Thermal analysis on charging and discharging behaviour of a phase change material-based evacuated tube solar air collector

Abstract

The performance analysis on the phase change material-based evacuated tube solar air collector was examined under consecutive and simultaneous charging and discharging modes. Acetamide was used as phase change material. The system performance was evaluated on the basis of the phase change material storage system energy efficiency, exergy efficiency, collector efficiency, the instantaneous energy stored in the phase change material and total energy stored by the system at low and high air flow rates of 0.018 kg/s and 0.035 kg/s, respectively. The maximum average efficiency (17.9%) of the collector was obtained at a high air flow rate during simultaneously charging and discharging of the phase change material. The results obtained demonstrate that the system is more effective when it is operated with high air flow rate during simultaneously charging and discharging of the phase change material. The average total energy at high air flow rates is 1.01 to 1.02 times more in comparison to that at low air flow rates. The findings show the feasibility of the phase change material-based evacuated tube solar air collector for producing hot air for space heating during consecutive and simultaneous charging and discharging of the phase change material in northen Indian climatic conditions. This system would be relevant in areas with good sunlight.