Vortex power plant

from Wikipedia, the free encyclopedia
Gravitational eddy power plant with Zotlöterer turbine near Ober-Grafendorf

A water vortex power plant , also known as a gravitational water vortex power plant (GWWK), is a small hydropower plant that is suitable for generating energy from hydropower from a flow rate of 500 to 1000 liters of water per second with small height differences of 0.5 to 3 meters. The technology is based on a (round) basin with a central drain downwards. A stable water vortex forms above the drain, which drives a special slowly rotating water turbine. Water vortex power plants are less efficient than conventional small hydropower plants, but they are fish-safe.

functionality

A symmetrical water vortex forms in a rotationally symmetrical vessel over a drainage opening in the middle of the vessel bottom. For technical usability, a stable and symmetrical water vortex with a flow-free vortex center is aimed for, which drives a turbine rotating slowly at approx. 20 revolutions per minute.

In the ideal case, a potential vortex results , the tangential velocity of which increases steadily in the direction of the vortex center. Gravity is a prerequisite for the formation of a stable vertical axis of rotation . The water runoff is minimal when the diameter of the reservoir is significantly larger than the diameter of the drain.

advantages

Schematic representation of a water vortex power plant (the turbine is shown in yellow)

In practical operation (or for the operator) of a water vortex power plant, there is the advantage over hydropower plants with conventional water turbines that no emergency shutdown system has to be activated in the event of a sudden load shedding (e.g. in the event of an unexpected power failure of the power grid into which the feed is being fed). In other words, a large amount of water (e.g. the nominal flow rate) only flows into or through a water vortex power plant when the turbine is loaded. When the turbine is idling, the flow rate is reduced to around 10% of the nominal flow rate due to the special fluidic properties of the symmetrical water vortex. In this way, a flow control system or an automatic emergency shutdown system can be dispensed with when constructing a water vortex power plant and construction costs can be saved.

An alternatively usable water power machine with regard to the water vortex power plant is the undershot water wheel and the hydropower screw , whereas the application range of Kaplan , Francis or even Pelton turbines is at higher heads. Compared to the undershot water wheel, the water vortex power plant has the advantage of a smaller turbine with a higher speed. For example, an undershot water wheel with 7 kW power has a diameter of about 5 m at a speed of about 7 / min and a torque of about 9550 Nm, while the diameter of the turbine of a 7 kW water vortex power plant is about 1 m, the turbine speed at about 35 / min and the torque is 1910 Nm. Thus, because of the higher turbine speed in the water vortex power plant compared to the undershot water wheel, one gear stage, namely the most expensive one with the highest torque, can be saved.

In addition, in contrast to the acoustically very loud water wheels (about 88 dB at a distance of 1 m), the turbine of a water vortex power plant runs almost noiselessly (less than 50 dB at a distance of 1 m).

Similar to the hydrodynamic screw the water vortex power plant requires only an inexpensive bar screens for the retention of floating debris , which in comparison to conventional water turbines with sensitive expensive fine processing equipment cleaning intervals considerably larger.

Ecological impact

The water vortex power plant cooperative is carrying out independent studies on fish permeability at the Swiss pilot power plant in Schöftland an der Suhre, which have produced positive interim results.

A water vortex power plant is not a major encroachment on a flowing water . Usually low, already existing transverse structures, so-called floor steps , are used, which means that meter-high embankments on the banks are no longer necessary. In the case of turbines with a small number of blades, the efficiency remains low at 31 to 48.5%, as Franz Mühle was able to determine years ago at the Technical University of Munich. However, in principle, only low to medium overall efficiencies (from about 25 to 65%) can be achieved with a low drop height; only optimized water vortex power plants deliver higher values.

The proponents of water vortex power plants claim that because of the intensive water aeration by the gravitational water vortex in the rotation basin of a water vortex power plant, an ideal habitat for aquatic plants, small organisms and fish is created. After a short time, the walls of the round reservoir are densely overgrown with spring mosses , between which numerous river flea shrimp and caddis fly larvae nest.

Critics such as the WWF and others point out that water vortex power plants are also a barrier that prevents the revitalization of rivers , and that the patency for slowly swimming fish species has not been proven.

The Austrian technician Franz Zotlöterer assumes that there is fish passage, which is also confirmed by an official study / report. For this purpose, a trap was used a few meters upstream in front of the rotation basin in the inflow channel. Fish that migrated upstream through the Zotlöterer turbine were intercepted by it, including species such as cops , trout , aitel and huchen . According to the manufacturer, an unspecified study by university graduates confirmed that the water vortex power plant should be ecologically sustainable for numerous fish species. For the very simple report, similar measurements from 2006 and 2011 are subsumed with the measurements from 2013. These measurements are published exclusively on the manufacturer's website.

application

The concept of generating energy from a water vortex that forms over the outflow of a water reservoir is used in various devices. For example, a device patented in 1968 by the American Kenard D. Brown (1968 / US patent 3372905) and in 1996 by the Australian Paul Kouris is based on the generation of energy from such a water vortex at a great drop height and with the help of a long suction pipe.

