Technical Performance of an Inflatable Solar Dryer for Drying Amaranth Leaves in Kenya

CFD-Simulink Modeling of the Inflatable Solar Dryer for Drying Paddy Rice

Small-scale farmers in developing Asian countries have minimal agricultural mechanisms available to them. In the Philippines, postharvest losses in rice production can reach about 36% in the drying process alone. Thus, the inflatable solar dryer (ISD) was developed through the collaboration of the University of Hohenheim, the International Rice Research Institute, and GrainPro Philippines Inc. Although the ISD was successfully tested with different agricultural products, further characterization of the ISD design is required for predicting the drying performance. To this end, the airflow behavior in the ISD was simulated using computational fluid dynamics (CFD) via ANSYS Fluent. Moreover, a thermal model was developed in MATLAB/Simulink by taking into account heat transfer in the heating area and coupled heat and mass transfer within the drying area. Three batches of drying experiments were performed and airflow measurements were taken inside the dryer to validate the models. The MATLAB/Simulink model was further used to predict the drying performance under various weather conditions spanning 10 years. The simulated temperatures and moisture content in the ISD showed high accuracy (mean absolute percentage error (MAPE) < 10%) with the experimental data. The proposed dynamic model provides an efficient computational tool that can be applied to predict the drying performance and to optimize the ISD design.

A comprehensive review of solar photovoltaic hybrid food drying systems

Demand for all resources, especially food, water, and energy, has increased with the rapid increase in the world population. These resources are limited and not enough for the growing population of the world. Therefore, the food-energy-water nexus approach has gained much attention in recent years. Less energy and water consumption and less waste generation became the target for the more sustainable food production. Qualitative and quantitative losses in agricultural commodities growing in rural areas depend both on the structure of foods and incorrect or inadequate process applied to postharvest operations to preserve food. Therefore, drying is the most preferred food preservation method. To minimize the energy consumption during drying process, renewable energy technologies are emerging as an alternative solution. It reduces dependency of fossil fuels, adds value to agricultural products to meet the increasing demand, and minimizes qualitative and quantitative losses. In this work, theoretical and experimental studies of photovoltaic-thermal (PV/T) or photovoltaic (PV) integrated food-drying systems were comprehensively reviewed. The researches covered in this review are classified into three groups: PV module integrated, PV/T collector-assisted food-drying systems, and PV/T-assisted heat pump-drying systems.