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  • 151.
    Barankova, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Deposition using the Magnetized Hollow Cathode Activated Magnetron2018Konferansepaper (Annet vitenskapelig)
  • 152.
    Barankova, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Hollow Cathode and Hybrid Atmospheric Plasma Sources2007Inngår i: Proceedings of the: PLENARY PAPER, 2007Konferansepaper (Fagfellevurdert)
  • 153.
    Barankova, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Pulsed Atmospheric Pressure Plasma Reforming Of Ethanol2016Inngår i: Hakone XV: International Symposium On High Pressure Low Temperature Plasma Chemistry: With Joint Cost TD1208 Workshop: Non-Equilibrium Plasmas With Liquids For Water And Surface Treatment / [ed] Cernak, M; Hoder, T, 2016, s. 380-381Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The plasma source with a coaxial geometry was used for generation of plasma inside water and the ethanol-water mixtures. The hydrogen-rich synthesis gas with hydrogen content up to 60% was produced in submerged dc pulsed plasma. The effect of various plasma generation regimes on the performance of plasma, on the hydrogen production efficiency and on the reaction rise-time was examined. A role of the solution temperature, composition of the mixture and current delivered to the discharge are investigated.

  • 154.
    Barankova, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Pulsed DC Hollow Cathode Deposition of Cr and CrN Films2007Konferansepaper (Fagfellevurdert)
  • 155.
    Barankova, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Special issue on atmospheric pressure plasma2013Inngår i: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 234, s. 1-1Artikkel i tidsskrift (Annet vitenskapelig)
  • 156.
    Barankova, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära. BB Plasma Design AB, SE-75643 Uppsala, Sweden..
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära. BB Plasma Design AB, SE-75643 Uppsala, Sweden..
    Bardos, A.
    BB Plasma Design AB, SE-75643 Uppsala, Sweden..
    Magnetized hollow cathode activated magnetron2015Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 107, nr 15, artikkel-id 153501Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Planar magnetron in which the target is coupled with a magnetized hollow cathode is presented. Detailed principles of such arrangements are explained. The hollow cathode activated magnetron produces intense and stable plasmas in a wider interval of the working gas pressures as compared to the conventional magnetrons at the same power. The developed arrangements enhance sputtering from the magnetron target by the high-density hollow cathode plasma and increase the number of sputtered/evaporated species. Results of the test experiments of these arrangements on a commercial planar magnetron with the Ti target are presented and their capabilities discussed.

  • 157.
    Barankova, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Adela
    Reactive Deposition by Magnetron with Magnetized Hollow Cathode Enhanced Target2018Konferansepaper (Fagfellevurdert)
  • 158.
    Barankova, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Silins, Kaspars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Amorphous Carbon Films on Glass Prepared by Hollow Cathodes at Moderate Pressure2016Inngår i: ECS Journal of Solid State Science and Technology, ISSN 2162-8769, E-ISSN 2162-8777, Vol. 5, nr 9, s. N57-N60Artikkel i tidsskrift (Fagfellevurdert)
  • 159.
    Barankova, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära. BB Plasma Design AB, Uppsala, Sweden.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära. BB Plasma Design AB, Uppsala, Sweden.
    Silins, Kaspars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, A.
    BB Plasma Design AB.
    Reactive Deposition of TiN Films by Magnetron with Magnetized Hollow Cathode Enhanced Target2018Inngår i: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 152, s. 123-127Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Magnetized Hollow Cathode Activated Magnetron in which the target is coupled with the hollow cathode magnetized by the magnetic field of the magnetron was tested in the reactive process of TiN deposition. Increased deposition rate compared to the Ti metal deposition rate was confirmed. The depositions as well as optical measurements were performed at several pressures in the reactor. The results of the TiN reactive deposition are presented and discussed, including the TiN deposition in pure nitrogen.

  • 160.
    Barati, Paraham
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Research of gravity foundation2010Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    The material consumption of the foundation of a WEC is a big part of the totalmaterial consumption of the entire power plant. To reduce these consumption, it isrequired to optimize the foundation. To find out how small the foundation could beconstructed and still be able to cope with the requirements, it is necessary to knowabout the various forces that affects the foundation. The focus in this thesis is on theforces acting on the buoy. The forces are calculated theoretical with experimentsconducted to reach conclusions about the size of the gravity foundation.Experiments will also be conducted to investigate experimentally whether there is anydifference between the suction force of sand and clay soil.Results from experiments with buoys show that the theoretical calculations arereasonably close with results from experiments. Conclusion of the differencesbetween theory and experiment is found that this may be due to the wave tank abilityto reproduce waves, and the angle between the buoy and the wave direction.Results from experiments of the suction force shows that there is no differencebetween sand and clay. The conclusion from this experiment is that the results applyonly to the clay that was investigated in this experiment and cannot be compared withother clay types with different properties.A discussion about the foundations is carried out where the conclusion is drawn thatthe foundations for the minimum mass to maintain equilibrium at 4 m wave height isapproximately 33 ton.

