京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19288号 / 工博第4085号 / 新制||工||1630(附属図書館) / 32290 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 細田 尚, 教授 戸田 圭一, 教授 後藤 仁志 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

This study focused on three potential problems with the operation of aerobic package treatment systems: hydraulic retention time, laundry detergents, and hydraulic surges. To determine the effect of hydraulic retention time on system performance, six bench scale activated sludge systems were constructed. Wastewater from an actual residence was collected twice per week and fed to the small activated sludge systems. Two of the systems had a hydraulic retention time of 2 days, two had a hydraulic retention time of 1 day and two had a hydraulic retention time of 0.5 days. Effluent quality was stable and good with regard to chemical oxygen demand (COD) and ammonia (NH)-N) and seemed to be independent of hydraulic retention time. All of the systems performed well, despite considerable variability in influent strength. To study the effect of high concentrations of laundry detergents on the operation of package treatment systems, three of the six laboratory systems were fed high concentrations of detergent. Other than some residual COD from the detergent, no effect on system performance was observed. The final component of the study was the modification of an existing package treatment system to equalize flows from an automatic washing machine. After a month of operation the modified system produced a more constant effluent quality, than did the unmodified system. The field system, with and without modification, had a low mixed liquor suspended solids (MLSS) concentration (35 mg/L). This was probably the result of the long hydraulic retention time. As a result of the low MLSS the system, with and without modification, did not meet Virginia effluent requirements for BODs, TSS or D.O. or generally accepted levels of NH₃-N. / Master of Science

Waterhammer is an undesirable event, caused by sudden flow changes in a confined pipe system. When it occurs, its consequences can be very costly and even sometimes deadly. In general, it may be encountered in the penstocks of hydropower plants, water transmission lines, water networks, etc. Therefore, the operation guidelines of the hydropower plants should be defined correctly. In this thesis, waterhammer problems in pumped storage hydropower plants are investigated. Time dependent flow conditions in the penstocks are studied by the help of computer software, HAMMER. The software solves nonlinear differential equations by using method of characteristics. Firstly, hydraulic transients for various operational cases are investigated using some scenarios. Then a surge tank, protective device for waterhammer, is added to the system and for the same operational cases, hydraulic transients are studied again. Finally, the results obtained from the operation of the system with and without surge tank are compared. Wind-hydro hybrid systems are also included in the study.

Orientador: Paulo Vatavuk / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-11T08:47:49Z (GMT). No. of bitstreams: 1 Souza_EdsonVictorde_M.pdf: 1243495 bytes, checksum: 65a1b651d2f304cfca69e91ab51e9514 (MD5) Previous issue date: 2008 / Resumo: O estudo do transitório hidráulico em condutos forçados tem grande relevância em projetos de sistemas de tubulações. A quantificação das pressões máximas e mínimas é de fundamental interesse para o projetista, a fim de que este possa dimensionar a tubulação e/ou prever dispositivos de proteção, cuja finalidade é amortecer as variações de carga, prejudiciais à vida útil da instalação. Neste trabalho optou-se pelo estudo de um destes dispositivos, o reservatório hidropneumático, que protege as instalações contra sobrepressões e subpressões, impedindo assim a descontinuidade do escoamento quando o sistema de bombeamento é desligado ou quando ocorre um fechamento rápido de válvula de bloqueio. O objetivo principal da presente pesquisa é o de formular tabelas e gráficos de aplicação para o pré-dimensionamento de reservatórios hidropneumáticos para a atenuação de transitórios hidráulicos em sistemas de condutos forçados, facilitando, desta maneira, o trabalho dos projetistas na escolha deste tipo de dispositivo de proteção de sistemas hidráulicos / Abstract: The evaluation of hydraulic transients is very important in the design of pipe networks. The determination of the maximum and minimum pressures is of great interest to the designer, so that he can size the pipes and/or design protection devices, with the objective of decrease head variations, that can decrease the instalation life. In this work, one of those devices was chosen for study, the air vessel, that protects the instalation against overpressures and underpressures, avoiding the interruption of the flow when the pumping system is turned off or when a valve closes too fast. The present work has the main objective of making charts and graphs of application for pre-sizing of air vessels to the mitigation of Waterhammer in pressure pipes by facilitating, in this way, the work of designers in choosing this type of protection of hydraulic systems / Mestrado / Recursos Hidricos / Mestre em Engenharia Civil

