Predicted Efficiency of a Nanofluid-Based Direct Absorption Solar Receiver

2007 ◽  
Author(s):  
Himanshu Tyagi ◽  
Patrick Phelan ◽  
Ravi Prasher
Keyword(s):  
Flat Plate ◽  
Pure Water ◽  
Incident Radiation ◽  
Operating Conditions ◽  
Heat Transfer Analysis ◽  
Working Fluid ◽  
Direct Absorption ◽  
Low Efficiency ◽  
Flat Plate Collector ◽  
Solar Receiver

Due to its renewable and non-polluting nature solar energy is often used in applications such as electricity generation, thermal heating and chemical processing. The most cost-effective solar heaters are of the “flat-plate” type, but these suffer from relatively low efficiency and outlet temperatures. The present study theoretically investigates the feasibility of using a direct absorption solar receiver (DAR) and compares its performance with that of a typical flat-plate collector. Here a nanofluid—a mixture of water and aluminum nanoparticles—is used as the absorbing medium. A two-dimensional heat transfer analysis was developed in which direct sunlight was incident on a thin flowing film of nanofluid. The effects of absorption and scattering within the nanofluid were accounted for. In order to evaluate the temperature profile and intensity distribution within the nanofluid the energy balance equation and heat transport equation were solved numerically. It was observed that the presence of nanoparticles increases the absorption of incident radiation by more than 9 times over that of pure water. According to the results obtained from this study, under similar operating conditions, the efficiency of a DAR using nanofluid as the working fluid is found to be up to 10% higher (on an absolute basis) than that of a flat-plate collector.

Predicted Efficiency of a Low-Temperature Nanofluid-Based Direct Absorption Solar Collector

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Himanshu Tyagi ◽  
Patrick Phelan ◽  
Ravi Prasher
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Pure Water ◽  
Operating Conditions ◽  
Heat Transfer Analysis ◽  
Working Fluid ◽  
Direct Absorption ◽  
Direct Absorption Solar Collector ◽  
Low Efficiency ◽  
Flat Plate Collector

Due to its renewable and nonpolluting nature, solar energy is often used in applications such as electricity generation, thermal heating, and chemical processing. The most cost-effective solar heaters are of the “flat-plate” type, but these suffer from relatively low efficiency and outlet temperatures. The present study theoretically investigates the feasibility of using a nonconcentrating direct absorption solar collector (DAC) and compares its performance with that of a typical flat-plate collector. Here a nanofluid—a mixture of water and aluminum nanoparticles—is used as the absorbing medium. A two-dimensional heat transfer analysis was developed in which direct sunlight was incident on a thin flowing film of nanofluid. The effects of absorption and scattering within the nanofluid were accounted for. In order to evaluate the temperature profile and intensity distribution within the nanofluid, the energy balance equation and heat transport equation were solved numerically. It was observed that the presence of nanoparticles increases the absorption of incident radiation by more than nine times over that of pure water. According to the results obtained from this study, under similar operating conditions, the efficiency of a DAC using nanofluid as the working fluid is found to be up to 10% higher (on an absolute basis) than that of a flat-plate collector. Generally a DAC using nanofluids as the working fluid performs better than a flat-plate collector, however, much better designed flat-plate collectors might be able to match or outperform a nanofluids based DAC under certain conditions.

Energy and Exergy Analysis of Marquise Shaped Channel Flat Plate Solar Collector Using Al2O3–Water Nanofluid and Water

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Sahil Arora ◽  
Geleta Fekadu ◽  
Sudhakar Subudhi
Keyword(s):  
Flat Plate ◽  
Flow Rate ◽  
Volume Fraction ◽  
Pure Water ◽  
Maximum Energy ◽  
Working Fluid ◽  
Absorber Plate ◽  
Energy And Exergy ◽  
Aluminum Plates ◽  
Flat Plate Collector