    Fulltekst (pdf)
    FULLTEXT01
  • 161.
    Bardos, Ladislav
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Barankova, Hana
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Comparison of Pulsed DC and RF Hollow Cathode Depositions of CrN2007Konferansepaper (Annet vitenskapelig)
  • 162.
    Bardos, Ladislav
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Barankova, Hana
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Plasma Processes at Atmospheric and Low Pressures2007Konferansepaper (Fagfellevurdert)
  • 163.
    Bardos, Ladislav
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Barankova, Hana
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Plasma processes at atmospheric and low pressures2008Inngår i: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 83, nr 3, s. 522-527Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the last few decades there has been an intense development in non-equilibrium ("cold") plasma surface processing systems at atmospheric pressure. This new trend is stimulated mainly to decrease equipment costs by avoiding expensive pumping systems of conventional low-pressure plasma devices. This work summarizes physical and practical limitations where atmospheric plasmas cannot compete with low-pressure plasma and vice-versa. As the processing conditions for atmospheric plasma are rather different from reduced pressure systems in many cases these conditions may increase final equipment costs substantially. In this work we briefly review the main principles, advantages and drawbacks of atmospheric plasma for a better understanding of the capabilities and limitations of the atmospheric plasma processing technology compared with conventional low-pressure plasma processing. 2008 Elsevier Ltd. All rights reserved.

  • 164.
    Bardos, Ladislav
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära. BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden..
    Baránková, Hana
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära. BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden..
    Bardos, A.
    BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden..
    Production of Hydrogen-Rich Synthesis Gas by Pulsed Atmospheric Plasma Submerged in Mixture of Water with Ethanol2017Inngår i: Plasma chemistry and plasma processing, ISSN 0272-4324, E-ISSN 1572-8986, Vol. 37, nr 1, s. 115-123Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hydrogen-rich synthesis gas was produced by pulsed dc plasma submerged into ethanol-water mixtures using an original system with a coaxial geometry. The ignition of the discharge is immediately followed by production of hydrogen and after a short time necessary for filling the outlet tubing a flame can be ignited. No auxiliary gas was used for the reforming process. The synthesis gas containing up to 60% of hydrogen was formed, at the outflow rate of 250 sccm at the average power as low as 10 W. The hydrogen production efficiency corresponds to 12 kWh/kg H-2.

    Fulltekst (pdf)
    fulltext
  • 165.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Hollow cathode and hybrid atmospheric plasma sources2008Inngår i: Pure and Applied Chemistry, ISSN 0033-4545, E-ISSN 1365-3075, Vol. 80, nr 9, s. 1931-1937Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Generation and features of the radio frequency (RF) hollow cathode discharge (HCD) are compared for the atmospheric and moderate pressures. The atmospheric-pressure plasma systems, fused hollow cathode (FHC) and hybrid hollow electrode-activated discharge (H-HEAD), are described. Examples of applications where both FHC and H-HEAD have already been employed are given, and potentials for new processes are discussed.

  • 166.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära. BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära. BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden.
    Bardos, Adela
    BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden.
    Non-Conventional Atmospheric Pressure Plasma Sources for Production of Hydrogen2018Inngår i: MRS ADVANCES, ISSN 2059-8521, Vol. 3, nr 18, s. 921-929Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The atmospheric pressure plasma sources with a coaxial geometry were used for generation of the radio frequency, microwave and pulsed dc plasmas inside water and aqueous solutions. Pulsed dc plasma generated in ethanol-water mixtures leads to production of the hydrogen-rich synthesis gas with hydrogen content up to 65 % The effect of various plasma generation regimes on the performance of plasma, on the hydrogen production efficiency and on the hydrogen-rich synthesis gas production was examined. A role of the composition of the ethanol-water mixture was investigated.

  • 167.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Silins, Kaspars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    DLC coatings prepared by hollow cathodes at moderate pressure2015Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    DLC coatings were prepared using the rf powered cylindrical and linear hollow cathodes. The deposition process is hybrid, combining both the PE CVD and PVD. A cylindrical graphite nozzle and graphite plates were used as targets. The gas mixture used in the deposition process was argon with acetylene.

     

    Compared to e.g. magnetron sputtering, the optimum content of acetylene is lower. The effect of the acetylene content in the gas mixture as well as rf power on the deposition rate and properties of the coatings are evaluated.

     

    The geometrical effect is studied, the cylindrical hollow cathode and the linear hollow cathode are compared and the transfer of the optimized process from the cylindrical into the linear hollow cathode is discussed.

    Fulltekst (pdf)
    fulltext
  • 168.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bardos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Silins, Silins
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    DLC coatings prepared by hollow cathodes at moderate pressure2015Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    DLC coatings were prepared using the rf powered cylindrical and linear hollow cathodes. The deposition process is hybrid, combining both the PE CVD and PVD. A cylindrical graphite nozzle and graphite plates were used as targets. The gas mixture used in the deposition process was argon with acetylene.

     

    Compared to e.g. magnetron sputtering, the optimum content of acetylene is lower. The effect of the acetylene content in the gas mixture as well as rf power on the deposition rate and properties of the coatings are evaluated.

     

    The geometrical effect is studied, the cylindrical hollow cathode and the linear hollow cathode are compared and the transfer of the optimized process from the cylindrical into the linear hollow cathode is discussed.

