Development and experimental analysis of a novel dual-mode counter-flow evaporative cooling device

Abstract

The recent energy demand for cooling increases rapidly, which has forced researchers to think about the technological shift. Evaporative cooling is an eco-friendly option, uses much less energy. Direct evaporative coolers are used worldwide and effective for arid climates. Regenerative evaporative coolers can cool up to dew point without adding moisture to the supply air. The dual-mode evaporative cooler is a novel idea that can operate in both regenerative and direct modes. In this work, the testing unit of this novel cooler is fabricated and experimentally investigated in both direct and regenerative modes. The important operating parameters (extraction ratio, inlet air temperature, inlet air velocity, inlet air specific humidity, water flow rate and water inlet temperature) are varied to get their effect on energy and environmental performance parameters (supply air temperature, cooling capacity, dew-point effectiveness, COP and CO2 emission). Technical comparison with conventional vapor compression air-conditioner is presented as well. The water inlet temperature affects regenerative mode more as compared to direct mode. The high water flow rate decreases the COP sharply in both modes. Comparison shows that direct mode can be used for higher cooling capacity (lower carbon emission) and COP while regenerative mode can be used for higher effectiveness.