Pre-formed Inter-blade Profile Plug for Turbine Runner Precision
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Solution Overview
Problem
The fabrication of inter-blade profiles for turbine runners is challenging due to difficulties in precise positioning and limited workspace, leading to potential flow separations and cavitation, and existing methods require complex and costly modifications to adapt to new operating conditions.
Innovation Solution
The use of pre-shaped inter-blade profiles with a plug system for correct orientation and a removable cover plate for easy maintenance and modification, reducing assembly time and risks of misalignment, and allowing for adjustments without disassembling the turbine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If inter-blade profiles are installed after runner assembly, then positioning precision is difficult to ensure, but assembly flexibility is maintained
Solution Approach 1:
The inter-blade profile is pre-assembled with the plug before insertion into the turbine runner. This preliminary assembly ensures precise positioning and orientation of the profile relative to the blade air channel, eliminating positioning difficulties during final assembly while maintaining assembly flexibility through the modular plug design
2Adaptability or versatility
If turbine runner geometry is modified, then new operating conditions can be achieved, but disassembly and replacement are required
Solution Approach 1:
The inter-blade profile system is segmented into modular components (profile, plug, cover plate) that can be independently assembled, inserted, and replaced. This segmentation allows the profile geometry to be changed by simply replacing the profile-plug assembly without disassembling the entire turbine runner, enabling operational adaptability while minimizing downtime
3Manufacturing precision
If precise positioning is attempted in limited workspace, then orientation accuracy improves, but assembly time increases
Solution Approach 1:
The precise orientation of the inter-blade profile is established during preliminary assembly with the plug, where sufficient workspace is available. The pre-assembled unit is then inserted as a complete package into the limited workspace of the turbine runner, maintaining orientation accuracy while significantly reducing final assembly time
4Manufacturing precision
If inter-blade profiles are pre-shaped on plugs, then positioning and orientation are ensured, but fabrication complexity increases
Solution Approach 1:
The fabrication process is segmented into independent steps: plug manufacturing with positioning features, separate profile manufacturing with hydraulic features, and final assembly. This segmentation allows each component to be manufactured with optimal precision using appropriate processes, improving overall manufacturing precision while maintaining fabrication ease through modular production
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 approach simplifies the fabrication and maintenance of turbine runners by ensuring correct orientation and reducing hydraulic issues, while enabling modifications to be made without major stoppages or tooling, thus improving manufacturability and reducing operational downtime.
Implementation Method 1
The plug, in cooperation with the hole, determines the position and orientation of the inter-blade profile in the correct orientation
Implementation Method 2
air is injected into the water flow in order to increase dissolved oxygen content in the water flowing through the turbine
Implementation Method 3
Oxygen of the injected air is then transferred to the oxygen depleted flowing water, increasing dissolved oxygen levels as the air bubbles mix with the surrounding water
Implementation Method 4
at least one zone, or fillet with at least one finite radius of curvature r between at least a lower part of the profile and at least part of an upper side of the plug, which reduces negative hydraulic phenomena, in particular horseshoe vortex behaviour
Data Source
AI summary
The invention concerns an inter-blade profile (14) for a turbine runner blade, said inter-blade profile (14) comprising a profile (16), and a plug (18), forming a basis of the profile (16) and intended for being inserted into a corresponding hole (21) made in a blade.