these aims data from the Carrickmines catchment in Ireland have been collected; a simulation model has been adapted to carry out the study, the model has been calibrated and validated, results have been analysed, and finally, a sensitivity analysis has been carried out. The results show that rainwater harvesting systems are comparatively more effective than greywater recycling techniques in reducing flood frequency and intensity. Under five year return period rainfall events, the implementation of rainwater harvesting at any scale and number of units is a useful technique to control river flow and floods. However, the study also shows that under extreme conditions the efficiency of rainwater harvesting systems decreases. The study concludes that implementing the two technologies within a single catchment is not a solution to several forms of hydrological problem. The study shows that implementing rainwater harvesting or re-use technologies are a very useful way to protect local freshwater reserves and therefore conserve our environment.

Submitted by Caroline Falcao (caroline.rfalcao@ufpe.br) on 2017-06-01T16:58:59Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Flavio Trojan TESE.pdf: 2776137 bytes, checksum: 55e95b9ae53f2fce24e0caa97923ffeb (MD5) / Made available in DSpace on 2017-06-01T16:58:59Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Flavio Trojan TESE.pdf: 2776137 bytes, checksum: 55e95b9ae53f2fce24e0caa97923ffeb (MD5) Previous issue date: 2012-04-25 / Por conta das dificuldades implícitas ao processo decisório em grupo e dos problemas correlatos no setor de abastecimento de água, tais como: perdas físicas e econômicas, uso incorreto da água e custos com manutenção, fica evidente a necessidade de elaboração de pesquisas e estudos, envolvendo métodos para apoiar decisões, a fim de diminuir desperdícios de água e sua exploração desnecessária. Este trabalho tem como objetivo auxiliar nas tomadas de decisões de problemas emergentes no setor de manutenção de redes de distribuição de água. Dois dos principais problemas do setor são abordados. O primeiro deles explora a classificação de áreas de medição de vazão, conforme sua criticidade, para auxiliar no controle de perdas de água. Para este problema é proposto um modelo multicritério para classificação de áreas críticas de medição de vazão, baseado no método ELECTRE TRI, sendo sua estrutura quantitativa com o levantamento dos dados feito por meio de um sistema automatizado. O segundo problema abordado baseia-se na classificação realizada no modelo anterior e explora quais alternativas de manutenção são potencialmente eficazes para serem implementadas nas classes, de acordo com a visão de um grupo de decisores, para reduzir perdas de água e custos de manutenção. Assim, este segundo modelo trata da problemática de ordenação de alternativas de manutenção por meio de uma tomada de decisão em grupo, sendo baseado no método ELECTRE II, a fim de apoiar as ordenações individuais numa primeira fase, e posteriormente, no método COPELAND, para agregação das preferências do grupo. Estes modelos consideram aspectos subjetivos e objetivos ao mesmo tempo, a fim de fornecer como resultado aos decisores uma visão mais clara e global sobre quais alternativas poderão atender os múltiplos objetivos estabelecidos pela organização, decorrentes das preferências de um grupo de decisores de diferentes áreas. Com os modelos desenvolvidos é possível conhecer as áreas críticas de uma rede de distribuição de água para apoiar a gestão da manutenção e priorizar as alternativas potenciais para redução das perdas de água. / Because of the difficulties implied in the group decision making process and related problems in the sector of water supply, such as: physical and economic losses, incorrect use of water and maintenance costs, the need for research and studies developing methods to support the decisions, reducing unnecessary exploitation and waste becomes evident. This work aims to assist decision-making for arising problems in the maintenance area of the water networks. Two major problems in the sector are addressed. The first explores the correct classification of critical areas of flow measurement, classifying them according to their priorities to help control water loss. For this problem, a multicriteria model that deals with the classification of critical flow measurement is proposed, it is based on the ELECTRE TRI method, presenting an overview of its structure with quantitative data collection through an automated system. The second problem addressed is based on the classification carried out in the previous model and explores which maintenance alternatives are potentially effective to be implemented in priority classes according to the group of decision makers point of view to reduce water losses. The following multicriteria model proposes that a group of decision makers sort out maintenance and investment alternatives for areas previously classified according to their criticality. Thus, this second model deals with the problem of sorting out maintenance alternatives through group decision making, initially based on ELECTRE II, to support individual ordinations, and subsequently, on the Copeland method, for group preference aggregation. These models consider subjective and objective aspects simultaneously, in order to provide the decision makers with a clearer and comprehensive view in which the alternatives can attend the multiple objectives set by companies, arising from the preferences of a group of decision makers from different areas. With the models developed, it is possible to recognize priority classes to support the maintenance management, where the critical points are, and the major potential alternatives to solve maintenance problems and water loss in these classes through aggregation of preferences and global ordering.

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This thesis is focused on the optimization of pressure conditions in the water supply network. There is a deep theoretical and critical search of the state of the art and there are fields where there is an insufficient field of knowledge, the so-called "knowledge gap". Experiments are proposed here to determine the dependence of water consumption on pressure conditions. There is a description of experiments and way how it was carried out, which were carried out on the water connection, in the pressure zone and in the laboratory on the hydraulic loop. There is proposed a methodology of experimental determination of the mathematical dependence of water consumption on pressure so that it can be used for optimization problems, where consumption is considered as an optimization criterion. The results of individual experiments are evaluated and a critical discussion of the achieved results is carried out. Finally, the achieved results are compared with the values found in a deep literature search.

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