  • 169.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bàrdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Atmospheric pressure plasma conversion of CO2 to solid deposits2015Inngår i: Results in Physics, ISSN 2211-3797, Vol. 5, s. 257-258Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fused Hollow Cathode (FHC) with aerodynamic stabilization was used for the gas conversion processes. During the conversion of NO into NO2 in air mixtures, the CO2 reduction occurs, without forming gaseous CO. In these processes brownish glassy solid deposits are formed in the plasma region. The deposits were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction.

    Fulltekst (pdf)
    fulltext
  • 170.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Atmospheric Pressure Plasma Sources and Processing2009Inngår i: Handbook of Deposition Technologies for Films and Coatings / [ed] Peter M. Martin, Oxford: Elsevier, William Andrew , 2009, 3, s. 865-880Kapittel i bok, del av antologi (Annet (populærvitenskap, debatt, mm))
  • 171.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Cold Atmospheric Plasma in Liquids2012Konferansepaper (Fagfellevurdert)
  • 172.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Cold Atmospheric Plasma Inside Water2012Konferansepaper (Fagfellevurdert)
  • 173.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Cold Atmospheric Plasma Processing of Inner Surfaces: INVITED PAPER2012Konferansepaper (Annet vitenskapelig)
  • 174.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Cold Atmospheric Plasma Treatment of Energy System Components: INVITED PAPER2010Konferansepaper (Annet vitenskapelig)
  • 175.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Convergion of Nitrogen Oxides by the Atmospheric Hollow Cathode Discharges: INVITED PAPER2010Inngår i: IEEE 37th International Conference on Plasma Science, Norfolk, Virginia, USA, 2010Konferansepaper (Annet vitenskapelig)
  • 176.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Conversion of Nitrogen and Carbon Oxides by the Atmospheric Hollow Cathode Discharges2012Inngår i: IEEE Transactions on Plasma Science, ISSN 0093-3813, E-ISSN 1939-9375, Vol. 40, nr 5, s. 1324-1328Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have successfully tested the fused hollow cathode with aerodynamic stabilization as a 100% oxidation catalyst in conversion of NOx in air mixtures. Plasma chemical kinetics and the processing window width are controlled by plasma characteristics. Results show that, besides the plasma source design itself, the material of the electrodes plays a crucial role. It was found that, by using graphite electrodes, a 100% removal of NO from the air mixtures is possible without necessity of adding hydrocarbons. This paper presents results of oxygen screening, discusses the mechanisms of the process, and reports also on the CO2 reduction in some discharge regimes.

  • 177.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Design and Applications of the Atmospheric Pressure Hollow Cathodes2008Konferansepaper (Annet vitenskapelig)
  • 178.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Design and Performance of the Hollow Cathode Cold Atmospheric Plasma Sources2008Inngår i: Jahrbuch Oberflächentechnik 2008-BAND 64 / [ed] R. Suchentrunk, Bad Saulgau: Eugen G. Leuze Verlag KG , 2008Kapittel i bok, del av antologi (Fagfellevurdert)
  • 179.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Effect of the Electrode Material in the Atmospheric Plasma Abatement of Nitrogen Oxides: Paper SE -MoA32009Konferansepaper (Annet vitenskapelig)
  • 180.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Effect of the Electrode Material on the Atmospheric Plasma Conversion of NO in Air Mixtures2009Konferansepaper (Fagfellevurdert)
  • 181.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Effect of the electrode material on the atmospheric plasma conversion of NO in air mixtures2010Inngår i: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 84, nr 12, s. 1385-1388Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Non-thermal atmospheric pressure plasma is widely used for conversion of hazardous gases. Results from different laboratories confirm importance of energy non-equilibrium in the plasma where dominant energy carriers are electrons and a dominant chemistry is based on formation and interactions of radicals. Because of rather high electric fields required for generation and sustaining of air discharges at atmospheric pressure many plasma systems were found rather to create a lot of NO instead of removing it. A widely supported way to clean NO and NO2 from air mixtures is a plasma assisted catalytic reduction where the cold plasma is combined with the solid-state catalyst. In an ideal case the plasma acts as an oxidation catalyst where an atomic oxygen from air oxidizes NO to NO2 and the solid-state catalysts are then capable to convert all NO2 to N-2 and O-2. In most cases it is also necessary to involve auxiliary gases, e.g., propylene, to make the process efficient enough. This work introduces an original cold plasma system based on atmospheric hollow cathodes generated by a nanopulse DC power with controllable voltage and pulse frequency. The system was optimized in both the geometry and the applied power. However, the material of electrodes was found to be the most important factor affecting the plasma performance and consequently the chemical kinetics. A 100% conversion of NO to NO2 was achieved with a graphite electrode, without using any auxiliary gas and without catalyst. Plasma performance and conversion efficiency are compared for several electrode materials.

