The transformation of the energy industry towards CO2-free energy supply requires not only the substitution of fossil primary energy sources such as coal, oil and gas with CO2-free/neutral energy sources such as solar, wind, hydrogen or biomass, but also an increase in energy efficiency in distribution as well as conversion into other required forms of energy by rotating machines such as motors and generators. In addition, energy storage is playing an increasingly important role in balancing the volatile share of energy generation due to weather conditions. In addition to power-to-X technologies, kinetic energy storage systems are also being used here as grid-stabilizing short-term storage systems. The reduction of losses in the bearing of rotating machine parts by conventional plain or roller bearings offers great potential for this.
The project aims to increase the efficiency of turbomachinery by using low-loss and low-maintenance magnetic bearings. The focus is on the use of these units under extreme environmental conditions, such as those encountered in offshore wind turbines or gas turbines. In the previous project, the theoretical basis for this was developed in the sense of holistic, practical solutions. The aim was to develop and optimize magnetic bearing components for these operating conditions without the need for ancillary systems such as cooling systems.
The current project involves the experimental validation and verification of the solutions developed and implemented for the magnetic bearings, position sensors and catcher bearings. In addition to extensive laboratory equipment, the large-scale MFLP test rig developed and set up as part of the Zittau power plant laboratory is available for this purpose. Furthermore, automation technology potentials are being developed in the project with the aim of using modern algorithms of information and communication technology for the evaluation of operating conditions in real time, for forecasts of resource-optimal and safe operation and for plant diagnostics. Networking (grid computing) is essential for processing the large volumes of data (big data) generated in the process. Powerful algorithms (fuzzy, KNN, AI) structure and reduce the resulting flood of data.
As a result of the work, solutions are available for energy-efficient, safe and reliable magnetic bearings for turbomachinery for use under extreme environmental conditions.
The project is part of the research and development within the research focus "Energy and Environment" of the University of Applied Sciences Zittau/Görlitz.
With the deployment of active magnet bearings the energy efficiency of turbomachinery ought to be increased. In doing so, extreme environment conditions put high requirements on construction of magnet and catcher bearings as well as on selection of materials.
The question for suitable concepts for catcher bearings for turbomachines is answered insufficiently until now. In this project we aim to create a scientific and technical basis for the development of appropriate catcher bearing concepts für heavy machinery with active magnetic bearings.
For this purpose we compile the theoretical basis for design, modeling and simulation of friction and roller bearings, and develop, construct and errect a suitable major test stand for the qualification of catcher bearings. This enables us to test catcher bearings and validate models under extreme environmental conditions.
The project is worked on in the "Zittau Power Plant Laboratory" and is part of the research and development within the research focus "Energy and Environment" of the University of Applied Sciences Zittau/Görlitz.
Steam turbines are usually fitted with friction bearings. Oil is used for lubrication and cooling of the bearings. For speed control valves as well as for safety shutdown valves oil is needed too. These non-negligible amounts of oil pose a high safety risk. Through the deployment of magnet bearings and electro-mechanical valve drives the usage of oil with steam turbines can be abandoned, because magnet bearings stabilize a turbine rotor only with magnetic force and hence don't need lubricant.
To industrially deploy an oil-free magnetic bearings using steam turbine in the power plant Jänschwalde we have tested this technology using a test stand in Zittau and have delivered the proof of function.
Furthermore, we have conducted experiments for cooling of magnet bearings using air and have found optimal operating points for air cooling. In addition to that we have verified the performance of the emergency systems during failure of the magnet bearings.
After finishing experiments the prototype of a feed pump drive turbine was manufacured by the Turbinenwerk Görlitz (Siemens AG) and installed in the power plant Jänschwalde. There, the turbine is in operation since 2014, initially in trial operation and in power operation since 2015.