Primary energy saving potential of a liquid desiccant and evaporative cooling-assisted 100% outdoor air system in underground spaces

Abstract

The purpose of this paper is to evaluate the applicability of a liquid desiccant and evaporative cooling-assisted 100% outdoor air system (LD-IDECOAS) in underground spaces. A detailed energy simulation is performed for estimating the energy saving potential of the LD-IDECOAS. The simulation is conducted using TRNSYS 17 and a commercial engineering equation solver program (EES). The ground source heat pump (GSHP) is integrated with the liquid desiccant (LD) system in the LD-IDECOAS to supply heating for the desiccant solution. The thermal load of underground spaces shows a different pattern compared with that of above ground spaces. Maximum cooling and heating loads are relatively small in the underground spaces because of the almost stable condition of the surrounding environment, in comparison to an above ground building. As a result, the size of HVAC systems in underground spaces can be smaller than those in above ground spaces. In this study, the regeneration heat source was applied to GSHP system. The GSHP system yields 20% operating primary energy savings compared with the conventional gas-boiler in the summer because of the constant temperature in the underground space. The results also show that the integrated system was more suitable for underground spaces.