scholarly journals The Performance and Efficiency of Flat Plate Collectors with Different Absorbers and Different Convection Heat Loss Levels

2019 ◽  
Vol 16 (3) ◽  
pp. 261-270
Author(s):  
S.S. Mustafa
Keyword(s):  
Stainless Steel ◽  
Flat Plate ◽  
Heat Balance ◽  
Solar Collector ◽  
Working Fluid ◽  
Convection Heat ◽  
Factors Affecting ◽  
Cooling Conditions ◽  
Copper Aluminum ◽  
Flat Plate Solar Collector

The performance of a flat plate solar collector with thin absorber is studied. The temperature of the absorber and its variation along the local day time is obtained by solving a heat balance equation. The temperature of the working fluid is also estimated. A published solar source functionto predict the hourly daily incident solar irradiance on horizontal surface is considered. Five absorbers of different materials: Copper, Aluminum, Stainless steel, Glass and Mica are treated. Two cooling conditions at the absorber front irradiated surface are also taken into consideration. Factors affecting its efficiency are revealed.

scholarly journals Higher Order Accurate Transient Numerical Model to Evaluate the Natural Convection Heat Transfer in Flat Plate Solar Collector

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1508
Author(s):  
Nagesh Babu Balam ◽  
Tabish Alam ◽  
Akhilesh Gupta ◽  
Paolo Blecich
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Flat Plate ◽  
Solar Collector ◽  
Convection Heat Transfer ◽  
Air Gap ◽  
Convection Flow ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Flat Plate Solar Collector

The natural convection flow in the air gap between the absorber plate and glass cover of the flat plate solar collectors is predominantly evaluated based on the lumped capacitance method, which does not consider the spatial temperature gradients. With the recent advancements in the field of computational fluid dynamics, it became possible to study the natural convection heat transfer in the air gap of solar collectors with spatially resolved temperature gradients in the laminar regime. However, due to the relatively large temperature gradient in this air gap, the natural convection heat transfer lies in either the transitional regime or in the turbulent regime. This requires a very high grid density and a large convergence time for existing CFD methods. Higher order numerical methods are found to be effective for resolving turbulent flow phenomenon. Here we develop a non-dimensional transient numerical model for resolving the turbulent natural convection heat transfer in the air gap of a flat plate solar collector, which is fourth order accurate in both spatial and temporal domains. The developed model is validated against benchmark results available in the literature. An error of less than 5% is observed for the top heat loss coefficient parameter of the flat plate solar collector. Transient flow characteristics and various stages of natural convection flow development have been discussed. In addition, it was observed that the occurrence of flow mode transitions have a significant effect on the overall natural convection heat transfer.

Investigating the Effect of Al2O3/Water Nanofluid on the Efficiency of a Thermosyphon Flat-Plate Solar Collector

2016 ◽  
Author(s):  
Mohamed Nabeel A. Negm ◽  
Ahmed A. Abdel-Rehim ◽  
Ahmed A. A. Attia
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Fossil Fuels ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Green Energy ◽  
Working Fluid ◽  
Steady Increase ◽  
Solar Collectors ◽  
Flat Plate Solar Collector

The world is still dependent on fossil fuels as a continuous and stable energy source, but rising concerns for depletion of these fuels and the steady increase in demand for clean “green” energy have led to the rapid growth of the renewable energy field. As one of the most available energy sources with high energy conversion efficiency, solar energy is the most prominent of these energies as it also has the least effect on the environment. Flat plate collectors are the most common solar collectors, while their efficiency is limited by their absorber’s effectiveness in energy absorption and the transfer of this energy to the working fluid. The efficiency of flat plate solar collectors can be increased by using nanofluids as the working fluid. Nanofluids are a relatively recent development which can greatly enhance the thermophysical properties of working fluids. In the present study, the effect of using Al2O3/Water nanofluid as the working fluid on the efficiency of a thermosyphon flat-plate solar collector was experimentally investigated. The results of this experiment show an increase in efficiency when using nanofluids as the working fluid compared to distilled water. It was found that Al2O3/water nanofluids are a viable enhancement for the efficiency of flat-plate solar collectors.

scholarly journals Heat transfer in a low latitude flat-plate solar collector

2012 ◽  
Vol 16 (2) ◽  
pp. 583-591
Author(s):  
C.O.C. Oko ◽  
S.N. Nnamchi
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Solar Collector ◽  
Design Parameters ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Port Harcourt ◽  
Collector Efficiency ◽  
One Year ◽  
Flat Plate Solar Collector

