Rotor Blade Lifting Frame With Pitching for Wind-Stable Hoisting
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Solution Overview
Problem
The vertical movement of elongated components, such as wind turbine rotor blades, during installation is problematic due to wind-induced pressure differences causing tilting, which restricts installation to low wind conditions and prolongs installation times, especially in offshore environments.
Innovation Solution
A lifting apparatus with a pitching system that rotates the component around its longitudinal axis to counteract wind-induced tilting by altering the aerodynamic orientation, using synchronized holding means and actuators controlled by sensors to adjust the component's spatial orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the component is carried with horizontal orientation to reduce crane loads, then the crane load is reduced, but vertical movement occurs due to wind-induced pressure differences
Solution Approach 1:
The pitching system generates an aerodynamic counter-torque to balance the wind-induced tilting moment. By rotating the component around its longitudinal axis, the system creates opposing aerodynamic forces that counteract the suction effect, thereby stabilizing the component's vertical position during lifting operations
Solution Approach 2:
The system dynamically adjusts the component's spatial orientation by actively controlling the pitching angle. The pitching system allows real-time modification of the component's attitude around its longitudinal axis, enabling adaptive response to varying wind conditions and maintaining stability throughout the lifting process
2Stability of the object's composition
If installation is restricted to low wind conditions to avoid vertical movement, then vertical stability is maintained, but the weather window for installation is narrowed
Solution Approach 1:
The system converts the harmful effect of wind acting on the component into a controllable aerodynamic force. By utilizing the wind itself to generate aerodynamic pressure differences through controlled pitching, the system creates a beneficial counter-torque that stabilizes the component, allowing installation to proceed in previously unsuitable windy conditions
3Stability of the object's composition
If the component is rotated around its longitudinal axis to counteract tilting, then vertical movement is compensated, but the device complexity increases
Solution Approach 1:
The pitching system serves multiple functions: it generates aerodynamic counter-torque for stability, enables active control of the component's spatial orientation, and provides adaptability to various wind conditions. This multi-functional capability allows a single system to address multiple challenges in the lifting process
Solution Approach 2:
The pitching system acts as an intermediary mechanism between the lifting crane and the component. It mediates the interaction between the component and wind forces by introducing a controlled rotational degree of freedom, thereby decoupling the direct relationship between wind loading and component stability
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
Enables faster and more stable installation of rotor blades at higher wind speeds by compensating unwanted vertical movements, expanding the weather window for installation and allowing for larger blades to be installed efficiently.
Implementation Method 1
different wind speeds are given at the upper and the lower side of the blade, resulting in a pressure difference between the upper and the lower side. These pressure difference leads to a certain suction or drag effect moving the blade to the lower pressure side
Data Source
AI summary
Provided is a lifting apparatus for a lifting crane, adapted to carry an elongated component having a non-circular cross section extending over the major part of its length, especially a rotor blade of a wind turbine, including a frame with at least one holder for holding the component with a horizontal orientation, wherein a pitching system for pitching the component around its longitudinal axis is provided.