Solar Energy Harvesting Using Nanofluids-Based Concentrating Solar Collector

2012 ◽  
Author(s):  
Vikrant Khullar ◽  
Himanshu Tyagi ◽  
Patrick E. Phelan ◽  
Todd P. Otanicar ◽  
Harjit Singh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Solar Collector ◽  
Base Fluid ◽  
Incident Angle ◽  
Convective Heat Transfer Coefficient ◽  
Radiant Energy ◽  
Absorption Capacity ◽  
Solar Collectors ◽  
Solar Insolation ◽  
Solar Energy Harvesting

Dispersing trace amounts of nanoparticles into the base-fluid has significant impact on the optical as well as thermo-physical properties of the base-fluid. This characteristic can be utilized in effectively capturing as well as transporting the solar radiant energy. Enhancement of the solar irradiance absorption capacity of the base fluid scales up the heat transfer rate resulting in higher & more efficient heat transfer. This paper attempts to introduce the idea of harvesting the solar radiant energy through usage of nanofluid-based concentrating parabolic solar collectors. In order to theoretically analyze the nanofluid-based concentrating parabolic solar collector (NCPSC) it has been mathematically modeled, and the governing equations have been numerically solved using finite difference technique. The results of the model were compared with the experimental results of conventional concentrating parabolic solar collectors under similar conditions. It was observed that while maintaining the same external conditions (such as ambient/inlet temperatures, wind speed, solar insolation, flow rate, concentration ratio etc.) the NCPSC has about 5–10% higher efficiency as compared to the conventional parabolic solar collector. Furthermore, some parametric studies were carried out which reflected the effect of various parameters such as solar insolation, incident angle, convective heat transfer coefficient etc. on the performance indicators such as thermal efficiency etc.

Solar Energy Harvesting Using Nanofluids-Based Concentrating Solar Collector

2012 ◽  
Vol 3 (3) ◽  
Author(s):  
Vikrant Khullar ◽  
Himanshu Tyagi ◽  
Patrick E. Phelan ◽  
Todd P. Otanicar ◽  
Harjit Singh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Solar Collector ◽  
Incident Angle ◽  
Convective Heat Transfer Coefficient ◽  
Radiant Energy ◽  
Absorption Capacity ◽  
Solar Collectors ◽  
Solar Insolation ◽  
Solar Energy Harvesting ◽  
Efficient Heat Transfer

Dispersing trace amounts of nanoparticles into common base-fluids has a significant impact on the optical as well as thermophysical properties of the base-fluid. This characteristic can be utilized to effectively capture and transport solar radiation. Enhancement of the solar irradiance absorption capacity leads to a higher heat transfer rate resulting in more efficient heat transfer. This paper attempts to introduce the idea of harvesting solar radiant energy through usage of nanofluid-based concentrating parabolic solar collectors (NCPSC). In order to theoretically analyze the NCPSC, it has been mathematically modeled, and the governing equations have been numerically solved using finite difference technique. The results of the model were compared with the experimental results of conventional concentrating parabolic solar collectors under similar conditions. It was observed that while maintaining the same external conditions (such as ambient/inlet temperatures, wind speed, solar insolation, flow rate, concentration ratio, etc.) the NCPSC has about 5–10% higher efficiency as compared to the conventional parabolic solar collector. Furthermore, parametric studies were carried out to discover the influence of various parameters on performance and efficiency. The following parameters were studied in the present study: solar insolation, incident angle, and the convective heat transfer coefficient. The theoretical results clearly indicate that the NCPSC has the potential to harness solar radiant energy more efficiently than a conventional parabolic trough.

scholarly journals ENHANCEMENT OF EFFICACY AND HEAT TRANSFER CHARACTERISTICS OF TIO2 NANO FLUIDS UNDER TURBULENT FLOW CONDITIONS IN PARABOLIC TROUGH SOLAR COLLECTOR

2020 ◽  
Author(s):  
K.Dilip Kumar ◽  
T.Srinivasa Rao ◽  
M.Srinivas ◽  
K.Ashok Reddy
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Solar Collector ◽  
Base Fluid ◽  
Volume Fraction ◽  
Convective Heat Transfer Coefficient ◽  
Energy Parameter ◽  
Maximum Efficiency ◽  
Parabolic Trough ◽  
Parabolic Trough Solar Collector

