Hydraulic Turbine Discharge Ring Resurfacing Without Runner Removal

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Cavitation in hydraulic turbines leads to erosion and pitting of metallic surfaces, requiring costly and time-consuming resurfacing processes that involve disassembling the turbine runner, which can be avoided by developing methods to resurface the discharge ring without removing the runner.

Innovation Solution

The method involves mounting adjustable fixtures to the turbine runner blades, attaching cutting or welding equipment, and using a drive unit to rotate the runner while the resurfacing tools remove or add material to the discharge ring, allowing for concurrent operations without disassembling the turbine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the turbine runner is disassembled and removed to resurface the discharge ring, then access to the discharge ring is improved, but the time and cost for disassembly, reassembly, and heavy machinery setup increase

Engineering Contradiction:

Improveaccess to discharge ringVSAvoiddisassembly and reassembly time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The turbine runner itself is utilized as the mounting structure for resurfacing equipment. Fixtures are attached to the runner blades, which remain in place on the turbine, allowing the runner to serve both its operational function and as a support structure for maintenance equipment.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The turbine runner serves dual purposes: maintaining its primary function of converting water energy to mechanical energy while simultaneously serving as a mounting platform for resurfacing equipment. This multi-functionality eliminates the need for complete disassembly.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of operation

If the turbine runner is disassembled and removed to resurface the discharge ring, then access to the discharge ring is improved, but the expense for heavy machinery and setup increases

Engineering Contradiction:

Improveaccess to discharge ringVSAvoidmaintenance cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The resurfacing operation is extracted from the traditional approach requiring complete runner removal and is performed instead with the runner in place, removing only the necessary access barrier while maintaining the runner's position.

Inventive Principle:

Principle #2Taking out (Extraction)

3Productivity

If multiple resurfacing tools are used concurrently on the rotating runner, then resurfacing efficiency is improved, but the complexity of coordinating tool positions and speeds increases

Engineering Contradiction:

Improveresurfacing efficiencyVSAvoidtool coordination complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The resurfacing system transitions from static tools on a stationary runner to dynamic tools mounted on rotating runner blades. The fixtures and tools rotate with the runner, maintaining constant engagement with the discharge ring surface throughout the rotation cycle.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Multiple resurfacing tools are positioned on different runner blades to perform cutting or welding operations at different angular positions and vertical heights. As the runner rotates, each tool periodically engages the discharge ring surface, allowing concurrent operations across different zones.

Inventive Principle:

Principle #19Periodic action

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 enables efficient resurfacing of the discharge ring while the turbine runner remains in place, reducing the need for heavy machinery and minimizing downtime and costs associated with disassembly and reassembly.

Implementation Method 1

controlling the drive unit to rotate the runner at a specified speed

Methodology Applied

Scientific EffectRotational motion:

Implementation Method 2

controlling the cutting equipment attached to each adjustable fixture to concurrently remove material from the discharge ring as the turbine runner rotates

Methodology Applied

Scientific EffectMechanical cutting:

Data Source

PatentUS11433491B1Resurfacing discharge ring of hydraulic turbine with runner in place

Publication Date: 2022.09.06 ANDRITZ HYDRO CORP

AI summary

A method for repairing a discharge ring of a hydraulic turbine with a turbine runner in place includes: mounting adjustable fixtures to runner blades that are approximately evenly spaced around the turbine runner, where each adjustable fixture is mounted to a different runner blade at a different predetermined vertical position with respect to a surface of the discharge ring; attaching cutting equipment configured to remove material from the discharge ring to each adjustable fixture installed on the runner blades; installing a drive unit configured to rotate the turbine runner; controlling the drive unit to rotate the runner at a specified speed; and controlling the cutting equipment attached to each adjustable fixture to concurrently remove material from the discharge ring as the turbine runner rotates.