#*------------------------------------------------------------------- * EMSO Model Library (EML) Copyright (C) 2004 - 2007 ALSOC. * * This LIBRARY is free software; you can distribute it and/or modify * it under the therms of the ALSOC FREE LICENSE as available at * http://www.enq.ufrgs.br/alsoc. * * EMSO Copyright (C) 2004 - 2007 ALSOC, original code * from http://www.rps.eng.br Copyright (C) 2002-2004. * All rights reserved. * * EMSO is distributed under the therms of the ALSOC LICENSE as * available at http://www.enq.ufrgs.br/alsoc. * *------------------------------------------------------------------- * Author: Gerson Balbueno Bicca * $Id: HeatExchangerDetailed.mso 126 2007-01-22 22:29:08Z bicca $ *------------------------------------------------------------------*# using "HEX_Engine"; #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Basic Model for Detailed Shell and Tubes Heat Exchangers #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Model HeatExchangerDetailed_Basic PARAMETERS ext PP as CalcObject (Brief="External Physical Properties"); ext NComp as Integer (Brief="Number of Components"); HE as CalcObject (Brief="STHE Calculations",File="heatex"); M(NComp) as molweight (Brief="Component Mol Weight"); VARIABLES in Inlet as Inlet_Main_Stream; out Outlet as Outlet_Main_Stream; Properties as Main_Properties; Details as Details_Main; Tubes as Tube_Side_Main; Shell as Shell_Side_Main; Resistances as Main_Resistances; Baffles as Baffles_Main; SET M = PP.MolecularWeight(); EQUATIONS #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Properties # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# "Hot Stream Average Temperature" Properties.Hot.Average.T = 0.5*Inlet.Hot.T + 0.5*Outlet.Hot.T; "Cold Stream Average Temperature" Properties.Cold.Average.T = 0.5*Inlet.Cold.T + 0.5*Outlet.Cold.T; "Hot Stream Average Pressure" Properties.Hot.Average.P = 0.5*Inlet.Hot.P+0.5*Outlet.Hot.P; "Cold Stream Average Pressure" Properties.Cold.Average.P = 0.5*Inlet.Cold.P+0.5*Outlet.Cold.P; "Hot Stream Average Molecular Weight" Properties.Hot.Average.Mw = sum(M*Inlet.Hot.z); "Cold Stream Average Molecular Weight" Properties.Cold.Average.Mw = sum(M*Inlet.Cold.z); if Inlet.Cold.v equal 0 then "Cold Stream Average Heat Capacity" Properties.Cold.Average.Cp = PP.LiquidCp(Properties.Cold.Average.T,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Inlet Heat Capacity" Properties.Cold.Inlet.Cp = PP.LiquidCp(Inlet.Cold.T,Inlet.Cold.P,Inlet.Cold.z); "Cold Stream Outlet Heat Capacity" Properties.Cold.Outlet.Cp = PP.LiquidCp(Outlet.Cold.T,Outlet.Cold.P,Outlet.Cold.z); "Cold Stream Average Mass Density" Properties.Cold.Average.rho = PP.LiquidDensity(Properties.Cold.Average.T,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Inlet Mass Density" Properties.Cold.Inlet.rho = PP.LiquidDensity(Inlet.Cold.T,Inlet.Cold.P,Inlet.Cold.z); "Cold Stream Outlet Mass Density" Properties.Cold.Outlet.rho = PP.LiquidDensity(Outlet.Cold.T,Outlet.Cold.P,Outlet.Cold.z); "Cold Stream Average Viscosity" Properties.Cold.Average.Mu = PP.LiquidViscosity(Properties.Cold.Average.T,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream inlet Viscosity" Properties.Cold.Inlet.Mu = PP.LiquidViscosity(Inlet.Cold.T,Inlet.Cold.P,Inlet.Cold.z); "Cold Stream Outlet Viscosity" Properties.Cold.Outlet.Mu = PP.LiquidViscosity(Outlet.Cold.T,Outlet.Cold.P,Outlet.Cold.z); "Cold Stream Average Conductivity" Properties.Cold.Average.K = PP.LiquidThermalConductivity(Properties.Cold.Average.T,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Inlet Conductivity" Properties.Cold.Inlet.K = PP.LiquidThermalConductivity(Inlet.Cold.T,Inlet.Cold.P,Inlet.Cold.z); "Cold Stream Outlet Conductivity" Properties.Cold.Outlet.K = PP.LiquidThermalConductivity(Outlet.Cold.T,Outlet.Cold.P,Outlet.Cold.z); "Cold Stream Heat Capacity at Wall Temperature" Properties.Cold.Wall.Cp = PP.LiquidCp(Properties.Cold.Wall.Twall,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Viscosity at Wall Temperature" Properties.Cold.Wall.Mu = PP.LiquidViscosity(Properties.Cold.Wall.Twall,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Conductivity at Wall Temperature" Properties.Cold.Wall.K = PP.LiquidThermalConductivity(Properties.Cold.Wall.Twall,Properties.Cold.Average.P,Inlet.Cold.z); else "Cold Stream Average Heat Capacity" Properties.Cold.Average.Cp = PP.VapourCp(Properties.Cold.Average.T,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Inlet Heat Capacity" Properties.Cold.Inlet.Cp = PP.VapourCp(Inlet.Cold.T,Inlet.Cold.P,Inlet.Cold.z); "Cold Stream Outlet Heat Capacity" Properties.Cold.Outlet.Cp = PP.VapourCp(Outlet.Cold.T,Outlet.Cold.P,Outlet.Cold.z); "Cold Stream Average Mass Density" Properties.Cold.Average.rho = PP.VapourDensity(Properties.Cold.Average.T,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Inlet Mass Density" Properties.Cold.Inlet.rho = PP.VapourDensity(Inlet.Cold.T,Inlet.Cold.P,Inlet.Cold.z); "Cold Stream Outlet Mass Density" Properties.Cold.Outlet.rho = PP.VapourDensity(Outlet.Cold.T,Outlet.Cold.P,Outlet.Cold.z); "Cold Stream Average Viscosity " Properties.Cold.Average.Mu = PP.VapourViscosity(Properties.Cold.Average.T,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Inlet Viscosity " Properties.Cold.Inlet.Mu = PP.VapourViscosity(Inlet.Cold.T,Inlet.Cold.P,Inlet.Cold.z); "Cold Stream Outlet Viscosity " Properties.Cold.Outlet.Mu = PP.VapourViscosity(Outlet.Cold.T,Outlet.Cold.P,Outlet.Cold.z); "Cold Stream Average Conductivity " Properties.Cold.Average.K = PP.VapourThermalConductivity(Properties.Cold.Average.T,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Inlet Conductivity " Properties.Cold.Inlet.K = PP.VapourThermalConductivity(Inlet.Cold.T,Inlet.Cold.P,Inlet.Cold.z); "Cold Stream Outlet Conductivity " Properties.Cold.Outlet.K = PP.VapourThermalConductivity(Outlet.Cold.T,Outlet.Cold.P,Outlet.Cold.z); "Cold Stream Heat Capacity at Wall Temperature" Properties.Cold.Wall.Cp = PP.VapourCp(Properties.Cold.Wall.Twall,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Viscosity at Wall Temperature" Properties.Cold.Wall.Mu = PP.VapourViscosity(Properties.Cold.Wall.Twall,Properties.Cold.Average.P,Inlet.Cold.z); "Cold Stream Conductivity at Wall Temperature" Properties.Cold.Wall.K = PP.VapourThermalConductivity(Properties.Cold.Wall.Twall,Properties.Cold.Average.P,Inlet.Cold.z); end if Inlet.Hot.v equal 0 then "Hot Stream Average Heat Capacity" Properties.Hot.Average.Cp = PP.LiquidCp(Properties.Hot.Average.T,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Inlet Heat Capacity" Properties.Hot.Inlet.Cp = PP.LiquidCp(Inlet.Hot.T,Inlet.Hot.P,Inlet.Hot.z); "Hot Stream Outlet Heat Capacity" Properties.Hot.Outlet.Cp = PP.LiquidCp(Outlet.Hot.T,Outlet.Hot.P,Outlet.Hot.z); "Hot Stream Average Mass Density" Properties.Hot.Average.rho = PP.LiquidDensity(Properties.Hot.Average.T,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Inlet Mass Density" Properties.Hot.Inlet.rho = PP.LiquidDensity(Inlet.Hot.T,Inlet.Hot.P,Inlet.Hot.z); "Hot Stream Outlet Mass Density" Properties.Hot.Outlet.rho = PP.LiquidDensity(Outlet.Hot.T,Outlet.Hot.P,Outlet.Hot.z); "Hot Stream Average Viscosity" Properties.Hot.Average.Mu = PP.LiquidViscosity(Properties.Hot.Average.T,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Inlet Viscosity" Properties.Hot.Inlet.Mu = PP.LiquidViscosity(Inlet.Hot.T,Inlet.Hot.P,Inlet.Hot.z); "Hot Stream Outlet Viscosity" Properties.Hot.Outlet.Mu = PP.LiquidViscosity(Outlet.Hot.T,Outlet.Hot.P,Outlet.Hot.z); "Hot Stream Average Conductivity" Properties.Hot.Average.K = PP.LiquidThermalConductivity(Properties.Hot.Average.T,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Inlet Conductivity" Properties.Hot.Inlet.K = PP.LiquidThermalConductivity(Inlet.Hot.T,Inlet.Hot.P,Inlet.Hot.z); "Hot Stream Outlet Conductivity" Properties.Hot.Outlet.K = PP.LiquidThermalConductivity(Outlet.Hot.T,Outlet.Hot.P,Outlet.Hot.z); "Hot Stream Heat Capacity at Wall Temperature" Properties.Hot.Wall.Cp = PP.LiquidCp(Properties.Hot.Wall.Twall,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Viscosity at Wall Temperature" Properties.Hot.Wall.Mu = PP.LiquidViscosity(Properties.Hot.Wall.Twall,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Conductivity at Wall Temperature" Properties.Hot.Wall.K = PP.LiquidThermalConductivity(Properties.Hot.Wall.Twall,Properties.Hot.Average.P,Inlet.Hot.z); else "Hot Stream Average Heat Capacity" Properties.Hot.Average.Cp = PP.VapourCp(Properties.Hot.Average.T,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Inlet Heat Capacity" Properties.Hot.Inlet.Cp = PP.VapourCp(Inlet.Hot.T,Inlet.Hot.P,Inlet.Hot.z); "Hot Stream Outlet Heat Capacity" Properties.Hot.Outlet.Cp = PP.VapourCp(Outlet.Hot.T,Outlet.Hot.P,Outlet.Hot.z); "Hot Stream Average Mass Density" Properties.Hot.Average.rho = PP.VapourDensity(Properties.Hot.Average.T,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Inlet Mass Density" Properties.Hot.Inlet.rho = PP.VapourDensity(Inlet.Hot.T,Inlet.Hot.P,Inlet.Hot.z); "Hot Stream Outlet Mass Density" Properties.Hot.Outlet.rho = PP.VapourDensity(Outlet.Hot.T,Outlet.Hot.P,Outlet.Hot.z); "Hot Stream Average Viscosity" Properties.Hot.Average.Mu = PP.VapourViscosity(Properties.Hot.Average.T,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Inlet Viscosity" Properties.Hot.Inlet.Mu = PP.VapourViscosity(Inlet.Hot.T,Inlet.Hot.P,Inlet.Hot.z); "Hot Stream Outlet Viscosity" Properties.Hot.Outlet.Mu = PP.VapourViscosity(Outlet.Hot.T,Outlet.Hot.P,Outlet.Hot.z); "Hot Stream Average Conductivity" Properties.Hot.Average.K = PP.VapourThermalConductivity(Properties.Hot.Average.T,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Inlet Conductivity" Properties.Hot.Inlet.K = PP.VapourThermalConductivity(Inlet.Hot.T,Inlet.Hot.P,Inlet.Hot.z); "Hot Stream Outlet Conductivity" Properties.Hot.Outlet.K = PP.VapourThermalConductivity(Outlet.Hot.T,Outlet.Hot.P,Outlet.Hot.z); "Hot Stream Heat Capacity at Wall Temperature" Properties.Hot.Wall.Cp = PP.VapourCp(Properties.Hot.Wall.Twall,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Viscosity at Wall Temperature" Properties.Hot.Wall.Mu = PP.VapourViscosity(Properties.Hot.Wall.Twall,Properties.Hot.Average.P,Inlet.Hot.z); "Hot Stream Conductivity at Wall Temperature" Properties.Hot.Wall.K = PP.VapourThermalConductivity(Properties.Hot.Wall.Twall,Properties.Hot.Average.P,Inlet.Hot.z); end #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Thermal Details # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# "Hot Stream Heat Capacity" Details.Ch =Inlet.Hot.F*Properties.Hot.Average.Cp; "Cold Stream Heat Capacity" Details.Cc =Inlet.Cold.F*Properties.Cold.Average.Cp; "Minimum Heat Capacity" Details.Cmin = min([Details.Ch,Details.Cc]); "Maximum Heat Capacity" Details.Cmax = max([Details.Ch,Details.Cc]); "Heat Capacity Ratio" Details.Cr = Details.Cmin/Details.Cmax; #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Energy Balance #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# "Energy Balance Hot Stream" Details.Q = Inlet.Hot.F*(Inlet.Hot.h-Outlet.Hot.h); "Energy Balance Cold Stream" Details.Q =-Inlet.Cold.F*(Inlet.Cold.h-Outlet.Cold.h); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Material Balance #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# "Flow Mass Inlet Cold Stream" Properties.Cold.Inlet.Fw = sum(M*Inlet.Cold.z)*Inlet.Cold.F; "Flow Mass Outlet Cold Stream" Properties.Cold.Outlet.Fw = sum(M*Outlet.Cold.z)*Outlet.Cold.F; "Flow Mass Inlet Hot Stream" Properties.Hot.Inlet.Fw = sum(M*Inlet.Hot.z)*Inlet.Hot.F; "Flow Mass Outlet Hot Stream" Properties.Hot.Outlet.Fw = sum(M*Outlet.Hot.z)*Outlet.Hot.F; "Molar Balance Hot Stream" Inlet.Hot.F = Outlet.Hot.F; "Molar Balance Cold Stream" Inlet.Cold.F = Outlet.Cold.F; #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Constraints #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# "Hot Stream Molar Fraction Constraint" Outlet.Hot.z=Inlet.Hot.z; "Cold Stream Molar Fraction Constraint" Outlet.Cold.z=Inlet.Cold.z; "No Phase Change In Cold Stream" Inlet.Cold.v=Outlet.Cold.v; "No Phase Change In Hot Stream" Inlet.Hot.v=Outlet.Hot.v; end Model Heatex_Detailed as HeatExchangerDetailed_Basic PARAMETERS #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Basic Parameters # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# ext PP as CalcObject (Brief="External Physical Properties"); side as Integer (Brief="Fluid Alocation Flag",Lower=0,Upper=1); Pi as constant (Brief="Pi Number",Default=3.14159265); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Shell Geometrical Parameters # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Tpass as Integer (Brief="Number of Tube Passes",Lower=1); Nss as Integer (Brief="Number of Sealing Strips pairs",Lower=1); Dishell as length (Brief="Inside Shell Diameter",Lower=10e-6); Donozzle_Shell as length (Brief="Shell Outlet Nozzle Diameter",Lower=10e-6); Dinozzle_Shell as length (Brief="Shell Inlet Nozzle Diameter",Lower=10e-6); Aonozzle_Shell as area (Brief="Shell Outlet Nozzle Area",Lower=10e-6); Ainozzle_Shell as area (Brief="Shell Inlet Nozzle Area",Lower=10e-6); Aeonozzle_Shell as area (Brief="Shell Outlet Escape Area Under Nozzle",Lower=10e-6); Aeinozzle_Shell as area (Brief="Shell Inlet Escape Area Under Nozzle",Lower=10e-6); Hinozzle_Shell as length (Brief="Height Under Shell Inlet Nozzle",Lower=10e-6); Honozzle_Shell as length (Brief="Height Under Shell Outlet Nozzle",Lower=10e-6); Lcf as length (Brief="Bundle-to-Shell Clearance",Lower=10e-8); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Tubes Geometrical Parameters # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Ntt