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

Journal of Solar Energy Engineering, Transactions of the ASME - Tập 131 Số 4 - 2009
Himanshu Tyagi1, Patrick E. Phelan2, Ravi Prasher1
1School of Mechanical, Aerospace, Chemical, and Materials Engineering, Arizona State University, Tempe, AZ 85287-6106
2School of Mechanical, Aerospace, Chemical and Materials Engineering, National Center of Excellence on SMART Innovations, Arizona State University, Tempe, AZ 85287-6106

Tóm tắt

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.

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Tài liệu tham khảo

Okujagu, Performance of a Simple Flat-Plate Collector at an Equatorial Location, Sol. Wind Technol., 6, 283, 10.1016/0741-983X(89)90081-7

Minardi, Performance of a Black Liquid Flat-Plate Solar Collector, Sol. Energy, 17, 179, 10.1016/0038-092X(75)90057-2

Bertocchi, Experimental Evaluation of a Non-Isothermal High Temperature Solar Particle Receiver, Energy, 29, 687, 10.1016/j.energy.2003.07.001

Miller, Thermal Modeling of a Small-Particle Solar Central Receiver, ASME J. Sol. Energy Eng., 122, 23, 10.1115/1.556277

Abdelrahman, Study of Solid-Gas Suspension Used for Direct Absorption of Concentrated Solar Radiation, Sol. Energy, 22, 45, 10.1016/0038-092X(79)90058-6

Kumar, Analysis of Combined Radiation and Convection in a Particulate Laden Liquid Film, ASME J. Sol. Energy Eng., 112, 293, 10.1115/1.2929937

Prasher, Modeling of Radiative and Optical Behavior of Nanofluids Based on Multiple and Dependent Scattering Theories, 10.1115/IMECE2005-80302

Prasher, Modification of Planck Blackbody Emissive Power and Intensity in Particulate Media Due to Multiple and Dependent Scattering, ASME J. Heat Transfer, 127, 903, 10.1115/1.1928912

Prasher, Thermal Conductivity of Nanoscale Colloidal Solutions (Nanofluids), Phys. Rev. Lett., 94, 025901, 10.1103/PhysRevLett.94.025901

Bhattacharya, Brownian Dynamics Simulation to Determine the Effective Thermal Conductivity of Nanofluids, J. Appl. Phys., 95, 6492, 10.1063/1.1736319

Prasher, Brownian-Motion-Based Convective-Conductive Model for the Effective Thermal Conductivity of Nanofluids, ASME J. Heat Transfer, 128, 588, 10.1115/1.2188509

Prasher, Effect of Aggregation Kinetics on the Thermal Conductivity of Nanoscale Colloidal Solutions (Nanofluids), Nano Lett., 6, 1529, 10.1021/nl060992s

Krishnamurthy, Enhanced Mass Transport in Nanofluids, Nano Lett., 6, 419, 10.1021/nl0522532

Phelan, Nanofluids for Heat Transfer Applications, Annu. Rev. Heat Transfer, 14, 255, 10.1615/AnnualRevHeatTransfer.v14.160

Bohren, Absorption and Scattering of Light by Small Particles, 10.1002/9783527618156

Duffie, Solar Engineering of Thermal Processes, 10.1002/9781118671603

Streed, Results and Analysis of a Round Robin Test Program for Liquid-Heating Flat-Plate Solar Collectors, Sol. Energy, 22, 235, 10.1016/0038-092X(79)90139-7

Brewster, Thermal Radiative Transfer and Properties

Cengel, Heat Transfer: A Practical Approach, 2nd ed.

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Journal of Solar Energy Engineering, Transactions of the ASME

Tập 131 Số 4

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