Pelton hydro turbines

Pelton turbines are impulse type turbines - turbines that use the kinetic energy in water

They can operate under a wide range of heads, from 200 to 1800 meters.

Based on our experience in the field, we offer vertical shaft machines that are equipped with multi-jet collectors up to an output of about 350 MW, and with runner diameters up to 4 m.

For smaller units, we provide horizontal shaft single or double runner Pelton turbines with one or two jets. These turbines operate economically with the lowest discharges.

Alstom patented Hooped Pelton runners design, whose buckets are supported by 2 separate hoops, minimises the fatigue stress at bucket fixation, reducing the inspection and maintenance costs and maximising the plant availability. Capable of providing the same hydraulic efficiency levels as a standard Pelton, but better resisting to mechanical stress, the need for repeated quality inspections and associated labour costs and plant outages. As it is possible to replace individual buckets instead of the complete runner, replacement costs of ageing runners are reduced.

Silt abrasion protective solutions
Alstom develops, case by case, design and coating solutions for customers to combat silt abrasion problems.

High Velocity Oxy Fuel (HVOF) hard coating
This technology is particularly well suited to Pelton runners. Coating is sprayed onto all surface areas by a robot. The high abrasion and fatigue resistance of the HVOF coating is achieved using a metal substance embedded with tungsten carbide ceramic powder. The application technique used creates a high-density layer of coating with very strong bonding capabilities, which is on average 0.3 mm thick.

Specific hydraulic design initiatives
Analysing the flow dynamics in order to adjust the turbine design profile in areas that are more prone to erosion.

Use of numerical computational fluid dynamics simulation tools to predict effects of silt abrasion on turbine performance. 

Key references

Ji Sha (China), 2005 - 2 x 61.5 MW Hooped Runner - Head: 485 m.
Daï Ninh (Vietnam), 2007 - 2 x 153 MW - Head: 627 m.
Vishnupravag (India), 2006 - 4 x 103 MW - Head: 914 m.
Yele (China), 2000 - 2 x 122.5 MW - Head: 580 m.