Inspection and maintenance innovations for hydropower generation equipment

The deterioration of hydropower generation structures and equipment reduces efficiency and increases the risk of failures. Hydro-Québec has developed in situ solutions that will extend the service life of installed hydropower generation equipment such as turbines and gates and minimize service interruptions associated with inspections and refurbishment.

Assessing the actual condition of submerged structures such as concrete dams is a significant challenge, given the depth and turbidity of the water and the strength of the current.

Another major challenge is accurately measuring the flatness and profile of underwater parts to ensure the proper operation of the structure.

Our inspection and maintenance solutions were specifically designed for these conditions in order to respond to the needs of the hydropower generation environment.

WireScan – 3D inspection of vertical surfaces

The WireScan system measures the geometry of surfaces and long vertical sections above and below the waterline. Its double laser system produces accurate 3D scans of dam walls and gate and stoplog slots.

It is compact and easy to transport and install, even in tight spaces. In-depth WireScan inspections produce crucial data to prevent and solve problems such as water leaks and jammed gates and stoplogs.

For example, WireScan data on a gate’s guide rails can be used by Scompi to make in situ repairs to the defects it reveals.

WireScan benefits

  • Efficiency: Scans above and below the waterline
  • Precision: High-precision laser scans, even in murky water, georeferenced by plumb lines (patented system)
  • Safety: No divers required for underwater scans
  • Reliability: 3D models make it possible to identify the smallest anomalies
  • Speed: Instant validation of measurements, results available on the site, automatically-generated graphics
  • Portability: Compact and easily manoeuvered in tight spaces
  • Ruggedness: Designed for use on worksites and in hostile environments

WireScan applications

  • Inspection of vertical surfaces

Typical WireScan use cases

  • Hydropower generation equipment:
    • Spillway gate slots (above the waterline)
    • Water intake gate slots (above and below the waterline)
    • Stoplog slots (underwater)
    • Gate lintels
    • Dam piles
  • Locks:
    • gate and cofferdam slots

Value creation

  • Costs avoided thanks to timely repairs to only components with defects
  • Investments can be prioritized based on degradation
  • Costs avoided by performing minor repairs instead of complete refurbishment
  • Extended service life for mechanical and electrical components
  • Generation asset downtime reduced because cofferdam installation not required
  • Risk management improved by detecting slot anomalies that impede the proper operation of gates

Specifications

Click to enlarge
  • Required clearance: varies by configuration
  • Scanning environment: Under calm waters and above water
  • Precision: ±1 mm
  • Maximum depth: 30 m
  • Number of operators: 2
  • Time to deploy: about 2 hours
  • Inspection time: about 1 day per slot