BULETINUL INSTITUTULUI POLITEHNIC DIN IAŞI

118 Petru Cârlescu et al
indicate overheating or unheating areas and can layer a uniform temperature. By
knowing the temperature profile in the layer of barley can optimize the air flow
and temperature in the bed.
Many mathematical models have been developed to simulate the heat and
the moisture transfer in aerated bulk stored grains. The models were obtained at
relatively low temperatures and low humidity to grain.
The partial differential equation models for wheat storage with aeration
were developed by (Metzger, 1983) and (Wilson, 1988).
The models simulated forced convective heat and moisture transfer in
vertical direction, but the model was not validated. (Chang et al., 1993, 1994)
and (Sinicio et al., 1997) developed a rigorous model to predict the temperature
and moisture content of wheat during storage with aeration, and found that
prediction result is in reasonable agreement with observed data. (Sun&Wood,
1997), (Jia et al., 2001), (Andrade, 2001) and (Devilla, 2002) simulated the
temperature changes in a wheat storage bin respectively, and however, the
moisture changes were not done. (Iguaz et al., 2004) developed a model for the
storage of rough rice during periods with aeration.
Two models of the phenomenon of mass and heat transfer in a bed of
grains was developed and analyzed (Thorpe, 2007). In a subsequent paper
(Thorpe, 2008) is calculated on CFD models to a software that simulates heat
and moisture transfer in the bad grain. Based model and simulation of (Thorpe,
2008), (Wang et al., 2010) developed and validated by experimental
measurements of temperature transducers introduction the theoretical model at
different points in a grain silo. The models proposed by the authors cited were
introduced and air temperature of product less than 30 ° C, and two-dimensional
simulations were preformed. This paper proposes the modeling and simulations
in FLUENT software in the 3D heat transfer in the malt bed temperatures of up
to 95 ° C.
2. Mathematical Modeling of the Physical Phenomenon of Drying
2.1. Transfer Equation
The physical drying phenomenon that occurs in the grain bed obeys the law
of conservation. However, to solve such a diversity of problems the equations
that govern heat and mass transfer are expressed in very general terms and they
do not model heat and mass transfer in the malt bulks during malt drying per se.
As a result they have to be tailored to suit malt drying applications. To date,
making the modifications to the standard CFD software appears to have been a
stumbling block for most grain-dry technologists. This physical phenomenon is
d escribed mathematically by a partial differential equation of general form
∂
( ρ φ )
a
∂t
( ρ v ) ( )
+∇ φ =∇ Γ∇ φ + Sφ
, (1)
a