Application potential of solar air-conditioning systems for displacement ventilation

摘要

Solar air-conditioning can have higher application potential for buildings through the strategy of high temperature cooling. In recent years, displacement ventilation (DV), which makes use of the indoor ris ing plumes from the internal heat gains, provides a more effective supply air option than the traditional mixing ventilation (MV) in terms of both thermal comfort and indoor air quality. As it is possible to raise the supply air temperature to 19℃ for DV, it would enhance the competitive edge of the solar air-conditioning against the conventional vapour compression refrigeration. Through dynamic simulation, a solar-desiccant-cooling displacement ventilation system (SDC.DV) was developed for full-fresh-air pro vision, while a solar-hybrid-desiccant-cooling displacement ventilation system (SHDC.DV) for return air arrangement. The latter was further hybridized with absorption chiller (AB) to become SHDC_(AB)-DV, or adsorption chiller (AD) to be SHDC_(AD)-DV, in order to be wholly energized by the solar thermal gain. Benchmarked with the conventional system using MV, the SDC_DV had 43.3% saving in year-round pri mary energy consumption for a typical office in the subtropical climate;the SHDC_(AB)-DV had 49.5% saving, and the SHDC_(AD)-DV had 18.3% saving. Compared with their MV counterparts, the SDCDV, the SHDC_(AB)-DV and the SHDC_(AD)DV could have 42.4%. 21.9% and 30.3% savins resDectivelv.