Operating Energy Savings of a Liquid Desiccant and Evaporative Cooling-Assisted Air-Handling System in Marine Applications

Abstract

The aim of this study is to analyze the operating energy savings of a liquid desiccant and an indirect and direct evaporative cooling-assisted 100% outdoor air system (LD-IDECOAS) for marine applications. The LD-IDECOAS comprises a liquid desiccant (LD) unit and indirect and direct evaporative coolers (IEC and DEC) to meet the target supply air (SA) conditions. In this study, seawater was used as the cooling source and the waste heat reclaimed from the engine was used as the heating source in the proposed system. The operating energy of the LD-IDECOAS was determined based on detailed energy simulations conducted on two cabins with an area of 16.5 m(2), which was compared to a conventional system. The thermal loads on the cabins were estimated using design weather data under various oceanic climate conditions (normal, extremely hot, and extremely cold climates), by adhering to the ISO-7547 standard. The operating energy consumption of the LD-IDECOAS was calculated by modeling the proposed system with a commercial equation solver program (i.e., EES). The results were then compared to those of a conventional constant air volume (CAV) system. The operating energy consumption of the proposed system was reduced by 57-70% in cooling operations and 39% in heating operations under normal climate conditions. In the extremely hot climate regions, the energy consumed by the proposed system was reduced by 56-63% for cooling applications and 39% for heating applications.