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Wäckelgård, E
Alternative names
Publications (10 of 60) Show all publications
Wäckelgård, E. & Svedung, H. (2016). Optical characterization and modelling of paint top-coatings for low-emittance applications. Infrared physics & technology, 78, 275-281
Open this publication in new window or tab >>Optical characterization and modelling of paint top-coatings for low-emittance applications
2016 (English)In: Infrared physics & technology, ISSN 1350-4495, E-ISSN 1879-0275, Vol. 78, p. 275-281Article in journal (Refereed) Published
Abstract [en]

The study reports on characterization of low-infrared-emittance paint top-coatings for interior building applications in which the thermal radiation becomes important in comparison with thermal conductance. The top-coating that consist of a binder with aluminium flakes has been optically characterized in the infrared wavelength range in order to determine single flake and binder emittance from reflectance measurements. The single flake emittance was found to be 0.12 for non-leafing cornflake. The absorption coefficient that determines the binder emittance as a function of binder thickness was 0.060 [mu m](-2) and 0.085 [mu m](-2) for Lumiflon and polyester respectively. These results were used as parameters in a simple model of the flake-binder top-coating to investigate how the emittance of the top-coating was influence by the two components and compared with a state-of-art low-emittance commercial paint. It was found from the modelling that replacing the polyester binder with Lumiflon reduces the infrared emittance (at room temperature) from 0.36 to 0.30. Increasing flake reflectance from 0.88 to 0.96 and at the same time reduce flake thickness from 2 to 1 mu m gives an emittance of 0.20. However, the real samples prepared with Lumiflon showed a severe degradation caused by the flakes floating up closer to the surface which indicates a viscosity problem that needs to be solved for practical use. Thinner flakes with higher reflectance can be found if vacuum metallised pigments are used instead of ball-milled.

National Category
Atom and Molecular Physics and Optics Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-308781 (URN)10.1016/j.infrared.2016.08.011 (DOI)000386407200036 ()
Funder
Knowledge Foundation
Available from: 2016-12-08 Created: 2016-11-30 Last updated: 2017-11-29Bibliographically approved
Wäckelgård, E., Mattsson, A., Bartali, R., Gerosa, R., Gloria, G., Gustavsson, F., . . . Rivolta, B. (2015). Development of W–SiO2 and Nb–TiO2 solar absorber coatings for combined heat and power systems at intermediate operation temperatures. Solar Energy Materials and Solar Cells, 133, 180-193
Open this publication in new window or tab >>Development of W–SiO2 and Nb–TiO2 solar absorber coatings for combined heat and power systems at intermediate operation temperatures
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2015 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 133, p. 180-193Article in journal (Refereed) Published
Abstract [en]

Two new absorber coatings for mid-temperature operation (300–350 1C) in collectors for solar thermal electricity plants are presented in this study. The absorbers consist of two cermet layers of either W–SiO2 or Nb–TiO2, deposited on a molybdenum infrared reflector and coated with an antireflection layer of silicon oxide. The optimization of the optical performance was made in two steps. First, the layer structure was optimized in model calculations. The optical constants used in this modelling were derived directly from sputtered films of the cermet constituents using reflectance and transmittance measure- ments. The absorber coatings were then sputter-deposited using parameters from the modelling. The results show good agreement between modelled and sputtered optical performance evaluated as solar absorptance and thermal emittance at 350 1C. The optimal values reached for W–SiO2 was 0.91 in combination with 0.08 and 0.93 in combination with 0.09 for Nb–TiO2. The materials characterization from XRD, AES and TEM shows that the composite coatings contain nano-metal inclusions, meaning that they are cermet coatings. Scratch tests show that the coatings adhere well to the substrate of stainless steel. Temperature testing at 350 1C in vacuum for up to 1500 h shows that both coatings are stable under such conditions. Only a slight change occurs during the first 72 h that decreases the emittance but does not change the solar absorptance. ERDA confirms that there is no detectable level of ion migration between layers, only a small decrease in hydrogen content was observed, which indicates outgassing.