The present study deals with the experimental performance of a Marquise shaped channel solar flat-plate collector using Al2O3/water nanofluid and base fluid (pure water). The experimental setup comprises a special type of solar flat plate collector, closed working fluid systems, and the measurement devices. The absorber plate is made of two aluminum plates sandwiched together with Marquise-shaped flow channels. The volume fraction of 0.1% of Al2O3/water nanofluid is used for this study. The various parameters used to investigate performance of the collector energy and exergy efficiency are collector inlet and outlet fluid temperatures, mass flow rate of the fluid, solar radiation, and ambient temperature. The flow rate of nanofluid and water varies from 1 to 5 lpm. The maximum energy efficiencies attained are 83.17% and 59.72%, whereas the maximum exergy efficiencies obtained are 18.73% and 12.29% for the 20 nm—Al2O3/water nanofluids and pure water, respectively, at the flow rate of 3 lpm. These higher efficiencies may be due to the use of nanofluids and the sophisticated design of the absorber plate with the Marquise shaped channel.

First and Second Law Analysis of a Flat Plate Collector Working With Nanofluids

2018 ◽  
Author(s):  
M. T. Nitsas ◽  
I. P. Koronaki ◽  
L. Prentza
Keyword(s):  
Flat Plate ◽  
Second Law Of Thermodynamics ◽  
Climatic Conditions ◽  
Working Fluid ◽  
Second Law ◽  
Inlet Temperature ◽  
Water Tank ◽  
Systems Quality ◽  
Typical Day ◽  
Flat Plate Collector

The utilization of solar energy in thermal energy systems was and always be one of the most effective alternative to conventional energy resources. Energy efficiency is widely used as one of the most important parameters in order to evaluate and compare thermal systems including solar collectors. Nevertheless, the first law of thermodynamics is not solely capable of describing the quantitative and qualitative performance of such systems and thus exergy efficiency is used so as to introduce the systems’ quality. In this work, the performance of a flat plate solar collector using water based nanofluids of different nanoparticle types as a working fluid is analyzed theoretically under the climatic conditions in Greece based on the First and Second Law of Thermodynamics. A mathematical model is built and the model equations are solved iteratively in a MATLAB code. The energy and exergy efficiencies as well as the collector losses coefficient for various parameters such as the inlet temperature, the particles concentration and type are determined. Moreover, a dynamic model is built so as to determine the performance of a flat plate collector working with nanofluids and the useful energy that can be stored in a water tank. The exergy destruction and exergy leakage are determined for a typical day in summer during which high temperatures and solar intensity values are common for the Greek climate.

scholarly journals Integration of a Pulsating Heat Pipe in a Flat Plate Heat Sink

2014 ◽  
Author(s):  
Mitchell P. Hoesing ◽  
Gregory J. Michna
Keyword(s):  
Thermal Resistance ◽  
Flat Plate ◽  
Heat Pipe ◽  
Heat Sink ◽  
New Technologies ◽  
Operating Conditions ◽  
Working Fluid ◽  
High Heat Flux ◽  
Pulsating Heat Pipe ◽  
Plate Heat

The ongoing development of faster and smaller electronic components has led to a need for new technologies to effectively dissipate waste thermal energy. The pulsating heat pipe (PHP) shows potential to meet this need, due to its high heat flux capacity, simplicity, and low cost. A 20-turn flat plate PHP was integrated into an aluminum flat plate heat sink with a simulated electronic load. The PHP heat sink used water as the working fluid and had 20 parallel channels with dimensions 2 mm × 2 mm × 119 mm. Experiments were run under various operating conditions, and thermal resistance of the PHP was calculated. The performance enhancement provided by the PHP was assessed by comparing the thermal resistance of the heat sink with no working fluid to that of it charged with water. Uncharged, the PHP was found to have a resistance of 1.97 K/W. Charged to a fill ratio of approximately 75% and oriented vertically, the PHP achieved a resistance of .49 K/W and .53 K/W when the condenser temperature was set to 20°C and 30°C, respectively. When the PHP was tilted to 45° above horizontal the PHP had a resistance of .76 K/W and .59 K/W when the condenser was set 20°C and 30°C, respectively. The PHP greatly improves the heat transfer properties of the heat sink compared to the aluminum plate alone. Additional considerations regarding flat plate PHP design are also presented.

scholarly journals Approximate Representation and Exposition of ISI Flat Plate Collector including Revised Flat Plate Collector : A Review

