Tesis:
New design methodology for branched hydraulic networks that accounts for variable water demand and energy assessment
- Autor: MARTÍN CANDILEJO, Araceli
- Título: New design methodology for branched hydraulic networks that accounts for variable water demand and energy assessment
- Fecha: 2020
- Materia: Sin materia definida
- Escuela: E.T.S. DE INGENIEROS DE CAMINOS, CANALES Y PUERTOS
- Departamentos: INGENIERIA CIVIL: HIDRAULICA, ENERGIA Y MEDIO AMBIENTE
- Acceso electrónico: http://oa.upm.es/65435/
- Director/a 1º: GARROTE DE MARCOS, Luis
- Director/a 2º: SANTILLÁN SÁNCHEZ, David
- Resumen: The design of water supply systems has to consider all costs involved from the moment of its construction until the end of the installation, for it to be effective and sustainable. This implies accounting not only for the building expenses but also for the energy investments of the operation of the facility when pumping is required. A key variable for the calculation of the electrical costs is the value of the pump efficiency. Up to now, the prediction of the pump efficiency was made using conservative values, in the absence of a better estimation. On the other hand, because water demand varies over time depending on numerous factors, such as seasonal irrigation, or population displacements, etc., it is desirable that the design methodology is able to adequately manage this phenomenon. For these reasons, the aim of this work is to present a new design methodology for water supply systems for branch networks that effectively accounts for energy expenses as well as variable demand patterns. The methodology will be based on the Granados’ System, which is a very practical and intuitive gradient based procedure. This thesis intends to carry out an extensive pump analysis with the purpose of defining the expected value of the pump efficiency and in this way simplify Granados’ calculation process. At the same time, because Granados’ System requires a constant design flow rate, this thesis also pursues to provide a solution by which variable demand distributions can be converted to constant regimes. For the pump efficiency analysis, 226 commercial pumps were studied in depth, collecting the characteristic features at their optimum operation point. As a result, a strong relationship between the pump efficiency and the flow rate was spotted, which allowed the elaboration of an empiric curve that designers can use to predict the expected value of the pump efficiency, and thus perform a proper energy assessment. This also simplifies calculations in the Granados’ System by braking an iterative process for guessing the pump efficiency. Regarding the variable water demand issue, this work presents a straightforward methodology that, using a constant flow rate, the total cost is equivalent to that of the variable demand flow. Following this logic, the concepts of the Equivalent Flow Rate and the Equivalent Volume are developed. These concepts can be applied to, not only the Granados’ System, but also to any other design methodology that requires a constant flow rate as input. Combining all of these contributions and reorganising the steps of the procedure, a new design methodology for branch water supply networks is proposed and applied in a case study to fully illustrate its use.