Performance evaluation of an enhanced fruit solar dryer using concentrating panels
Energy for Sustainable Development
University of California Davis, Mechanical and Aerospace Engineering, 1 Shields Avenue, Davis, CA 95616, United States; University of California Davis, Chemical Engineering and Materials Science, 1 Shields Avenue., Davis, CA 95616, United States; University of California Davis, Biological and Agricultural Engineering, 1 Shields Avenue, Davis, CA 95616, United States; Ministry of Agriculture Food Security and Cooperatives, Dar Es Salaam, Tanzania; University of California Davis, Program for International Energy Technologies, Davis 95616, United States; University of California Davis, Food Science and Technology, One Shields Avenue, Davis, CA 95616, United States
Concentrating solar panels (CSP) improve the process of solar drying Roma tomatoes. This paper presents a performance comparison between two mixed-mode solar dryers. The dryers were identically constructed, however one of the dryers utilized mobile and easily adjustable flat concentrating solar panels to maximize incident solar energy on the dryer. Temperatures inside the dryer that utilized the concentrating solar panels were approx. 10. °C higher than those in the normal dryer during the majority of a sunny day testing period. This increase in temperature led to shorter Roma tomato drying times in the dryer with CSP. The concentrating solar panels showed a considerable increase in drying rate on sunny days, with a 27% decrease in total drying time as compared to the normal dryer to reach the target dimensionless moisture content of 0.2. A less significant increase in drying capacity was achieved when the dryer was tested in simulated cloudy conditions. The faster drying rate achieved in the dryer utilizing solar concentrators, under both sunny and simulated cloudy conditions, demonstrates the ability to dry produce to an acceptable moisture content in a reasonable time, with the objective of reducing postharvest loss and preventing spoilage. © 2012 Elsevier Ltd.
humidity; performance assessment; solar power; vegetable; Lycopersicon esculentum