Performance evaluation of a mixed-mode solar thermal dryer with black pebble-based sensible heat storage for drying marine products

The study presents the performance of a mixed-mode solar thermal dryer integrated with black pebble-based thermal energy storage material for drying marine product-shrimps. The indigenously developed system was installed at a fishing co-operative near Khandhera village in Gujarat, the western part of India (21 degrees 26 ' N, 72 degrees 07 ' E). The energy storage material positioned on the absorber plate in the drying chamber continued to release thermal energy till 7 h after sundown. The overall thermal efficiency of the system was calculated to be 25.47 %. The quality analyses for the dried shrimps showed improved results for samples dried in the energy storage-based unit, and the acceptability was better than the conventional open sundried samples. The total volatile basic substances as nitrogen (TVB-N) and trimethylamine (TMA-N) values of dried shrimps were 20.65 +/- 2.39 & 13.65 +/- 2.10 mg/100 g respectively. Techno-economic analysis of the system with energy storage yielded a payback period of 1.7 years. 38 % income augmentation is envisaged for individuals involved in shrimp drying in coastal regions due to higher throughput and better quality of the dried product in this solar dryer. The present work demonstrates an economical and environmentally benign alternative for the off-sunshine hour operation of the solar dryer.