Tuning the Extinction Coefficient for Direct Absorption Solar Thermal Collector Optimization

2010 ◽  
Author(s):  
Todd P. Otanicar ◽  
Patrick E. Phelan ◽  
Robert A. Taylor ◽  
Himanshu Tyagi
Keyword(s):  
Energy Conversion ◽  
Extinction Coefficient ◽  
Solar Thermal ◽  
Direct Absorption ◽  
Promising Technology ◽  
Solar Thermal Collector ◽  
Solar Thermal Collectors ◽  
Collector Efficiency ◽  
Overall Performance

Direct-absorption solar thermal collectors have recently been shown to be a promising technology for photothermal energy conversion but many parameters affecting the overall performance of such systems haven’t been studied in depth, yet alone optimized. Earlier work has shown that the overall magnitude of the extinction coefficient can play a drastic role, with too high of an extinction coefficient actually reducing the efficiency. This study investigates how the extinction coefficient impacts the collector efficiency and how it can be tuned as a function of depth to optimize the efficiency, and why this presents a unique design over conventional solar thermal collection systems. Three extinction profiles are investigated: uniform, linearly increasing, and exponentially increasing.

Spatially Varying Extinction Coefficient for Direct Absorption Solar Thermal Collector Optimization

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Todd P. Otanicar ◽  
Patrick E. Phelan ◽  
Robert A. Taylor ◽  
Himanshu Tyagi
Keyword(s):  
Energy Conversion ◽  
Extinction Coefficient ◽  
Solar Thermal ◽  
Efficiency Improvement ◽  
Direct Absorption ◽  
Solar Thermal Collector ◽  
Solar Thermal Collectors ◽  
Collector Efficiency ◽  
Overall Performance ◽  
Spatially Varying

Direct absorption solar thermal collectors have recently been shown to be a promising technology for photothermal energy conversion but many parameters affecting the overall performance of such systems have not been studied in depth, yet alone optimized. Earlier work has shown that the overall magnitude of the extinction coefficient can play a drastic role, with too high of an extinction coefficient actually reducing the efficiency. This study investigates how the extinction coefficient impacts the collector efficiency and how it can be tuned spatially to optimize the efficiency, and why this presents a unique design over conventional solar thermal collection systems. Three specific extinction profiles are investigated: uniform, linearly increasing, and exponentially increasing with the exponentially increasing profile demonstrating the largest efficiency improvement.

Trends and Opportunities in Direct-Absorption Solar Thermal Collectors

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Patrick Phelan ◽  
Todd Otanicar ◽  
Robert Taylor ◽  
Himanshu Tyagi
Keyword(s):  
Energy Conversion ◽  
Thermal Energy ◽  
Solar Thermal ◽  
Working Fluid ◽  
Direct Absorption ◽  
Solar Thermal Energy ◽  
Thermal Energy Conversion ◽  
Recent Developments ◽  
Solar Thermal Collectors ◽  
Photocatalytic Reactions

Efficient conversion of sunlight into useful heat or work is of increasing global interest. Solar-to-thermal energy conversion, as opposed to solar-to-electricity, is enabled by solar thermal collectors that convert sunlight into heat at some useful temperature. We review here recent developments in solar thermal energy conversion. Our emphasis is on “direct-absorption” solar thermal collectors, in which incident sunlight is absorbed directly by a working fluid. This contrasts with conventional solar thermal collectors where the sunlight strikes and is absorbed by a solid receiver, which then transfers heat to the working fluid. Both liquid-based and gas-based direct-absorption collectors are described, although liquid-based systems are emphasized. We propose that if “direct-absorption” technologies could be developed further, it would open up a number of emerging opportunities, including applications exploiting thermochemical and photocatalytic reactions and direct absorption of a binary fluid for absorption refrigeration.

scholarly journals Design of a New Solar Thermal Collector with Ceramic Materials Integrated into the Building Facades

Designs ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 44
Author(s):  
Jordi Roviras Miñana ◽  
Vicente Sarrablo Moreno
Keyword(s):  
Ceramic Materials ◽  
Building Envelope ◽  
Hot Water ◽  
Solar Thermal ◽  
Collector System ◽  
System A ◽  
Solar Thermal Collector ◽  
Building Facades ◽  
Solar Thermal Collectors ◽  
High Degree

The work presented here aims to demonstrate the technical, architectural, and energy viability of solar thermal collectors made with ceramic materials and their suitability for domestic hot water (DHW) and building heating systems in the Mediterranean climate. The proposal is for the design of a ceramic shell, formed by collector and non-collecting panels, which forms part of the building system itself, and is capable of responding to the basic requirements of a building envelope and harnessing solar energy. Ceramics considerably reduce the final cost of the collector system and offer the new system a variety of compositional and chromatic finishes, occupying the entire building surface and achieving a high degree of architectural integration, although less energy-efficient compared to a conventional metallic collector.

scholarly journals Evaluating the Performance of Two Solar Domestic Hot Water Systems of the Archetype Sustainable Houses

2021 ◽  
Author(s):  
Kamyar Tanha
Keyword(s):  
Flat Plate ◽  
Hot Water ◽  
Experimental Results ◽  
Solar Thermal ◽  
Energy Output ◽  
Evacuated Tube Collector ◽  
Solar Thermal Collector ◽  
Solar Thermal Collectors ◽  
Evacuated Tube Collectors ◽  
Evacuated Tube

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.

scholarly journals Performance Evaluation of a Direct Absorption Collector for Solar Thermal Energy Conversion

