Testing of uncovered solar thermal collectors under dynamic conditions and identification of performance parameters - for nocturnal radiative cooling applications
This paper presents the first part of a research-work conducted at the University of Applied Sciences (HFT-Stuttgart). The aim of the research was to investigate the potential of low-cost renewable energy systems to reduce the energy demand of the building sector in hot and dry areas. Radiative cool...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-01-01
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| Series: | Solar Energy Advances |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2667113123000062 |
| _version_ | 1797822536623325184 |
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| author | Nermeen Abdelnour Reiner Braun Herena Torio Ursula Eicker |
| author_facet | Nermeen Abdelnour Reiner Braun Herena Torio Ursula Eicker |
| author_sort | Nermeen Abdelnour |
| collection | DOAJ |
| description | This paper presents the first part of a research-work conducted at the University of Applied Sciences (HFT-Stuttgart). The aim of the research was to investigate the potential of low-cost renewable energy systems to reduce the energy demand of the building sector in hot and dry areas. Radiative cooling to the night sky represents a low-cost renewable energy source. The dry desert climate conditions promote radiative cooling applications. The system technology adopted in this work is based on uncovered solar thermal collectors integrated into the building's hydronic system. By implementing different control strategies, the same system could be used for cooling as well as for heating applications. This paper focuses on identifying the collector parameters which are required as the coefficients to configure such an unglazed collector for calibrating its mathematical model within the simulation environment. The parameter identification process implies testing the collector for its thermal performance. This paper attempts to provide an insight into the dynamic testing of uncovered solar thermal collectors (absorbers), taking into account their prospective operation at nighttime for radiative cooling applications. In this study, the main parameters characterizing the performance of the absorbers for radiative cooling applications are identified and obtained from standardized testing protocol. For this aim, a number of plastic solar absorbers of different designs were tested on the outdoor test-stand facility at HFT-Stuttgart for the characterization of their thermal performance. The testing process was based on the quasi-dynamic test method of the international standard for solar thermal collectors EN ISO 9806. The test database was then used within a mathematical optimization tool (GenOpt) to determine the optimal parameter settings of each absorber under testing. Those performance parameters were significant to compare the thermal performance of the tested absorbers. The coefficients (identified parameters) were used then to plot the thermal efficiency curves of all absorbers, for both the heating and cooling modes of operation. Based on the intended main scope of the system utilization (heating or cooling), the tested absorbers could be benchmarked. Hence, one of those absorbers was selected to be used in the following simulation phase as was planned in the research-project. |
| first_indexed | 2024-03-13T10:10:34Z |
| format | Article |
| id | doaj.art-70ce13ccf7c845ed87c87ef12ab7c16c |
| institution | Directory Open Access Journal |
| issn | 2667-1131 |
| language | English |
| last_indexed | 2024-03-13T10:10:34Z |
| publishDate | 2023-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Solar Energy Advances |
| spelling | doaj.art-70ce13ccf7c845ed87c87ef12ab7c16c2023-05-22T04:05:11ZengElsevierSolar Energy Advances2667-11312023-01-013100038Testing of uncovered solar thermal collectors under dynamic conditions and identification of performance parameters - for nocturnal radiative cooling applicationsNermeen Abdelnour0Reiner Braun1Herena Torio2Ursula Eicker3Center of Applied Research Sustainable Energy Technologies (zafh.net), University of Applied Sciences Stuttgart (HFT-Stuttgart), Schellingstraße 24, 70174 Stuttgart, Germany; Postgraduate Programme Renewable Energy (PPRE), University of Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, Germany; Corresponding author at: Center of Applied Research Sustainable Energy Technologies (zafh.net), University of Applied Sciences Stuttgart (HFT-Stuttgart), Schellingstraße 24, 70174 Stuttgart, Germany.Reutlingen University, Herman Hollerith Zentrum (HHZ), Danziger Str. 6, 71034 Böblingen, Germany; Dept. of Building, Civil and Environmental Engineering, Concordia University, 