Library Subscription:
Guest

ISSN Online: **2688-7231**

ISBN Online: **978-1-56700-524-0**

Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India

Solar-assisted heat pump dryer is fabricated for intermittent drying. An experiment is performed for different intermittency ratio (continuous (α=1), α= 0.66, α= 0.33 and α= 0.2) for radish chips drying. The radish chips were dried to extract moisture from 92.4 % to 11.9% at constant air-flow rate (v=1.0 m/s) in the system. The energy and drying efficiency and moisture extraction rate is estimated higher for the intermittency ratio of 0.2. The average values of moisture extraction rate with solar assisted heat pump drying for the intermittency ratio of continuous (α=1), α= 0.66, α= 0.33 and α= 0.2 were 1.1045 kg/h, 1.43 kg/h, 1.736 kg/h and 2.025 kg/h respectively. The average SMER for the intermittency ratio of continuous (α=1), α= 0.66, α= 0.33 and α= 0.2 were found as 1.334 kg/kWh, 1.77 kg/kWh, 2.007 kg/kWh and 2.143 kg/kWh. The effective diffusivity and the mass transfer coefficient were found higher for the intermittency ratio of the 0.2 and lower for the continuous drying. The average value of effective diffusivity for the intermittency ratio of continuous (α=1), α= 0.66, α= 0.33 and α= 0.2 were found as 1.12 E^{-11} m^{2}/s, 3.17 E^{-11} m^{2}/s, 5.38 E^{-11} m^{2}/s, and 7.46 E^{-11} m^{2}/s, respectively. The value of mass transfer coefficient for the intermittency ratio of continuous (α=1), α= 0.66, α= 0.33 and α= 0.2 were found as 2.18 E^{-7} m/s, 4.23 E^{-7} m/s, 6.23 E^{-7} m/s, and 9.82 E^{-6} m/s, respectively. The rate of water loss from the product was found to be higher for the intermittency ratio of the 0.2. The heat and mass transfer analysis reveals that intermittent drying is much better than continuous drying with the solar assisted heat pump drying system.