Variable Radius Wind Turbine Blades for Self-Starting
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Solution Overview
Problem
Darrieus-type vertical axis wind turbines face challenges in self-starting and maintaining operation during variable wind conditions, particularly due to issues with aerodynamic efficiency and inertia, leading to energy losses and inefficient energy collection.
Innovation Solution
The implementation of a variable rotor solidity mechanism, achieved through telescopic translation of blades, which adjusts the radius of the rotor to minimize inertia during startup and maximize it during wind decreases, allowing the turbine to maintain rotation speed and prevent unnecessary stopping, thereby enhancing self-starting and energy generation capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rotor radius is increased to maximize inertia during wind decreases, then the turbine can maintain rotation speed better, but the device complexity and structural burden increase
Solution Approach 1:
The patent implements a variable rotor radius mechanism where blades can telescopically translate radially along the rotation axis. This dynamic adjustment allows the rotor radius to be maximized during wind decreases to maintain rotation speed through increased inertia, and minimized during normal operation to reduce structural burden and complexity. The blades are guided by rails and actuated by hydraulic or electric motors, enabling continuous adjustment of the rotor geometry.
2Ease of operation
If the rotor radius is decreased to minimize inertia during startup, then self-starting capability is improved, but the ability to maintain rotation during wind drops deteriorates
Solution Approach 1:
The variable rotor radius mechanism allows the system to adapt its moment of inertia dynamically. During startup, the blades are positioned at minimum radius to minimize inertia and facilitate self-starting in low wind conditions. Once operational, the blades can be extended to maximum radius to increase inertia and maintain rotation during wind drops, thus resolving the contradiction between ease of startup and reliability during variable wind conditions.
3Device complexity
If fixed rotor geometry is used, then device complexity is reduced, but adaptability to variable wind conditions deteriorates
Solution Approach 1:
The patent transforms the fixed rotor geometry into a dynamic, variable geometry system. The blades can telescopically adjust their radial position along the rotation axis, changing the effective rotor radius based on wind conditions. This dynamic adaptability allows optimization of performance across varying wind speeds while the mechanical guidance system (rails, wheels, hydraulic actuators) maintains reasonable structural organization.
4Productivity
If the rotor radius is variable, then energy collection efficiency is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The variable rotor radius mechanism employs precision rails and guided wheels to ensure accurate blade positioning during radial translation. Hydraulic or electric motors provide controlled actuation with feedback systems to maintain precise blade positions throughout the adjustment range. This precision guidance system enables the variable geometry configuration to achieve optimal energy collection efficiency while meeting manufacturing and positioning precision requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution improves the turbine's operation by allowing it to exploit more efficient power curves during variable wind speeds, reducing energy consumption for restarting and maintaining higher rotation speeds, even during brief wind drops, thus enhancing energy collection efficiency.
Implementation Method 1
a spring bound with one end to the blade and with the other end to the arm, wherein the spring is coaxial with the arm
Implementation Method 2
Each of the N blades is able to carry out a translational motion in the radial direction with respect to the relative arm due to the centrifugal force created during the rotation of the blades themselves
Implementation Method 3
Each of the N blades has an airfoil particularly shaped
Implementation Method 4
The recent push for energy policies focused on more eco-sustainable economic development has led to the extraction of energy from the wind source
Data Source
AI summary
A wind turbine includes a rotation axis suited to be positioned in space in any way and N blades indirectly constrained to the axis through one or more radial arms that are integral with the axis, wherein the blades can translate in a radial direction with respect to the axis during the rotation of the blades.