Exergy and energy analysis of a novel dual-chilling-source refrigerating system applied to temperature and humidity independent control

Highlights: • A novel dual-chilling-source refrigerating system was proposed. • Performance of the dual-chilling-source refrigerating system was studied. • A comparison to the conventional system was conducted. • The system has high energy-saving potential. • Outdoor relative humidity has a significant impact on system exergy loss. -- Abstract: This paper proposed a novel dual-chilling-source refrigerating system using R407C applied in the temperature and humidity independent control system. The theoretical model was established to analyze the performance of this system regarding the coefficient of performance, exergy loss and exergy efficiency in comparisons with a single-chilling-source refrigerating system. The results showed that the dual-chilling-source refrigerating system had obvious advantages over the single-chilling-source refrigerating system. The dual-chilling-source refrigerating system improved the coefficient of performance and exergy efficiency by about 25% and 30%, respectively, and decreased exergy loss by around 25%. The outdoor relative humidity had the most significant effects on the system exergy loss. With the outdoor relative humidity increasing from 40% to 90%, the exergy loss value was increased by about 43% and 42% for the single-chilling-source refrigerating system and dual-chilling-source refrigerating system, respectively. The effects of low-temperature chilled water temperature on the coefficient of performance, exergy loss and exergy efficiency were more remarkable than those of high-temperature chilled water temperature. Overall, the dual-chilling-source refrigerating system had significant potential in saving energy and improving exergy efficiency, especially for the high humidity load area.