National Category
Other Engineering and Technologies
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-239313 (URN)10.1016/j.solmat.2014.10.022 (DOI)000348015100027 ()
Projects
Digespo project
Funder
EU, FP7, Seventh Framework Programme
Available from: 2014-12-22 Created: 2014-12-22 Last updated: 2017-12-05Bibliographically approved
Wäckelgård, E., Mattsson, A., Bartali, R., Gerosa, R., Gottardi, G., Gustavsson, F., . . . Rivolta, B. (2014). Development of W-SiO2 and Nb-TiO2 solar absorber coatings for combined heat and power systems at intermediate operation temperatures. Solar Energy Materials and Solar Cells, 133
Open this publication in new window or tab >>Development of W-SiO2 and Nb-TiO2 solar absorber coatings for combined heat and power systems at intermediate operation temperatures
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2014 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 133Article in journal (Refereed) Published
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-286696 (URN)
Available from: 2016-04-21 Created: 2016-04-21 Last updated: 2017-11-30
Wäckelgård, E., Bartali, R., Gerosa, R., Laidani, N., Mattsson, A., Micheli, V. & Rivolta, B. (2014). New cermet coatings for mid-temperature applications for solar concentrated combine heat and power system. In: Haberle, A (Ed.), Proceedings of the 2ND International Conference on Solar Heating and Cooling for Buildings and Industry (SHC 2013): . Paper presented at 2nd International Conference on Solar Heating and Cooling for Buildings and Industry (SHC), SEP 23-25, 2013, Freiburg, GERMANY (pp. 242-249).
Open this publication in new window or tab >>New cermet coatings for mid-temperature applications for solar concentrated combine heat and power system
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2014 (English)In: Proceedings of the 2ND International Conference on Solar Heating and Cooling for Buildings and Industry (SHC 2013) / [ed] Haberle, A, 2014, p. 242-249Conference paper, Published paper (Refereed)
Abstract [en]

New cermet (ceramic-metal) composite coatings have been developed for solar absorbers in a solar concentrating system for combined heat and power operating in a mid-temperature range between 250 to 350 degrees C. The coatings were applied on stainless steel substrates. Two types of cermet with expected good duration properties were chosen: Nb-TiO2 and W-SiO2. The basic layer-structure concept consisted of four sub-layers, counted from the substrate: molybdenum infrared reflector, high metal concentration cermet of either Nb-TiO2 or W-SiO2, low metal concentration cermet of either Nb-TiO2 or W-SiO2 and SiO2 antireflection layer. The results from optimised coating fabrication gave solar absorptance and thermal emittance of 0.93 and 0.09 respectively for the Nb-TiO2 cermet and 0.91 and 0.08 for the W-SiO2 cermet based absorbers. Annealing at 350 degrees C did not change the absorptance but decreased the thermal emittance with 0.01 units. Adhesion to substrate and between sub-layers was good and even improved after annealing. In a next step up-scaling to deposition on tubes has been made for the Nb-TiO2 cermet type coating and such absorbers are now operating in the solar concentrating combined heat and power demonstration plant in Malta.

