Thermal and energy performance of a solar-driven desiccant cooling system using an internally cooled desiccant wheel in various climate conditions

• Published in: Applied thermal engineering 2021-02, Vol.185, p.116077, Article 116077
• Main Author: Zhou, Xingchao
• Format: Article
• Language: English
• Subjects: Air conditioning; Commercial buildings; Cooling; Cooling systems; Desiccants; Dewpoint evaporative cooler; Drying agents; Electricity consumption; Energy consumption; Internally cooled desiccant wheel; Low temperature; Office buildings; Regeneration; Temperature; Thermal energy; Thermal simulation; TRNSYS simulation; Working hours
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2020.116077

•Proposed independent temperature and humidity control strategy for desiccant cooling.•Desiccant cooling could fulfil the cooling task in sub-tropical and temperate areas.•Solar driven desiccant cooling required above 8% backup heat to perform cooling task.•Desiccant cooling consumed 50% less electricity than the conventional cooling system. A comprehensive thermal and energy performance analysis of a solar-driven desiccant cooling system, using low temperature of regeneration air (below 70 °C) was carried out via TRNSYS simulations for three different types of commercial office buildings under three climatic conditions – tropical, subtropical and temperate. The simulated temperature and humidity of the building space were used to analyse thermal performance, while simulated gas and electricity consumption were used to analyse energy performance. These results were then compared with the performance of a conventional vapour-compression air-conditioning system applied to the same buildings and conditions. The findings indicated that, in tropical areas, the simulated desiccant cooling system cannot maintain a comfortable thermal level in the building for at least 28.36% of its working time. However, in subtropical and temperate areas, the system could provide enough cooling and heating to the building for more than 98% of working time. The desiccant cooling system was also found to require at least 5% of regenerated heat from backup heater to work continually. Because its electricity consumption was at least 50% less than that of a conventional system, the resulting coefficient of performance was twice as high.