as Integer (Brief="Total Number of Tubes in Shell",Default=100,Lower=1); Pattern as Integer (Brief="Tube Layout Characteristic Angle",Lower=30); Ltube as length (Brief="Effective Tube Length",Lower=0.1); pitch as length (Brief="Tube Pitch",Lower=1e-8); Kwall as conductivity (Brief="Tube Wall Material Thermal Conductivity"); Dotube as length (Brief="Tube Outside Diameter",Lower=10e-6); Ditube as length (Brief="Tube Inside Diameter",Lower=10e-6); Donozzle_Tube as length (Brief="Tube Outlet Nozzle Diameter",Lower=10e-6); Dinozzle_Tube as length (Brief="Tube Inlet Nozzle Diameter",Lower=10e-6); Aonozzle_Tube as area (Brief="Tube Outlet Nozzle Area",Lower=10e-6); Ainozzle_Tube as area (Brief="Tube Inlet Nozzle Area",Lower=10e-6); Kinlet_Tube as positive (Brief="Tube Inlet Nozzle Pressure Loss Coeff",Default=1.1); Koutlet_Tube as positive (Brief="Tube Outlet Nozzle Pressure Loss Coeff",Default=0.7); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Baffles Geometrical Parameters # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Bc as Integer (Brief="Baffle Cut",Default=25,Lower=25); Nb as Real (Brief="Number of Baffles",Lower=1); Lcd as length (Brief="Baffle-to-Shell Clearance",Lower=10e-8); Ltd as length (Brief="Tube-to-Bafflehole Clearance",Lower=10e-8); SET #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Set Parameters for heatex Calculation # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Pi = 3.14159265; HE.Tpass = Tpass; HE.Nss = Nss; HE.Ntt = Ntt; HE.Pattern = Pattern; HE.Bc = Bc; HE.Donozzle_Shell = Donozzle_Shell; HE.Dinozzle_Shell = Dinozzle_Shell; HE.Honozzle_Shell = Honozzle_Shell; HE.Hinozzle_Shell = Hinozzle_Shell; HE.Donozzle_Tube = Donozzle_Tube; HE.Dinozzle_Tube = Dinozzle_Tube; HE.Nb = Nb; HE.Dishell = Dishell; HE.Lcf = Lcf; HE.Ltube = Ltube; HE.pitch = pitch; HE.Dotube = Dotube; HE.Ditube = Ditube; HE.Lcd = Lcd; HE.Ltd = Ltd; side = HE.FluidAlocation(); #"Tube Side Inlet Nozzle Area" Ainozzle_Tube = (Pi*Dinozzle_Tube*Dinozzle_Tube)/4; #"Tube Side Outlet Nozzle Area" Aonozzle_Tube = (Pi*Donozzle_Tube*Donozzle_Tube)/4; #"Tube Inlet Nozzle Pressure Loss Coeff" Kinlet_Tube = 1.1; #"Tube Outlet Nozzle Pressure Loss Coeff" Koutlet_Tube = 0.7; #"Shell Outlet Nozzle Area" Aonozzle_Shell = (Pi*Donozzle_Shell*Donozzle_Shell)/4; #"Shell Inlet Nozzle Area" Ainozzle_Shell = (Pi*Dinozzle_Shell*Dinozzle_Shell)/4; #"Shell Outlet Escape Area Under Nozzle" Aeonozzle_Shell = Pi*Donozzle_Shell*Honozzle_Shell + 0.6*Aonozzle_Shell*(1-Dotube/pitch); #"Shell Inlet Escape Area Under Nozzle" Aeinozzle_Shell = Pi*Dinozzle_Shell*Hinozzle_Shell + 0.6*Ainozzle_Shell*(1-Dotube/pitch); EQUATIONS #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Heat Transfer Correction Factors # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# "Ji Factor" Shell.HeatTransfer.Ji = HE.JiFactor(Shell.HeatTransfer.Re); "Jc Factor" Shell.HeatTransfer.Jc = HE.JcFactor(); "Jl Factor" Shell.HeatTransfer.Jl = HE.JlFactor(Shell.HeatTransfer.Sm); "Jb Factor" Shell.HeatTransfer.Jb = HE.JbFactor(Shell.HeatTransfer.Re,Baffles.Ls,Shell.HeatTransfer.Sm); "Jr Factor" Shell.HeatTransfer.Jr = HE.JrFactor(Shell.HeatTransfer.Re); "Total J Factor" Shell.HeatTransfer.Jtotal = Shell.HeatTransfer.Jc*Shell.HeatTransfer.Jl*Shell.HeatTransfer.Jb*Shell.HeatTransfer.Jr*Shell.HeatTransfer.Js; #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Pressure Drop and Velocities # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# if side equal 1 then "Tube Side Pressure Drop" Tubes.PressureDrop.PdTube = HE.DeltaPtube(Tubes.HeatTransfer.Re,Properties.Cold.Average.rho,Tubes.HeatTransfer.Vtube,Tubes.HeatTransfer.Phi); "Pressure Drop Tube Side Inlet Nozzle" Tubes.PressureDrop.Pdnozzle_in = 0.5*Kinlet_Tube*Properties.Cold.Inlet.rho*Tubes.PressureDrop.Vnozzle_in^2; "Velocity Tube Side Inlet Nozzle" Tubes.PressureDrop.Vnozzle_in = Properties.Cold.Inlet.Fw/(Properties.Cold.Inlet.rho*Ainozzle_Tube); "Pressure Drop Tube Side Outlet Nozzle" Tubes.PressureDrop.Pdnozzle_out = 0.5*Koutlet_Tube*Properties.Cold.Outlet.rho*Tubes.PressureDrop.Vnozzle_out^2; "Velocity Tube Side Outlet Nozzle" Tubes.PressureDrop.Vnozzle_out = Properties.Cold.Inlet.Fw/(Properties.Cold.Outlet.rho*Aonozzle_Tube); "Shell Pressure Drop Inlet Nozzle" Shell.PressureDrop.Pdnozzle_in = (0.5*Properties.Hot.Inlet.Fw^2/Properties.Hot.Inlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Inlet Nozzle" Shell.PressureDrop.Vnozzle_in = Properties.Hot.Inlet.Fw/(Properties.Hot.Inlet.rho*Ainozzle_Shell); "Shell Pressure Drop Outlet Nozzle" Shell.PressureDrop.Pdnozzle_out = (0.5*Properties.Hot.Outlet.Fw^2/Properties.Hot.Outlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Outlet Nozzle" Shell.PressureDrop.Vnozzle_out = Properties.Hot.Outlet.Fw/(Properties.Hot.Outlet.rho*Aonozzle_Shell); "Pressure Drop Hot Stream" Outlet.Hot.P = Inlet.Hot.P - Shell.PressureDrop.Pdtotal; "Pressure Drop Cold Stream" Outlet.Cold.P = Inlet.Cold.P - Tubes.PressureDrop.Pdtotal; else "Tube Side Pressure Drop" Tubes.PressureDrop.PdTube = HE.DeltaPtube(Tubes.HeatTransfer.Re,Properties.Hot.Average.rho,Tubes.HeatTransfer.Vtube,Tubes.HeatTransfer.Phi); "Pressure Drop Tube Side Inlet Nozzle" Tubes.PressureDrop.Pdnozzle_in = 0.5*Kinlet_Tube*Properties.Hot.Inlet.rho*Tubes.PressureDrop.Vnozzle_in^2; "Velocity Tube Side Inlet Nozzle" Tubes.PressureDrop.Vnozzle_in = Properties.Hot.Inlet.Fw/(Properties.Hot.Inlet.rho*Ainozzle_Tube); "Pressure Drop Tube Side Outlet Nozzle" Tubes.PressureDrop.Pdnozzle_out = 0.5*Koutlet_Tube*Properties.Hot.Outlet.rho*Tubes.PressureDrop.Vnozzle_out^2; "Velocity Tube Side Outlet Nozzle" Tubes.PressureDrop.Vnozzle_out = Properties.Hot.Inlet.Fw/(Properties.Hot.Outlet.rho*Aonozzle_Tube); "Shell Pressure Drop Inlet Nozzle" Shell.PressureDrop.Pdnozzle_in = (0.5*Properties.Cold.Inlet.Fw^2/Properties.Cold.Inlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Inlet Nozzle" Shell.PressureDrop.Vnozzle_in = Properties.Cold.Inlet.Fw/(Properties.Cold.Inlet.rho*Ainozzle_Shell); "Shell Pressure Drop Outlet Nozzle" Shell.PressureDrop.Pdnozzle_out = (0.5*Properties.Cold.Outlet.Fw^2/Properties.Cold.Outlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Outlet Nozzle" Shell.PressureDrop.Vnozzle_out = Properties.Cold.Outlet.Fw/(Properties.Cold.Outlet.rho*Ainozzle_Shell); "Pressure Drop Hot Stream" Outlet.Hot.P = Inlet.Hot.P- Tubes.PressureDrop.Pdtotal; "Pressure Drop Cold Stream" Outlet.Cold.P = Inlet.Cold.P - Shell.PressureDrop.Pdtotal; end #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Nozzles rho-V^2 # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# if side equal 1 then "Shell Side inlet Nozzle rho-V^2" Shell.PressureDrop.RVsquare_in = Properties.Hot.Inlet.rho*(Shell.PressureDrop.Vnozzle_in)^2; "Shell Side Outlet Nozzle rho-V^2" Shell.PressureDrop.RVsquare_out = Properties.Hot.Outlet.rho*(Shell.PressureDrop.Vnozzle_out)^2; else "Shell Side inlet Nozzle rho-V^2" Shell.PressureDrop.RVsquare_in = Properties.Cold.Inlet.rho*(Shell.PressureDrop.Vnozzle_in)^2; "Shell Side Outlet Nozzle rho-V^2" Shell.PressureDrop.RVsquare_out = Properties.Cold.Outlet.rho*(Shell.PressureDrop.Vnozzle_out)^2; end #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Phi correction # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# if side equal 1 then "Shell Side Phi correction" Shell.HeatTransfer.Phi = HE.PhiCorrection(Properties.Hot.Average.Mu,Properties.Hot.Wall.Mu); "Tube Side Phi correction" Tubes.HeatTransfer.Phi = HE.PhiCorrection(Properties.Cold.Average.Mu,Properties.Cold.Wall.Mu); else "Shell Side Phi correction" Shell.HeatTransfer.Phi = HE.PhiCorrection(Properties.Cold.Average.Mu,Properties.Cold.Wall.Mu); "Tube Side Phi correction" Tubes.HeatTransfer.Phi = HE.PhiCorrection(Properties.Hot.Average.Mu,Properties.Hot.Wall.Mu); end #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # # Heat Transfer # # #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# if side equal 1 then "Hot Wall Temperature" Properties.Hot.Wall.Twall = (Properties.Hot.Average.T+Properties.Cold.Average.T)/2; "ColdWall Temperature" Properties.Cold.Wall.Twall = (Properties.Hot.Average.T+Properties.Cold.Average.T)/2; "Tube Side Velocity" Tubes.HeatTransfer.Vtube = Properties.Cold.Inlet.Fw*Tpass/((Pi*Ditube*Ditube/4)*Properties.Cold.Average.rho*Ntt); "Tube Side Reynolds Number" Tubes.HeatTransfer.Re = (Properties.Cold.Average.rho*Tubes.HeatTransfer.Vtube*Ditube)/Properties.Cold.Average.Mu; "Tube Side Prandtl Number" Tubes.HeatTransfer.PR = ((Properties.Cold.Average.Cp/Properties.Cold.Average.Mw)*Properties.Cold.Average.Mu)/Properties.Cold.Average.K; "Tube Side Prandtl Number at Wall Temperature" Tubes.HeatTransfer.PRw = ((Properties.Cold.Wall.Cp/Properties.Cold.Average.Mw)*Properties.Cold.Wall.Mu)/Properties.Cold.Wall.K; "Tube Side Film Coefficient" Tubes.HeatTransfer.htube = HE.TubeFilmCoeff(Tubes.HeatTransfer.Re,Tubes.HeatTransfer.PR,Properties.Cold.Average.K)*Tubes.HeatTransfer.Phi; "Shell Side Prandtl Number" Shell.HeatTransfer.PR = ((Properties.Hot.Average.Cp/Properties.Hot.Average.Mw)*Properties.Hot.Average.Mu)/Properties.Hot.Average.K; "Shell Side Prandtl Number at Wall Temperature" Shell.HeatTransfer.PRw = ((Properties.Hot.Wall.Cp/Properties.Hot.Average.Mw)*Properties.Hot.Wall.Mu)/Properties.Hot.Wall.K; else "Hot Wall Temperature" Properties.Hot.Wall.Twall = (Properties.Hot.Average.T+Properties.Cold.Average.T)/2; "Cold Wall Temperature" Properties.Cold.Wall.Twall = (Properties.Hot.Average.T+Properties.Cold.Average.T)/2; "Tube Side Velocity" Tubes.HeatTransfer.Vtube = Properties.Hot.Inlet.Fw*Tpass/((Pi*Ditube*Ditube/4)*Properties.Hot.Average.rho*Ntt); "Tube Side Reynolds Number" Tubes.HeatTransfer.Re = (Properties.Hot.Average.rho*Tubes.HeatTransfer.Vtube*Ditube)/Properties.Hot.Average.Mu; "Tube Side Prandtl Number" Tubes.HeatTransfer.PR = ((Properties.Hot.Average.Cp/Properties.Hot.Average.Mw)*Properties.Hot.Average.Mu)/Properties.Hot.Average.K; "Tube Side Prandtl Number at Wall" Tubes.HeatTransfer.PRw = ((Properties.Hot.Wall.Cp/Properties.Hot.Average.Mw)*Properties.Hot.Wall.Mu)/Properties.Hot.Wall.K; "Tube Side Film Coefficient" Tubes.HeatTransfer.htube= HE.TubeFilmCoeff(Tubes.HeatTransfer.Re,Tubes.HeatTransfer.PR,Properties.Hot.Average.K)*Tubes.HeatTransfer.Phi; "Shell Side Prandtl Number" Shell.HeatTransfer.PR = ((Properties.Cold.Average.Cp/Properties.Cold.Average.Mw)*Properties.Cold.Average.Mu)/Properties.Cold.Average.K; "Shell Side Prandtl Number at Wall" Shell.HeatTransfer.PRw=((Properties.Cold.Wall.Cp/Properties.Cold.Average.Mw)*Properties.Cold.Wall.Mu)/Properties.Cold.Wall.K; end "Tube Resistance" Resistances.Rtube*(Tubes.HeatTransfer.htube*Ditube) = Dotube; "Wall Resistance" Resistances.Rwall=Dotube*ln(Dotube/Ditube)/(2*Kwall); "Shell Resistance" Resistances.Rshell*(Shell.HeatTransfer.hshell)=1; "Shell Side Cross Flow Area" Shell.HeatTransfer.Sm = HE.CrossFlowArea(Baffles.Ls); "Overall Heat Transfer Coefficient Dirty" Details.Ud=1/(Dotube/(Tubes.HeatTransfer.htube*Ditube)+Resistances.Rfo+Resistances.Rfi*(Dotube/Ditube)+(Dotube*ln(Dotube/Ditube)/(2*Kwall))+(1/(Shell.HeatTransfer.hshell))); "Overall Heat Transfer Coefficient Clean" (1/Details.Ud)=(1/Details.Uc)+Resistances.Rfo+Resistances.Rfi*(Dotube/Ditube); "Exchange Surface Area" Details.A=Pi*Dotube*Ntt*Ltube; "Baffles Spacing" Ltube = Baffles.Lsi+Baffles.Lso+Baffles.Ls*(Nb-1); end Model Heatex_Detailed_NTU as Heatex_Detailed VARIABLES Eft as positive (Brief="Effectiveness",Default=0.05,Lower=1e-8); EQUATIONS "Duty" Details.Q = Eft*Details.Cmin*(Inlet.Hot.T-Inlet.Cold.T); end Model Heatex_Detailed_LMTD as Heatex_Detailed VARIABLES DT0 as temp_delta (Brief="Temperature Difference at Inlet",Lower=1); DTL as temp_delta (Brief="Temperature Difference at Outlet",Lower=1); LMTD as temp_delta (Brief="Logarithmic Mean Temperature Difference",Lower=1); Fc as positive (Brief="LMTD Correction Factor",Lower=0.4); MTD as temp_delta (Brief="Mean Temperature Difference",Lower=1); EQUATIONS #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Log Mean Temperature Difference #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# if abs(DT0 - DTL) > 0.05*max(abs([DT0,DTL])) then "Log Mean Temperature Difference" LMTD= (DT0-DTL)/ln(DT0/DTL); else if DT0*DTL equal 0 then "Log Mean Temperature Difference" LMTD = 0.5*(DT0+DTL); else "Log Mean Temperature Difference" LMTD = 0.5*(DT0+DTL)*(1-(DT0-DTL)^2/(DT0*DTL)*(1+(DT0-DTL)^2/(DT0*DTL)/2)/12); end end "Exchange Surface Area" Details.Q = Details.Ud*Details.A*MTD; "Mean Temperature Difference" MTD = Fc*LMTD; end Model E_Shell_NTU_Det as Heatex_Detailed_NTU #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Shell and Tubes Heat Exchanger with 1 shell pass - LMTD Method #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# EQUATIONS "TEMA E Shell Effectiveness" # Eft = 2*(1+Details.Cr+sqrt(1+Details.Cr^2)*((1+exp(-Details.NTU*sqrt(1+Details.Cr^2)))/(1-exp(-Details.NTU*sqrt(1+Details.Cr^2)))) )^-1; Eft = HE.EshellEffectiveness(Details.Cr,Details.NTU); "Js Factor" Shell.HeatTransfer.Js = HE.JsFactor(Shell.HeatTransfer.Re,Baffles.Lsi,Baffles.Lso,Baffles.Ls); if side equal 1 then "Shell Side Reynolds Number" Shell.HeatTransfer.Re=(Dotube*Properties.Hot.Inlet.Fw/Shell.HeatTransfer.Sm)/Properties.Hot.Average.Mu; "Shell Heat Transfer Coefficient" Shell.HeatTransfer.hshell=Shell.HeatTransfer.Ji*(Properties.Hot.Average.Cp/Properties.Hot.Average.Mw)*(Properties.Hot.Inlet.Fw/Shell.HeatTransfer.Sm)*(Shell.HeatTransfer.PR^(-2/3))*Shell.HeatTransfer.Jtotal*Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Shell.PressureDrop.PdCross = HE.DeltaPcross(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Hot.Average.rho); "Shell