The efficacy of a parabolic trough solar collector (PTSC) was improved by using TiO2/DI-H2O (De-Ionized water) nanofluid. Working samples consisting of nanofluids with concentrations of 0.05%, 0.1%, 0.2%, 0.3% and 0.5% were compared with deionized water (the base fluid) at different flow rates under turbulent flow regimes (2850 ˂Re ˂ 7440). The experiments were designed as per ASHRAE 93 (2010) standards. Heat transfer and the flow characteristics of nanofluids through the collector were studied, and empirical correlations were developed in terms of the Nusselt number, friction factor, and performance index. The convective heat transfer coefficient was improved up to 23.84% by using TiO2 nanofluids instead of the base fluid. It was found that TiO2 nanofluid with a volume fraction of 0.3% (at a mass flow rate of 0.0689 kg/s) will provide the maximum efficiency enhancement in the PTSC (9.66% higher than the water-based collector). Consequently, the absorbed energy parameter was found to be 10.3% greater than that of the base fluid.

scholarly journals CONVECTIVE HEAT TRANSFER AND POWER SAVING APPLICATION OF SI BASED NANOPARTICLES IN A CIRCULAR PIPE

2020 ◽  
Vol 50 (4) ◽  
pp. 321-327
Author(s):  
Md Insiat Islam Rabby ◽  
Farzad Hossain ◽  
S.A.M. Shafwat Amin ◽  
Tazeen Afrin Mumu ◽  
MD Ashraf Hossain Bhuiyan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Base Fluid ◽  
Volume Fraction ◽  
Numerical Study ◽  
Convective Heat Transfer Coefficient ◽  
Circular Pipe ◽  
Working Fluid ◽  
Pumping Power

A numerical study of laminar forced convection heat transfer for the fully developed region inside a circular pipe filled with Si based nanoparticle is presented for investigating the parameters of heat transfer. Four Si based nanoparticles Si, SiC, SiO2, Si3N4 with 1-5% volume fraction have been mixed with water to prepare nanofluids which is used for working fluid to flow over a circular pipe with 5mm diameter and 700mm length. Heat transfer characteristics and pumping power have been calculated at fully developed region with constant heat flux condition on pipe wall to identify the heat transfer enhancement ratio and pumping power reduction ratio among base fluid water and each nanofluids. It is worth mentioning that utilizing SiC nanoparticle shows not only the highest increment of Nusselt number and convective heat transfer coefficient but also the highest decrement of pumping power requirement and FOM in comparison to the base fluid.

scholarly journals Entropy Generation and Thermal Analysis of Nanofluid Flow Inside the Evacuated Tube Solar Collector

2021 ◽  
Author(s):  
S. Mojtaba Tabarhoseini ◽  
M. Sheikholeslami
Keyword(s):  
Heat Transfer ◽  
Entropy Generation ◽  
Solar Collector ◽  
Base Fluid ◽  
Pure Water ◽  
Working Fluid ◽  
Distribution Analysis ◽  
Nanoparticle Dispersion ◽  
Evacuated Tube Solar Collector ◽  
Evacuated Tube

Abstract In the current investigation, the thermal and thermodynamic behavior of a buoyancy-driven evacuated tube solar collector has undergone precise evaluation, and the efficacy of nanoparticle dispersion in the base fluid has been scrutinized using computational fluid dynamics based on the finite volume method. The natural convection process was analyzed in different vertical sections of the absorber tube. The temperature and velocity distributions of water as the conventional working fluid and the nanofluid were compared at various cutting planes along the tube during the simulation time. In this problem, CuO nanoparticles with optimum thermal properties were suspended in the base fluid. According to the surveyed results, the temperature distribution analysis illustrates that the mean temperature of the tank experiences more enhancement when the nanofluid is used. The comparison of the heat transfer coefficient between two simulated cases shows the competency of utilizing CuO/water nanofluid in the thermal performance improvement of the collector. The results related to entropy generation assessment show that the irreversibility owing to fluid friction rises when the nanofluid is applied during the flow time. In contrast, the entropy generation of pure water owing to heat transfer surpasses the case with nanofluid.

