Thermal analysis of greenhouses installed under semi arid climate

Autor: Kheireddine Meguellati, Pierre-Emmanuel Bournet, K. Mesmoudi
Přispěvatelé: Université Hadj Lakhdar Batna 1, Unité de Recherche Environnement Physique de la plante Horticole (EPHOR), Université d'Angers (UA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
Rok vydání: 2017
Předmět:
Zdroj: International Journal of Heat and Technology
International Journal of Heat and Technology, International Information and Engineering Technology Association, 2017, 35 (3), pp.474-486. ⟨10.18280/ijht.350304⟩
ISSN: 0392-8764
DOI: 10.18280/ijht.350304
Popis: International audience; The greenhouse design as well as the cover material properties in particular may strongly impact the greenhouse energy. To study the effect of these parameters, three typical unheated greenhouses equipped with rows of canopy were considered. Experiments were launched to establish the boundary conditions and validate the model. Two parametric studies were carried out: for the nocturnal period when the energy performance of each type of greenhouse was investigated, and for the diurnal period, when the sun path was simulated taking into account the type of the cover, its spectral optical and thermal properties. Results indicate that for the nocturnal period, the ambient air temperature in the tunnel and vertical wall greenhouse was relatively homogenous and warmer compared with the temperature distribution in the Venlo greenhouse. The plastic greenhouse, especially the tunnel one had better performances concerning the homogenization of the climate and the thermal energy storage. Concerning the diurnal period, and for both plastic greenhouses equipped with fully opened side vents, the air located between the rows of canopy and ground surfaces remained very slow, not exceeding 0.2 ms-1; for the Venlo glasshouse, the recirculation loop situated above the crop improved the air mixing and induced a good homogenization. Results indicate that the cover material with highest absorptivity, deteriorated the natural ventilation, increasing the air temperature by convection, and reduced the available Photosynthetically Active Radiation.
Databáze: OpenAIRE