  • 182.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Environmental Applications of the Atmospheric Pressure Plasma Sources: Paper JAPT-112009Konferansepaper (Fagfellevurdert)
  • 183.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Hollow Cathode and Hybrid Plasma Processing at Low and High Pressures2008Konferansepaper (Fagfellevurdert)
  • 184.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Hollow Cathode High Density Plasma PVD of Cr and CrN films2008Konferansepaper (Fagfellevurdert)
  • 185.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    New plasma sources for atmospheric pressure applications2008Konferansepaper (Fagfellevurdert)
  • 186.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Non-thermal atmospheric plasma: Sources, processes and applications, INVITED PAPER2011Inngår i: Encontro de Física, Foz do Iguacu, Brazil, Foz do Iguacu, Brazil, 2011Konferansepaper (Fagfellevurdert)
  • 187.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Optimal Dimensions of the Atmospheric Hollow Cathodes2008Konferansepaper (Fagfellevurdert)
  • 188.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Optimization and performance of atmospheric Fused Hollow Cathodes2013Inngår i: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 87, s. 128-131Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Experimental results on the atmospheric hollow cathode plasma generation and performance, using a special configuration with tunable wall separations, are presented. The influence of the gas and type of the power used for generation on the optimum size of the cathode slit is investigated. The experimental results are in agreement with the hollow cathode model. The plasma source/plasma reactor design is of utmost importance for control of plasma-chemical kinetics. An example of the atmospheric hollow cathode plasma application for the NOx conversion is given. The energy consumption and plasma characteristics are discussed.

  • 189.
    Baránková, Hana
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bárdos, Ladislav
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Bergkvist, Mikael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Waters, Rafael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Grabbe, Mårten
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Leijon, Mats
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Coatings for Renewable Energy: Paper JAPT-142009Konferansepaper (Fagfellevurdert)
  • 190. Batten, W.M.J.
    et al.
    Harrison, M.E.
    Bahaj, A. S.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    The accuracy of the actuator disc-RANS approach for predicting the performance and far wake of a horizontal axis tidal stream turbine2013Inngår i: Philosophical Transactions. Series A: Mathematical, physical, and engineering science, ISSN 1364-503X, E-ISSN 1471-2962Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The actuator disc-RANS model has been widely used in wind and tidal energy to predict the wake of a horizontal axis turbine. The model is appropriate where large scale effects of the turbine on a flow are of interest, for example, when considering environmental impacts, or arrays of devices. The accuracy of the model for modelling the wake of tidal stream turbines has not been demonstrated, and flow predictions presented in the literature for similar modelled scenarios vary significantly. This paper compares the results of the actuator disc-RANS model, where the turbine forces have been derived using a blade element approach, to experimental data measured in the wake of a scaled turbine. It also compares the results to those of a simpler uniform actuator disc model. The comparisons show that the model is accurate and can predict up to 94\% of the variation in the experimental data measured on the centreline of the wake. The study demonstrates that the actuator-disc RANS model is an accurate approach for modelling a turbine wake, and conservative approach to predict performance and loads. It can therfore applied to similar scenarios with confidence.

  • 191.
    Baudoin, Antoine
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Cooling Strategies for Wave Power Conversion Systems2016Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The Division for Electricity of Uppsala University is developing a wave power concept. The energy of the ocean waves is harvested with wave energy converters, consisting of one buoy and one linear generator. The units are connected in a submerged substation. The mechanical design is kept as simple as possible to ensure reliability.

    The submerged substation includes power electronics and different types of electrical power components. Due to the high cost of maintenance operations at sea, the reliability of electrical systems for offshore renewable energy is a major issue in the pursuit of making the electricity production economically viable. Therefore, proper thermal management is essential to avoid the components being damaged by excessive temperature increases.

    The chosen cooling strategy is fully passive, and includes no fans. It has been applied in the second substation prototype with curved heatsinks mounted on the inner wall of the pressurized vessel. This strategy has been evaluated with a thermal model for the completed substation. First of all, 3D-CFD models were implemented for selected components of the electrical conversion system. The results from these submodels were used to build a lumped parameter model at the system level.

    The comprehensive thermal study of the substation indicates that the rated power in the present configuration is around 170 kW. The critical components were identified. The transformers and the inverters are the limiting components for high DC-voltage and low DC-voltage respectively. The DC-voltage—an important parameter in the control strategy for the WEC—was shown to have the most significant effect on the temperature limitation.

    As power diodes are the first step of conversion, they are subject to large power fluctuations. Therefore, we studied thermal cycling for these components. The results indicated that the junction undergoes repeated temperature cycles, where the amplitude increased with the square root of the absorbed power.

    Finally, an array of generic heat sources was optimized. We designed an experimental setup to investigate conjugate natural convection on a vertical plate with flush-mounted heat sources. The influence of the heaters distribution was evaluated for different dissipated powers. Measurements were used for validation of a CFD model. We proposed optimal distributions for up to 36 heat sources. The cooling capacity was maximized while the used area was minimized.

