Reciprocating Fishway Slope Adjustment via Eccentric Mechanisms
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Solution Overview
Problem
Traditional fishways are inefficient in fish passage due to difficulties in adjusting bottom slope and hydraulic slope, leading to long construction costs and low fish passage efficiency, and often fail to facilitate fish migration.
Innovation Solution
A step-by-step paired and up-down reciprocating combined fishway system incorporating fishway units with mechanical transmission, fish repelling systems, and a recovery cableway, which adjusts slope through eccentric wheels and assists fish migration using a controlled fish repelling net and cable system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional fishway structures are used with fixed bottom slope and hydraulic slope, then the structure is simple and construction is straightforward, but the fishway length becomes too long and construction cost increases significantly
Solution Approach 1:
The patent applies the dynamics principle by making the bottom slope and hydraulic slope adjustable through mechanical transmission systems. The fishway units can change their inclination angles dynamically, allowing the fishway length to be optimized without compromising structural simplicity. This resolves the contradiction by enabling slope adjustment within a compact structure.
Solution Approach 2:
The patent implements parameter changes by allowing the bottom slope and hydraulic slope to be varied according to different topographical conditions and fish migration needs. The mechanical transmission system enables continuous adjustment of slope parameters, thereby reducing the required fishway length while maintaining construction feasibility.
2Device complexity
If traditional fishway structures with fixed slopes are used, then the structure is simple, but the fish passage efficiency is low and fish migration is not effectively facilitated
Solution Approach 1:
The patent employs dynamics by equipping fishway units with adjustable bottom slopes and hydraulic slopes that can be optimized for different fish species and migration conditions. This dynamic adjustment capability significantly improves fish passage efficiency while adding only moderate structural complexity through mechanical transmission components.
Solution Approach 2:
The patent utilizes parameter changes by allowing the slope parameters to be adjusted according to operational requirements. This enables the fishway to adapt to various fish behaviors and environmental conditions, thereby enhancing fish passage efficiency without requiring a completely complex structure.
3Speed
If fishway length is increased to reduce slope and limit flow velocity, then the flow velocity control is improved, but the construction cost increases
Solution Approach 1:
The patent applies dynamics by using adjustable bottom slopes to control flow velocity. Instead of increasing fishway length, the system dynamically adjusts the slope angle to maintain optimal flow velocity within a shorter fishway structure, thereby reducing construction costs while achieving velocity control.
Solution Approach 2:
The patent implements parameter changes by varying the bottom slope parameter to control flow velocity. This allows the fishway to achieve the required velocity limitations without extending the fishway length, thus avoiding increased construction costs associated with longer structures.
4Productivity
If the bottom slope and hydraulic slope are made adjustable, then the fish passage efficiency is improved and construction cost is reduced, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the fishway into multiple independent fishway units, each equipped with its own mechanical transmission system for slope adjustment. This modular approach improves fish passage efficiency through localized control while managing overall structural complexity by standardizing repeatable units.
Solution Approach 2:
The patent implements universality by designing fishway units with multi-functional mechanical transmission systems that can adjust both bottom slope and hydraulic slope. This integrated approach achieves multiple objectives (slope control, flow velocity management, fish passage optimization) within a single structural framework, thereby limiting the increase in device complexity.
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 system reduces construction costs, enhances fish passage efficiency, and adapts to different topographies, ensuring continuous fish migration while minimizing energy consumption and preventing water leakage.
Implementation Method 1
6. The curved followers are fixed on lower surfaces of the bottom plates, and the eccentric wheels are located directly under the curved followers and are in sliding contact with the grooves of the curved followers
Implementation Method 2
the wing walls of adjacent fishway units are in an embedment connection and in sliding engagement with each other through the sliding slots and the sliders
Implementation Method 3
the inner sides of the wing walls are provided with the gear belts, and a rotating shaft of the motor is connected to the transmission shaft through a reduction gear set
Data Source
AI summary
Disclosed are a step-by-step paired and up-down reciprocating combined fishway and a fish passage method thereof, belonging to the technical field of fish passage facilities. The present disclosure aims to provide an efficient fish passage technology for a low-head water control project, which overcomes the defects of long construction length and low fish passage efficiency of the traditional fishway. The present disclosure includes several fishway units, a mechanical transmission system, a fish repelling system, a control system, and a recovery cableway. Under the combined action of the mechanical transmission system and the fish repelling system, the fishway units reciprocate up and down step by step to form a fish passage way. The weight of the fishway units is balanced through the rotation of coaxial eccentric wheels, and the energy consumption of the mechanical transmission system is reduced. The joint of the fishway units is achieved through embedment and sliding between a sliding slot and a slider and tangent rolling between a roller row and a partition plate. In accordance with the present disclosure, the fishway construction length can be shortened, the construction cost is saved, the influence of water conservancy and hydropower projects on river connectivity is effectively decreased, and broad engineering application prospects and important ecological and economic benefits are achieved.