Modeling and optimization of a greenhouse-type solar dryer system
Modeling and optimization of a greenhouse-type solar dryer system
Date
2022-11-18
Authors
Valencia Islas, José Olaf
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad Autónoma Chapingo
Abstract
Solar drying in greenhouses is an
economical and safe alternative for drying, it
allows to increase the shelf life of products
in an innocuous way. The objectives of the
thesis were 1) to model the drying kinetics of
tomato in a greenhouse-type solar dryer; 2)
to model and control the internal conditions
in a greenhouse-type solar dryer; 3) to
evaluate design alternatives to improve the
drying process. The greenhouse-type solar
dryer is located at the Universidad
Autonoma Chapingo (Mexico) and has a 6-
mm-thick parabolic-shaped polycarbonate
cover; 15 cm thick concrete floor; two
exhaust fans for the air and four air inlets;
with an approximate volume of 211 m3
.
Thirty-five thin-layer models were tested for
drying tomato slices. The innovation at this
stage was to analyze the models in terms of
their structure, and number of parameters
and evaluate them with data from another
experiment. The best model was the Page
VI model with an RMSE of 0.06 and an R2 of
0.993. To improve drying, a controller based
on "Model Predictive Control" for the
greenhouse was modeled and designed.
The main innovation was the use of system
identification with the N4SID algorithm,
obtaining a model with product temperature
as state and control based on product
temperature and not air temperature.
Finally, a literature review on the modeling
of greenhouse-type solar dryers using CFD
was carried out and a computational model
(CFD) for the dryer was developed. The
model was validated, and two designs were
tested to recirculate the air and improve the
temperature distribution inside the
greenhouse. Both systems showed higher
temperatures and a more uniform velocity
throughout the volume.
Description
Tesis (Maestría en Ingeniería Agrícola y Uso Integral del Agua)
Keywords
Secado solar, Control,
Modelación, CFD, Capa fina.