Simulator testing of evacuated flat plate solar collectors for industrial heat and building integration

Moss, R.W.; Henshall, Paul; Arya, Farid; Shire, G. S. F.; Eames, Philip C.; Hyde, Trevor

doi:10.1016/j.solener.2018.02.004

Cited by 34 publications

(14 citation statements)

References 35 publications

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“…It results in excellent performance up to 180 • C, but at higher temperatures the low selectivity of the absorber increases the thermal radiation losses, affecting the panel efficiency and limiting the stagnation temperature at about 320 • C with an illumination of 1000 W/m 2 . The increased panel efficiency due to high vacuum has been studied also from other researchers [31] and the superior performance up to 250 • C have been predicted [32], if an optimized SSA was mounted in HVFP. However, the authors did not give any indication on how to produce such optimized SSA.…”

Section: Introductionmentioning

confidence: 86%

A Selective Solar Absorber for Unconcentrated Solar Thermal Panels

et al. 2021

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A new Selective Solar Absorber, designed to improve the Sun-to-thermal conversion efficiency at mid temperatures in high vacuum flat thermal collectors, is presented. Efficiency has been evaluated by using analytical formulas and a numerical thermal model. Both results have been experimentally validated using a commercial absorber in a custom experimental set-up. The optimization procedure aimed at obtaining Selective Solar Absorber is presented and discussed in the case of a metal dielectric multilayer based on Cr2O3 and Ti. The importance of adopting a real spectral emissivity curve to estimate high thermal efficiency at high temperatures in a selective solar absorber is outlined. Optimized absorber multilayers can be 10% more efficient than the commercial alternative at 250 °C operating temperatures, reaching 400 °C stagnation temperature without Sun concentration confirming that high vacuum flat thermal collectors can give important contribution to the energy transition from fossil fuels to renewable energy for efficient heat production.

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Section: Introductionmentioning

confidence: 86%

A Selective Solar Absorber for Unconcentrated Solar Thermal Panels

et al. 2021

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“…High vacuum insulation reduces the internal gas convective and conductive losses to a negligible level, keeping high conversion efficiency at high working temperature. The increased panel efficiency due to high vacuum has been studied also from other researchers [33,34]. In HVFP the thermal radiation is the main loss mechanism and the radiative properties of SSA are an aspect of primary importance.…”

Section: Introductionmentioning

confidence: 95%

Efficiency of Selective Solar Absorber in High Vacuum Flat Solar Thermal Panels: The Role of Emissivity and Cut-Off Wavelength

Maio¹,

D’Alessandro²,

Caldarelli³

et al. 2020

Preprint

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A multilayer structure on a metallic substrate has been optically simulated and the optimization procedure aimed at obtaining Selective Solar Absorber (SSA) is discussed. This study refers to flat high vacuum thermal collectors and the overall Sun-to-thermal conversion efficiency has been evaluated using analytical formula and numerical thermal model. Both methods are in agreement and they have been validated using experimental results on a commercial absorber. The importance of a low emittance value to obtain high thermal efficiency at high temperatures and high stagnation temperature in selective solar absorber is highlighted. Optimized absorbers can be 8% more efficient than the commercial alternative at 250 °C operating temperatures and up to 27% more efficient at 300 °C. A stagnation temperature higher than 400 °C can be reached without Sun concentration if the proper design is adopted.

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“…A simulation of such a panel connected to a heating system [82] showed that it would generate an annual heat output by 66% higher than the equivalent area of evacuated tubes and by 112% higher than that obtained from conventional flat plate collectors. Despite the high efficiency of the evacuated flat plate collectors, a problem during their operation was indicated in study [83]. This was related mainly to absorbers, enclosures, and sealing highlights.…”

Section: Introductionmentioning

confidence: 97%

“…The purpose of comparing the two collectors was not only to obtain environmental factors, but also to help in the development of the proposed prototype. Among the collectors, there is an interesting solution currently available commercially, which are evacuated flat plate collectors [82][83][84][85][86]. Works available in the literature relate primarily to improved efficiency, energy optimization, or determining their performance.…”

Section: Introductionmentioning

confidence: 99%

Life Cycle Assessment of the Use of Phase Change Material in an Evacuated Solar Tube Collector

Jachura

Sekret

2021

Energies

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This paper presents an environmental impact assessment of the entire cycle of existence of the tube-vacuum solar collector prototype. The innovativeness of the solution involved using a phase change material as a heat-storing material, which was placed inside the collector’s tubes-vacuum. The PCM used in this study was paraffin. The system boundaries contained three phases: production, operation (use phase), and disposal. An ecological life cycle assessment was carried out using the SimaPro software. To compare the environmental impact of heat storage, the amount of heat generated for 15 years, starting from the beginning of a solar installation for preparing domestic hot water for a single-family residential building, was considered the functional unit. Assuming comparable production methods for individual elements of the ETC and waste management scenarios, the reduction in harmful effects on the environment by introducing a PCM that stores heat inside the ETC ranges from 17 to 24%. The performed analyses have also shown that the method itself of manufacturing the materials used for the construction of the solar collector and the choice of the scenario of the disposal of waste during decommissioning the solar collector all play an important role in its environmental assessment. With an increase in the application of the advanced technologies of materials manufacturing and an increase in the amount of waste subjected to recycling, the degree of the solar collector’s environmental impact decreased by 82% compared to its standard manufacture and disposal.

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Simulator testing of evacuated flat plate solar collectors for industrial heat and building integration

Cited by 34 publications

References 35 publications

A Selective Solar Absorber for Unconcentrated Solar Thermal Panels

A Selective Solar Absorber for Unconcentrated Solar Thermal Panels

Efficiency of Selective Solar Absorber in High Vacuum Flat Solar Thermal Panels: The Role of Emissivity and Cut-Off Wavelength

Life Cycle Assessment of the Use of Phase Change Material in an Evacuated Solar Tube Collector

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