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Analysis of Temperature Gradients in Greenhouse Equipped with Fan and Pad System by CFD Method  

Nam Sang Woon (Department of Bioresource Engineering, Chungnam National University)
Giacomelli Gene A. (Department of Agricultural and Biosystems Engineering, Controlled Environment Agriculture Center, University of Arizona)
Kim Kee Sung (Department of Agricultural and Biosystems Engineering, Controlled Environment Agriculture Center, University of Arizona)
Sabeh Nadia (Department of Agricultural and Biosystems Engineering, Controlled Environment Agriculture Center, University of Arizona)
Publication Information
Journal of Bio-Environment Control / v.14, no.2, 2005 , pp. 76-82 More about this Journal
Abstract
Evaporative cooling pad system is one of the main cooling methods in greenhouses and its efficiency is very high. However, it has some disadvantages such as greenhouse temperature distributions are not uniform and installation cost is expensive. In this study, a CFD simulation model f3r predicting the air temperature distribution in the fan and fad cooling greenhouse was developed. The model was calibrated and validated against experimental data and a good fit was obtained. The influence of different outside wind, fan and pad height, ventilation rate, shading, and greenhouse length, were then examined. In order to reduce the internal temperature gradients, it is desired that the prevail wind direction and the fan and pad heights are considered. The simulation indicates that high ventilation rates and shading contribute to reduce the temperature gradients in the fan and pad cooling greenhouse. In order to maintain the desired greenhouse temperature, the pad-to-fan distance should be restricted according to the design climate conditions, shading and ventilation rates. The developed CFD model can be a useful tool to evaluate and design the fan and pad systems in the greenhouses with various configurations.
Keywords
CFD simulation; fan and pad system; greenhouse cooling; temperature gradients;
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