Study of rate of heat transfer in a flat-plate solar collector is the main subject of this paper. Measurements of collector and working fluid temperatures were carried out for one year covering the harmattan and rainy seasons in Port Harcourt, Nigeria, which is situated at the latitude of 4.858oN and longitude of 8.372oE. Energy balance equations for heat exchanger were employed to develop a mathematical model which relates the working fluid temperature with the vital collector geometric and physical design parameters. The exit fluid temperature was used to compute the rate of heat transfer to the working fluid and the efficiency of the transfer. The optimum fluid temperatures obtained for the harmattan, rainy and yearly (or combined) seasons were: 317.4, 314.9 and 316.2 [K], respectively. The corresponding insolation utilized were: 83.23, 76.61 and 79.92 [W/m2], respectively, with the corresponding mean collector efficiency of 0.190, 0.205 and 0.197 [-], respectively. The working fluid flowrate, the collector length and the range of time that gave rise to maximum results were: 0.0093 [kg/s], 2.0 [m] and 12PM - 13.00PM, respectively. There was good agreement between the computed and the measured working fluid temperatures. The results obtained are useful for the optimal design of the solar collector and its operations.

scholarly journals Numerical Investigation to Asses and Optimize Performance of Flat Plate Solar Collector by Using Different Working Fluid

2021 ◽  
Vol 87 (2) ◽  
pp. 44-55
Author(s):  
Yussra Malalah Abdula ◽  
Gadeer Salim ◽  
Salman K
Keyword(s):  
Numerical Model ◽  
Flat Plate ◽  
Solar Collector ◽  
Current Model ◽  
Effective Means ◽  
Industrial Applications ◽  
Working Fluid ◽  
Literature Study ◽  
Maximum Temperatures ◽  
Flat Plate Solar Collector

Sustainable energy becomes an optimal alternative to overcome environmental pollution economical cost of fossil fuel. One of the most effective means to invest solar radiation is flat plate solar collectors. A study carried out to optimize and assess the performance of flat plate solar collector (FPSC) for domestic and industrial applications in the Iraq climate. A 3D numerical model of FPSC has modeled by ANSYS19, CFD tool has been used to investigate thermal transfer through FPSC based on different working fluid. Water, and nanofluid of water/copper nanomaterials were used as working fluid with three different concentrations levels, 0.011 %, 0.055%, and 0,101 %. The velocity of water was 0.3, and 0.5 m/sec respectively. The result of the numerical model was compared with a literature study to prove the reliability of the current model. The result of the current study indicated that, adding Cu nanoparticular to the working fluid enhanced temperatures outlet of FPSC. Also, maximum temperatures can be achieved by reducing the velocity value.

Exergy Analysis of a Flat Plate Solar Collector With Grooved Absorber Tube Configuration Using Aqueous ZnO–Ethylene Glycol

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Yash Kashyap ◽  
Apurva Singh ◽  
Y. Raja Sekhar
Keyword(s):  
Ethylene Glycol ◽  
Flat Plate ◽  
Solar Collector ◽  
Volume Fraction ◽  
Exergy Efficiency ◽  
Working Fluid ◽  
Plain Tube ◽  
Collector Temperature ◽  
Grooved Tube ◽  
Flat Plate Solar Collector

In this study, the exergetic performance of a flat plate solar collector (FPSC) setup with ZnO-based ethylene glycol (EG)/water nanofluid as a working fluid has been evaluated against that of EG/water. As a passive means to augment the rate of heat transfer, internally grooved tubes of two different pitches (e = 0.43 and e = 0.44) have been examined and compared against the performance of plain tube. The mass flow rate was fixed at 0.015 kg/s and the volume fraction of ZnO nanoparticles is ф = 0.02% v/v. The results indicate an enhancement in exergy efficiency of 44.61% when using the grooved tube (e = 0.44) against plain tube without the nanofluid and 39.17% when nanofluid is used. Using the nanofluid enhanced the exergy efficiency of the FPSC by a maximum of 73.81%. Maximum exergy efficiency obtained was 5.95% for grooved tube (e = 0.44) with nanofluid as working fluid and is in good agreement with previous literature. Exergy destruction/irreversibility due to temperature differences and heat flow within the system has been reported. Sun-collector temperature difference accounts for nearly 86–94% of the irreversibility. The results for thermal efficiency of this experimental setup have been published and summarized in this study for reference.