Pressure Baffle Window" Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Sm,Properties.Hot.Average.rho,Properties.Hot.Average.Mu,Baffles.Ls); "Shell Pressure End Zones" Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Hot.Average.rho); else "Shell Side Reynolds Number" Shell.HeatTransfer.Re=(Dotube*Properties.Cold.Inlet.Fw/Shell.HeatTransfer.Sm)/Properties.Cold.Average.Mu; "Shell Heat Transfer Coefficient" Shell.HeatTransfer.hshell=Shell.HeatTransfer.Ji*(Properties.Cold.Average.Cp/Properties.Cold.Average.Mw)*(Properties.Cold.Inlet.Fw/Shell.HeatTransfer.Sm)*(Shell.HeatTransfer.PR^(-2/3))*Shell.HeatTransfer.Jtotal*Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Shell.PressureDrop.PdCross = HE.DeltaPcross(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Cold.Average.rho); "Shell Pressure Baffle Window" Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Sm,Properties.Cold.Average.rho,Properties.Cold.Average.Mu,Baffles.Ls); "Shell Pressure End Zones" Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Cold.Average.rho); end end Model F_Shell_NTU_Det as Heatex_Detailed_NTU #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Shell and Tubes Heat Exchanger with 1 shell pass - LMTD Method #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# VARIABLES Eft1 as positive (Brief="Effectiveness Correction",Lower=0.01,Default=0.5); EQUATIONS "Effectiveness Correction" Eft1 = 2*(1+Details.Cr+sqrt(1+Details.Cr^2)*((1+exp(-Details.NTU*sqrt(1+Details.Cr^2)))/(1-exp(-Details.NTU*sqrt(1+Details.Cr^2)))) )^-1; "TEMA F Shell Effectiveness" Eft = ( ((1-Eft1*Details.Cr)/(1-Eft1))^2 -1 )*( ((1-Eft1*Details.Cr)/(1-Eft1))^2 - Details.Cr )^-1; "Js Factor" Shell.HeatTransfer.Js = HE.JsFactor(Shell.HeatTransfer.Re,Baffles.Lsi,Baffles.Lso,Baffles.Ls); if side equal 1 then "Shell Side Reynolds Number" Shell.HeatTransfer.Re=(Dotube*Properties.Hot.Inlet.Fw/Shell.HeatTransfer.Sm)/Properties.Hot.Average.Mu; "Shell Heat Transfer Coefficient" Shell.HeatTransfer.hshell= Shell.HeatTransfer.Ji*(Properties.Hot.Average.Cp/Properties.Hot.Average.Mw)*(Properties.Hot.Inlet.Fw/Shell.HeatTransfer.Sm)*(Shell.HeatTransfer.PR^(-2/3))*Shell.HeatTransfer.Jtotal*Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Shell.PressureDrop.PdCross = HE.DeltaPcross(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Hot.Average.rho); "Shell Pressure Baffle Window" Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Sm,Properties.Hot.Average.rho,Properties.Hot.Average.Mu,Baffles.Ls); "Shell Pressure End Zones" Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Hot.Average.rho); else "Shell Side Reynolds Number" Shell.HeatTransfer.Re=(Dotube*Properties.Cold.Inlet.Fw/Shell.HeatTransfer.Sm)/Properties.Cold.Average.Mu; "Shell Heat Transfer Coefficient" Shell.HeatTransfer.hshell=Shell.HeatTransfer.Ji*(Properties.Cold.Average.Cp/Properties.Cold.Average.Mw)*(Properties.Cold.Inlet.Fw/Shell.HeatTransfer.Sm)*(Shell.HeatTransfer.PR^(-2/3))*Shell.HeatTransfer.Jtotal*Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Shell.PressureDrop.PdCross = HE.DeltaPcross(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Cold.Average.rho); "Shell Pressure Baffle Window" Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Sm,Properties.Cold.Average.rho,Properties.Cold.Average.Mu,Baffles.Ls); "Shell Pressure End Zones" Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Cold.Average.rho); end end Model Multipass_NTU_Det #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Shell and Tubes Heat Exchanger In Series with 1 shell pass - LMTD Method #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# PARAMETERS Nshell as Integer (Brief="N Shell in Series",Default=2); ext PP as CalcObject (Brief="External Physical Properties"); HE as CalcObject (Brief="heatex Calculations", File="heatex"); side as Integer (Brief="Fluid Alocation",Lower=0,Upper=1); Pi as constant (Brief="Pi Number",Default=3.14159265); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Shell Geometrical Parameters #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Tpass as Integer (Brief="Number of Tube Passes",Lower=1); Nss as Integer (Brief="Number of Sealing Strips pairs",Lower=1); Dishell as length (Brief="Inside Shell Diameter",Lower=10e-6); Donozzle_Shell as length (Brief="Shell Outlet Nozzle Diameter",Lower=10e-6); Dinozzle_Shell as length (Brief="Shell Inlet Nozzle Diameter",Lower=10e-6); Hinozzle_Shell as length (Brief="Height Under Shell Inlet Nozzle",Lower=10e-6); Honozzle_Shell as length (Brief="Height Under Shell Outlet Nozzle",Lower=10e-6); Aonozzle_Shell as area (Brief="Shell Outlet Nozzle Area",Lower=10e-6); Ainozzle_Shell as area (Brief="Shell Inlet Nozzle Area",Lower=10e-6); Aeonozzle_Shell as area (Brief="Shell Outlet Escape Area Under Nozzle",Lower=10e-6); Aeinozzle_Shell as area (Brief="Shell Inlet Escape Area Under Nozzle",Lower=10e-6); Lcf as length (Brief="Bundle-to-Shell Clearance",Lower=10e-8); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Tubes Geometrical Parameters #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Ntt as Integer (Brief="Total Number of Tubes in Shell",Default=100,Lower=1); Pattern as Integer (Brief="Tube Layout Characteristic Angle",Lower=30); Ltube as length (Brief="Effective Tube Length",Lower=0.1); pitch as length (Brief="Tube Pitch",Lower=1e-8); Kwall as conductivity (Brief="Tube Wall Material Thermal Conductivity"); Dotube as length (Brief="Tube Outside Diameter",Lower=10e-6); Ditube as length (Brief="Tube Inside Diameter",Lower=10e-6); Donozzle_Tube as length (Brief="Tube Outlet Nozzle Diameter",Lower=10e-6); Dinozzle_Tube as length (Brief="Tube Inlett Nozzle Diameter",Lower=10e-6); Aonozzle_Tube as area (Brief="Tube Outlet Nozzle Area",Lower=10e-6); Ainozzle_Tube as area (Brief="Tube Inlet Nozzle Area",Lower=10e-6); Kinlet_Tube as positive (Brief="Tube Inlet Nozzle Pressure Loss Coeff",Default=1.1); Koutlet_Tube as positive (Brief="Tube Outlet Nozzle Pressure Loss Coeff",Default=0.7); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Baffles Geometrical Parameters #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Bc as Integer (Brief="Baffle Cut",Default=25,Lower=25); Nb as Real (Brief="Number of Baffles",Lower=1); Lcd as length (Brief="Baffle-to-Shell Clearance",Lower=10e-8); Ltd as length (Brief="Tube-to-Bafflehole Clearance",Lower=10e-8); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# VARIABLES Eft(Nshell) as positive (Brief="Effectiveness",Default=0.05,Lower=1e-8); Unity(Nshell) as HeatExchangerDetailed_Basic;# "Shell in Series" SET #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Set Parameters for heatex Calculation #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Pi = 3.14159265; HE.Tpass = Tpass; HE.Nss = Nss; HE.Ntt = Ntt; HE.Pattern = Pattern; HE.Bc = Bc; HE.Donozzle_Shell = Donozzle_Shell; HE.Dinozzle_Shell = Dinozzle_Shell; HE.Honozzle_Shell = Honozzle_Shell; HE.Hinozzle_Shell = Hinozzle_Shell; HE.Donozzle_Tube = Donozzle_Tube; HE.Dinozzle_Tube = Dinozzle_Tube; HE.Nb = Nb; HE.Dishell = Dishell; HE.Lcf = Lcf; HE.Ltube = Ltube; HE.pitch = pitch; HE.Dotube = Dotube; HE.Ditube = Ditube; HE.Lcd = Lcd; HE.Ltd = Ltd; side = HE.FluidAlocation(); #"Tube Side Inlet Nozzle Area" Ainozzle_Tube = (Pi*Dinozzle_Tube*Dinozzle_Tube)/4; #"Tube Side Outlet Nozzle Area" Aonozzle_Tube = (Pi*Donozzle_Tube*Donozzle_Tube)/4; #"Tube Inlet Nozzle Pressure Loss Coeff" Kinlet_Tube = 1.1; #"Tube Outlet Nozzle Pressure Loss Coeff" Koutlet_Tube = 0.7; #"Shell Outlet Nozzle Area" Aonozzle_Shell = (Pi*Donozzle_Shell*Donozzle_Shell)/4; #"Shell Inlet Nozzle Area" Ainozzle_Shell = (Pi*Dinozzle_Shell*Dinozzle_Shell)/4; #"Shell Outlet Escape Area Under Nozzle" Aeonozzle_Shell = Pi*Donozzle_Shell*Honozzle_Shell + 0.6*Aonozzle_Shell*(1-Dotube/pitch); #"Shell Inlet Escape Area Under Nozzle" Aeinozzle_Shell = Pi*Dinozzle_Shell*Hinozzle_Shell + 0.6*Ainozzle_Shell*(1-Dotube/pitch); CONNECTIONS Unity([1:Nshell-1]).Outlet.Hot to Unity([2:Nshell]).Inlet.Hot; Unity([2:Nshell]).Outlet.Cold to Unity([1:Nshell-1]).Inlet.Cold; EQUATIONS for i in [1:Nshell] "Shell Side Cross Flow Area" Unity(i).Shell.HeatTransfer.Sm = HE.CrossFlowArea(Unity(i).Baffles.Ls); "Ji Factor" Unity(i).Shell.HeatTransfer.Ji =HE.JiFactor(Unity(i).Shell.HeatTransfer.Re); "Jc Factor" Unity(i).Shell.HeatTransfer.Jc = HE.JcFactor(); "Jl Factor" Unity(i).Shell.HeatTransfer.Jl = HE.JlFactor(Unity(i).Shell.HeatTransfer.Sm); "Jb Factor" Unity(i).Shell.HeatTransfer.Jb = HE.JbFactor(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Ls,Unity(i).Shell.HeatTransfer.Sm); "Jr Factor" Unity(i).Shell.HeatTransfer.Jr = HE.JrFactor(Unity(i).Shell.HeatTransfer.Re); "Total J Factor" Unity(i).Shell.HeatTransfer.Jtotal=Unity(i).Shell.HeatTransfer.Jc*Unity(i).Shell.HeatTransfer.Jl*Unity(i).Shell.HeatTransfer.Jb*Unity(i).Shell.HeatTransfer.Jr*Unity(i).Shell.HeatTransfer.Js; #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Pressure Drop and Velocities #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# if side equal 1 then "Tube Side Pressure Drop" Unity(i).Tubes.PressureDrop.PdTube = HE.DeltaPtube(Unity(i).Tubes.HeatTransfer.Re,Unity(i).Properties.Cold.Average.rho,Unity(i).Tubes.HeatTransfer.Vtube,Unity(i).Tubes.HeatTransfer.Phi); "Pressure Drop Tube Side Inlet Nozzle" Unity(i).Tubes.PressureDrop.Pdnozzle_in = 0.5*Kinlet_Tube*Unity(i).Properties.Cold.Inlet.rho*Unity(i).Tubes.PressureDrop.Vnozzle_in^2; "Velocity Tube Side Inlet Nozzle" Unity(i).Tubes.PressureDrop.Vnozzle_in = Unity(i).Properties.Cold.Inlet.Fw/(Unity(i).Properties.Cold.Inlet.rho*Ainozzle_Tube); "Pressure Drop Tube Side Outlet Nozzle" Unity(i).Tubes.PressureDrop.Pdnozzle_out = 0.5*Koutlet_Tube*Unity(i).Properties.Cold.Outlet.rho*Unity(i).Tubes.PressureDrop.Vnozzle_out^2; "Velocity Tube Side Outlet Nozzle" Unity(i).Tubes.PressureDrop.Vnozzle_out = Unity(i).Properties.Cold.Inlet.Fw/(Unity(i).Properties.Cold.Outlet.rho*Aonozzle_Tube); "Shell Pressure Drop Inlet Nozzle" Unity(i).Shell.PressureDrop.Pdnozzle_in = (0.5*Unity(i).Properties.Hot.Inlet.Fw^2/Unity(i).Properties.Hot.Inlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Inlet Nozzle" Unity(i).Shell.PressureDrop.Vnozzle_in = Unity(i).Properties.Hot.Inlet.Fw/(Unity(i).Properties.Hot.Inlet.rho*Ainozzle_Shell); "Shell Pressure Drop Outlet Nozzle" Unity(i).Shell.PressureDrop.Pdnozzle_out = (0.5*Unity(i).Properties.Hot.Outlet.Fw^2/Unity(i).Properties.Hot.Outlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Outlet Nozzle" Unity(i).Shell.PressureDrop.Vnozzle_out = Unity(i).Properties.Hot.Outlet.Fw/(Unity(i).Properties.Hot.Outlet.rho*Aonozzle_Shell); "Pressure Drop Hot Stream" Unity(i).Outlet.Hot.P = Unity(i).Inlet.Hot.P - Unity(i).Shell.PressureDrop.Pdtotal; "Pressure Drop Cold Stream" Unity(i).Outlet.Cold.P = Unity(i).Inlet.Cold.P - Unity(i).Tubes.PressureDrop.Pdtotal; else "Tube Side Pressure Drop" Unity(i).Tubes.PressureDrop.PdTube = HE.DeltaPtube(Unity(i).Tubes.HeatTransfer.Re,Unity(i).Properties.Hot.Average.rho,Unity(i).Tubes.HeatTransfer.Vtube,Unity(i).Tubes.HeatTransfer.Phi); "Pressure Drop Tube Side Inlet Nozzle" Unity(i).Tubes.PressureDrop.Pdnozzle_in = 0.5*Kinlet_Tube*Unity(i).Properties.Hot.Inlet.rho*Unity(i).Tubes.PressureDrop.Vnozzle_in^2; "Velocity Tube Side Inlet Nozzle" Unity(i).Tubes.PressureDrop.Vnozzle_in = Unity(i).Properties.Hot.Inlet.Fw/(Unity(i).Properties.Hot.Inlet.rho*Ainozzle_Tube); "Pressure Drop Tube Side Outlet Nozzle" Unity(i).Tubes.PressureDrop.Pdnozzle_out = 0.5*Koutlet_Tube*Unity(i).Properties.Hot.Outlet.rho*Unity(i).Tubes.PressureDrop.Vnozzle_out^2; "Velocity Tube Side Outlet Nozzle" Unity(i).Tubes.PressureDrop.Vnozzle_out = Unity(i).Properties.Hot.Inlet.Fw/(Unity(i).Properties.Hot.Outlet.rho*Aonozzle_Tube); "Shell Pressure Drop Inlet Nozzle" Unity(i).Shell.PressureDrop.Pdnozzle_in = (0.5*Unity(i).Properties.Cold.Inlet.Fw^2/Unity(i).Properties.Cold.Inlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Inlet Nozzle" Unity(i).Shell.PressureDrop.Vnozzle_in = Unity(i).Properties.Cold.Inlet.Fw/(Unity(i).Properties.Cold.Inlet.rho*Ainozzle_Shell); "Shell Pressure Drop Outlet Nozzle" Unity(i).Shell.PressureDrop.Pdnozzle_out = (0.5*Unity(i).Properties.Cold.Outlet.Fw^2/Unity(i).Properties.Cold.Outlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Outlet Nozzle" Unity(i).Shell.PressureDrop.Vnozzle_out = Unity(i).Properties.Cold.Outlet.Fw/(Unity(i).Properties.Cold.Outlet.rho*Ainozzle_Shell); "Pressure Drop Hot Stream" Unity(i).Outlet.Hot.P = Unity(i).Inlet.Hot.P- Unity(i).Tubes.PressureDrop.Pdtotal; "Pressure Drop Cold Stream" Unity(i).Outlet.Cold.P = Unity(i).Inlet.Cold.P - Unity(i).Shell.PressureDrop.Pdtotal; end #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Phi correction #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# if side equal 1 then "Shell Side Phi correction for viscosity" Unity(i).Shell.HeatTransfer.Phi = HE.PhiCorrection(Unity(i).Properties.Hot.Average.Mu,Unity(i).Properties.Hot.Wall.Mu); "Tube Side Phi correction for viscosity" Unity(i).Tubes.HeatTransfer.Phi = HE.PhiCorrection(Unity(i).Properties.Cold.Average.Mu,Unity(i).Properties.Cold.Wall.Mu); else "Shell Side Phi correction for viscosity" Unity(i).Shell.HeatTransfer.Phi = HE.PhiCorrection(Unity(i).Properties.Cold.Average.Mu,Unity(i).Properties.Cold.Wall.Mu); "Tube Side Phi correction for viscosity" Unity(i).Tubes.HeatTransfer.Phi = HE.PhiCorrection(Unity(i).Properties.Hot.Average.Mu,Unity(i).Properties.Hot.Average.Mu); end if side equal 1 then "Shell Side inlet Nozzle rho-V^2" Unity(i).Shell.PressureDrop.RVsquare_in = Unity(i).Properties.Hot.Inlet.rho*(Unity(i).Shell.PressureDrop.Vnozzle_in)^2; "Shell Side Outlet Nozzle