Orientadores: Sandra Lucia da Cruz, João A. F. R. Pereira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-07-31T22:23:21Z (GMT). No. of bitstreams: 1 Souza_ArlanLucasde_D.pdf: 3739716 bytes, checksum: 40314e4f8359d3c06b6df822abda9f09 (MD5) Previous issue date: 2002 / Resumo: Uma nova técnica de detecção de vazamentos em tubulação é apresenta­da. A técnica é baseada na análise espectral de sinais de pressão medidos em trechos da tubulação que favorecem a formação de ondas estacionárias. Sendo baseada no espectro do sinal, e não na sua representação temporal, a análise possibilita a identificação do vazamento mesmo quando este ocorre durante a realização de operações que naturalmente encobririam o transiente de pressão gerado pelo vazamento. Testes experimentais foram realizados numa tubulação de 1250 m de comprimento em várias condições de fluxo e configurações de vazamento durante a partida e a parada de uma bomba centrífuga. Transientes de pressão foram obtidos por quatro transdutores conectados a um computador padrão PC comandado por um software de aquisição de dados e controle desenvolvido. Os testes mostraram que a análise espectral dos transientes de pressão, juntamente com o conhecimento dos pontos de reflexão na tubulação, consiste em um método simples e eficiente de se detectar vazamentos / Abstract: The development and test of a technique for leak detection in pipelines is presented. The technique is based on the spectral analysis of pressure signals measured in pipeline sections where the formation of stationary waves is favoured, allowing leakage detection during the start stop of pumps. Experimental tests were performed in a 1250 m long pipeline for various operational conditions of the pipeline (liquid flow rate and leakage configuration). Pressure transients were obtained by four transducers connected to a PC compute. The obtained results show that the spectral analysis of pressure transients, together with the knowledge of reflection points provide a simple and efficient way of identifying leaks during the start stop of pumps in pipelines / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

[pt] O estudo de fenômenos transitórios em sistemas hidráulicos está presente em diversos ramos da engenharia, encontra-se na área de hidrelétricas e na indústria do petróleo. O presente trabalho apresenta uma análise comparativa deste fenômeno utilizando três abordagens de modelagem distintas: o clássico método das características, a técnica de grafos de ligação e o tratamento através do fluxo de potência. No caso do método das características emprega-se o procedimento proposto por Streeter. Na modelagem através de grafo de ligação adota-se a analogia generalizada entre os sistemas fluido, mecânico e elétrico. Na representação pelo fluxo de potência acopla-se módulos previamente desenvolvidos considerando as relações de causa e efeito entre os componentes de um sistema. Todos os métodos foram implementados em Matlab e foram testados e comparados a partir de simulações em dois sistemas simples compostos de um reservatório, linha fluida e válvula. Os resultados obtidos através da metodologia de fluxo de potência aproximam-se dos encontrados pelas abordagens tradicionais. / [en] The study of transitory phenomena in hydraulic systems is present in several branches of the engineering, in the hydroelectric power stations area and in the petroleum industry. The present work introduce a comparative analysis of this phenomenon using three approaches of distinct modeling: the classic characteristics method, the technique of bond graphs and the treatment through the power flow. In the case of characteristics method is used the procedure proposed by Streeter. In the modeling through bond graphs is adopted the generalized analogy among the fluid, mechanic and electric systems. In the representation by power flow modules previously developed are coupled considering the cause and effect relationships between components of one system. All methods were implemented in Matlab and were tested and compared from simulations in two simple systems composed of a reservoir, fluid lines and valve. The results obtained through the methodology of power flow are near of the discoveries by the traditional approaches.