2020 ◽  
pp. 345-350
Author(s):  
Rajeshkumar U. Sambhe ◽  
Sagar S. Gaddamwar
Keyword(s):  
Flat Plate ◽  
Natural Circulation ◽  
Renewable Energy Sources ◽  
Tube Length ◽  
Outlet Temperature ◽  
Solar Collectors ◽  
Pv System ◽  
Comparative Performance ◽  
Low Efficiency ◽  
Flat Plate Collector

Cosmic power is one of the numerous renewable energy sources that can use in a Photovoltaic (PV) system or Thermal. Solar collectors play a crucial role in solar thermal systems. They convert solar radiation into heat and transfer the heat to working fluids Such as water or air. The Flat-plate collectors are the numerous common type of solar collectors and typically used as a water heater or air heater. These collectors have low efficiency and low outlet temperature. Recently, many scientists have attempted to improve the efficiency and performance of flat-plate collectors via different methods. This review paper describes the results of the experimentation carried out to study and compare the performance of the modified flat plate collector having increasing riser tube diameter and reducing riser tube length with the conventional ISI marked solar liquid flat plate collector. To study, the comparative performance characteristics of a modified flat plate collector with ISI flat plate collector operated under natural circulation mode. The suggested design found to be better than the existing ISI design of the absorber plate from an efficiency point of view. The actual useful heat gain (Qu) in the suggested design understudy found to be more by 30% than that in the case of ISI collector. However, the modified flat plate collector found to operate at a relatively lower exit temperature than the conventional ISI marked collector.

scholarly journals Investigation of Performance of Solar Flat and Curved Plate Collectors through Numerical Simulations

2021 ◽  
Vol 40 (1) ◽  
pp. 66-74
Author(s):  
Luqman Ahmed Pirzada ◽  
Xiaoli Wu . ◽  
Qaiser Ali ◽  
Asif Khateeb .
Keyword(s):  
Solar Energy ◽  
Flat Plate ◽  
Solar Collector ◽  
Numerical Study ◽  
Hot Water ◽  
Working Fluid ◽  
Solar Panels ◽  
Modeling Tools ◽  
Design Work ◽  
Flat Plate Collector

Solar energy is radiant light as a form of thermal heat energy which can be obtained and used by means of a variety of solar apparatus. As apparatus the flat and curved plate solar collector is specifically designed for assembling solar energy as a solar water heater system. The designing potency of this collector lone can generate medium level hot water from radiant sunlight source via absorbed plates. Standard type flat and curved plates solar collector plates are mostly used in remote coldest regions of the world where hot water is consumed for commercial and domestic purposes. These types of solar collector Plates can cheaply be manufactured compared to other solar panels like solar Shingles, Polycrystalline Solar Panels, Mono-crystalline Solar Panels, and Thin Film Solar Panels. For future work, this proposed pre-design is recommended for fabrication. A numerical study was carried-out on eight city locations in China by tracing their horizontal and vertical longitudinal, latitudinal lines noting the date, time and sunlight feeding of temperatures in the Celsius scale with the help of simulation and modeling tools like CFD, ANSYS FLUENT software, mesh geometry tools, and by using the Navier-Stokes and Continuity equations by fluid flow discharge rate, mass flow, water temperature and dropping of temperature, radiation working mechanisms, dimensions of water flowing tubes and absorber plates, density, the velocity of water as the working fluid, the viscosity of water in a cold and hot state as a process of Pre-design. Work also focuses on the comparison between flat plate collector and curved plate collector radiant sunlight absorption, As end result it is found the Curved plate collector produces 22% more elevated heat of outgoing water than flat plate collector.

Thermodynamic analysis of hybrid nanofluid based solar flat plate collector

2018 ◽  
Vol 15 (1) ◽  
pp. 27-39
Author(s):  
Ranga Babu J.A. ◽  
Kiran Kumar K. ◽  
Srinivasa Rao S.
Keyword(s):  
Pressure Drop ◽  
Flat Plate ◽  
Hybrid Nanoparticles ◽  
Working Fluid ◽  
Hybrid Nanofluid ◽  
Heat Gain ◽  
Content Type ◽  
Energy And Exergy ◽  
Hybrid Nanofluids ◽  
Flat Plate Collector

