ISHS Acta Horticulturae 719: International Symposium on Greenhouse Cooling
VENTILATION RATE MODELS OF MEDITERRANEAN GREENHOUSES FOR CONTROL PURPOSES |
| Authors: | J. Pérez-Parra, M. Berenguel, F. Rodriguez, A. Ramirez-Arias |
| Keywords: | control model, empirical model, cooling |
| DOI: | 10.17660/ActaHortic.2006.719.20 |
| Abstract:
Crop growth is a very delicate subject that requires, among other things, adequate greenhouse climate conditions. These can be achieved by advanced control strategies that commonly rely on accurate models of greenhouse environmental conditions. In most Mediterranean countries, the greatest problem faced by far is cooling which, for economical reasons, leads to natural ventilation as a standard tool. With the focus set on a typical greenhouse structure in the southeast region of Spain, viz. the parral greenhouse with ridged covering, fitted with roof and/or sidewall ventilators, this paper presents a study of a simplified empirical ventilation rate model, based on tracer gas test regression results. The methodology applied to obtain the unknown parameters and some comments about its use in conjunction with advanced control techniques are also addressed. A first principles model calibrated for the target greenhouse has provided with verified data, and a parral greenhouse located in Almería, southeast Spain is also exploited for calibration and validation purposes. Finally, predicted ventilation rates obtained for summer and winter seasons are displayed, showing promising results. | |
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