Calorimetric testing of solar thermal absorbers for high vacuum flat panels

D’Alessandro, Carmine; Maio, Davide De; Caldarelli, Antonio; Musto, Marilena; Giamberardino, Francesco Di; Monti, Matteo; Mundo, Teresa; Gennaro, Emiliano Di; Russo, R.; Palmieri, V.G.

doi:10.1016/j.solener.2022.07.039

Cited by 7 publications

(4 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The curve represents the variation in thermal emittance with respect to the absorber temperature, providing important insights into the performance characteristics of the heat absorber. The absorber emittance curve was experimentally obtained by averaging the thermal emittance measured with a calorimetric approach [30,31]. The MT-Power operates at a maximum temperature of 200 °C and employs a commercial absorber with a multi-layer structure consisting of an aluminum substrate coated with an absorption layer and an anti-reflection layer.…”

Section: Application Of Proposed Hvfpcs Efficiency Model To Mt-power ...mentioning

confidence: 99%

See 1 more Smart Citation

Formulation of an Efficiency Model Valid for High Vacuum Flat Plate Collectors

Gaudino,

Caldarelli,

Russo

et al. 2023

Energies

Self Cite

View full text Add to dashboard Cite

High Vacuum Flat Plate Collectors (HVFPCs) are the only type of flat plate thermal collectors capable of producing thermal energy for middle-temperature applications (up to 200 °C). As the trend in research plans is to develop new Selective Solar Absorbers to extend the range of HVFPC application up to 250 °C, it is necessary to correctly evaluate the collector efficiency up to such temperatures to predict the energy production accurately. We propose an efficiency model for these collectors based on the selective absorber optical properties. The proposed efficiency model explicitly includes the radiative heat exchange with the ambient, which is the main source of thermal losses for evacuated collectors at high temperatures. It also decouples the radiative losses that depend on the optical properties of the absorber adopted from the other thermal losses due to HVFPC architecture. The model has been validated by applying it to MT-Power HVFPC manufactured by TVP-Solar. The dissipative losses other than thermal radiation were found to be mostly conductive with a linear coefficient k = 0.258 W/m2K. The efficiency model has been also used to predict the energy production of HVFPCs equipped with new, optimized Selective Solar Absorbers developed in recent years. Considering the 2019 meteorological data in Cairo and an operating temperature of 250 °C, the annual energy production of an HVFPC equipped with an optimized absorber is estimated to be 638 kWh/m2.

show abstract

Section: Application Of Proposed Hvfpcs Efficiency Model To Mt-power ...mentioning

confidence: 99%

“…When deriving the thermal efficiency formula of MT-Power, the optical properties of the SSA, such as absorptance α and effective emittance ε e (T), were obtained through calorimetric measurements following the procedure described in [31,32].…”

Section: Application Of Proposed Hvfpcs Efficiency Model To Mt-power ...mentioning

confidence: 99%

Formulation of an Efficiency Model Valid for High Vacuum Flat Plate Collectors

Gaudino,

Caldarelli,

Russo

et al. 2023

Energies

Self Cite

View full text Add to dashboard Cite

show abstract

“…1), optimized to work at temperature of 200 °C in high vacuum flat plate collectors, is computed using a MATLAB script based on the transfer matrix method. The computed emittance was compared with experimental measurements performed with a dedicated experimental set-up [13].…”

Section: Introductionmentioning

confidence: 99%

Hemispherical Emittance in Multilayer Solar Absorbers: A MATLAB-Based Approach for Optimizing Solar Thermal Efficiency

Gaudino,

Caldarelli,

Luca

et al. 2024

Preprint

View full text Add to dashboard Cite

“…These collectors belong to the family of non-concentrating solar panels and are direct descendants of the much less efficient flat plate solar collectors [3]. The distinctive feature of these collectors is that they have an evacuated air gap between the absorber and the protective glass, in which an air-pressure of 10 −4 mbar is reached [4]. This air evacuation is much deeper than in the traditional evacuated collectors [5] and allows convective heat exchanges between absorber and glass to be almost eliminated, resulting in a net reduction of the device's heat losses, and, consequently, in high heat absorption efficiencies even at relatively high operating temperatures [6].…”

mentioning

confidence: 99%

Energy comparison analysis between direct and indirect dry saturated steam generation, thermally powered by EFPCs’ solar fields

Levrano,

Anacreonte,

Gaudino

et al. 2024

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Steam is a key energy vector in the industrial sector and each application requires it at a specific pressure and temperature. In this paper the production of low pressure dry saturated steam for industrial use through high-vacuum flat plate solar collectors (HVFPCs) is discussed. This technology can produce steam from solar energy, hybridizing it with existing fossil powered steam generators to obtain significant energy savings and reduce CO 2 emissions. An energy comparison using the 0-D TRNSYS® software between numerical results of different plant configurations is made, which differ in the type of dry saturated steam production device. These devices are necessary as it is not possible to produce steam directly inside collectors. Two possible steam generation methods were analysed: direct steam production, using a Flash vessel, and indirect steam production, using a Kettle reboiler. Finally, each configuration was simulated by imposing a solar field ΔT of 10 °C and 20 °C. Dynamic results show that flash vessel configurations are generally the most efficient, with the same operating parameters, compared to the configurations with Kettle reboiler. Furthermore, configurations with certain ΔT, such as to determine lower operational solar field temperatures, lead to the best results due to the higher HVFPCs’ efficiency.

show abstract

Calorimetric testing of solar thermal absorbers for high vacuum flat panels

Cited by 7 publications

References 34 publications

Formulation of an Efficiency Model Valid for High Vacuum Flat Plate Collectors

Formulation of an Efficiency Model Valid for High Vacuum Flat Plate Collectors

Hemispherical Emittance in Multilayer Solar Absorbers: A MATLAB-Based Approach for Optimizing Solar Thermal Efficiency

Energy comparison analysis between direct and indirect dry saturated steam generation, thermally powered by EFPCs’ solar fields

Contact Info

Product

Resources

About