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Simulated performance of a greenhouse cooling control strategy with natural ventilation and fog cooling
Year:
2012
Source of publication :
Biosystems Engineering
Authors :
Arbel, Avraham
;
.
Volume :
111
Co-Authors:
Villarreal-Guerrero, F., Facultad de Agronomía, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
Kacira, M., Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ, United States
Fitz-Rodríguez, E., Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ, United States
Linker, R., Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Haifa, Israel
Kubota, C., School of Plant Sciences, The University of Arizona, Tucson, AZ, United States
Giacomelli, G.A., Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ, United States
Arbel, A., Agricultural Research Organization, Bet Dagan, Israel
Facilitators :
From page:
217
To page:
228
(
Total pages:
12
)
Abstract:
In addition to ventilation, daily cooling must be provided for greenhouses located in semiarid climates to maintain the desired climate conditions for year-round crop production. High-pressure fogging systems have been successfully developed for greenhouse cooling. However the lack of control strategies, in combination with ventilation systems, especially passive ventilation, has limited their capabilities. A new cooling control strategy, which considered the contribution of humidification and cooling from the crop, was evaluated by computer simulations. The strategy controlled the amount of fog introduced into the greenhouse, as well as the percentage of vent openings to maintain desired values of greenhouse atmospheric vapour pressure deficit (VPD) and enthalpy, respectively, which would consequently affect air temperature. The performance was compared to constant fogging rate strategy, which was based on VPD. On average, the new strategy saved 36% water and consumed 30% less electric energy. Smaller air temperature and relative humidity fluctuations, and more consistent control, were achieved by varying the fog system operating pressure to provide a more optimum amount of fog for evaporative cooling. It was demonstrated by simulations that dynamically varying the fog rate and properly selecting the number of nozzles, savings of water and electric energy were increased, while still maintaining acceptable VPD and temperature. The improvements in the greenhouse climate achieved by the new strategy were due to its ability to dynamically manipulate fog rates, as well as, the vent configurations. © 2011.
Note:
Related Files :
computer simulation
Crop Production
Crops
Fogging system
greenhouses
ventilation systems
Show More
Related Content
More details
DOI :
11
Article number:
Affiliations:
Database:
Scopus
Publication Type:
article
;
.
Language:
English
Editors' remarks:
ID:
27611
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:32
You may also be interested in
Scientific Publication
Simulated performance of a greenhouse cooling control strategy with natural ventilation and fog cooling
111
Villarreal-Guerrero, F., Facultad de Agronomía, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
Kacira, M., Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ, United States
Fitz-Rodríguez, E., Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ, United States
Linker, R., Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Haifa, Israel
Kubota, C., School of Plant Sciences, The University of Arizona, Tucson, AZ, United States
Giacomelli, G.A., Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ, United States
Arbel, A., Agricultural Research Organization, Bet Dagan, Israel
Simulated performance of a greenhouse cooling control strategy with natural ventilation and fog cooling
In addition to ventilation, daily cooling must be provided for greenhouses located in semiarid climates to maintain the desired climate conditions for year-round crop production. High-pressure fogging systems have been successfully developed for greenhouse cooling. However the lack of control strategies, in combination with ventilation systems, especially passive ventilation, has limited their capabilities. A new cooling control strategy, which considered the contribution of humidification and cooling from the crop, was evaluated by computer simulations. The strategy controlled the amount of fog introduced into the greenhouse, as well as the percentage of vent openings to maintain desired values of greenhouse atmospheric vapour pressure deficit (VPD) and enthalpy, respectively, which would consequently affect air temperature. The performance was compared to constant fogging rate strategy, which was based on VPD. On average, the new strategy saved 36% water and consumed 30% less electric energy. Smaller air temperature and relative humidity fluctuations, and more consistent control, were achieved by varying the fog system operating pressure to provide a more optimum amount of fog for evaporative cooling. It was demonstrated by simulations that dynamically varying the fog rate and properly selecting the number of nozzles, savings of water and electric energy were increased, while still maintaining acceptable VPD and temperature. The improvements in the greenhouse climate achieved by the new strategy were due to its ability to dynamically manipulate fog rates, as well as, the vent configurations. © 2011.
Scientific Publication
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