Experimental Study of Hygrothermal Exchanges in an Evaporative Heat Exchanger Based on Fired Clay Plates for Air Cooling in Hot and Dry Climates
Salifou Cisse *
Laboratoire d’Énergies Thermiques Renouvelables (L.E.T.RE), Université Joseph KI-ZERBO, Ouagadougou, Burkina Faso.
Abdoul Aziz Ouiminga
Laboratoire d’Énergies Thermiques Renouvelables (L.E.T.RE), Université Joseph KI-ZERBO, Ouagadougou, Burkina Faso and Laboratoire Interdisciplinaire de Recherche en Sciences Appliquées, Ecole Normale Supérieure (ENS), Koudougou, Burkina Faso.
Arnaud Ouermi
Laboratoire d’Énergies Thermiques Renouvelables (L.E.T.RE), Université Joseph KI-ZERBO, Ouagadougou, Burkina Faso and Laboratoire Multidisciplinaire de Recherche en Sciences de l’Ingénieur, Ecole Polytechnique de Ouagadougou (EPO), Ouagadougou, Burkina Faso.
Boureima Kabore
Laboratoire d’Énergies Thermiques Renouvelables (L.E.T.RE), Université Joseph KI-ZERBO, Ouagadougou, Burkina Faso and UFR-ST, Laboratoire de Chimie Analytique, Physique Spatiale et Energétique (L@CAPSE), Université Norbert ZONGO, Koudougou, Burkina Faso.
Sié Kam
Laboratoire d’Énergies Thermiques Renouvelables (L.E.T.RE), Université Joseph KI-ZERBO, Ouagadougou, Burkina Faso.
Dieudonné Joseph Bathiebo
Laboratoire d’Énergies Thermiques Renouvelables (L.E.T.RE), Université Joseph KI-ZERBO, Ouagadougou, Burkina Faso.
*Author to whom correspondence should be addressed.
Abstract
In hot and dry climates like Burkina Faso, conventional air conditioning is energy-intensive and costly, accounting for 20% of global energy consumption according to the International Energy Agency. The "Argiclim" evaporative heat exchanger, developed at the Renewable Thermal Energy Laboratory (L.E.T.RE) of Joseph KI-ZERBO University, uses porous fired clay plates to cool air through evaporation. Tested from April to June 2023, the prototype (18x18x2 cm, PVC casing) achieved a saturation efficiency of 92%. It reduced the temperature from 42°C to 29°C and increased relative humidity from 30% to 95% under conditions with an inlet air temperature of 42°C and 30% relative humidity, with a 2 cm plate spacing. Measurements using type K thermocouples (accuracy ±1°C) and hygrometers showed a 15°C temperature drop and a relative humidity of 95% at 2 cm from the duct. Simulations using Matlab, based on Luikov’s equations, validated the experimental results (deviations <5%). Despite high outlet humidity and water dependency, "Argiclim" offers a sustainable and cost-effective alternative to traditional air conditioners, leveraging local materials for accessible thermal comfort in Sahelian regions.
Keywords: Heat exchanger, evaporation, fired clay, thermal efficiency, hygrothermal, hot and dry climate