China unveils world's largest-capacity pelton turbine runner

(ECNS) -- China has developed the world's largest single-capacity Pelton turbine runner, Harbin Electric Corporation announced Wednesday, marking a key breakthrough in high-head, large-capacity hydropower technology and clean energy development.
The runner, considered the "heart" of the hydroelectric generator unit, will power the Zhala Hydropower Station in Xizang Autonomous Region. As part of the West-to-East Electricity Transmission Project, the station includes two 500-megawatt impulse turbines, the largest of their kind globally.
With a maximum outer diameter of 6.23 meters and a width of 1.34 meters, it comprises a forge-welded structure that includes a central hub and 21 bucket forgings. The final post-welding weight equals 90.8 tons.
All welding and processing technologies, given the material, shape, and size, are at the forefront of their respective fields.
To overcome welding challenges, engineers employed 3D metrology and simulation calculations to refine assembly and welding methods. The hub and buckets, crafted from martensitic stainless steel forgings, were joined using high-strength, fatigue-resistant joints, significantly enhancing the runner's impact durability under high-impact loads.
Zhala Hydropower Station is considered the most complex impulse hydropower project under construction globally. As China's flagship demonstration project for 500 MW high-head impulse turbines, it sets new benchmarks for capacity, output, and engineering sophistication.
(By Zhang Dongfang)