Stationary Trough Hydroelectric Screw for Fish Passage

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Solution Overview

Problem

Conventional hydroelectric power plants face issues with durability and ecological acceptance due to bearing damage, inefficient energy generation, and fish mortality caused by the rotating support structure and guiding currents, which deter fish from using fish ladders.

Innovation Solution

The design features a stationary trough with independently operating screws, where the working screw and conveyor screw rotate independently, with the conveyor screw using the water flow from the working screw to create an attractive current for fish, and a semi-cylindrical trough to reduce material and weight, allowing for efficient energy generation and safe fish passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the working screw and conveyor screw are combined in a single rotating support tube, then the fish transport is gentle and efficient, but the moving masses become very large causing bearing damage and out-of-true running over medium to long time scale

Engineering Contradiction:
Improvefish transport gentlenessVSAvoidbearing durability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent divides the combined rotating structure into separate independent components: the working screw remains attached to the rotating support tube for gentle fish transport, while the conveyor screw is detached and mounted independently on the stationary trough. This segmentation allows each component to function optimally without the excessive moving masses of the combined structure, thereby improving bearing durability while maintaining fish transport gentleness.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the trough is designed to rotate with the working screw, then the working screw can be larger for efficient energy generation, but the moving masses increase causing bearing damage and reduced operational reliability

Engineering Contradiction:
Improveenergy generation efficiencyVSAvoidbearing durability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent extracts the conveyor screw from the rotating support tube structure and mounts it independently on the stationary trough. This allows the working screw to be larger for efficient energy generation while the conveyor screw operates separately without adding to the rotating mass, thereby maintaining bearing durability and operational reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If the working screw and conveyor screw rotate at the same speed, then they form a structural unit for gentle fish transport, but the moving masses are very large causing bearing damage

Engineering Contradiction:
Improvefish transport safetyVSAvoidsystem durability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent segments the rotation function by allowing the working screw to rotate with the support tube while the conveyor screw rotates independently on the stationary trough. This segmentation reduces the moving masses that would cause bearing damage while maintaining safe fish transport through the coordinated action of the two screws.

Inventive Principle:
Principle #1Segmentation

4Strength

If the trough is made fully cylindrical to enclose the working screw, then the structure is complete and protective, but the material and weight increase

Engineering Contradiction:
Improvestructural completenessVSAvoidtrough weight
Core Design Contradiction:
StrengthVSWeight of stationary object

Solution Approach 1:

The patent applies local quality by providing a semi-cylindrical trough that encloses the working screw on the necessary sides while leaving the top open. This partial enclosure provides adequate structural protection and functionality without the excessive material and weight of a fully enclosed cylindrical structure.

Inventive Principle:
Principle #3Local quality

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 design enhances the durability and ecological acceptance of hydroelectric power plants by minimizing rotating masses, reducing fish mortality, and encouraging fish to ascend and descend safely through the system, while maintaining efficient energy generation.

Implementation Method 1

a working screw (6) arranged in a trough (5) and a generator (4) driven by it

Methodology Applied
Scientific EffectHydrodynamic screw: Archimedes Screw

Implementation Method 2

a screw conveyor (9) arranged in the same longitudinal extent as the working screw (6), which runs in the opposite direction to the working screw (6)

Methodology Applied
Scientific EffectScrew conveyor: Archimedes Screw

Implementation Method 3

the water flowing out of the hydrodynamic screw to generate electricity creates a so-called 'guiding current' or 'lure current' for the fish willing to climb

Methodology Applied
Scientific EffectGuiding current: Flow Separation

Data Source

PatentEP2735728B1Water power plant
Publication Date: 2016.07.20 REHART
  • EP2735728B1 patent drawingFigure 1
  • EP2735728B1 patent drawingFigure 2
  • EP2735728B1 patent drawingFigure 3

AI summary

The invention relates to a hydroelectric power plant for generating electrical energy by converting the flow energy of a flowing body of water, comprising a working screw (6) arranged in a trough (5) and a generator (4) driven by it, and a counter-rotating conveying screw (9) arranged with the same longitudinal extent as the working screw (6). The trough (5) is designed to be stationary and is connected to a base structure (14, 15, 16, 17).