Comparison of Heat Transfer in Solar Collectors With Heat-Pipe Versus Flow-Through Absorbers

1987 ◽  
Vol 109 (4) ◽  
pp. 253-258 ◽  
Author(s):  
J. R. Hull
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Solar Collector ◽  
Hot Water ◽  
Solar Collectors ◽  
Heat Transfer Characteristics ◽  
Absorption Chiller ◽  
Transfer Characteristics ◽  
Proper Design ◽  
Flow Through

Analysis of heat transfer in solar collectors with heat-pipe absorbers is compared to that for collectors with flow-through absorbers for systems that produce hot water or other heated fluids. In these applications the heat-pipe absorber suffers a heat transfer penalty compared with the flow-through absorber, but in many cases the penalty can be minimized by proper design at the heat-pipe condenser and system manifold. When the solar collector is used to drive an absorption chiller, the heat-pipe absorber has better heat transfer characteristics than the flow-through absorber.

Natural Convection in Collector Cavities With an Isoflux Absorber Plate

1983 ◽  
Vol 105 (1) ◽  
pp. 19-22 ◽  
Author(s):  
W. M. M. Schinkel ◽  
C. J. Hoogendoorn
Keyword(s):  
Heat Transfer ◽  
Boundary Condition ◽  
Natural Convection ◽  
Solar Collector ◽  
Numerical Study ◽  
Cold Wall ◽  
Solar Collectors ◽  
Absorber Plate ◽  
Hot Plate ◽  
Expected Values

The boundary condition at the hot absorber plate in a solar collector will influence the natural convection in the enclosure. For the isoflux boundary condition and an isothermal cold wall an experimental and numerical study has been made for Ra numbers from 105 to 107 and inclinations from 20 to 90 deg with the horizontal. For vertical enclosures the heat transfer by natural convection was about 19 percent above that for an isothermal hot plate. This decreases with angle of inclination, to 9 percent at 20 deg. For solar collectors it means that for cases where the absorber plate is not isothermal the convective losses can be about 10 percent above the usually expected values.

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].

Applicability of Heat Mirrors in Reducing Thermal Losses in Concentrating Solar Collectors

2016 ◽  
Author(s):  
Prashant Mahendra ◽  
Vikrant Khullar ◽  
Madhup Mittal
Keyword(s):  
Heat Transfer ◽  
Thermal Efficiency ◽  
Solar Irradiance ◽  
Solar Collector ◽  
Flux Distribution ◽  
Heat Transfer Analysis ◽  
Transfer Model ◽  
Solar Collectors ◽  
Parabolic Trough ◽  
Glass Envelope

Flux distribution around the parabolic trough receiver being typically non-uniform, only a certain portion of the receiver circumference receives the concentrated solar irradiance. However, radiative and convective losses occur across the entire receiver circumference. This paper attempts to introduce the idea employing transparent heat mirror to effectively reduce the heat loss area and thus improve the thermal efficiency of the solar collector. Transparent heat mirror essentially has high transmissivity in the solar irradiance wavelength band and high reflectivity in the mid-infrared region thus it allows the solar irradiance to pass through but reflects the infrared radiation back to the solar selective metal tube. Practically, this could be realized if certain portion of the conventional low iron glass envelope is coated with Sn-In2O3 so that its acts as a heat mirror. In the present study, a parabolic receiver design employing the aforesaid concept has been proposed. Detailed heat transfer model has been formulated. The results of the model were compared with the experimental results of conventional concentrating parabolic trough solar collectors in the literature. It was observed that while maintaining the same external conditions (such as ambient/initial temperatures, wind speed, solar insolation, flow rate, concentration ratio etc.) the heat mirror-based parabolic trough concentrating solar collector has about 3–12% higher thermal efficiency as compared to the conventional parabolic solar collector. Furthermore, steady state heat transfer analysis reveals that depending on the solar flux distribution there is an optimum circumferential angle (θ = θoptimum, where θ is the heat mirror circumferential angle) up to which the glass envelope should be coated with Sn-In2O3. For angles higher than the optimum angle, the collector efficiency tends to decrease owing to increase in optical losses.

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