Deterministic matrix-based radiative design using a new general formulation of exergy and exergy efficiency for hybrid solar collectors

2021 ◽  
Vol 182 ◽  
pp. 115318
Author(s):  
Tudor Baracu ◽  
Monica Patrascu ◽  
Catalin Teodosiu ◽  
Marius-Victor Birsan ◽  
Adina Gheorghian ◽  
...  
Author(s):  
Ahmad Fudholi ◽  
Kamaruzzaman Sopian

<span>Among the most important components of solar energy systems, solar collectors are devices that receive solar energy and convert it into thermal energy, as most essential components of solar dryer. This review presents description and previous work performed on performances of solar air collector for agricultural produce. In addition, various solar collectors are classified and described. Solar air collectors for drying application of agricultural produce are presented and summarize. The energy and exergy efficiency of the solar air collector ranges from 28% to 62% and from 30% to 57%, respectively. </span>


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Navid Tonekaboni ◽  
Mahdi Feizbahr ◽  
Nima Tonekaboni ◽  
Guang-Jun Jiang ◽  
Hong-Xia Chen

The low efficiency of solar collectors can be mentioned as one of the problems in solar combined cooling, heating, and power (CCHP) cycles. For improving solar systems, nanofluid and porous media are used in solar collectors. One of the advantages of using porous media and nanoparticles is to absorb more energy under the same conditions. In this research, a solar combined cooling, heating, and power (SCCHP) system has been optimized by porous media and nanofluid for generating electricity, cooling, and heating of a 600 m2 building in a warm and dry region with average solar radiation of Ib = 820 w/m2 in Iran. In this paper, the optimal amount of nanofluid in porous materials has been calculated to the extent that no sediment is formed. In this study, solar collectors were enhanced with copper porous media (95% porosity) and CuO and Al2O3 nanofluids. 0.1%–0.6% of the nanofluids were added to water as working fluids; it is found that 0.5% of the nanofluids lead to the highest energy and exergy efficiency enhancement in solar collectors and SCCHP systems. Maximum energy and exergy efficiency of parabolic thermal collector (PTC) riches in this study are 74.19% and 32.6%, respectively. Figure 1 can be mentioned as a graphical abstract for accurately describing the cycle of solar CCHP.


2016 ◽  
Vol 20 (1) ◽  
pp. 327-335 ◽  
Author(s):  
Farzad Jafarkazemi ◽  
Emad Ahmadifard ◽  
Hossein Abdi

In this paper, a heat pipe evacuated tube solar collector has been investigated both theoretically and experimentally. A detailed theoretical method for energy and exergy analysis of the collector is provided. The method is also evaluated by experiments. The results showed a good agreement between the experiment and theory. Using the theoretical model, the effect of different parameters on the collector?s energy and exergy efficiency has been investigated. It is concluded that inlet water temperature, inlet water mass flow rate, the transmittance of tubes and absorptance of the absorber surface have a direct effect on the energy and exergy efficiency of the heat pipe evacuated tube solar collector. Increasing water inlet temperature in heat pipe evacuated solar collectors leads to a decrease in heat transfer rate between the heat pipe?s condenser and water.


1989 ◽  
Vol 13 (4) ◽  
pp. 405-409 ◽  
Author(s):  
A. K. Kar ◽  
M. Shaahid

Author(s):  
Omar Behar ◽  
Saumitra Saxena ◽  
William L. Roberts

Abstract The techno-economic assessment of the concentrating solar power thermo-acoustic power conversion systems is carried out to identify the optimum conditions, under-which the solar thermo-acoustic might be competitive to the current commercial solar thermal power technologies. The thermal and economic performance of a thermo-acoustic engine integrated to five different solar collectors including Compound Parabolic Collector, Linear Fresnel, Parabolic Trough, Central receiver, and Solar Dish is compared to the current commercial solar thermal power technologies as well as to their corresponding Carnot-cycle. To do so, a modular modeling approach is used to consider all the available commercial technologies, through combining a modular energy model with a simplified economic model. Jeddah city (Saudi Arabia) has been chosen as a reference site for the present study. The results indicate that the integration of compound and dish solar collectors to a thermo-acoustic engine might offer competitive solutions. Compound collectors might be more suitable for integration with the thermo-acoustic engine than linear Fresnel collectors, if the exergy efficiency of the engine reaches 40%. Besides, dish-thermo-acoustic system becomes more competitive than current dish-mechanical Stirling engine, if the investment costs of the thermo-acoustic engine are reduced to 3500 $/kWe, but the operating temperature should be above 700°C. Improving the exergy efficiency of the thermos-acoustic engines, from 35% to 40%, could make the dish-thermo-acoustic system more competitive than current dish-mechanical Stirling engines at a working temperature of 500°C. The study concludes that more efforts must be focused on reducing the costs of the TA devices rather than on improving efficiency.


Equipment ◽  
2006 ◽  
Author(s):  
J. Deans ◽  
A. Weerakoon ◽  
P. Richards ◽  
I. McClew
Keyword(s):  

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