Publicação
Estudo comparativo de 2 alternativas de dimensionamento duma rede de rega: alta e baixa pressão
| Resumo: | The purpose of this thesis is to compare two ways of water delivering in an irrigation scheme, considering the investment and maintenance costs: high and low pressure. The irrigation scheme considered is the “Circuito Hidráulico de Baleizão-Quintos”, included in the Multi-purpose Project of Alqueva. The scheme is divided in 5 blocks, with a gross scheme area of 7992 ha. The secondary aim is to determine for the blocks that in the original project require pumping stations (blocks 4 and 5), which is the combination between hydraulic head in the beginning of the secondary network and pipe size along that network, which allows the best ratio between investment costs and maintenance costs, and determine the lowest total present costs, or a close value, for the assumed life span of the project, assuring a pre-determined pressure on the hydrants. It was concluded that the distribution in low pressure has lower investment and annual maintenance costs and also presents lower annual energy consumption. A sensitivity analysis to what farmers pay for energy annually showed that if they pay 2.2 times what the managing entity pays, the total present costs for the assumed life span of the project are lower for high pressure distribution. |
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| Autores principais: | Matias, Virgílio José Jesus |
| Assunto: | on demand irrigation irrigation systems hydrant energy costs pumping stations hydraulic optimization |
| Ano: | 2012 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | português |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | The purpose of this thesis is to compare two ways of water delivering in an irrigation scheme, considering the investment and maintenance costs: high and low pressure. The irrigation scheme considered is the “Circuito Hidráulico de Baleizão-Quintos”, included in the Multi-purpose Project of Alqueva. The scheme is divided in 5 blocks, with a gross scheme area of 7992 ha. The secondary aim is to determine for the blocks that in the original project require pumping stations (blocks 4 and 5), which is the combination between hydraulic head in the beginning of the secondary network and pipe size along that network, which allows the best ratio between investment costs and maintenance costs, and determine the lowest total present costs, or a close value, for the assumed life span of the project, assuring a pre-determined pressure on the hydrants. It was concluded that the distribution in low pressure has lower investment and annual maintenance costs and also presents lower annual energy consumption. A sensitivity analysis to what farmers pay for energy annually showed that if they pay 2.2 times what the managing entity pays, the total present costs for the assumed life span of the project are lower for high pressure distribution. |
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