A New Approach on the Protection Against Overheating of Flat Plate Solar-Thermal Collectors

Author(s):  
Mircea Neagoe ◽  
Ion Visa ◽  
Anca Duta ◽  
Nadia Cretescu
2018 ◽  
Vol 4 (3) ◽  
pp. 25 ◽  
Author(s):  
Daniel Ferrández ◽  
Carlos Moron ◽  
Jorge Pablo Díaz ◽  
Pablo Saiz

ResumenEl actual Código Técnico de la Edificación (CTE) pone de manifiesto la necesidad de cubrir parte de la demanda energética requerida para el abastecimiento de agua caliente sanitaria y climatización de piscinas cubiertas mediante sistemas de aprovechamiento de la energía solar térmica. En este artículo se presenta una comparativa entre las dos principales tipologías de captadores solares térmicos que existen en el mercado: el captador de placa plana y el captador de tubo de vacío, atendiendo a criterios de fracción solar, diseño e integración arquitectónica. Todo ello a fin de discernir en qué circunstancias es más favorable el uso de uno u otro sistema, comparando los resultados obtenidos mediante programas de simulación con la toma de medidas in situ.AbstractThe current Technical Building Code (CTE) highlights the need to cover part of the energy demand required for the supply of hot water and heating of indoor swimming pools using solar thermal systems. This article presents a comparison between the two main types of solar thermal collectors that exist in the market: the flat plate solar collector and the vacuum tube solar collector, according to criteria of solar fraction, design and architectural integration. All of this in order to discern in what circumstances the use of one or the other system is more favourable, comparing the results obtained through simulation programs with the taking of measurements in situ.


2021 ◽  
Author(s):  
Kamyar Tanha

This thesis is focused on the performance of the two SDHW systems of the sustainable Archetype houses in Vaughan, Ontario with daily hot water consumption of 225 litres. The first system consists of a flat plate solar thermal collector in conjunction with a gas boiler and a DWHR. The second SDHW system consists of an evacuated tube collector, an electric tank and a DWHR. The experimental results showed that the DWHRs were capable of an annual heat recovery of 789 kWh. The flat plate and evacuated tube collectors had an annual thermal energy output of 2038 kWh and 1383 kWh. The systems were also modeled in TRNSYS and validated with the experimental results. The simulated results showed that Edmonton has the highest annual energy consumption of 3763.4 kWh and 2852.9 kWh by gas boiler and electric tank and that the solar thermal collectors and DWHRs are most beneficial in Edmonton.


2014 ◽  
Vol 521 ◽  
pp. 539-542
Author(s):  
Da Yu Zheng ◽  
Juan Zheng ◽  
Xiang Yi Guan ◽  
Jia Zheng ◽  
Yi Ming Zhang

To cover the main contributions and developments in solar thermal collectors through focusing on materials, heat transfer characteristics and manufacturing challenges. A range of published papers and internet research including research work on various solar thermal collectors (flat plate, evacuated tubes, and heat pipe tube) were used. Evaluation of solar collectors performance is critiqued to aid solar technologies make the transition into a specific dominant solar collector. The sources are sorted into sections: finding an academic job, general advice, teaching, research and publishing, tenure and organizations. Provides information about types of solar thermal collectors, indicating what can be added by using evacuated tube collectors instead of flat plate collectors and what can be added by using heat pipe collectors instead of evacuated tubes. Focusing only on three types of solar thermal collectors (flat plate, evacuated tubes, and heat pipe tube). Useful source of information for consultancy and impartial advice for graduate students planning to do research in solar thermal technologies. This paper fulfils identified information about materials and heat transfer properties of materials and manufacturing challenges of these three solar thermal collectors. Describes some changes made to improve the environment which have had unforeseen and adverse effects on safety and the reasons why we need more case histories. Also discusses the reasons why there are no permanent solutions to safety problems and the reasons why senior managers should become more involved in safety problems.


Solar Energy ◽  
2016 ◽  
Vol 127 ◽  
pp. 250-261 ◽  
Author(s):  
Paul Henshall ◽  
Philip Eames ◽  
Farid Arya ◽  
Trevor Hyde ◽  
Roger Moss ◽  
...  

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2391 ◽  
Author(s):  
Francesco Calise ◽  
Francesco Liberato Cappiello ◽  
Massimo Dentice d’Accadia ◽  
Maria Vicidomini

This work presents a thermoeconomic comparison between two different solar energy technologies, namely the evacuated flat-plate solar collectors and the photovoltaic panels, integrated as auxiliary systems into two renewable polygeneration plants. Both plants produce electricity, heat and cool, and are based on a 6 kWe organic Rankine cycle (ORC), a 17-kW single-stage H2O/LiBr absorption chiller, a geothermal well at 96 °C, a 200 kWt biomass auxiliary heater, a 45.55 kWh lithium-ion battery and a 25 m2 solar field. In both configurations, electric and thermal storage systems are included to mitigate the fluctuations due to the variability of solar radiation. ORC is mainly supplied by the thermal energy produced by the geothermal well. Additional heat is also provided by solar thermal collectors and by a biomass boiler. In an alternative layout, solar thermal collectors are replaced by photovoltaic panels, producing additional electricity with respect to the one produced by the ORC. To reduce ORC condensation temperature and increase the electric efficiency, a ground-cooled condenser is also adopted. All the components included in both plants were accurately simulated in a TRNSYS environment using dynamic models validated versus literature and experimental data. The ORC is modeled by zero-dimensional energy and mass balances written in Engineering Equation Solver and implemented in TRNSYS. The models of both renewable polygeneration plants are applied to a suitable case study, a commercial area near Campi Flegrei (Naples, South Italy), a location well-known for its geothermal sources and good solar availability. The economic results suggest that for this kind of plant, photovoltaic panels show lower pay back periods than evacuated flat-plate solar collectors, 13 years vs 15 years. The adoption of the electric energy storage system leads to an increase of energy-self-sufficiency equal to 42% and 47% for evacuated flat-plate solar collectors and the photovoltaic panels, respectively.


Author(s):  
Dhrupad Sarma ◽  
Parimal Bakul Barua ◽  
Deva Kanta Rabha ◽  
Nidhi Verma ◽  
Soumyajyoti Purkayastha ◽  
...  

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Sarvenaz Sobhansarbandi ◽  
Uğur Atikol

There is a growing interest in using solar energy in underfloor heating systems. However, the large areas required for the installation of solar thermal collector's array can be discouraging, especially in the apartment buildings where the apartment's roof is a common area. The objective of this study is to investigate the possibility of using compound parabolic concentrating (CPC) solar collectors instead of the commonly used flat-plate collectors (FPCs) in such systems. It is aimed to explore the feasibility of area reduction required by the collectors. Second, the temperature profiles of circulating water loop and the concrete slabs are sought to be examined. The system consists of solar thermal collectors, a storage tank, and circulation of water to transport the heat to four similar floor slabs. The CPC collector outlet fluid's temperature can reach a maximum of 95 °C, compared to 70 °C obtained from the FPCs. The results from the simulations show that a 2 m2 CPC collector array can perform satisfactorily to match the job of an 8 m2 FPC array, obtaining the same required circulating water's temperature in the slabs.


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