Session: 11-44-01: Heat and Mass Transfer for Renewable Energy Conversion Processes

Paper Number: 94938

94938 - Numerical Study of Inclination Effect on a Flat-Place Direct Absorption With Water-Nanofluid Mixtures in Summer and Winter Conditions 

Nowadays with progresses across different industrial and domestic fields, the need for more energy is felt around the world. This demand leads to an unprecedented increase in fossil fuel consumption, while the surplus of fossil fuels can also damage the environment and warm the earth. Therefore, implementing alternative energy policy has become a major issue in the world. The application of renewable energies, specifically solar energy, which is one of the most popular and available energy sources, can be an appropriate alternative to fossil fuel consumption. In addition, utilizing this clean energy, because of being free, can reduce costs. Emerging nanotechnology with solar collector technology has attracted the attention of researchers to enhance the performance of solar systems in order to develop efficient solar thermal systems for future sustainability. Flat-plate solar collectors are regarded as a good alternative to meet the thermal energy demand from the domestic and industrial sectors. Thermal performance enhancement of flat-plate solar collectors is progressing either by advancing the absorber plate or improving the heat transfer fluid effectiveness. The shortage of contact surface of the working fluid with hot solid-phase as well as the relatively low thermal conductivity of common fluids such as water are considered as limitations in applications, specifically engineering thermal devices such as flat plate solar collectors. Nanotechnology is one of the top issues in the world, nowadays. One of the important parts of nanotechnology is nanofluid. The importance of using this material is due to the significant demands for increasing the rate of heat transfer in the current industries.

In the present work, a numerical investigation on two-dimensional steady state forced convection inside a direct absorption volumetric solar collector (DAVSC), employing as working fluid a nanofluid mixture of water and carbon nanohorn. The investigation is performed in order to evaluate behaviors of the DAVSC as a function of the inclination angle under different conditions in summer and winter regimes for residential use site in Aversa (Italy). The analysis allows to evaluate the thermal and fluid dynamic behaviors of a solar collector with a distance between the glass and the collecting plate of 1.2 mm and a length of 1.0 m and an inclination angle, with respect to the horizontal plane, equal to 0, 30, 60 and 90 degrees. The solar collector presents heat losses from the upper wall towards the external ambient by a surface heat transfer coefficient. The governing flow equations for the nanofluid are written assuming the single-phase flow and the radiative heat transfer equation in the participating media for the presence of the local absorption of nanoparticles is solved adopting the non-grey discrete ordinates method. The optical and thermal behaviors of the nanofluid are modelled according to the properties available in the literature. The finite volume method is employed to solve the problem and the results are carried out by means of the ANSYS-FLUENT code. The results are given in terms of temperature and velocity fields and transversal profiles inside the channel for different values of mass flow rates, solar irradiance, volumetric nanoparticle concentrations and external surface heat transfer coefficient and temperature.

Presenting Author: Oronzio Manca Università degli Studi della Campania "Luigi Vanvitelli"

Presenting Author Biography: Oronzio Manca is professor at Università degli Studi della Campania “Luigi Vanvitelli”. Member of Scientific Council of International Center for Heat and Mass Transfer, American Society of Mechanical Engineering, AIGE and UIT. He was Associate Editor for ASME Journal of Heat Transfer and he is AE for Journal of Porous Media and Alexandria Journal of Engineering. Member of the Editorial Advisory Boards for several journals. He is author or coauthor of 610 scientific papers, 170 on peer reviewed journals and 16 book chapters. Head of PhD School of Polythecnic and Basic Sciences at his University. His h-index on Scopus is 38. Recent research interests are related to heat transfer in porous media, metal foams, heat transfer in microchannels, enhancement heat transfer techniques, such as baffles in channels and nanofluids, sensible and latent thermal energy storage systems analysis and nano PCM.

Authors:

Bernardo Buonomo Università degli Studi della Campania “Luigi Vanvitelli”
Fabio Cardillo Università degli Studi della Campania “Luigi Vanvitelli”
Pietro Chirico Università degli Studi della Campania “Luigi Vanvitelli”
Oronzio Manca Università degli Studi della Campania "Luigi Vanvitelli"
Sergio Nardini Università degli Studi della Campania “Luigi Vanvitelli”
Giovanna Russo Università degli Studi della Campania “Luigi Vanvitelli”
Angela Scapaticci Università degli Studi della Campania “Luigi Vanvitelli”
Ivan Vicidomini Università degli Studi della Campania “Luigi Vanvitelli”