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

Abstract

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.

Evaluación experimental de un secador solar inflable de bolsa para el secado de cacao

“…Adicionalmente, dicho aire desecante también intercambia calor por convección forzada con las partes internas del equipo. A su vez, la parte externa del equipo intercambia calor por convección con el aire ambiente, por radiación con el cielo y por conducción con el suelo; todo lo cual, por lo general, es considerado como pérdidas energéticas (Condori, 2016;Salvatierra-Rojas, Ramaj, Romuli, & Müller, 2021).…”

Rice for Food Security: Revisiting Its Production, Diversity, Rice Milling Process and Nutrient Content

“…To date, numerous cost-effective drying techniques have been developed, including solar, infrared, convective, desiccant, fluidised, and spouted bed dryers [135]. Solar dryers appear to be a promising alternative for small farmers, due to low energy consumption, as well as reasonable investment and operating costs when compared to commercial dryers that heat the air with petrol fuels [136]. The infrared drying is believed to extend the shelf life of brown and white rice by inactivating the lipase enzyme and thus minimising lipid oxidation by using infrared heating.…”

A review of the inflated solar dryer for improving the quality of agricultural product

“…The materials dried by the open sun drying are dispersed on a thin layer of heavy-duty waterproof cloth on the ground, floor, or trays. However, this traditional method has many shortcomings, for example, it needs a large open space, the process is timeconsuming [4][5], it cannot be carried out in the rainy season or when sudden rainfall occurs [6], and it Y E Maryana 1,* , D Saputra 2 , G Priyanto 3 and K Yuliati 4 yields poor quality product because the drying temperature cannot be controlled and also can be contaminated by the animals and the dust [7][8].…”

“…Inflated solar-energy-utilized dryers are used to dry agricultural products with their unique features such as being simple in design, easily transportable, and low maintenance compared to mechanical dryers. They can be installed in new locations in a very short time and prevent excessive heat from the top-layer objects exposed to sun rays [6]. The inflated solar-energy-utilized dryer provides an opportunity to increase the quality of the product because it inactivates mycotoxigenic fungi, enteric bacteria, and browning enzymes [20].…”