    Delarbeid
    1. Optimized distribution of a large number of heat sources cooled by conjugate turbulent natural convection
    Åpne denne publikasjonen i ny fane eller vindu >>Optimized distribution of a large number of heat sources cooled by conjugate turbulent natural convection
    (engelsk)Inngår i: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606Artikkel i tidsskrift (Fagfellevurdert) Submitted
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-307944 (URN)
    Tilgjengelig fra: 2016-11-24 Laget: 2016-11-23 Sist oppdatert: 2017-11-29
    2. Temperature and velocity measurements in a buoyant flow induced by a heat source array on a vertical plate
    Åpne denne publikasjonen i ny fane eller vindu >>Temperature and velocity measurements in a buoyant flow induced by a heat source array on a vertical plate
    2017 (engelsk)Inngår i: Experimental Thermal and Fluid Science, ISSN 0894-1777, E-ISSN 1879-2286, Vol. 88, s. 234-245Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Heat source arrays are common in engineering applications. Natural convection is a reliable and silent cooling strategy. Therefore, an array of flush-mounted heat sources has been studied under conjugate conduction and natural convection condition. This studies was performed for a system with relatively large dimensions, typical for power electronics, and a modified Rayleigh number up to 2 . 10(10) A modular set of heaters was designed to vary the distribution of heat sources on the plate and investigate the influence of the spacing. Velocity and temperature were measured in the convective flow with particle image velocimetry and micro-thermocouple. The velocity field was analyzed with proper orthogonal decomposition. The first instabilities of the convective flows were described. The results gave abetter understanding of the heat transfers in these configurations and are valuable for model validation.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-307943 (URN)10.1016/j.expthermflusci.2017.06.002 (DOI)000409285600023 ()
    Forskningsfinansiär
    SweGRIDS - Swedish Centre for Smart Grids and Energy StorageStandUp
    Tilgjengelig fra: 2016-11-24 Laget: 2016-11-23 Sist oppdatert: 2017-12-01bibliografisk kontrollert
    3. Experimental Optimization of Passive Cooling of a Heat Source Array Flush-Mounted on a Vertical Plate
    Åpne denne publikasjonen i ny fane eller vindu >>Experimental Optimization of Passive Cooling of a Heat Source Array Flush-Mounted on a Vertical Plate
    2016 (engelsk)Inngår i: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 9, nr 11, artikkel-id 912Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Heat sources, such as power electronics for offshore power, could be cooled passively—mainly by conduction and natural convection. The obvious advantage of this strategy is its high reliability. However, it must be implemented in an efficient manner (i.e., the area needs to be kept low to limit the construction costs). In this study, the placement of multiple heat sources mounted on a vertical plate was studied experimentally for optimization purposes. We chose a regular distribution, as this is likely to be the preferred choice in the construction process. We found that optimal spacing can be determined for a targeted source density by tuning the vertical and horizontal spacing between the heat sources. The optimal aspect ratio was estimated to be around two.

    Emneord
    discrete heat sources, source array, natural convection, optimization
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-307831 (URN)10.3390/en9110912 (DOI)000388580000054 ()
    Forskningsfinansiär
    SweGRIDS - Swedish Centre for Smart Grids and Energy StorageStandUp
    Tilgjengelig fra: 2016-11-22 Laget: 2016-11-22 Sist oppdatert: 2017-11-29bibliografisk kontrollert
    4. Assessment of Thermal Cycling in a Rectifier For WavePower Generation
    Åpne denne publikasjonen i ny fane eller vindu >>Assessment of Thermal Cycling in a Rectifier For WavePower Generation
    2016 (engelsk)Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Natural convection allows for passive cooling which isused in many engineering applications. Placing dissipatingcomponents on a common vertical heatsink can be opti-mized to give the best possible cooling capacity. In thisstudy, a numerical model for three-dimensional conjugatedconvective and conductive heat transfer was used to evalu-ate the distribution of up to 36 ush-mounted rectangularheaters. The temperature proles and the heat uxes werecompared with experimental data for validation. The dis-sipated power was set as an input parameter and the op-timal distribution was selected as the one with the lowesttemperature elevation. Two dierent heuristicsa geo-metric parameter and an articial neural networkwereproposed and evaluated as alternatives to heavy CFD cal-culations.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-307945 (URN)
    Konferanse
    IET Renewable Power Generation
    Tilgjengelig fra: 2016-11-23 Laget: 2016-11-23 Sist oppdatert: 2016-11-25
    5. Thermal Rating of a Submerged Substation for Wave Power
    Åpne denne publikasjonen i ny fane eller vindu >>Thermal Rating of a Submerged Substation for Wave Power
    2016 (engelsk)Inngår i: IEEE Transactions on Sustainable Energy, ISSN 1949-3029, E-ISSN 1949-3037, Vol. 7, nr 1, s. 436-445Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The costs of offshore maintenance operations put high reliability-requirements on offshore equipment for ocean energy, especially on submerged ones. Thermal management is thus essential in the design of the prototypes of a marine substation, developed at Uppsala University, for grid interface of wave power parks. The cooling system itself should be efficient as well as reliable. Therefore, the feasibility of a completely passive cooling strategy was evaluated. The studied substation includes various power components, which dissipate heat and are installed in one pressurized vessel. Thermal cross-coupling was investigated with 3-D submodels and a thermal network model. An electric circuit was coupled to determine the rated power of the substation. The results depend mainly on the dc-voltage, the seawater temperature, and the thermal contact between the components and the hull.

