Rotor Blade Tip Retaining Device for Moisture Drainage
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Solution Overview
Problem
The accumulation of moisture in rotor blade tips of wind turbines leads to imprecise lightning arresters due to inadequate drainage, causing damage from lightning strikes, as current strikes at conductive points with high electric fields, resulting in local heating and destruction.
Innovation Solution
A rotor blade tip with a retaining device in front of the drainage opening to catch solid particles, separating them from moisture, which is then drained, using a series of filters and flow obstacles to prevent clogging and ensure effective moisture removal, while maintaining aerodynamic considerations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If drainage openings are made larger to improve moisture drainage, then moisture removal efficiency is improved, but aerodynamic performance deteriorates
Solution Approach 1:
The drainage opening is equipped with a filter device that has different structural characteristics at different locations: the first region has a larger cross-section for efficient moisture drainage, while the second region has a smaller cross-section to minimize aerodynamic impact. This local differentiation allows the system to optimize for both drainage efficiency and aerodynamic performance in different spatial zones.
2Object-affected harmful factors
If drainage openings are made smaller to maintain aerodynamic performance, then aerodynamic performance is improved, but drainage efficiency deteriorates and clogging risk increases
Solution Approach 1:
The filter device is divided into two distinct regions: a first region with a larger cross-section for effective moisture drainage, and a second region with a smaller cross-section for aerodynamic compatibility. This segmentation allows each region to fulfill its specific function optimally while working together as an integrated system.
Solution Approach 2:
The filter device acts as an intermediary structure between the drainage opening and the external environment. It mediates between the conflicting requirements of drainage efficiency and aerodynamic performance, allowing moisture to pass through while maintaining the aerodynamic profile required for optimal rotor blade performance.
3Object-affected harmful factors
If drainage openings are made smaller to maintain aerodynamic performance, then aerodynamic performance is improved, but reliability deteriorates due to increased clogging risk
Solution Approach 1:
The filter device is installed in advance in the drainage opening to prevent solid particles from entering and causing clogs. This preliminary protective action ensures that the drainage system maintains its reliability over time without requiring frequent maintenance or repairs.
4Reliability
If filter devices are added to prevent clogging, then reliability is improved, but device complexity increases
Solution Approach 1:
The filter device performs multiple functions simultaneously: it filters solid particles to prevent clogging, maintains aerodynamic performance through its streamlined design, and facilitates moisture drainage through its optimized cross-sectional geometry. This multi-functionality reduces the need for separate components and simplifies the overall system.
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
Prevents moisture accumulation and ensures efficient drainage, reducing the risk of lightning strikes and damage by separating liquid from solid particles, thus protecting the rotor blade from bursting due to vapor pressure.
Implementation Method 1
moisture present within the rotor blade body cavity can be drained
Implementation Method 2
a retaining device for solid particles is arranged in front of the drainage opening, by means of which solid particles are caught
Implementation Method 3
The briefly high current and the insufficiently low electrical resistance of the mixture of adhesive material, glass fiber dust and water lead to extremely high local heating
Implementation Method 4
as a result of the heating, the water inside the rotor blade suddenly evaporates
Implementation Method 5
The vapor pressure built up inside the rotor blade as a result of the evaporation finally causes it to burst open
Implementation Method 6
which in turn leads to high electrical field strengths in the presence of moisture and electrostatic charging
Data Source
Figure 1
Figure 2~4
Figure 5~6
AI summary
The invention relates to a rotor blade with a rotor blade body (2) which has a rotor blade body cavity (21), and a rotor blade tip (3) which is connected to the rotor blade body cavity (21) and which has at least one drainage opening (4) through which moisture present inside the rotor blade body cavity (21) can be discharged, wherein in the rotor blade tip (3) at least one retaining device (6, 7, 8) for solid particles is arranged in front of the drainage opening (4).