Two European hydropower plant operators have replaced the bearings on their Francis-type turbines with water-lubricated bearings from Canada’s Thordon Bearings after oil was leaking from their original metal bearings.
In two separate contracts, Croatia-based Skoring d.o.o., Thordon’s authorized distributor for the region, supplied wicket gate bearings to the 36.8MW Hrvatska Elektroprivreda-operated plant in Rijeka, Croatia, in July. In August, they retrofitted new turbine guide bearings to turbines at the 1500kW Elektro Ljubljana-operated HPP Sava Brod plant, in Slovenia.
For Hrvatska Elektroprivreda (HEP Group), the decision to replace the original greased bronze wicket gate bearings on the Rijeka plant’s 18.4MW Turbine B was an easy one to make: Skoring has been supplying Thordon bearings to this operator for more than twenty years.
Skoring’s Technical Manager, Goran Orlic, provides more insight: “We have a great relationship with Hrvatska Elektroprivreda, an important customer for us. We have provided the utility supplier with numerous bearings over the years, with our first installation taking place at the Ozalj hydropower plant in 2002. Since then, we have retrofitted turbines at HEP plants in Fuzine, Zagreb, Lepenica, and more.”
In July 2021, ThorPlas-Blue wicket gate bearings were retrofitted to Turbine A of the Rijeka plant, and in May 2023 Turbine B was fitted out with the same.
For each turbine, the Thordon scope of supply comprised of twenty self-lubricating ThorPlas-Blue bearings, machined to fit outside shaft diameters of 105mm (4.13in), and twenty 135mm (5.31in) Thorseal polymer lip seals.
The smaller 100-year-old Elektro Ljubljana plant near Ljubljana, Slovenia, was retrofitted with Thordon SXL water-lubricated turbine guide bearings to both 499kW Francis turbines in August. Skoring supplied the SXL bearing material to local turbine refurbishment company Hydro-hit for final machining to fit shaft diameters of 305mm (12in).
“Skoring has a long history supplying Thordon seals and bearings to these operators,” said Axel Swanson, Thordon Bearings’ Business Development Manager – Hydro & Industrial. Both HEP Group and Elektro Ljubljana have been very satisfied with the performance and environmental efficiency of our products and they often upgrade their turbines with Thordon’s bearing and seal solutions at each refurbishment to achieve the ultimate wear life and eliminate the risk of pollution.
“Thordon solutions do not pollute, are simple to maintain, and offer excellent wear performance and abrasion resistance compared to other oil- or water-lubricated bearing solutions in the marketplace. Of course, shorter lead times and competitive pricing also play a part!”
“Globally, more than half of all active hydropower plants were originally commissioned over half a century ago but upgrades, refurbishments, and the use of more reliable turbine components, such as Thordon’s pioneering elastomer technology, can be hugely beneficial in reducing downtime and keeping the lights on,” said Thordon Bearings’ Regional Manager – Southern Europe & Gulf Med, Malcolm Barratt.
Commissioned in 1968, HPP Rijeka is a high-pressure derivation plant that takes water from the Rječina watercourse at an elevation of 229.50m (753ft) above sea level. About 84.45GWh of electricity is produced annually.
The historic HPP Sava Brod is a Mini Hydro Power Plant that started generating electricity in 1928 from a small facility in Brod, a village north of Ljubljana, Slovenia. The plant takes water from the Sava River.