1455 Maisonneuve W. Montreal, Quebec H3G 1M8, CanadaPostgraduate Programme Renewable Energy (PPRE), University of Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, GermanyDept. of Building, Civil and Environmental Engineering, Concordia University, 1455 Maisonneuve W. Montreal, Quebec H3G 1M8, CanadaThis paper presents the first part of a research-work conducted at the University of Applied Sciences (HFT-Stuttgart). The aim of the research was to investigate the potential of low-cost renewable energy systems to reduce the energy demand of the building sector in hot and dry areas. Radiative cooling to the night sky represents a low-cost renewable energy source. The dry desert climate conditions promote radiative cooling applications. The system technology adopted in this work is based on uncovered solar thermal collectors integrated into the building's hydronic system. By implementing different control strategies, the same system could be used for cooling as well as for heating applications. This paper focuses on identifying the collector parameters which are required as the coefficients to configure such an unglazed collector for calibrating its mathematical model within the simulation environment. The parameter identification process implies testing the collector for its thermal performance. This paper attempts to provide an insight into the dynamic testing of uncovered solar thermal collectors (absorbers), taking into account their prospective operation at nighttime for radiative cooling applications. In this study, the main parameters characterizing the performance of the absorbers for radiative cooling applications are identified and obtained from standardized testing protocol. For this aim, a number of plastic solar absorbers of different designs were tested on the outdoor test-stand facility at HFT-Stuttgart for the characterization of their thermal performance. The testing process was based on the quasi-dynamic test method of the international standard for solar thermal collectors EN ISO 9806. The test database was then used within a mathematical optimization tool (GenOpt) to determine the optimal parameter settings of each absorber under testing. Those performance parameters were significant to compare the thermal performance of the tested absorbers. The coefficients (identified parameters) were used then to plot the thermal efficiency curves of all absorbers, for both the heating and cooling modes of operation. Based on the intended main scope of the system utilization (heating or cooling), the tested absorbers could be benchmarked. Hence, one of those absorbers was selected to be used in the following simulation phase as was planned in the research-project.http://www.sciencedirect.com/science/article/pii/S2667113123000062Solar thermal collectorsGenOpt for parameters identificationCollector parametersNocturnal radiative coolingRenewable cooling technologiesTesting standard EN ISO 9806 |
| spellingShingle | Nermeen Abdelnour Reiner Braun Herena Torio Ursula Eicker Testing of uncovered solar thermal collectors under dynamic conditions and identification of performance parameters - for nocturnal radiative cooling applications Solar Energy Advances Solar thermal collectors GenOpt for parameters identification Collector parameters Nocturnal radiative cooling Renewable cooling technologies Testing standard EN ISO 9806 |
| title | Testing of uncovered solar thermal collectors under dynamic conditions and identification of performance parameters - for nocturnal radiative cooling applications |
| title_full | Testing of uncovered solar thermal collectors under dynamic conditions and identification of performance parameters - for nocturnal radiative cooling applications |
| title_fullStr | Testing of uncovered solar thermal collectors under dynamic conditions and identification of performance parameters - for nocturnal radiative cooling applications |
| title_full_unstemmed | Testing of uncovered solar thermal collectors under dynamic conditions and identification of performance parameters - for nocturnal radiative cooling applications |
| title_short | Testing of uncovered solar thermal collectors under dynamic conditions and identification of performance parameters - for nocturnal radiative cooling applications |
| title_sort | testing of uncovered solar thermal collectors under dynamic conditions and identification of performance parameters for nocturnal radiative cooling applications |
| topic | Solar thermal collectors GenOpt for parameters identification Collector parameters Nocturnal radiative cooling Renewable cooling technologies Testing standard EN ISO 9806 |
| url | http://www.sciencedirect.com/science/article/pii/S2667113123000062 |
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