Pivotable Hydraulic Turbine Runner for Fish-Safe Flow Passage
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Solution Overview
Problem
Hydropower plants often disrupt the natural movement of fish and other aquatic organisms, and existing turbines do not effectively balance environmental impact, efficiency, and installation costs, particularly in low and medium-head applications.
Innovation Solution
A pivotable turbine runner with adjustable pitch blades featuring a thick leading edge and angled pivot axes, designed to minimize gaps and reduce fish mortality, and angled pivot axes, configured to promote safe downstream passage of fish and other aquatic organisms through the turbine, while achieving high efficiency across a wide range of applications, including retrofit installations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional turbine designs are used, then installation and operation costs are reduced, but fish mortality increases and environmental impact worsens
Solution Approach 1:
The turbine blades are designed with pivotability, allowing them to rotate about a pivot axis that is angled relative to the shaft axis. This dynamic capability enables the blades to adjust their pitch angle in response to varying flow conditions, optimizing both fish passage safety and turbine efficiency across different operating scenarios. The pivotable mechanism allows the blade leading edges to maintain favorable angles with incoming flow while reducing fish strike mortality.
Solution Approach 2:
The invention specifies particular geometric parameters for the turbine runner, including a length-to-diameter ratio less than 0.55, chord length ratios between 0.6 and 1.2, and leading edge thickness ratios between 0.05 and 0.2. These parameter optimizations balance hydraulic efficiency with fish safety, creating a design that achieves both environmental and operational goals without requiring complete system replacement.
2Productivity
If turbine efficiency is maximized, then energy production increases, but fish passage safety decreases
Solution Approach 1:
The pivotable blade mechanism enables dynamic adjustment of blade pitch angles, allowing the turbine to maintain high efficiency across varying flow conditions while simultaneously reducing fish strike mortality. The blades can optimize their angle of attack for maximum energy extraction while the angled pivot axis configuration reduces the likelihood of fish strikes compared to fixed-blade designs.
Solution Approach 2:
The turbine runner combines multiple geometric features including pivotable blades with specific chord length distributions, angled pivot axes, and optimized leading edge thicknesses. This composite design approach integrates multiple functional requirements (efficiency, fish safety, structural integrity) into a unified system that achieves both high energy production and reduced environmental impact.
3Adaptability or versatility
If the turbine is designed for wide operating range, then adaptability increases, but device complexity increases
Solution Approach 1:
The pivotable blade design with angled pivot axes provides inherent adaptability to varying flow conditions without requiring complex control systems. The mechanical pivot mechanism allows automatic adjustment of blade angles in response to flow changes, enabling wide operating range while maintaining relatively simple structure compared to actively controlled variable pitch systems.
Solution Approach 2:
The turbine runner design incorporates multiple geometric optimizations (pivotable blades, angled pivot axes, specific length and chord ratios) that collectively enable the single device to function effectively across a wide range of operating conditions. This multi-functional geometric configuration allows the turbine to adapt to different flow rates and head conditions without requiring multiple specialized designs.
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
The pivotable turbine runner with adjustable pitch blades featuring a thick leading edge and angled pivot axes, designed to minimize gaps and reduce fish mortality, and angled pivot axes, configured to promote safe downstream passage of fish and other aquatic organisms through the turbine, while achieving high efficiency and low installation, operation, and maintenance costs.
Implementation Method 1
A runner for a hydraulic turbine can include a hub and a plurality of pivotable blades extending from the hub
Implementation Method 2
A leading edge thickness can be greater than a trailing edge thickness... A portion of the leading edge at the tip of each pivotable blade can be slanted relative to a radial axis of the runner at an angle between approximately 20 degrees and approximately 90 degrees
Data Source
AI summary
A runner for a hydraulic turbine, including a hub and a plurality of pivotable blades extending from the hub. Each pivotable blade of the plurality of pivotable blades includes a root located at the hub, a tip opposite the root, and a leading edge. Each pivotable blade of the plurality of pivotable blades is pivotable relative to the hub about a respective pivot axis. For at least one blade, the leading edge at the root is positioned along a radial axis of the runner and the leading edge at the tip is cantilevered beyond the radial axis in a circumferential direction of the runner.