Performance of the Flat Plate Solar Collector Operated with Water-Al2O3 Nanofluid

2016 ◽  
Vol 831 ◽  
pp. 181-187 ◽  
Author(s):  
Janusz T. Cieśliński ◽  
Bartosz Dawidowicz ◽  
Aleksandra Popakul
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Base Fluid ◽  
Fossil Fuels ◽  
Thermal Characteristics ◽  
Working Fluid ◽  
Solar Collectors ◽  
Recent Method ◽  
Flat Plate Solar Collector

Solar collectors is one of the technologies absorbing energy from solar beam and utilizing it for heating purposes, displacing the need to burn fossil fuels. There are many ways to improve effectiveness of the solar collectors [1,2]. Recent method to absorb more heat from the solar beam is to modify thermal characteristics of the working fluid. For this purpose one can use nanofluids, i.e. suspensions of metallic or nonmetallic nanoparticles in a base fluid [3].

scholarly journals Numerical study of flat plate solar collector performance with square shape wicked evaporator

2019 ◽  
Vol 12 (2) ◽  
pp. 90-97
Author(s):  
Basil Noori Merzah ◽  
Majid H. Majeed ◽  
Fouad A. Saleh
Keyword(s):  
Flat Plate ◽  
Heat Pipe ◽  
Flow Rate ◽  
Solar Collector ◽  
Numerical Study ◽  
Charge Ratio ◽  
Working Fluid ◽  
Evaporator Section ◽  
Fill Charge Ratio ◽  
Flat Plate Solar Collector

In this work, a system of a heat pipe is implemented to improve the performance of flat plate solar collector. The model is represented by square shape portion of the evaporator section of wicked heat pipe with a constant total length of 510 mm, and the evaporator section inclined by an angle of 30o. In this models the evaporator, adiabatic and condenser lengths are 140mm, 140mm, and 230mm respectively. The omitted energies from sunlight simulator are 200, 400, 600, 800 and 1000 W/m2 which is close to the normal solar energy in Iraq. The working fluid for all models is water with fill charge ratio of 240%. The efficiency of the solar collector is investigated with three values of condenser inlet water temperatures, namely (12, 16 and 20o C). The numerical result showed an optimum volume flow rate of cooling water in condenser at which the efficiency of collector is a maximum. This optimum agree well with the ASHRAE standard volume of flow rate for conventional tasting for flat plate solar collector. When the radiation incident increases the thermal resistance of wicked heat pipe is decreases, where the heat transfer from the evaporator to condenser increases. The numerical results showed the performance of solar collector with square shape evaporator greater than other types of evaporator as a ratio 15 %.

scholarly journals Improving the Thermal Efficiency of Flat Plate Solar Collector Using Nano-Fluids as a Working Fluids: A Review

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Saif Ali Kadhim ◽  
Osama Abd AL-Munaf Ibrahim
Keyword(s):  
Flat Plate ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Base Fluid ◽  
Working Fluid ◽  
Solar Collectors ◽  
Nano Fluid ◽  
Flat Plate Solar Collector ◽  
Nano Fluids ◽  
Better Than

Solar energy is one of the most important types of renewable energy and is characterized by its availability, especially in Iraq. It can be used in many applications, including supply thermal energy by solar collectors. Improving the thermal efficiency of solar collector leads to an increase in the thermal energy supplied. Using a nano-fluid instead of base fluid (water is often used) as a working fluid is a method many used to increase the thermal efficiency of solar collectors. In this article, the latest research that used nano-fluid as a working fluid in evaluating the thermal efficiency of solar collector, type flat plate was reviewed. The thermal efficiency improvement of flat plate solar collector was reviewed based on the type of nanoparticles (metal oxides, semiconductors oxides, carbon compounds) used in the base fluid and comparison was made between these nanoparticles under the same conditions. Moreover, the effect of varying the concentration of nanoparticles in the base fluid and changing the working fluid flow rate on the thermal efficiency of flat plate solar collector was also reviewed. The results of the review showed that nano-fluids containing carbon compounds are better than other nano-fluids and that copper oxide is better than the rest of the metal oxides used in improving the thermal efficiency of flat plate solar collectors.

Performance analysis of hybrid nanofluids in flat plate solar collector as an advanced working fluid

Solar Energy ◽  
2018 ◽  
Vol 167 ◽  
pp. 231-241 ◽  
Author(s):  
Sujit Kumar Verma ◽  
Arun Kumar Tiwari ◽  
Sandeep Tiwari ◽  
Durg Singh Chauhan
Keyword(s):  
Performance Analysis ◽  
Flat Plate ◽  
Solar Collector ◽  
Working Fluid ◽  
Hybrid Nanofluids ◽  
Flat Plate Solar Collector
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