Mathematical modeling of biomass drying dynamics

Abstract

Developed a mathematical model and a numerical method for calculating the dynamics of heat and mass transfer during the drying of biomass used as a raw material in the production of fuel. The mathematical model was built on the basis of the differential equation of substance transfer (energy, mass, momentum) for deformable systems. The results of numerical simulation are confirmed by a physical experiment on the dehydration of particles of energy willow in the air stream. This testifies to the adequacy of the mathematical model, the effectiveness of the method of its implementation, and allows you to use it to study the dynamics of heat and mass transfer during the drying of particles of various types of crushed biomass; determine the time to reach the equilibrium moisture content, depending on the properties of the material and the drying agent. It is shown that during high-temperature drying there is intensive dehydration caused by small particle sizes and high coefficients of heat transfer from flue gases. When the material reaches equilibrium moisture content, the temperature on the outer surfaces of the particles has a value below the temperature of the drying agent. To intensify the drying process and reduce its energy intensity, it is possible to carry out the process at temperatures of the coolant exceeding the temperature of thermodestruction for this material. The results of the study allow you to select the optimal operating parameters of the process in terms of reducing energy consumption and ensuring the quality of the dried product. The prospect of further work on this topic is to conduct studies to assess the impact of the process of thermodestruction of biomass on the dynamics of its dehydration.