    Emneord
    Computational fluid dynamics;Computational modeling;Heat transfer;Heating;Integrated circuit modeling;Substations;Wave power;Computational fluid dynamic (CFD);natural convection;ocean energy;passive cooling;power electronics;thermal management;wave power
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-267226 (URN)10.1109/TSTE.2015.2425045 (DOI)000367340700044 ()
    Forskningsfinansiär
    SweGRIDS - Swedish Centre for Smart Grids and Energy StorageStandUpSwedish Energy Agency
    Tilgjengelig fra: 2015-11-19 Laget: 2015-11-19 Sist oppdatert: 2017-12-01bibliografisk kontrollert
    6. Thermal modelling of a passively cooled inverter for wave power
    Åpne denne publikasjonen i ny fane eller vindu >>Thermal modelling of a passively cooled inverter for wave power
    2015 (engelsk)Inngår i: IET Renewable Power Generation, ISSN 1752-1416, E-ISSN 1752-1424, Vol. 9, nr 4, s. 389-395Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Owing to very costly maintenance operations, the reliability of electrical systems for offshore renewable energy is a major issue to make electricity production economical. Therefore proper thermal management is essential in order to avoid the components from being damaged by excessive temperature increase. Both analytic and computational fluid dynamics (CFD) models were implemented to assess the temperature increase in the inverter installed in a submerged substation and during working conditions. It was shown that this inverter could transmit a total power of up to about 35 kW. This limit is dependent on a certain distance between the modules and a perfect thermal contact with the hull. The influence of several of such parameters as well as the efficiency of passive cooling were studied.

    Emneord
    wave power plants, invertors, substations, cooling, thermal modelling, passively cooled inverter, wave power, CFD models, submerged substation, thermal contact, passive cooling
    HSV kategori
    Forskningsprogram
    Teknisk fysik med inriktning mot elektricitetslära
    Identifikatorer
    urn:nbn:se:uu:diva-252981 (URN)10.1049/iet-rpg.2014.0112 (DOI)000352809300011 ()
    Tilgjengelig fra: 2015-05-19 Laget: 2015-05-18 Sist oppdatert: 2017-12-04bibliografisk kontrollert
    7. Wave Energy Research at Uppsala University and The Lysekil Research Site, Sweden: A Status Update
    Åpne denne publikasjonen i ny fane eller vindu >>Wave Energy Research at Uppsala University and The Lysekil Research Site, Sweden: A Status Update
    Vise andre…
    2015 (engelsk)Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    This paper provides a summarized status update ofthe Lysekil wave power project. The Lysekil project is coordinatedby the Div. of Electricity, Uppsala University since 2002, with theobjective to develop full-scale wave power converters (WEC). Theconcept is based on a linear synchronous generator (anchored tothe seabed) driven by a heaving point absorber. This WEC has nogearbox or other mechanical or hydraulic conversion systems,resulting in a simpler and robust power plant. Since 2006, 12 suchWECs have been build and tested at the research site located atthe west coast of Sweden. The last update includes a new andextended project permit, deployment of a new marine substation,tests of several concepts of heaving buoys, grid connection,improved measuring station, improved modelling of wave powerfarms, implementation of remote operated vehicles forunderwater cable connection, and comprehensive environmentalmonitoring studies.

    Emneord
    Wave energy, point absorber, experiments, arrays, generators, ROVs
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-265218 (URN)
    Konferanse
    Proceedings of the 11th European Wave and Tidal Energy Conference. Nantes, France, September 2015
    Tilgjengelig fra: 2015-10-26 Laget: 2015-10-26 Sist oppdatert: 2019-08-19bibliografisk kontrollert
    8. Measurement System For Wave Energy Converter - Design And Implementation
    Åpne denne publikasjonen i ny fane eller vindu >>Measurement System For Wave Energy Converter - Design And Implementation
    2014 (engelsk)Inngår i: 33Rd International Conference On Ocean, Offshore And Arctic Engineering, 2014, Vol 9A: Ocean Renewable Energy, AMER SOC MECHANICAL ENGINEERS , 2014Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    A Wave Energy Converter (WEC) measurement system has been constructed and installed with the purpose to measure, log and evaluate the WEC's performance during operation at sea. The WEC is to be deployed at Uppsala University's wave power research site in Lysekil on the west coast of Sweden. In designing such a system the key research objectives has been (1) to study the risk of overheating due to high currents in the stator windings, (2) to evaluate how the WEC's outer structure withstands drag and bending forces from the buoy line and (3) to construct a detection system which indicates if water leaks into the generator. The measurement system was designed to collect data essential to study these key objectives. Transducers were used to measure: buoy line force, translator position, phase currents, bending and tensile strain on the generator hull, water level inside generator and the temperature at multiple places inside the generator. The measurement system has been installed and calibrated in the WEC. Furthermore, the design has been evaluated in lab experiments in order to verify the function and accuracy of the different measurements. This paper presents the underlying research objectives for developing the WEC generator measurement system, together with a description of the technical implementation.

    sted, utgiver, år, opplag, sider
    AMER SOC MECHANICAL ENGINEERS, 2014
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-272118 (URN)000363499000005 ()978-0-7918-4553-0 (ISBN)
    Konferanse
    33Rd International Conference On Ocean, Offshore And Arctic Engineering
    Merknad