Purpose This paper aims to present an analytical investigation of energy and exergy performance on a solar flat plate collector (SFPC) with Cu-CuO/water hybrid nanofluid, Cu/water and CuO/water nanofluids as collector running fluids. Design/methodology/approach Heat transfer characteristics, pressure drop and energy and exergy efficiencies of SFPC working on these nanofluids are investigated and compared. In this study, a comparison is made by varying the mass flow rates and nanoparticle volume concentration. Thermophysical properties of hybrid nanofluids are estimated using distinctive correlations available in the open literature. Then, the influence of these properties on energy and exergy efficiencies of SFPC is discussed in detail. Findings Energy analysis reveals that by introducing the hybrid nanoparticles in water, the thermal conductivity of the working fluid is enhanced by 17.52 per cent and that of the individual constituents is enhanced by 15.72 and 15.35 per cent for Cu/water and CuO/water nanofluids, respectively. This resulted in 2.16 per cent improvement in useful heat gain for hybrid nanofluid and 1.03 and 0.91 per cent improvement in heat gain for Cu/water and CuO/water nanofluids, respectively. In line with the above, the collector efficiency increased by 2.175 per cent for the hybrid nanofluid and 0.93 and 1.05 per cent enhancement for Cu/water and CuO/water nanofluids, respectively. Exergy analysis elucidates that by using the hybrid nanofluid, exergy efficiency is increased by 2.59 per cent, whereas it is 2.32 and 2.18 per cent enhancement for Cu/water and CuO/water nanofluids, respectively. Entropy generation is reduced by 3.31, 2.35 and 2.96 per cent for Cu-CuO/water, Cu/water and CuO/water nanofluids, respectively, as compared to water. Research limitations/implications However, this is associated with a penalty of increment in pressure drop of 2.92, 3.09 and 2.74 per cent for Cu-CuO/water, Cu/water and CuO/water nanofluids, respectively, compared with water. Originality/value It is clear from the analysis that Cu-CuO/water hybrid nanofluids possess notable increment in both energy and exergy efficiencies to use them in SFPCs.

Glass Cover Temperature and Upward Heat Losses of a Single Glazed Collector With Nearly Vertical Configuration

2010 ◽  
Author(s):  
Suresh Kumar ◽  
Subhash C. Mullick
Keyword(s):  
Numerical Solution ◽  
Flat Plate ◽  
Heat Balance ◽  
Empirical Relation ◽  
Heat Losses ◽  
Operating Conditions ◽  
Balance Equations ◽  
Maximum Absolute Error ◽  
Glass Cover ◽  
Flat Plate Collector

Estimation of upward heat losses is required for design or thermal performance evaluation of a flat plate collector. Collectors with vertical configuration are used at high latitudes and are integrated with building walls. Values of glass cover temperature are required for calculation of upward heat losses under different operating conditions. Glass cover temperature can be determined from numerical solution of heat balance equations. In the present work an empirical relation for glass cover temperature of a single glazed flat plate collector for angle of tilt 60 to 90 degree is proposed. Values of glass cover temperature obtained from this empirical relation have been used for computation of top heat loss coefficient of flat plate collector. Analytical equation has been employed for estimation of Ut. The range of variables covered in the present analysis is 20 °C to 150 °C for absorber plate temperature, 0.1 to 0.95 for absorber coating emittance, 20 mm to 50 mm for air gap spacing, 60 deg to 90 deg for collector tilt, 5 W/m2K to 30 W/m2K for wind heat transfer coefficient and −10 °C to + 40 °C for ambient temperature. The maximum absolute error in values of Ut is within two percent in comparison to values obtained by numerical solution of heat balance equations over the entire range of variables covered in the present work.

Comparison of the effects of Al2O3 and CuO nanoparticles on the performance of a solar flat-plate collector

2015 ◽  
Vol 40 (4) ◽  
Author(s):  
Dinesh Babu Munuswamy ◽  
Venkata Ramanan Madhavan ◽  
Mukunthan Mohan
Keyword(s):  
Flat Plate ◽  
Cuo Nanoparticles ◽  
Working Fluid ◽  
Water Heater ◽  
Flat Plate Collector

AbstractTo improve the efficiency of solar flat-plate collectors further, a study had been carried out wherein the conventional working fluid was replaced by nanofluids. A 25-L/day solar flat-plate water heater with collector area of 0.5

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