Refurbishment for Old Hydropower Plant

WHY – Renovation, Modernization and Uprating

• Hydro-Electric Power Generation has many well recognized advantages.

• For overall economic interests, hydro generation is to be kept up by constant maintenance, renovation and modernisation of hydropower plants.

• Uprating to be attempted wherever possible.

• Normal life expectancy of a hydroelectric power plant is 30 to 35 years and conventionally renovation is planned thereafter.

• In a fast changing technological environment, however the plant can also become somewhat outdated in a period of about 15 years itself, after which it needs to be modernised to produce reliable and higher yields especially in present market dynamics.

• Most hydro plants use the most advanced and efficient technology economically available at the time they are built.

• Incorporate new technology into existing plants, for making them more efficient.

• Modernisation is a continuous process.

• Modern instruments for monitoring vibrations, silt in water etc. and silt resistive epoxy painting on turbine blades, static excitation, SCADA, electronic governors, high speed static relays for improving reliability as-well-as quality of generation.

Attention Required for All kind of Works

• Presently RMU proposals are electrical and mechanical works centric.

• Perhaps people preparing the proposals primarily are responsible for operation and maintenance the hydropower plant or related E&M people.

• The civil works and hydro mechanical works are often not considered or do not get adequate attention in RMU plans may be due to expected longer life of civil works.

• Erosion and damages on the civil works specially the diversion works, channels, tunnels, desilting tank, spilling works, penstock, valves, gates, trash racks also require a special attention for preparing the renovation of plant.

Outputs from Renovation and Upgradations

• Increasing Installed Capacity

Can be increased by replacing or reshaping turbine runners and increasing the discharge, speed governors, shafts, bearings, distributors and draft tubes, runners

• Improving performance of machines and water conveyance capacity

Comprehensive and coordinated work can the performances of hydraulic machinery and conveyance systems be improved.

• Improving Plant Availability

• Improving Energy Efficiency

Regularly measuring efficiency, controlling wear in turbines, and improving the operating ratio between the angle of the guide vanes and the angle of the blades.

•Refurbishing Penstock Linings

Refurbishing the inner linings of penstocks will extend the life of penstock, CFD analysis of penstock for assessment problem location

• Controlling wear in Turbines

• Improving operating ratios

• Renovation in civil works for reducing the water loss and head losses

Water conductor system may have water and head losses

Possibility of modifying the layout to reduce the overall water and head loss be studied with techno economic evaluation.

Afforestation, stabilization of hill slopes and soil conservation

• Renovation on Hydro mechanical works

Gates, hoisting arrangements and valves requires careful RLA studies

Automatic trash cleaning machine for reducing the high head losses and power losses even without waiting for a comprehensive RMU proposal of the plant.