Title: An experimental evaluation of indirect direct evaporative cooling unit for hot climate
Authors: Bourhan Tashtoush; Nelson Chilengwe; Mohamed Musthafa; Yousef Al Horr
Addresses: Gulf Organisation for Research and Development, QSTP 210162, Doha, Qatar ' Gulf Organisation for Research and Development, QSTP 210162, Doha, Qatar ' Gulf Organisation for Research and Development, QSTP 210162, Doha, Qatar ' Gulf Organisation for Research and Development, QSTP 210162, Doha, Qatar
Abstract: Direct and indirect evaporative cooling system is experimentally investigated using a plate heat exchanger for hot climate conditions. The effects of chilled water and ambient temperatures, water flow rates, humidity, and the operating cooling mode on the supply air temperature was investigated for three configurations. The system dry bulb and wet effectiveness was estimated for all conditions under consideration. It was found that the dry bulb effectiveness approached 17%, while it was in the range of 72-98% for the wet bulb effectiveness. In addition, the secondary air saturation effectiveness was calculated with varying water flow rates. It was found that the increase of water quantity in the heat exchanger would increase the refrigeration capacity and lead to a higher secondary air temperature difference. This resulted in higher saturation effectiveness for the system. These results were compared with available numerical data for calibration and validation purposes.
Keywords: direct cooling; indirect cooling; cross flow; wet bulb effectiveness; dry bulb effectiveness; saturation effectiveness; psychrometric chart; coefficient of performance; hot climate; evaporative cooling.
International Journal of Global Warming, 2021 Vol.24 No.3/4, pp.237 - 260
Received: 14 Aug 2019
Accepted: 27 Nov 2019
Published online: 30 Jul 2021 *