BR-102020004560-B1 - Wind turbine using double-bladed, one-piece blades for power generation.

Abstract

WIND ROTOR USING DOUBLE-BLADED UNIFORMS FOR POWER GENERATION. This refers to a rotor geometry (1) for Horizontal Axis Wind Turbines (HAWT), assembled with double-bladed integral blades for power generation with aerodynamic profiles in the same direction (17), which promotes the extraction of additional kinetic energy through the second aerodynamic surface on the blade with low solidity and proportional longitudinal torsion.

Inventors

• RODOLFO RODRIGUES LOPES
• TURAN DIAS OLIVEIRA
• LUZIA APARECIDA TOFANELI
• ALEX ÁLISSON BANDEIRA SANTOS

Assignees

• SERVICO NACIONAL DE APRENDIZAGEM INDUSTRIAL

Dates

Publication Date

20260317

Application Date

20200306

Claims (1)

1. 1) “WIND TURBINE ROTOR USING DOUBLE-BLADED UNIFORMS FOR POWER GENERATION”, comprising, in a horizontal axis wind turbine, a rotor with three double-blades (1) arranged at 120° (3) around a hub (2), wherein each double-blade (1) is constituted by two aerodynamic surfaces with profiles in the same direction (17), characterized by having a twist angle (β) along the length of the aerodynamic surfaces, varying from root to tip from 13.08° to 0°.

Description

INTRODUCTION [001] This invention patent relates to a novel rotor geometry that uses blades with duplicated and integral aerodynamic surfaces with aerodynamic profiles in the same direction, in order to promote greater power generation compared to conventional designs, and which can efficiently use a minimum amount of material to obtain excess aerodynamic efficiency because each surface contributes to the extraction of kinetic energy from the wind that passes through the area corresponding to the rotor, during its operation. FIELD OF THE INVENTION [002] The invention in question can be used in a variety of applications, including the power generation segment with application in horizontal axis wind turbines (HAWT), as an alternative to locations with greater wind potential, and/or installation points capable of amplifying wind capacity by accelerating the air mass that passes through the region where the rotor is located based on the concept of double-blades - see Venturi effect. CONVINCING [003] Wind energy is one of the most important renewable energy sources and has grown the most in the world (EPE, 2018). [004] The UN submitted 17 goals during the Paris Agreement in September 2015, where goal 7 aims to ensure access to reliable, sustainable, modern and affordable energy for all, promoting a better balance between the social, environmental and economic dimensions of sustainable development (UNITED NATIONS, 2016). [005] As indicated in the Ten-Year Plan, the renewable share of the Brazilian energy matrix will reach 48% by the end of the ten-year horizon, while 86% of the electricity supply will come from renewable sources. To meet the growing demand for energy while maintaining the renewable nature of the matrix, investments of around R$ 1.8 trillion are expected in the period 2018-2027. Despite the encouraging projections, many actions are needed to keep Brazil in the lead in the field of sustainable development (EPE, 2018). [006] By doubling the aerodynamic surface area of the blades, it is possible to increase the rotor's power coefficient, which aligns with the Ten-Year Energy Expansion Plan and UN Goal 7 by improving turbine performance. Beyond the innovation aspect of creating alternatives for the wind turbine industry, which has intensified its projects in most cases, the growth in rotor dimensions is also opportune. It is also opportune to reduce dependence on fossil fuels and, consequently, decrease emissions. THEORETICAL FOUNDATION [007] Classically, wind turbines are devices that use airfoils to transform the kinetic energy of the wind into electrical energy (MANWELL; MCGOWAN; ROGERS, 2009) through rotor-wind interaction. In these machines, aerodynamic forces act on their blades based on the variation in the relative speed of the wind, thus causing the resulting torque on the rotor shaft. [008] During the passage of wind through the disc formed by the rotor, it can be considered that the passage of the air mass through the rotor is separated from that which does not pass through and does not decelerate, generating a boundary surface that encompasses the affected flow, which extends before and after the passage through the rotor forming a tubular flow structure with a circular cross-section. [009] Both flows can be considered as having no air crossing, maintaining a constant volumetric flow rate within the tubular flow. As this flow passes through the rotor, it gradually decelerates upstream due to the presence of the rotor (BURTON et al., 2011), increasing its static pressure, and consequently absorbing part of its kinetic energy. [010] Thus, one of the lines of study involving alternatives in reducing gas emissions from the use of fossil fuels, and improving rotor efficiency, is aerodynamic enhancement through the doubling of surfaces. That is, increasing the absorption of kinetic energy in wind turbine rotors. [011] This line of research encompasses the aerodynamic study of horizontal axis turbines in power generation. Doubling the aerodynamic surface area on the blades increases rotor efficiency, providing greater absorption of kinetic energy as wind passes through the rotor. [012] This absorption occurs gradually as the flow passes through the rotor longitudinally, since part of the kinetic energy is absorbed on the first surface and another part by the second. Justifying the increase in power generation. [013] After the flow passes through the rotor, it settles down with lower speed and static pressure, and as it moves away from the rotor it forms a wake that normalizes with the air outside the flow, regaining equilibrium. [014] This behavior can be evidenced by analyzing the flow lines after a simulation, where they will be visually further apart, obeying the aforementioned condition. This phenomenon is accentuated with the doubling of the aerodynamic surface on the rotor blades, which suggests greater absorption of kinetic energy, which maximizes its aerodynamic efficiency and consequent