Dynamic performance of an evaporative cooling pad investigated in a wind tunnel for application in hot and arid climate. (April 2017)

• Record Type: Journal Article
• Authors: Rong, Li; Pedersen, Poul; Jensen, Thomas Ladegaard; Morsing, Svend; Zhang, Guoqiang
• Is Part Of: Biosystems engineering. Volume 156(2017)
• Page Start: 173
• Page End: 182
• Publication Date: 2017-04
• Subjects: Evaporative cooling pad -- Dynamic performance -- Cooling efficiency -- Mass transfer -- Control time cycle -- Temperature; Bioengineering -- Periodicals; Agricultural engineering -- Periodicals; Biological systems -- Periodicals; Génie rural -- Périodiques; Systèmes biologiques -- Périodiques; 631
• DOI: 10.1016/j.biosystemseng.2017.02.003
• Languages: English
• ISSNs: 1537-5110

Abstract

Abstract : Evaporative cooling pad are widely used in poultry production houses in hot and arid climate to provide an appropriate indoor thermal conditions for animals. Currently, the main challenge of this system is to maintain the indoor thermal conditions stable so that the productivity is ensured. This study used wind tunnel measurements to investigate the dynamic performance of evaporative cooling pad under different control strategies including altering water supply duration which was defined as pump-on time (ranging from 3 s to 120 s) and control time cycle (3, 4 and 5 min), which was defined as the sum of pump-on and pump-off time in a cycle. A cross-fluted design of impregnated cellulose pad with dimensions of 1.8 m × 0.6 m × 0.15 m (height × length × thickness) was used and constant water flowrate of 7.5 l min −1 is applied. The results indicated that periodic pattern of temperature and cooling efficiency was observed due to the setting of pump-on time. Larger variation in air temperature difference between inlet and outlet of evaporative cooling pad occurred when the control time cycle was longer and face air speed was bigger. Supplying water to the pad caused higher resistance to the air travelling through the pad. A relationship was presented between cooling efficiency and a ratio defined by pump-on time, water flow rate, control time cycle and air flow rate. The ratio of water to air can be implemented by the controller. Highlights: Present dynamic performance of ECP under different controlled parameters. Illustrate the relationship between cooling efficiency and water to air ratio. Propose control suggestions for the studied ECP as well as practical challenges.