This paper presents a simulation study of dryers. A two-dimensional deep-bed drying model, which incorporates modifications in existing one-dimensional models, has been developed and has the capability of handling both non-uniform velocity profiles and material properties dependence on temperature and moisture content. A corn drying system was simulated in order to analyze its temporal and spatial drying behavior. Both intermittent and continuous drying were simulated. The results showed that continuous drying is more efficient than intermittent drying with respect to drying time. However, intermittent drying led to more uniform temperature and moisture distributions, which improve grain quality. The model can be easily extended to three-dimensional drying analysis.

Numerical simulation of intermittent and continuous deep-bed drying of biological materials

This paper aims at presenting an application developed in Java for optimizing the design of centralized solar water heating systems with forced circulation, based on the f-chart method The program uses data from the Brazilian Solar Atlas, performance data of flat plate collectors and thermal reservoirs from the standardized tests run within the Brazilian Labeling Program, and values of water consumption of appliances defined by the ABNT The program finds the inclination of the collector that maximizes the annual solar fraction, or for the winter, and enables the use of arrays in series and parallel collectors From the investment costs and O & M (operations and maintenance) of solar heating systems, the program carries out economical analysis using classical parameters as net present value, discounted payback and internal rate of return The program was validated through examples from the book of Duffie & Beckman and also by comparison with the results from a project developed at UFRGS, having obtained good agreement

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Ufvsol - programa de simulacao de sistemas de aquecimento por energia solar