Series
Energy Procedia, ISSN 1876-6102 ; 48
Keyword
solar absorber, cermet coating, sputtering-deposition
National Category
Environmental Analysis and Construction Information Technology
Identifiers
urn:nbn:se:uu:diva-240883 (URN)10.1016/j.egypro.2014.02.029 (DOI)000345410700028 ()
Conference
2nd International Conference on Solar Heating and Cooling for Buildings and Industry (SHC), SEP 23-25, 2013, Freiburg, GERMANY
Available from: 2015-01-08 Created: 2015-01-08 Last updated: 2015-01-08Bibliographically approved
Wäckelgård, E., Bartali, R., Gerosa, R., Laidani, N., Mattsson, A., Micheli, V. & Rivolta, B. (2014). New Cermet Coatings for Mid-temperature Applications for Solar Concentrated Combine Heat and Power System. Energy Procedia, 48, 242-249
Open this publication in new window or tab >>New Cermet Coatings for Mid-temperature Applications for Solar Concentrated Combine Heat and Power System
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2014 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 48, p. 242-249Article in journal (Refereed) Published
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-286693 (URN)
Available from: 2016-04-21 Created: 2016-04-21 Last updated: 2017-11-30
Åberg, M., Widén, J., Wäckelgård, E. & Henning, D. (2012). Large-scale introduction of new residential district-heating loads to increase renewable electricity generation in CHP plants. In: Proceedings of the World Renewable Energy Forum 2012, Denver, Colorado, USA, May 13-17, 2012. Paper presented at World Renewable Energy Forum 2012, Denver, Colorado, USA, May 13-17, 2012 (pp. 2407-2414).
Open this publication in new window or tab >>Large-scale introduction of new residential district-heating loads to increase renewable electricity generation in CHP plants
2012 (English)In: Proceedings of the World Renewable Energy Forum 2012, Denver, Colorado, USA, May 13-17, 2012, 2012, p. 2407-2414Conference paper, Published paper (Refereed)
Abstract [en]

Combined heat and power (CHP) plants enable an efficient use of low-grade energy carriers, such as domestic waste and biomass, for co-generation of district heating (DH) and electricity. Expected future building energy-efficiency improvements reduce the demand for space heating and may limit the possibilities to cogenerate electricity. The use of DH for new applications, such as household appliances, can improve conditions for co-generation of electricity. This paper investigates the future potential to increase DH demand and co-generation of electricity due to large-scale implementation of household appliances that use DH instead of electricity. The analysis is applied to the DH system in Uppsala, Sweden. Results show that co-generation of electricity and total fuel use increase with implementation of household appliances connected to a building hot water circuit (HWC). The impact on CO2 emissions depends on DH fuel mix and electricity assessment approach.

National Category
Energy Systems
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-174620 (URN)978-162276092-3 (ISBN)
Conference
World Renewable Energy Forum 2012, Denver, Colorado, USA, May 13-17, 2012
Available from: 2012-05-22 Created: 2012-05-22 Last updated: 2015-01-22Bibliographically approved
Crema, L., Bozzoli, A., Alberti, F., Wäckelgård, E., Hesse, S., Hislop, D., . . . Restall, B. (2012). Novel m-CHP generation from small scale Concentrated Solar Power. In: World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conference. Paper presented at World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conference, 13 May 2012 through 17 May 2012, Denver, CO (pp. 735-742).
Open this publication in new window or tab >>Novel m-CHP generation from small scale Concentrated Solar Power
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2012 (English)In: World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conference, 2012, p. 735-742Conference paper, Published paper (Refereed)
Abstract [en]

The paper describes the realization of a modular 1-3 kWe, 3-9 kWth micro Combined Heat and Power (m-CHP) system based on innovative Concentrated Solar Power (CSP) and Stirling engine technology. This CSP m-CHP will provide electrical power, heating and cooling for single and multiple domestic dwellings and other small buildings. The cogeneration of energy at distributed level is one of leading argument in large part of energy policies related to renewable energy resources and systems. The actual marketable solar systems for domestic and distributed applications (PV and Solar thermal) suffer of notable limitation: i) the low overall (electrical) efficiency of PV systems create a small collected energy from available space, sometimes restricted in surface to few square meters, ii) the stagnation temperatures on solar thermal collectors actually limiting the diffusion of solar thermal systems, iii) fixed and not retrofittable systems may generate energy in intermittent way not aligned with the auto consumption profile of domestic spaces.