The Austrian technician Franz Zotlöterer realized a gravitational water vortex power plant with a patented, slightly spiral-shaped rotation tank (2003 / Austrian AT12363 and AT413579 as well as 2007 / Swiss CH699133) and the patented Zotlöterer turbine (PCT WO2011051421). Relatively slowly rotating turbines are used (approx. 20 revolutions per minute), which are passable for small debris, debris and fish. In cooperation with the University of Applied Sciences Northwestern Switzerland , attempts were made to further optimize the rotor in order to harvest more energy from the vortex. This turbine, which is also supposed to use the vertical currents, only has an efficiency of 50%, because it restricts the development of the gravitational water vortex and the torque available for the turbine decreases.

In the world's first pilot plant , the m in 2005 with a pelvic diameter of 5.5, a drop height m of 1.5 and a flow rate of 0.9 m³ / s in the Austrian Ober-Grafendorf was built by the research and development department of the company Zotlöterer , are generated with the Zotlöterer turbine according to their own information with a maximum turbine efficiency of 80% up to 10  kW electrical power and between 40,000 and 65,000  kWh / a . The turbine rotation frequency is 33 min −1 (0.55  Hz ).

Another water vortex power plant was built in 2009 in Switzerland on the Suhre in Schöftland . The plan was for an electrical output of up to 15 kW and an annual production of up to 80,000 to 130,000 kWh or electricity requirements of around 20 to 25 households. Due to technical problems and the bankruptcy of the operating cooperative, the plant is to be dismantled in autumn 2019.

It has been in operation in Austria in Carinthia am Wimitzbach with 2 × 3.5 kW and 27,000 kWh / a since the end of 2011 in Germany in Winterberg / Sauerland with 1 × 3.8 kW. However, typical but low noise emissions (60 dB) from the transmission were found in Winterberg. A system built in Indonesia in 2007 supplies a school building (Kul Kul School in Bali) and was able to go into operation after clarification with the local authority.

With greater heads and flow rates, significantly more electricity can be obtained (2.5 m, 10 m³ / s: 150 kW). For powers greater than approx. 150 kW, water vortex power plants are uneconomical because they have a lower control energy capacity (i.e. a lower overall efficiency) than conventional small hydropower plants .

Problems

Scientific studies have shown efficiencies below 50%. For example, the system that has existed in Schöftland, Switzerland since 2009 (see above) is examined in more detail in the article by Matthias Daum in the magazine "DIE ZEIT". Accordingly, the operators of the system, Heidi Zumstein and Andreas Steinmann, were initially disappointed with the efficiency of their system. “It was only 30 percent instead of the promised 60 percent. Two thirds of the energy in water literally went down the drain. Today, a few technical improvements later, the efficiency is 42 percent. A new rotor should soon help convert half of the water energy into electricity. ”In June 2016, the Cooperative Water Vortex Concepts Switzerland files for bankruptcy. Dismantling of the plant was planned for autumn 2019.

Scientific experiments and resulting articles such as the model studies by Franz Mühle, Christoph Rapp and Oliver Mayer also show efficiencies between 31 and 48.5%

The operator of the first German water vortex power plant describes his experiences on its own website. According to his own statements, he does this in order to provide additional information to the planners and manufacturers that have been drawn out of thin air. This power plant was built between 2011 and 2012 on Hillebach in Niedersfeld with Austrian participation. Both the planning errors and the low levels of efficiency are documented on the website.

Awards

  • 2007: Energy Globe Award Carinthia
  • 2010: Energy Globe Award Lower Austria 2010 and Austria 2010 (special category inventor)
  • 2011: Watt d'Or 2011 in the Renewable Energy category for river restoration with a hydro-vortex power plant in Schöftland , awarded by the Swiss Federal Office of Energy

See also

literature

  • Franz Mühle, Christoph Rapp, Oliver Mayer: Experimental investigations on a water vortex power plant. In: water management. 103 (7-8), Springer Vieweg, 2013, pp. 41-46.
  • F. Mühle: Experimental Investigations On A Water Vortex Power Plant Master's thesis. Technical University of Munich, Munich 2012.
  • C. Cerri, S. Gafner: Wasserwirbelkraftwerk. Technical report on the bachelor thesis. University of Applied Sciences Northern Switzerland, 2010.
  • Franz Zotlöterer: (unknown title) In: Stephan Heimerl (Hrsg.): Ninth International User Forum for Small Hydropower Plants. Ostbayerisches Technologie-Transfer-Inst., Regensburg 2006, ISBN 3-934681-47-6 , pp. 108-112.
  • Franz Zotlöterer: Increasing the water quality through a new type of hydropower plant. (PDF; 76 kB), 5th International Energy Industry Conference at the Vienna University of Technology, 2007.
  • Franz Zotlöterer: Water, Energy, Air. (Title of the collective work). In: Swiss Water Management Association (Ed.): Water, Energy, Air. 4/2007, Baden 2007, ISSN  0377-905X .
  • Franz Zotlöterer: The gravitational water vortex power plant . In: cement and concrete. Issue 3_11, pp. 36–39.
  • Ben Schwan: We could replace a nuclear power plant. July 26, 2010, Technology Review (Online)
  • Franz Zotlöterer: Function and potential of gravitational water vortex power plants . (PDF; 733 kB) In: Bulletin-electrosuisse. Trade journal for electrical energy generation 2_12, pp. 29–32.
  • Franz Zotlöterer: zek-hydro - specialist journal for Hydroenergy. Issue 5_12, pp. 62–65.
  • Franz Zotlöterer: Gravitational water vortex power plants. In: Hydropower & Energy. Edition 3/2013, pp. 2–11.

