Performance evaluation and economic analysis of modified solar dryer with thermal energy storage for drying of blood fruit (Haematocarpus validus)

In the present work, a modified solar dryer (MSD) assembled with a solar collector consisting of phase change material (PCM)-thermal storage unit has been designed and the dryer performance investigated while drying blood fruit. The proposed design of MSD with double-glazed glass on a solar collector increased the drying air temperature by 15%-18%. The mean temperature in the drying chamber of MSD was 60 degrees C with 10-12 hr of the continuous drying period. The Midilli model was well suitable to explain the drying kinetics of the blood fruit in MSD. The quality parameters like color, TPC, TFC, and antioxidant activity of dried slices were compared with fresh samples. Simulated model behaviors were similar to experimental values with an RMSE and RMSE% remaining below 1.2 degrees C and 0.86%, respectively. Environmental impact analysis of MSD showed that the energy payback and cost payback periods were estimated as 1.23 and 2.16 years, respectively. Practical application A proposed modified solar dryer with thermal energy storage was designed and investigated for drying of blood fruit. The energy storage unit in the MSD increases the drying time by 19%, effective at off-sunshine hour and retains the quality of dried products as well as improves the drying rate compared to tray dryer. The exergy analysis, energy payback period, CO2 emission, and cost payback period are performed for MSD and found to be better than tray dryer (TD). The MSD's energy payback time is 1.23 years, and the calculated CO2 reduction is 4.14 tons in 5 years, 9.64 tons in 10 years, and 20.65 tons in 20 years, respectively. The solar dryer that has been built will be ideal for marginal farmers and small scale entrepreneurs and can be extended to any capacity.