CFD investigation of the behavior of a solar dryer for the dehydration of olive pomace

ABSTRACT

CFD investigation of the behavior of a solar dryer for the dehydration of olive pomace Solar dehydration is a process that reduces the percentage of moisture in the product without using nonrenewable energy. The present research analyses the behavior of olive pomace in the drying process. This process is important due to the need to reduce its humidity since with low humidity, olive pomace has good energy potential and can be used as biomass. The drying curve is determined in which a reduction from 67.34 to 40.73% of humidity can be observed in 12 days of dehydration, and the lower heating value curve and the elemental analysis of the olive pomace sample collected in the olive mill are determined experimentally in the solar dehydrator and in a laboratory. The dehydrator is analyzed with the help of computational fluid dynamics in ANSYS Student software. In this study, attention was focused on observing the effects produced by variations in the height of the dehydration chamber, and it was determined that the optimal height of the dehydration chamber is 300 mm.

KEYWORDS:

• Dehydration
• olive pomace
• prototype
• CFD
• clean energy

Nomenclature

SCA	=	Cooperative Society
H	=	Moisture content in olive pomace sample [% by weight]
P	=	Sample weight of olive pomace [kg]
PCS	=	Higher calorific power [kJ/kg]
PCI	=	Lower heating value [kJ/kg]
CFD	=	Computational Fluid Dynamics
t	=	Time [s]
u	=	x component of velocity [m/s]
v	=	y component of velocity [m/s]
w	=	z component of velocity [m/s]
P	=	Pressure [Pa]
U	=	Specific internal energy [J/kg]
T	=	Temperature [K]
K	=	Thermal conductivity [W/m.k]
I	=	Radiation intensity [W/m2]
a	=	Absorption coefficient [1/m]
n	=	Refractive index
$\overrightarrow{r}$	=	Position vector
$\overrightarrow{s}$	=	Director vector
$\overrightarrow{s^{\prime }}$	=	Scattering direction vector
$s$	=	Path length
DO	=	Discrete Ordinates Radiation Model
Greek letters	=
$\rho$	=	Densidad [kg/m3]
$\sigma$	=	Stefan-Boltzmann constant [5.67×10−8 W/m2.K4]
${\sigma }_s$	=	Scattering coefficient [m−1]
$\mathrm{\Phi }$	=	Phase funtion
${\mathrm{\Omega }}^{\prime }$	=	Solid angle [Degrees]
Subscripts	=
i	=	Wet
f	=	Dry

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

José Cabrera-Escobar

José Cabrera-Escobar is a research professor at the National University of Chimborazo, a mechanical engineer, a master in mathematical engineering and computing, a master in mechanical design and currently studying a doctorate in advances in materials engineering and sustainable energy.

David Vera

David Vera Candeas has a PhD in Industrial Engineering from the University of Jaén. He has worked for 3 years in the private sector (Energylab, Vigo) on technology transfer projects to companies in the energy sector such as Naturgy, Repsol, Finsa and Inditex, among others. Regarding his research activity, he has published more than 40 indexed works and has participated as a researcher in more than 15 projects. Currently, he is Coordinator of the European Project REFFECT AFRICA funded by the European Commission with a total budget of €8.1 M. Its objective is to promote renewable resources in African countries through access to electricity and drinking water.

Francisco Jurado

Francisco Jurado (Senior Member, IEEE) was born in Linares, Jaén, Spain. He received the M.Sc. and Dr.Ing. degrees from the National University of Distance Education, Madrid, Spain, in 1995 and 1999, respectively. Since 1985, he has been a Professor with the Department of Electrical Engineering, University of Jaén, Jaén. His current research interests include power systems, modeling, and renewable energy. His research activities have been devoted to several topics, including power systems, and renewable energy. He is author of more than 380 papers in journals included in the Journal Citation Report (JCR), about 190 papers in the proceedings of International Conferences and 6 books. He has been involved in research projects funded by Spanish Ministries and European Commission. Researcher among the most influential in the world according to the classification made by Stanford University (USA).

Raúl Cabrera-Escobar

Raúl Cabrera-Escobar is a research professor at the Higher Polytechnic School of Chimborazo, specializing in Renewable Energies.