Design and Optimization of Terracotta Tube-Based Direct Evaporative Cooling Exchanger: An Analytical Approach to Heat and Mass Transfer  

作　　者：Windnigda Zoungrana Makinta Boukar Ousmane Coulibaly Guy Christian Tubreoumya Antoine Bere Windnigda Zoungrana;Makinta Boukar;Ousmane Coulibaly;Guy Christian Tubreoumya;Antoine Bere(Laboratoire dEnergtique, dElectronique, dElectrotechnique, dAutomatique et dinformatique Industrielle, Universit Abdou Moumouni, Niamey, Niger;Laboratoire de Physique et de Chimie de lEnvironnement, Universit Joseph Ki Zerbo, Ouagadougou, Burkina Faso)

机构地区：[1]Laboratoire dEnergtique, dElectronique, dElectrotechnique, dAutomatique et dinformatique Industrielle, Universit Abdou Moumouni, Niamey, Niger [2]Laboratoire de Physique et de Chimie de lEnvironnement, Universit Joseph Ki Zerbo, Ouagadougou, Burkina Faso

出　　处：《Open Journal of Applied Sciences》2025年第1期352-373,共22页应用科学(英文)

摘　　要：This study develops an analytical model to evaluate the cooling performance of a porous terracotta tubular direct evaporative heat and mass exchanger. By combining energy and mass balance equations with heat and mass transfer coefficients and air psychrometric correlations, the model provides insights into the impact of design and operational parameters on the exchanger cooling performance. Validated against an established numerical model, it accurately simulates cooling behavior with a Root Mean Square Deviation of 0.43 - 1.18˚C under varying inlet air conditions. The results show that tube geometry, including equivalent diameter, flatness ratio, and length significantly influences cooling outcomes. Smaller diameters enhance wet-bulb effectiveness but reduce cooling capacity, while increased flatness and length improve both. For example, extending the flatness ratio of a 15 mm diameter, 0.6 m long tube from 1 (circular) to 4 raises the exchange surface area from 0.028 to 0.037 m2, increasing wet-bulb effectiveness from 60% to 71%. Recommended diameters range from 5 mm for tubes under 0.5 m to 1 cm for tubes 0.5 to 1 m in length. Optimal air velocities depend on tube length: 1 m/s for tubes under 0.8 m, 1.5 m/s for lengths of 0.8 to 1.2 m, and up to 2 m/s for longer tubes. This model offers a practical alternative to complex numerical and CFD methods, with potential applications in cooling tower optimization for thermal and nuclear power plants and geothermal heat exchangers.This study develops an analytical model to evaluate the cooling performance of a porous terracotta tubular direct evaporative heat and mass exchanger. By combining energy and mass balance equations with heat and mass transfer coefficients and air psychrometric correlations, the model provides insights into the impact of design and operational parameters on the exchanger cooling performance. Validated against an established numerical model, it accurately simulates cooling behavior with a Root Mean Square Deviation of 0.43 - 1.18˚C under varying inlet air conditions. The results show that tube geometry, including equivalent diameter, flatness ratio, and length significantly influences cooling outcomes. Smaller diameters enhance wet-bulb effectiveness but reduce cooling capacity, while increased flatness and length improve both. For example, extending the flatness ratio of a 15 mm diameter, 0.6 m long tube from 1 (circular) to 4 raises the exchange surface area from 0.028 to 0.037 m2, increasing wet-bulb effectiveness from 60% to 71%. Recommended diameters range from 5 mm for tubes under 0.5 m to 1 cm for tubes 0.5 to 1 m in length. Optimal air velocities depend on tube length: 1 m/s for tubes under 0.8 m, 1.5 m/s for lengths of 0.8 to 1.2 m, and up to 2 m/s for longer tubes. This model offers a practical alternative to complex numerical and CFD methods, with potential applications in cooling tower optimization for thermal and nuclear power plants and geothermal heat exchangers.

关 键 词：Analytical Modeling Porous Terracotta Tube Direct Evaporative Cooling Heat and Mass Exchanger Performance Optimization 

分 类 号：TG3[金属学及工艺—金属压力加工]