Wärtsilä’s history dates back more than 180 years, and during this time the company has accumulated extensive experience and knowledge in developing innovative products, systems, and integrated solutions for the marine, energy and industrial sectors.
With a solid understanding of these industries, Wärtsilä has been able to adapt technologies that were originally intended for one sector, to meet the requirements and needs of another. An example of this can be seen in the way in which Wärtsilä has successfully adapted capabilities originally developed for marine applications for use in hydro installations.
Complete hydropower solutions
Wärtsilä’s broad range of seal and bearing solutions was originally developed for stern tube applications in ships. Today the range has been extended and further developed to provide complete and effective solutions for hydro installations. These are complemented with services ranging from repairs and fabrications, retrofits, upgrades, oil-to-water lubrication conversions and component reconditioning.
The focus of the company’s R&D efforts in hydro applications for seals, bearings and complementary equipment including water quality systems, is on providing sustainable designs that maximize turbine capacity and efficiency, whilst eliminating cavitation. This work can be seen in the following innovative product developments:
Wärtsilä REvolution System
This new digital management system has taken sealing technology to a new level. The Wärtsilä REvolution system incorporates model predictive control (MPC) techniques to provide customers with intelligent, real-time active management of the sealing interface fluid film. This minimizes wear and removes sealing components from the maintenance schedule critical path, helping to ensure that operations will not suffer from costly and unexpected interruptions.
Wärtsilä composite bearings
Journal bearings used in hydro turbines have become the focus of continuing technology development. This work has produced superior filament wound bearing materials that provide outstanding bearing properties and performance. Wärtsilä’s composite bearings are water lubricated, with all the long-term economic and environmental benefits that this implies.
The wear resistance of the bearing material is of high importance in increasing turbine efficiency. Wärtsilä has carried out extensive laboratory testing at its research and development facilities to produce the best possible composite material for such applications. The company’s horizontal journal bearing test rig is capable of applying pressure as high as 16 bar to the bearing. Furthermore, the test procedure measures the bearing temperature, its load, the shaft’s rotational torque, the total friction, and the shaft’s rpm and positioning. This supplies real-time data that are critical for various test regimes. The result is a water lubricated composite bearing that delivers extended life and excellent performance.
Wärtsilä water quality system (WQS)
A conditioned water supply to remove particulates and contaminants from lubrication systems is essential for protecting water lubricated bearing assemblies from abrasive wear and damage. The modular designed WQS represents a state-of-the-art approach to achieving a specified water quality, in line with operating and environmental standards, to extend the life of the installation.
The system includes a hydro cyclone, which unlike filters and mechanical strainers, is not prone to blocking, which can cause a loss of output flow. A PLC-based control panel manages the operation of the water quality system to fully monitor its performance. The system also features a dual pump arrangement to limit risk and provide redundancy in the event of a failure of the duty pump. Centrifugal solid handling pumps are used to avoid any possibility of over-pressurising the system, thereby minimising the need for safety valves. The WQS feeds separate shafts independently.
Oil to water lubrication conversions
Wärtsilä has successfully completed a number of oil to water conversions. This work includes planning, approvals, equipment, installation supervision and project management. A typical on-site conversion involves shaft machining as well as the removal of all oil lubricated seals, bearings, systems and pipework. A water lubricated seal and bearing assembly that conforms to environmental legislation is then installed. The result is zero risk of operational oil leaks, extended service intervals and an efficient lifecycle solution.
One notable conversion project was carried out for the Loup River Public Power District in Nebraska, USA (see H&D Issue 4 for full article). For a number of years, the plant had been suffering from stoppages and high maintenance costs because of faults with the oil lubricated system. Wärtsilä was able to successfully design and install a complete conversion package, including the water lubricated seals, composite bearings, and a water quality system.
Wartsila also completed the successful grease to water conversion for the hydropower plant at La Tzintre, Switzerland. The operational challenges included rapidly rising bearing temperatures and unusual wear. In addition, the seals and bearings were consuming large quantities of grease. All these issues were overcome with the conversion to water lubrication and the plant is now operating normally.
Rehabilitation and upgrades
As part of an extensive pump house refurbishment, the Harland and Wolff shipyard in Belfast, Northern Ireland, required upgrades to their dry dock de-watering pump seals. These pumps are critical to the yard’s operations as the dry dock is central to being able to cope with planned and emergency ship repairs. The seal upgrades were completed within the scheduled time, providing fast installation with the pump shaft in-situ.
Wärtsilä is constantly looking for innovations that make products more efficient, durable and environmentally sound. On the cutting edge of this is the company’s new white metal technology, which significantly improves the mechanical and tribological properties of white metal applications across the industry.
Images show the Wärtsilä REvolution system and the Hartland and Wolff shipyard in Belfast.