Modelagem e simulação do resfriamento do leito de frutas não climatéricas com ar forçado. Estudo de caso: laranja valência.

Abstract

Fruit growing is an important activity worldwide, because it moves a large number of markets, in addition to promoting the development of many countries. Orange is the most widely produced fruit in the world and the second most consumed where, Brazil is the world's largest producer. Among the various forms of conservation of this fruit, for their in natura consumption, the forced air cooling method is most suitable. The objective of this research is to theoretically study the non-climatic fruit bed cooling with forced air, with particular reference to orange valence (Citrus sinensis O.). A mathematical modeling was performed to describe the mass and energy changes between the air and the product during the process. For the numerical solution of the governing equations the finite volume method and the upwind interpolation function were used. The results were obtained through the development of a computer code in Mathematica® software, where some cases distributed among groups denominated A, B and C were simulated. The simulations of group A served to validate the methodology and presented a relative error of 0.061 ± 0.03°C in a mesh of 20 nodal points and specific area A* = 180 m²/m³. In the second group, the height of the orange bed (H) was varied. In this group, it was verified that the lower the value of this parameter, the greater the efficiency in the thermal exchange cooling air temperature with the temperature of the fruit within the bed. The third group, the group C, was varied convective heat transfer coefficients (hc). The groups analyzed to assess the influence of some parameters on the cooling kinetics of valencia orange bed, such as: product temperature and cooling air, air saturation vapor pressure and relative humidity of it. The results were shown and analyzed, where there has been a great influence hc the cooling kinetics of Orange bed. The higher the value of this parameter, the higher the bed temperature gradients and faster cooling of oranges occurs. Showing its importance in the process.