Energy and exergy assessment of a novel parabolic hybrid active greenhouse solar dryer

In the present work, a parabolic hybrid active greenhouse solar dryer (PHAGSD) embraced with a solar air heater (SAH) has been designed and fabricated at MITS Campus, Gwalior. The dryer is operated in active mode in the winter season and experimentation is performed in the dryer with & without SAH and open sun drying (OSD). The energy and exergy analysis are carried out by drying two seasonable crops, green chilli and okra. In all cases, green chilli and Okra are dried from initial moisture content of 89.33 % (wb) and 91 % (wb) to 10 % (wb) and 7.53 % (wb) respectively. In the case of with SAH, the drying time of green chilli and Okra is 32 h and 26 h, while in the case of without SAH, it is 40 h and 31 h, and when dried in OSD, it is 48 h and 37 h, correspondingly, which is 15 h and 9 h more than the with SAH. The thermal efficiency of the SAH ranges from 57 to 97 %, and the dryer thermal efficiency in the case of with SAH is found 6 % higher than the dryer without SAH. The exergy efficiency of SAH is estimated 9 %. The exergy efficiency in the case of with SAH is found 19 %, while in the case of without SAH, it is 6 %. The dryer's exergy efficiency in the case of with SAH is found 13 % higher than the without SAH.

Automated summary

In this study, a parabolic hybrid active greenhouse solar dryer (PHAGSD) with a solar air heater (SAH) was designed and fabricated. The effects of SAH on the drying performance were investigated. The results showed that the dryer with SAH had higher thermal and exergy efficiency compared to the dryer without SAH.