Theoretical modelling and experimental study of air thermal conditioning process of a heat pump assisted solid desiccant cooling system

• Published in: Energy and buildings 2017-10, Vol.153, p.31-40
• Main Authors: Nie, Jinzhe, Li, Zan, Hu, Wenju, Fang, Lei, Zhang, Qunli
• Format: Article
• Language: English
• Subjects: Adsorption; Air conditioners; Air purification; Air quality; Air temperature; Contaminants; Cooling; Cooling systems; Dehumidification; Desiccant rotor; Differential equations; Energy consumption; Energy efficiency; Energy measurement; Evaporation; Heat; Heat pump; High temperature; Indoor air pollution; Indoor environments; Mathematical models; Moisture; Moisture absorption; Partial differential equations; Purification; Regeneration; Sensible cooling; Solid desiccant cooling; Temperature; Temperature effects; Thermal environments; Ventilation
• ISSN: 0378-7788; 1872-6178
• DOI: 10.1016/j.enbuild.2017.07.075

•A HP-SDC was proposed based on the VOCs and moisture adsorption of desiccant.•A theoretical model of air thermal process in desiccant rotor was modelled.•A prototype unit of the HP-SDC was developed and measured.•The HP-SDC has high energy efficiency in tropical climates.•The energy efficiency of the HP-SDC is sensitive to outdoor humidity ratio. Taking the integrated gaseous contaminants and moisture adsorption potential of desiccant material, a new heat pump assisted solid desiccant cooling system (HP-SDC) was proposed based on the combination of desiccant rotor with heat pump. The HP-SDC was designed for dehumidification, cooling and air purification aimed at improving indoor air quality and reducing building energy consumption. The heat and moisture transfer in adsorption desiccant rotor was theoretical modelled with one-dimensional partial differential equations. The theoretical model was validated with experimental measurements, and the results showed the model could be used to predict the heat and moisture transfer in desiccant rotor. The air thermal conditioning process and energy consumption of HP-SDC was then experimental measured under varied outdoor thermal environments. Results showed that compared to conventional ventilation system, the energy performance of HP-SDC was more efficient mainly due to high efficient air purification capacity, reduction of cooling load and raised evaporation temperature. The energy performance of HP-SDC was sensitive to outdoor humidity ratio. Further improvements of HP-SDC energy efficiency are suggested to be focused on low regeneration temperature desiccant rotor and more efficient high temperature refrigerant.