    Första författaren har bytt efternamn till Ulvgård

    Tilgjengelig fra: 2016-01-12 Laget: 2016-01-12 Sist oppdatert: 2017-09-28
    9. Status Update of the Wave Energy Research at Uppsala University
    Åpne denne publikasjonen i ny fane eller vindu >>Status Update of the Wave Energy Research at Uppsala University
    Vise andre…
    2013 (engelsk)Konferansepaper, Publicerat paper (Fagfellevurdert)
    sted, utgiver, år, opplag, sider
    Aalborg, Denmark: , 2013
    HSV kategori
    Forskningsprogram
    Teknisk fysik med inriktning mot elektricitetslära
    Identifikatorer
    urn:nbn:se:uu:diva-212701 (URN)
    Konferanse
    10th European Wave and Tidal Conference (EWTEC)
    Tilgjengelig fra: 2013-12-13 Laget: 2013-12-13 Sist oppdatert: 2017-12-07
    10. Temperature Study in a Marine Substation for Wave Power
    Åpne denne publikasjonen i ny fane eller vindu >>Temperature Study in a Marine Substation for Wave Power
    Vise andre…
    2012 (engelsk)Inngår i: International Journal of Mechanic Systems Engineering, ISSN 2225-7403, Vol. 2, nr 4, s. 126-131Artikkel i tidsskrift (Fagfellevurdert) Published
    HSV kategori
    Forskningsprogram
    Teknisk fysik med inriktning mot elektricitetslära
    Identifikatorer
    urn:nbn:se:uu:diva-190091 (URN)
    Tilgjengelig fra: 2013-01-07 Laget: 2013-01-07 Sist oppdatert: 2017-01-18bibliografisk kontrollert
    11. Marine substation design for grid-connection of a research wave power plant on the Swedish West coast
    Åpne denne publikasjonen i ny fane eller vindu >>Marine substation design for grid-connection of a research wave power plant on the Swedish West coast
    2013 (engelsk)Konferansepaper, Publicerat paper (Fagfellevurdert)
    sted, utgiver, år, opplag, sider
    Aalborg, Denmark: , 2013
    HSV kategori
    Forskningsprogram
    Teknisk fysik med inriktning mot elektricitetslära
    Identifikatorer
    urn:nbn:se:uu:diva-212687 (URN)
    Konferanse
    10th European Wave and Tidal Conference (EWTEC)
    Tilgjengelig fra: 2013-12-13 Laget: 2013-12-13 Sist oppdatert: 2016-11-24
    12. Lysekil Research Site, Sweden: A status update
    Åpne denne publikasjonen i ny fane eller vindu >>Lysekil Research Site, Sweden: A status update
    Vise andre…
    2011 (engelsk)Inngår i: 9th European Wave and Tidal Energy Conference, Southampton, UK, 2011, 2011Konferansepaper, Publicerat paper (Fagfellevurdert)
    HSV kategori
    Forskningsprogram
    Teknisk fysik med inriktning mot elektricitetslära
    Identifikatorer
    urn:nbn:se:uu:diva-160039 (URN)
    Konferanse
    9th European Wave and Tidal Energy Conference, Southampton, UK, 5-9 September 2011
    Tilgjengelig fra: 2011-10-13 Laget: 2011-10-13 Sist oppdatert: 2017-01-25
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  • 192.
    Baudoin, Antoine
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Thermal Study of a Submerged Substation for Wave Power2014Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    At the Division of Electricity of Uppsala University, a wave power concept is being developed.It relies on wave energy converters, one buoy and one linear generator placed on the seabed, connected together to a submerged substation. The mechanical design is kept as simple as possible to ensure reliability. The submerged substation includes power electronics and different types of electric components. High reliability requirements on such subsea devices make thermal management a keyaspect in the design. Besides, no fans are used and the cooling strategy is fully-passive. The overall approach for thermal modelling of the substation is based on a thermal network atthe system level, and both analytic- and CFD- modelling at the component level. This work is focusing on the second prototype of substation developed at Uppsala University. In this thesis, this overall strategy is presented as well as a comprehensive temperature study for the inverterinstalled in the substation.In the present configuration, the inverters are limited to about 35 kW. The seawater temperature,the choice of material for the heat-sink, and the spacing of the component, were identified tohave an influence on this value. The importance of a good thermal contact between the heat-sink and the hull was also illustrated.

  • 193.
    Baudoin, Antoine
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Boström, Cecilia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Thermal modelling of a passively cooled inverter for wave power2015Inngår i: IET Renewable Power Generation, ISSN 1752-1416, E-ISSN 1752-1424, Vol. 9, nr 4, s. 389-395Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Owing to very costly maintenance operations, the reliability of electrical systems for offshore renewable energy is a major issue to make electricity production economical. Therefore proper thermal management is essential in order to avoid the components from being damaged by excessive temperature increase. Both analytic and computational fluid dynamics (CFD) models were implemented to assess the temperature increase in the inverter installed in a submerged substation and during working conditions. It was shown that this inverter could transmit a total power of up to about 35 kW. This limit is dependent on a certain distance between the modules and a perfect thermal contact with the hull. The influence of several of such parameters as well as the efficiency of passive cooling were studied.

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  • 194.
    Baudoin, Antoine
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Boström, Cecilia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Leijon, Mats
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Thermal Rating of a Submerged Substation for Wave Power2016Inngår i: IEEE Transactions on Sustainable Energy, ISSN 1949-3029, E-ISSN 1949-3037, Vol. 7, nr 1, s. 436-445Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The costs of offshore maintenance operations put high reliability-requirements on offshore equipment for ocean energy, especially on submerged ones. Thermal management is thus essential in the design of the prototypes of a marine substation, developed at Uppsala University, for grid interface of wave power parks. The cooling system itself should be efficient as well as reliable. Therefore, the feasibility of a completely passive cooling strategy was evaluated. The studied substation includes various power components, which dissipate heat and are installed in one pressurized vessel. Thermal cross-coupling was investigated with 3-D submodels and a thermal network model. An electric circuit was coupled to determine the rated power of the substation. The results depend mainly on the dc-voltage, the seawater temperature, and the thermal contact between the components and the hull.

