Читать книгу Modeling, Simulation, and Optimization of Supercritical and Subcritical Fluid Extraction Processes - Zainuddin A. Manan - Страница 10

Nomenclature

SymbolDefinitionAAD:Average Absolute DeviationANFIS:Adaptive Neuro Fuzzy Inference SystemANN:Artificial Neural NetworkBi:Biot number, (kf Rp)/DsC (kg/m3):Oil concentration in the supercritical fluid phase:Oil concentration in the supercritical phaseCOG:Centre of Gravity:Oil concentration at the surface of the vetiver particleDext (m):Diameter of extraction column, , :Axial dispersion coefficient, Molecular diffusion coefficient, Diffusivity of oil in the vetiver particleF:Percent of extractFIS:Fuzzy Inference SystemFPM:First Principle ModelGA:Genetic AlgorithmGB:Gray BoxK:Extract equilibrium constant between solid and fluid phase (‐)k:Equilibrium constant:Mass transfer coefficientL(m):Length of extractorMLP:Multilayer Perceptronn0 (kmol):Initial mole of solute in the bedNF:Neuro‐FuzzyOECs:Overall Extraction CurvesP (MPa):PressurePDE:Partial differential equationPeb, Pep:Peclet number for the bed, (L ν)/Dl, Peclet number for the vetiver particle, (Rp ν)/DsQ:Degree of MembershipQ :Flow rate of supercritical fluid, (νAερf)q (kg/m3):Oil concentration in the solid phaseRe:Reynolds numberRMSE:Root Mean Square ErrorRp(m):Vetiver particle radiusr (m):Axial coordinate in the vetiver particleSFE:Supercritical Fluid ExtractionSc:Schmidt number, μf/(ρf Dm)Sh:Sherwood number, (2Rp kf)/DmT:Temperature (K)t:Time (s)V (m/s):Velocity of the fluidWB:White Boxx(m):Distance of a point in bed from place of input fluidxo:Initial mass fraction of extractable oil in solid phasez:Dimensionless axial coordinate along the bed, x/LSubscripta:Apparentb:Bedc:Criticalext:Fluidi:Inter phasep:Particles:Surface of particle0:At time zeroGreek Letter:Supercritical fluid viscosityμ:Membership functionρ:Dimensionless radial coordinate in the vetiver particle, r/Rpρ (kg/m3):Density:Supercritical fluid densityε:Void fraction of packed bed:Interstitial fluid velocityτ:Dimensionless time, (t ν)/L:Rate of increase of mass per unit volume−(∇. ρv):Net rate of mass addition per unit volume by convectionρv:Mass flux(∇. ρv):Net rate of mass efflux per unit volume:Mass per unit volume times acceleration− ∇ ρ:Pressure force on element per unit volume−[∇. τ]:Viscous force on element per unit volume+ρg:Gravitational force on element per unit volume−(∇. q):Rate of internal energy addition by heat conduction per unit volume−(τ : ∇ v):Irreversible rate of internal energy increase per unit volume by viscous dissipation