Design, fabrication, and testing of a compact regenerative evaporative cooler with finned channels

Abstract

Regenerative evaporative cooling is known as an environment-friendly and energy efficient cooling method. A regenerative evaporative cooler (REC) consisting of dry and wet channels is able to cool down the air stream below the inlet wet-bulb temperature. In the regenerative evaporative cooler, the cooling effect is achieved by redirecting a portion of the air that flows out of the dry channel into the wet channel and spraying water onto the redirected air. In this study, to improve the cooling performance of the regenerative evaporative cooler, optimization of the fin configuration within the channel was carried out and a special coating treatment was developed to improve the surface wettedness in the wet channel. Applying the optimized fin configuration design with the highly wetting surface treatment, a regenerative evaporative cooler was fabricated and tested to identify the cooling performance improvement and operation characteristics. From the experimental results at the intake condition of 32°C and 40% RH, the supply temperature was measured to be 19°C. The cooling effectiveness based on the inlet dew point temperature was evaluated at 83% which is quite close to the design expectation. The hydrophilic porous layer treatment was found to be very effective, resulting in the improvement of the cooling effectiveness by more than 14%. ？ 2011 by Begell House, Inc.