Keyword
Concentrated solar power, Distributed applications, Electrical power, Large parts, Micro-combined heat and power, PV system, Small scale, Solar thermal, Solar thermal collector, Solar thermal systems, Electric power generation, Energy policy, Innovation, Solar energy, Solar heating, Stirling engines, Cogeneration plants
National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-195445 (URN)9781622760923 (ISBN)
Conference
World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conference, 13 May 2012 through 17 May 2012, Denver, CO
Available from: 2013-02-26 Created: 2013-02-25 Last updated: 2013-03-04Bibliographically approved
Joudi, M. A., Rönnelid, M., Svedung, H. & Wäckelgård, E. (2011). Energy Efficient Buildings with Functional Steel Cladding. In: Low-Energy Architecture(LEA): . Paper presented at World Renewable Energy Congress 2011 –Sweden 8-11 May 2011, Linköping, Sweden.
Open this publication in new window or tab >>Energy Efficient Buildings with Functional Steel Cladding
2011 (English)In: Low-Energy Architecture(LEA), 2011Conference paper, Published paper (Refereed)
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-286700 (URN)
Conference
World Renewable Energy Congress 2011 –Sweden 8-11 May 2011, Linköping, Sweden
Available from: 2016-04-21 Created: 2016-04-21 Last updated: 2016-04-21
Boström, T., Valizadeh, S., Lu, J., Jensen, J., Westin, G. & Wäckelgård, E. (2011). Structure and morphology of nickel-alumina/silica solar thermal selective absorbers. Journal of Non-Crystalline Solids, 357(5), 1370-1375
Open this publication in new window or tab >>Structure and morphology of nickel-alumina/silica solar thermal selective absorbers
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2011 (English)In: Journal of Non-Crystalline Solids, ISSN 0022-3093, E-ISSN 1873-4812, Vol. 357, no 5, p. 1370-1375Article in journal (Refereed) Published
Abstract [en]

Nickel-alumina/silica thin film materials for the use in solar thermal absorbers have been investigated using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Elastic Recoil Detection Analysis (ERDA). The TEM images revealed that all layers have a very small thickness variation and that the layers are completely homogenous. High resolution images showed 5-10 nm (poly) crystalline nickel nano-particles. ERDA showed that both the silica and alumina compositions contain more oxygen than 2:1 and 3:2 respectively. SEM showed the surface morphology and characteristics of the top silica anti-reflection layer. Hybrid-silica has showed to generate a smoother surface with less cracking compared to pure silica. The final curing temperature revealed to be of importance for the formation of cracks and the surface morphology.

Keyword
Solar, Absorber, SEM, TEM, ERDA
National Category
Engineering and Technology Inorganic Chemistry
Research subject
Chemistry with specialization in Inorganic Chemistry; Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-151660 (URN)10.1016/j.jnoncrysol.2010.09.023 (DOI)000288726700004 ()
Available from: 2011-04-15 Created: 2011-04-15 Last updated: 2017-12-11Bibliographically approved
Widén, J. & Wäckelgård, E. (2010). A high-resolution stochastic model of domestic activity patterns and electricity demand. Applied Energy, 87(6), 1880-1892
Open this publication in new window or tab >>A high-resolution stochastic model of domestic activity patterns and electricity demand
2010 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 87, no 6, p. 1880-1892Article in journal (Refereed) Published
Abstract [en]

Realistic time-resolved data on occupant behaviour, presence and energy use are important inputs to various types of simulations, including performance of small-scale energy systems and buildings' indoor climate, use of lighting and energy demand. This paper presents a modelling framework for stochastic generation of high-resolution series of such data. The model generates both synthetic activity sequences of individual household members, including occupancy states, and domestic electricity demand based on these patterns. The activity-generating model, based on non-homogeneous Markov chains that are tuned to an extensive empirical time-use data set, creates a realistic spread of activities over time, down to a 1-min resolution. A detailed validation against measurements shows that modelled power demand data for individual households as well as aggregate demand for an arbitrary number of households are highly realistic in terms of end-use composition, annual and diurnal variations, diversity between households, short time-scale fluctuations and load coincidence. An important aim with the model development has been to maintain a sound balance between complexity and output quality. Although the model yields a high-quality output, the proposed model structure is uncomplicated in comparison to other available domestic load models.

Keyword
Bottom-up, Domestic electricity demand, Load model, Markov chain, Stochastic
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-132899 (URN)10.1016/j.apenergy.2009.11.006 (DOI)000278306300010 ()
Available from: 2010-10-28 Created: 2010-10-28 Last updated: 2017-12-12Bibliographically approved
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