  • 195.
    Baudoin, Antoine
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Boström, Cecilia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Saury, Didier
    Assessment of Thermal Cycling in a Rectifier For WavePower Generation2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Natural convection allows for passive cooling which isused in many engineering applications. Placing dissipatingcomponents on a common vertical heatsink can be opti-mized to give the best possible cooling capacity. In thisstudy, a numerical model for three-dimensional conjugatedconvective and conductive heat transfer was used to evalu-ate the distribution of up to 36 ush-mounted rectangularheaters. The temperature proles and the heat uxes werecompared with experimental data for validation. The dis-sipated power was set as an input parameter and the op-timal distribution was selected as the one with the lowesttemperature elevation. Two dierent heuristicsa geo-metric parameter and an articial neural networkwereproposed and evaluated as alternatives to heavy CFD cal-culations.

  • 196.
    Baudoin, Antoine
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Ekström, Rickard
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Boström, Cecilia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Rahm, Magnus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Svensson, Olle
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Strömstedt, Erland
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Savin, Andrej
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Waters, Rafael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Leijon, Mats
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Temperature Study in a Marine Substation for Wave Power2012Inngår i: International Journal of Mechanic Systems Engineering, ISSN 2225-7403, Vol. 2, nr 4, s. 126-131Artikkel i tidsskrift (Fagfellevurdert)
  • 197.
    Baudoin, Antoine
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Saury, Didier
    Univ Poitiers, ENSMA, CNRS, Inst PPRIME, BP 40109, F-86961 Futuroscope, France.
    Temperature and velocity measurements in a buoyant flow induced by a heat source array on a vertical plate2017Inngår i: Experimental Thermal and Fluid Science, ISSN 0894-1777, E-ISSN 1879-2286, Vol. 88, s. 234-245Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Heat source arrays are common in engineering applications. Natural convection is a reliable and silent cooling strategy. Therefore, an array of flush-mounted heat sources has been studied under conjugate conduction and natural convection condition. This studies was performed for a system with relatively large dimensions, typical for power electronics, and a modified Rayleigh number up to 2 . 10(10) A modular set of heaters was designed to vary the distribution of heat sources on the plate and investigate the influence of the spacing. Velocity and temperature were measured in the convective flow with particle image velocimetry and micro-thermocouple. The velocity field was analyzed with proper orthogonal decomposition. The first instabilities of the convective flows were described. The results gave abetter understanding of the heat transfers in these configurations and are valuable for model validation.

  • 198.
    Baudoin, Antoine
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Saury, Didier
    Boström, Cecilia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Optimized distribution of a large number of heat sources cooled by conjugate turbulent natural convectionInngår i: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606Artikkel i tidsskrift (Fagfellevurdert)
  • 199.
    Baudoin, Antoine
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Saury, Didier
    Univ Poitiers, ENSMA, CNRS, Inst PPRIME, BP 40109, F-86961 Futuroscope, France..
    Boström, Cecilia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Optimized distribution of a large number of power electronics components cooled by conjugate turbulent natural convection2017Inngår i: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 124, s. 975-985Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Natural convection allows for passive cooling which is used in many engineering applications. Placing dissipating components on a common vertical heatsink can be optimized to give the best possible cooling capacity. In this study, a numerical model for three-dimensional conjugated convective and conductive heat transfer was used to evaluate the distribution of up to 36 flush-mounted rectangular heaters. The temperature profiles and the heat fluxes were compared with experimental data for validation. The dissipated power was set as an input parameter and the optimal distribution was selected as the one with the lowest temperature elevation. Two different heuristics-a geometric parameter and an artificial neural network-were proposed and evaluated as alternatives to heavy CFD calculations.

  • 200.
    Baudoin, Antoine
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Saury, Didier
    Univ Poitiers, ENSMA, CNRS, Inst PPRIME, BP 40109, F-86961 Futuroscope, Chassencuil, France.
    Zhu, Bo
    Univ Poitiers, ENSMA, CNRS, Inst PPRIME, BP 40109, F-86961 Futuroscope, Chassencuil, France.
    Boström, Cecilia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Experimental Optimization of Passive Cooling of a Heat Source Array Flush-Mounted on a Vertical Plate2016Inngår i: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 9, nr 11, artikkel-id 912Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Heat sources, such as power electronics for offshore power, could be cooled passively—mainly by conduction and natural convection. The obvious advantage of this strategy is its high reliability. However, it must be implemented in an efficient manner (i.e., the area needs to be kept low to limit the construction costs). In this study, the placement of multiple heat sources mounted on a vertical plate was studied experimentally for optimization purposes. We chose a regular distribution, as this is likely to be the preferred choice in the construction process. We found that optimal spacing can be determined for a targeted source density by tuning the vertical and horizontal spacing between the heat sources. The optimal aspect ratio was estimated to be around two.

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