Estudo de turbina hidrocinética para operação em regime de marés em estuários

Abstract

An increase in the demand for sustainable electricity generation can be seen as the knowledge about the human influence on global warming expands associated with an increase in the world electricity demand. This characterizes the energy transition, seeking to reduce both environmental impacts and fossil fuels use, while keeping the energy security. It is relatively easy to transport and transform the electrical form of energy, but there is still a lack of access to electricity in many regions around the world. In this context, the development of hydrokinetic turbines can be valuable. This type of turbine transforms the kinetic energy of a river or ocean water flow into shaft power, that starts a generator. In contrast to conventional hydraulic turbomachines, these turbines do not require dams, as they are free flow turbines. To define strategies for the study of hydrokinetic turbines, the steps for classification in Technology Readiness Levels are proposed. This management tool is often used with the aim of technical validation and cost reduction in engineering projects. One study case was also carried out. Numerical modeling was conducted to study a hydrokinetic turbine operating in tidal regime, with flow in two opposite orientations intermittently. The ANSYS CFX® software was used to numerically solve local and global quantities that were used to analyze the blade project influence on the machine efficiency with a computational fluid dynamics approach. Hydrokinetic turbines can be used in small systems for electrification of villages or in farms with many turbines to achieve a higher installed power. In the first example, costs are limiting in the projects, while for large systems the efficiency usually defines the viability. The challenges for sustainable electricity generation increase the opportunities for development of new hydrokinetic turbines market. That can be beneficial to Brazil, the country already has a large participation of renewable sources for electricity generation but has challenges to keep this attribute. Hydrokinetic turbines are not a completely consolidated technology, therefore there is an opportunity for the development of new turbine models.