Web links
Media reports (selection)

Individual evidence

  1. ↑ a b technology. (No longer available online.) Water vortex power plant cooperative, archived from the original on February 9, 2015 ; accessed on February 2, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / gwwk.ch
  2. ↑ Reference systems , zotloeterer.com
  3. ↑ 6. Success control of fish permeability ( memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / gwwk.ch
  4. ^ A b Franz Mühle, Christoph Rapp, Oliver Mayer: Experimental investigations on a water vortex power plant. Springer Vieweg (2013), accessed September 30, 2013 .
  5. ^ A b Franz Zotlöterer: Ecology. Zotlöterer, accessed June 4, 2012 .
  6. ^ Franz Zotlöterer: Hydroelectric power station as a bioreactor. In: Youtube video. Zotlöterer, accessed June 4, 2012 .
  7. ↑ WWF information sheet on water vortex power plants (PDF; 2.4 MB)
  8. ↑ biologist Arthur Kirchhofer in the Bieler Tagblatt  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. of November 14, 2011 (PDF; 342 kB)@1@ 2Template: Dead Link / www.esb.ch  
  9. ↑ Franz Zotlöterer: fish monitoring. Zotlöterer, accessed February 7, 2018 .
  10. ↑ Patent US6114773 : Hydraulic Turbine Assembly. Applied January 25, 1996 , published September 5, 2000 , applicant: Paul S. Kouris, inventor: Paul S. Kouris. ‌
  11. ↑ Patent AT412363B . ‌
  12. ↑ Patent AT413579B . ‌
  13. ↑ patent CH699133 . ‌
  14. ↑ patent WO2011051421 . ‌
  15. ↑ Superturbine for small hydropower plants  ( page can no longer be accessed , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , Einstein (SF-Wissensmagazin) from June 23, 2011.@1@ 2Template: Dead Link / www.srf.ch  
  16. ↑ Thesis on the subject of "Wasserwirbelkraftwerk"  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. at the University of Applied Sciences Northwestern Switzerland in autumn 2010.@1@ 2Template: Toter Link / web.fhnw.ch  
  17. ↑ Information from the operator , zotloeterer.com, 2006-2014, accessed on: February 2, 2015
  18. ↑ hk-gebaeudetechnik.de (PDF file), accessed on June 4, 2012.
  19. ↑ Brochure from the Swiss water vortex power plant cooperative ( memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , gwwk.ch, accessed on February 2, 2015 @1@ 2Template: Webachiv / IABot / gwwk.ch
  20. ↑ a b https://www.srf.ch/news/regional/aargau-solothurn/zurueck-zu-natuerlichen-fluss-umstrittenes-wasserwirbelkraftwerk-an-der-suhre-verschwindet
  21. ↑ Reference systems , zotloeterer.com
  22. ↑ watervortex.net: performance data
  23. ↑ Franz Zotlöterer: The gravitational water vortex power plant (PDF; 612 kB)
  24. ↑ "Vortex around the eddy current" zeit.de
  25. ↑ www.aargauerzeitung.ch/aargau/aarau/der-energietraum-wirbelt-bachab-betreiber-des-wasserkraftwerks-schoeftland-ist-konkurs , website of the Aargauer Zeitung. Retrieved June 16, 2016
  26. ↑ www.srf.ch/news/regional/aargau-solothurn/aus-fuer-wasserwirbel-kraftwerk-schoeftland-umweltverbaende-freuts , SRF website. Retrieved June 16, 2016
  27. ↑ Tobias Kräling: Promise and actual production of a water vortex system. Accessed February 7, 2018 (German).
  28. ↑ Winner 2010 , energyglobe.com
  29. ↑ Winner of the Watt d'Or 2011 ( Memento of the original from January 26, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , SFOE on January 6, 2011. @1@ 2Template: Webachiv / IABot / www.bfe.admin.ch
  30. ↑ Genossenschaft Wasserwirbelkraftwerke Schweiz ( Memento of the original from January 16, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / gwwk.ch