SIMULATION MODELING OF GRAIN HEATING BY THE ENERGY OF ELECTROMAGNETIC MICROWAVE FIELD
Abstract
High speed and efficiency of microwave heating of dielectrics makes it possible to use the electromagnetic field to heat and dry almost any material containing moisture. One of the promising areas for the use of microwave energy is the intensification of the grain drying process. To ensure rapid prototyping and reduce the possibility of losses caused by errors at various stages of equipment development and implementation, model development is of particular importance. The purpose of this work is to perform simulation of a slotted waveguide grating for grain drying. The main task of the simulation is to ensure an even distribution of power to each slot. A specialized software package FEKO is used as a modeling environment. To describe the model, an exact calculation method is used - the method of moments. The distribution of the electric field and specific absorbed power in a layer of grain exposed to microwave radiation is obtained. The models were verified by comparing the results obtained with different mesh values of surface elements. Modeling the distribution of the electric field strength showed that moving the waveguides away from the cell with the grain leads to the leveling of the field irregularities, but in this case some of the radiated power is dissipated into space. In this case, an increase in the distance between the waveguides and the cell with grain does not affect the antenna SWR. It should be noted that in a real situation, the wave nature of the field is smoothed out due to heat transfer, and this phenomenon cannot be taken into account in the process of electromagnetic simulation. In addition, the entire variety of possible changes in the dielectric parameters of grain should be investigated in order to analyze the process of wave propagation in grain with high moisture. It is also advisable to consider other modifications of slotted waveguide antennas, which can provide more uniform heating in the container with grain.
