Study on the Application of Rotary Desiccant Air-Conditioning System on Ships

A rotary desiccant air conditioning (A/C) system consists of desiccant wheel, process air cooler and regeneration air heater, and is usually integrated with an auxiliary vapor-compression A/C unit. The regeneration process of desiccant material in the system can be driven by low-grade thermal energy, such as industrial waste heat and solar energy. There are a wealth of waste heat in ships and meanwhile abundant sea water readily available for acting as cooling medium. The application of the rotary desiccant A/C system on ships should be advantageous. In this paper, the up-to-date status of the technical development of rotary desiccant A/C system was first reviewed from three different aspects. In order to put forward the application of rotary desiccant A/C system on ships, four schemes of configuration for the marine rotary desiccant A/C system were developed and then analyzed. Taking into account of the limited installation space in ships, the one-rotor two-stage system should be practical for its application on ships. Among the four schemes, Scheme II where fresh air and return air were mixed before first-stage dehumidifying process was found superior with its moderate requirement for dehumidifying capability of desiccant wheel and its reduced operating cost. Finally, the energy-saving effect of the marine rotary desiccant A/C system adopted was investigated through comparing its demanded refrigerating capacity with that of the conventional A/C system. It was found that the auxiliary refrigerating capacity required for the marine rotary desiccant A/C system was only 47.1% of that of the conventional A/C system.