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4956
Author(s):  
Abdul Sattar ◽  
Muhammad Farooq ◽  
Muhammad Amjad ◽  
Muhammad A. Saeed ◽  
Saad Nawaz ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Energy Conversion ◽  
Thermal Energy ◽  
Solar Flux ◽  
Solar Thermal ◽  
Potential Candidate ◽  
Direct Absorption ◽  
Solar Thermal Energy ◽  
Thermal Energy Conversion ◽  
Water Based

The solar absorption efficiency of water as a base-fluid can be significantly improved by suspending nanoparticles of various materials in it. This experimental work presents the photo thermal performance of water-based nano-fluids of graphene oxide (GO), zinc oxide (ZnO), copper oxide (CuO), and their hybrids under natural solar flux for the first time. Nanofluid samples were prepared by the two-step method and the photothermal performance of these nanofluid samples was conducted under natural solar flux in a particle concentration range from 0.0004 wt % to 0.0012 wt %. The photothermal efficiency of water-based 0.0012 wt % GO nanofluid was 46.6% greater than that of the other nanofluids used. This increased photothermal performance of GO nanofluid was associated with its good stability, high absorptivity, and high thermal conductivity. Thus, pure graphene oxide (GO) based nanofluid is a potential candidate for direct absorption solar collection to be used in different solar thermal energy conversion applications.

Impact of Size and Scattering Mode on the Optimal Solar Absorbing Nanofluid

2009 ◽  
Author(s):  
Todd Otanicar ◽  
Robert A. Taylor ◽  
Patrick E. Phelan ◽  
Ravi Prasher
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Solar Thermal ◽  
Thermal System ◽  
Direct Absorption ◽  
Solar Thermal Energy ◽  
Nanoparticle Suspension ◽  
Solar Thermal Collector ◽  
Solar Thermal System ◽  
The Impact

The concept of using a direct absorbing nanofluid, a liquid-nanoparticle suspension, has recently been shown numerically and experimentally to be an efficient method for harvesting solar thermal energy. Studies show that the size and shape of the nanoparticles as well as the scattering mode (e.g. dependent, independent, and multiple) all impact the amount of energy absorbed and emitted by the nanofluid. In order to optimize the efficiency of a direct absorption solar thermal system the optimum nanoparticle-liquid combination needs to be developed. The optimum nanofluid for a direct absorption solar thermal collector is investigated numerically through the variation of particle size, including the impact of size on optical properties, and scattering mode. The study addresses both the absorption of solar energy within the fluid as well as the emission of the fluid.

scholarly journals CONTROL AND DATA COLLECTION SYSTEM FOR SOLAR THERMAL COLLECTORS

2010 ◽  
Vol 2 (1) ◽  
pp. 27-31
Author(s):  
Dominykas Vasarevičius
Keyword(s):  
Data Collection ◽  
Data Transfer ◽  
Weather Conditions ◽  
Solar Thermal ◽  
Operational Parameters ◽  
Collection System ◽  
Operating Cycle ◽  
Data Collection System ◽  
Solar Thermal Collector ◽  
Solar Thermal Collectors

The paper presents the architecture of the control and statistical data collection system for solar thermal collectors, describing its operating principle and analysis of individual elements, in order to anticipate possible problems and find their solutions. Expanding functionality of the controller of solar thermal collector with online features one can collect data on solar thermal collectors performance in different regions. The paper describes the structure diagram, according to which the system will register operational parameters of the heating system and weather conditions. Data transfer mode, which allows avoiding instant database server load is offered. It is shown, that the simulation of the solar thermal collector operating cycle and optimization of recorded data stream allows over 14 times to reduce the amount of transferred data.

scholarly journals A Review of Photovoltaic Thermal (PVT) Technology for Residential Applications: Performance Indicators, Progress, and Opportunities

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3853
Author(s):  
Sree Harsha Bandaru ◽  
Victor Becerra ◽  
Sourav Khanna ◽  
Jovana Radulovic ◽  
David Hutchinson ◽  
...  
Keyword(s):  
Solar Energy ◽  
Performance Indicators ◽  
Heat Pumps ◽  
Solar Thermal ◽  
Cultural Barriers ◽  
Future Research ◽  
Energy Technologies ◽  
Solar Thermal Collector ◽  
Solar Thermal Collectors

Solar energy has been one of the accessible and affordable renewable energy technologies for the last few decades. Photovoltaics and solar thermal collectors are mature technologies to harness solar energy. However, the efficiency of photovoltaics decays at increased operating temperatures, and solar thermal collectors suffer from low exergy. Furthermore, along with several financial, structural, technical and socio-cultural barriers, the limited shadow-free space on building rooftops has significantly affected the adoption of solar energy. Thus, Photovoltaic Thermal (PVT) collectors that combine the advantages of photovoltaic cells and solar thermal collector into a single system have been developed. This study gives an extensive review of different PVT systems for residential applications, their performance indicators, progress, limitations and research opportunities. The literature review indicated that PVT systems used air, water, bi-fluids, nanofluids, refrigerants and phase-change material as the cooling medium and are sometimes integrated with heat pumps and seasonal energy storage. The overall efficiency of a PVT system reached up to 81% depending upon the system design and environmental conditions, and there is generally a trade-off between thermal and electrical efficiency. The review also highlights future research prospects in areas such as materials for PVT collector design, long-term reliability experiments, multi-objective design optimisation, techno-exergo-economics and photovoltaic recycling.

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