rho-V^2" Unity(i).Shell.PressureDrop.RVsquare_out = Unity(i).Properties.Hot.Outlet.rho*(Unity(i).Shell.PressureDrop.Vnozzle_out)^2; else "Shell Side inlet Nozzle rho-V^2" Unity(i).Shell.PressureDrop.RVsquare_in = Unity(i).Properties.Cold.Inlet.rho*(Unity(i).Shell.PressureDrop.Vnozzle_in)^2; "Shell Side Outlet Nozzle rho-V^2" Unity(i).Shell.PressureDrop.RVsquare_out = Unity(i).Properties.Cold.Outlet.rho*(Unity(i).Shell.PressureDrop.Vnozzle_out)^2; end if side equal 1 then "Hot Wall Temperature" Unity(i).Properties.Hot.Wall.Twall = (Unity(i).Properties.Hot.Average.T+Unity(i).Properties.Cold.Average.T)/2; "ColdWall Temperature" Unity(i).Properties.Cold.Wall.Twall = (Unity(i).Properties.Hot.Average.T+Unity(i).Properties.Cold.Average.T)/2; "Tube Side Velocity" Unity(i).Tubes.HeatTransfer.Vtube = Unity(i).Properties.Cold.Inlet.Fw*Tpass/((Pi*Ditube*Ditube/4)*Unity(i).Properties.Cold.Average.rho*Ntt); "Tube Side Reynolds Number" Unity(i).Tubes.HeatTransfer.Re = (Unity(i).Properties.Cold.Average.rho*Unity(i).Tubes.HeatTransfer.Vtube*Ditube)/Unity(i).Properties.Cold.Average.Mu; "Tube Side Prandtl Number" Unity(i).Tubes.HeatTransfer.PR = ((Unity(i).Properties.Cold.Average.Cp/Unity(i).Properties.Cold.Average.Mw)*Unity(i).Properties.Cold.Average.Mu)/Unity(i).Properties.Cold.Average.K; "Tube Side Prandtl Number at Wall Temperature" Unity(i).Tubes.HeatTransfer.PRw = ((Unity(i).Properties.Cold.Wall.Cp/Unity(i).Properties.Cold.Average.Mw)*Unity(i).Properties.Cold.Wall.Mu)/Unity(i).Properties.Cold.Wall.K; "Tube Side Film Coefficient" Unity(i).Tubes.HeatTransfer.htube = HE.TubeFilmCoeff(Unity(i).Tubes.HeatTransfer.Re,Unity(i).Tubes.HeatTransfer.PR,Unity(i).Properties.Cold.Average.K)*Unity(i).Tubes.HeatTransfer.Phi; "Shell Side Prandtl Number" Unity(i).Shell.HeatTransfer.PR = ((Unity(i).Properties.Hot.Average.Cp/Unity(i).Properties.Hot.Average.Mw)*Unity(i).Properties.Hot.Average.Mu)/Unity(i).Properties.Hot.Average.K; "Shell Side Prandtl Number at Wall Temperature" Unity(i).Shell.HeatTransfer.PRw = ((Unity(i).Properties.Hot.Wall.Cp/Unity(i).Properties.Hot.Average.Mw)*Unity(i).Properties.Hot.Wall.Mu)/Unity(i).Properties.Hot.Wall.K; else "Hot Wall Temperature" Unity(i).Properties.Hot.Wall.Twall = (Unity(i).Properties.Hot.Average.T+Unity(i).Properties.Cold.Average.T)/2; "Cold Wall Temperature" Unity(i).Properties.Cold.Wall.Twall = (Unity(i).Properties.Hot.Average.T+Unity(i).Properties.Cold.Average.T)/2; "Tube Side Velocity" Unity(i).Tubes.HeatTransfer.Vtube = Unity(i).Properties.Hot.Inlet.Fw*Tpass/((Pi*Ditube*Ditube/4)*Unity(i).Properties.Hot.Average.rho*Ntt); "Tube Side Reynolds Number" Unity(i).Tubes.HeatTransfer.Re = (Unity(i).Properties.Hot.Average.rho*Unity(i).Tubes.HeatTransfer.Vtube*Ditube)/Unity(i).Properties.Hot.Average.Mu; "Tube Side Prandtl Number" Unity(i).Tubes.HeatTransfer.PR = ((Unity(i).Properties.Hot.Average.Cp/Unity(i).Properties.Hot.Average.Mw)*Unity(i).Properties.Hot.Average.Mu)/Unity(i).Properties.Hot.Average.K; "Tube Side Prandtl Number at Wall" Unity(i).Tubes.HeatTransfer.PRw = ((Unity(i).Properties.Hot.Wall.Cp/Unity(i).Properties.Hot.Average.Mw)*Unity(i).Properties.Hot.Wall.Mu)/Unity(i).Properties.Hot.Wall.K; "Tube Side Film Coefficient" Unity(i).Tubes.HeatTransfer.htube= HE.TubeFilmCoeff(Unity(i).Tubes.HeatTransfer.Re,Unity(i).Tubes.HeatTransfer.PR,Unity(i).Properties.Hot.Average.K)*Unity(i).Tubes.HeatTransfer.Phi; "Shell Side Prandtl Number" Unity(i).Shell.HeatTransfer.PR = ((Unity(i).Properties.Cold.Average.Cp/Unity(i).Properties.Cold.Average.Mw)*Unity(i).Properties.Cold.Average.Mu)/Unity(i).Properties.Cold.Average.K; "Shell Side Prandtl Number at Wall" Unity(i).Shell.HeatTransfer.PRw=((Unity(i).Properties.Cold.Wall.Cp/Unity(i).Properties.Cold.Average.Mw)*Unity(i).Properties.Cold.Wall.Mu)/Unity(i).Properties.Cold.Wall.K; end "Tube Resistance" Unity(i).Resistances.Rtube*(Unity(i).Tubes.HeatTransfer.htube*Ditube) = Dotube; "Wall Resistance" Unity(i).Resistances.Rwall=Dotube*ln(Dotube/Ditube)/(2*Kwall); "Shell Resistance" Unity(i).Resistances.Rshell*(Unity(i).Shell.HeatTransfer.hshell)=1; "Overall Heat Transfer Coefficient Clean" Unity(i).Details.Uc=1/(Dotube/(Unity(i).Tubes.HeatTransfer.htube*Ditube)+(Dotube*ln(Dotube/Ditube)/(2*Kwall))+(1/(Unity(i).Shell.HeatTransfer.hshell))); "Overall Heat Transfer Coefficient Dirty" (1/Unity(i).Details.Ud)=(1/Unity(i).Details.Uc)+Unity(i).Resistances.Rfo+Unity(i).Resistances.Rfi*(Dotube/Ditube); "Exchange Surface Area" Unity(i).Details.A=Pi*Dotube*Ntt*Ltube; "Baffles Spacing" Ltube = Unity(i).Baffles.Lsi+Unity(i).Baffles.Lso+Unity(i).Baffles.Ls*(Nb-1); "TEMA E Shell Effectiveness" Eft(i) = 2*(1+Unity(i).Details.Cr+sqrt(1+Unity(i).Details.Cr^2)*((1+exp(-Unity(i).Details.NTU*sqrt(1+Unity(i).Details.Cr^2)))/(1-exp(-Unity(i).Details.NTU*sqrt(1+Unity(i).Details.Cr^2)))) )^-1; "Js Factor" Unity(i).Shell.HeatTransfer.Js = HE.JsFactor(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Lsi,Unity(i).Baffles.Lso,Unity(i).Baffles.Ls); if side equal 1 then "Shell Side Reynolds Number" Unity(i).Shell.HeatTransfer.Re=(Dotube*Unity(i).Properties.Hot.Inlet.Fw/Unity(i).Shell.HeatTransfer.Sm)/Unity(i).Properties.Hot.Average.Mu; "Shell Heat Transfer Coefficient" Unity(i).Shell.HeatTransfer.hshell=Unity(i).Shell.HeatTransfer.Ji*(Unity(i).Properties.Hot.Average.Cp/Unity(i).Properties.Hot.Average.Mw)*(Unity(i).Properties.Hot.Inlet.Fw/Unity(i).Shell.HeatTransfer.Sm)*(Unity(i).Shell.HeatTransfer.PR^(-2/3))*Unity(i).Shell.HeatTransfer.Jtotal*Unity(i).Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Unity(i).Shell.PressureDrop.PdCross = HE.DeltaPcross(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Ls,Unity(i).Baffles.Lso,Unity(i).Baffles.Lsi,Unity(i).Properties.Hot.Inlet.Fw,Unity(i).Shell.HeatTransfer.Phi,Unity(i).Properties.Hot.Average.rho); "Shell Pressure Baffle Window" Unity(i).Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Unity(i).Properties.Hot.Inlet.Fw,Unity(i).Shell.HeatTransfer.Sm,Unity(i).Properties.Hot.Average.rho,Unity(i).Properties.Hot.Average.Mu,Unity(i).Baffles.Ls); "Shell Pressure End Zones" Unity(i).Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Ls,Unity(i).Baffles.Lso,Unity(i).Baffles.Lsi,Unity(i).Properties.Hot.Inlet.Fw,Unity(i).Shell.HeatTransfer.Phi,Unity(i).Properties.Hot.Average.rho); else "Shell Side Reynolds Number" Unity(i).Shell.HeatTransfer.Re=(Dotube*Unity(i).Properties.Cold.Inlet.Fw/Unity(i).Shell.HeatTransfer.Sm)/Unity(i).Properties.Cold.Average.Mu; "Shell Heat Transfer Coefficient" Unity(i).Shell.HeatTransfer.hshell=Unity(i).Shell.HeatTransfer.Ji*(Unity(i).Properties.Cold.Average.Cp/Unity(i).Properties.Cold.Average.Mw)*(Unity(i).Properties.Cold.Inlet.Fw/Unity(i).Shell.HeatTransfer.Sm)*(Unity(i).Shell.HeatTransfer.PR^(-2/3))*Unity(i).Shell.HeatTransfer.Jtotal*Unity(i).Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Unity(i).Shell.PressureDrop.PdCross = HE.DeltaPcross(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Ls,Unity(i).Baffles.Lso,Unity(i).Baffles.Lsi,Unity(i).Properties.Cold.Inlet.Fw,Unity(i).Shell.HeatTransfer.Phi,Unity(i).Properties.Cold.Average.rho); "Shell Pressure Baffle Window" Unity(i).Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Unity(i).Properties.Cold.Inlet.Fw,Unity(i).Shell.HeatTransfer.Sm,Unity(i).Properties.Cold.Average.rho,Unity(i).Properties.Cold.Average.Mu,Unity(i).Baffles.Ls); "Shell Pressure End Zones" Unity(i).Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Ls,Unity(i).Baffles.Lso,Unity(i).Baffles.Lsi,Unity(i).Properties.Cold.Inlet.Fw,Unity(i).Shell.HeatTransfer.Phi,Unity(i).Properties.Cold.Average.rho); end "Duty" Unity(i).Details.Q = Eft(i)*Unity(i).Details.Cmin*(Unity(i).Inlet.Hot.T-Unity(i).Inlet.Cold.T); end end Model E_Shell_LMTD_Det as Heatex_Detailed_LMTD #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Shell and Tubes Heat Exchanger with 1 shell pass - LMTD Method #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# EQUATIONS "LMTD Correction Factor" Fc = HE.EshellCorrectionFactor(Inlet.Hot.T,Outlet.Hot.T,Inlet.Cold.T,Outlet.Cold.T); "Temperature Difference at Inlet" DT0 = Inlet.Hot.T - Outlet.Cold.T; "Temperature Difference at Outlet" DTL = Outlet.Hot.T - Inlet.Cold.T; "Js Factor" Shell.HeatTransfer.Js = HE.JsFactor(Shell.HeatTransfer.Re,Baffles.Lsi,Baffles.Lso,Baffles.Ls); if side equal 1 then "Shell Side Reynolds Number" Shell.HeatTransfer.Re=(Dotube*Properties.Hot.Inlet.Fw/Shell.HeatTransfer.Sm)/Properties.Hot.Average.Mu; "Shell Heat Transfer Coefficient" Shell.HeatTransfer.hshell=Shell.HeatTransfer.Ji*(Properties.Hot.Average.Cp/Properties.Hot.Average.Mw)*(Properties.Hot.Inlet.Fw/Shell.HeatTransfer.Sm)*(Shell.HeatTransfer.PR^(-2/3))*Shell.HeatTransfer.Jtotal*Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Shell.PressureDrop.PdCross = HE.DeltaPcross(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Hot.Average.rho); "Shell Pressure Baffle Window" Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Sm,Properties.Hot.Average.rho,Properties.Hot.Average.Mu,Baffles.Ls); "Shell Pressure End Zones" Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Hot.Average.rho); else "Shell Side Reynolds Number" Shell.HeatTransfer.Re=(Dotube*Properties.Cold.Inlet.Fw/Shell.HeatTransfer.Sm)/Properties.Cold.Average.Mu; "Shell Heat Transfer Coefficient" Shell.HeatTransfer.hshell=Shell.HeatTransfer.Ji*(Properties.Cold.Average.Cp/Properties.Cold.Average.Mw)*(Properties.Cold.Inlet.Fw/Shell.HeatTransfer.Sm)*(Shell.HeatTransfer.PR^(-2/3))*Shell.HeatTransfer.Jtotal*Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Shell.PressureDrop.PdCross = HE.DeltaPcross(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Cold.Average.rho); "Shell Pressure Baffle Window" Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Sm,Properties.Cold.Average.rho,Properties.Cold.Average.Mu,Baffles.Ls); "Shell Pressure End Zones" Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Cold.Average.rho); end end Model F_Shell_LMTD_Det as Heatex_Detailed_LMTD #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Shell and Tubes Heat Exchanger with 2 shell pass - LMTD Method #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# EQUATIONS "LMTD Correction Factor" Fc = HE.FshellCorrectionFactor(Inlet.Hot.T,Outlet.Hot.T,Inlet.Cold.T,Outlet.Cold.T); "Temperature Difference at Inlet" DT0 = Inlet.Hot.T - Outlet.Cold.T; "Temperature Difference at Outlet" DTL = Outlet.Hot.T - Inlet.Cold.T; "Js Factor" Shell.HeatTransfer.Js = HE.JsFactor(Shell.HeatTransfer.Re,Baffles.Lsi,Baffles.Lso,Baffles.Ls); if side equal 1 then "Shell Side Reynolds Number" Shell.HeatTransfer.Re=(Dotube*Properties.Hot.Inlet.Fw/Shell.HeatTransfer.Sm)/Properties.Hot.Average.Mu; "Shell Heat Transfer Coefficient" Shell.HeatTransfer.hshell=Shell.HeatTransfer.Ji*(Properties.Hot.Average.Cp/Properties.Hot.Average.Mw)*(Properties.Hot.Inlet.Fw/Shell.HeatTransfer.Sm)*(Shell.HeatTransfer.PR^(-2/3))*Shell.HeatTransfer.Jtotal*Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Shell.PressureDrop.PdCross = HE.DeltaPcross(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Hot.Average.rho); "Shell Pressure Baffle Window" Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Sm,Properties.Hot.Average.rho,Properties.Hot.Average.Mu,Baffles.Ls); "Shell Pressure End Zones" Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Hot.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Hot.Average.rho); else "Shell Side Reynolds Number" Shell.HeatTransfer.Re=(Dotube*Properties.Cold.Inlet.Fw/Shell.HeatTransfer.Sm)/Properties.Cold.Average.Mu; "Shell Heat Transfer Coefficient" Shell.HeatTransfer.hshell=Shell.HeatTransfer.Ji*(Properties.Cold.Average.Cp/Properties.Cold.Average.Mw)*(Properties.Cold.Inlet.Fw/Shell.HeatTransfer.Sm)*(Shell.HeatTransfer.PR^(-2/3))*Shell.HeatTransfer.Jtotal*Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Shell.PressureDrop.PdCross = HE.DeltaPcross(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Cold.Average.rho); "Shell Pressure Baffle Window" Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Sm,Properties.Cold.Average.rho,Properties.Cold.Average.Mu,Baffles.Ls); "Shell Pressure End Zones" Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Shell.HeatTransfer.Re,Baffles.Ls,Baffles.Lso,Baffles.Lsi,Properties.Cold.Inlet.Fw,Shell.HeatTransfer.Phi,Properties.Cold.Average.rho); end end Model Multipass_LMTD_Det #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Shell and Tubes Heat Exchanger In Series with 1 shell pass - LMTD Method #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# PARAMETERS Nshell as Integer (Brief="N Shell in Series",Default=2); HE as CalcObject (Brief="STHE Calculations",File="heatex"); ext PP as CalcObject (Brief="External Physical Properties"); side as Integer (Brief="Fluid Alocation",Lower=0,Upper=1); Pi as constant (Brief="Pi Number",Default=3.14159265); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Shell Geometrical Parameters #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Tpass as Integer (Brief="Number of Tube Passes",Lower=1); Nss as Integer (Brief="Number of Sealing Strips pairs",Lower=1); Dishell as length (Brief="Inside Shell Diameter",Lower=10e-6); Donozzle_Shell as length (Brief="Shell Outlet Nozzle Diameter",Lower=10e-6); Dinozzle_Shell as length (Brief="Shell Inlet Nozzle Diameter",Lower=10e-6); Hinozzle_Shell as length (Brief="Height Under Shell Inlet Nozzle",Lower=10e-6); Honozzle_Shell as length (Brief="Height Under Shell Outlet Nozzle",Lower=10e-6); Aonozzle_Shell as area (Brief="Shell Outlet Nozzle Area",Lower=10e-6); Ainozzle_Shell as area (Brief="Shell Inlet Nozzle Area",Lower=10e-6); Aeonozzle_Shell as area (Brief="Shell Outlet Escape Area Under Nozzle",Lower=10e-6); Aeinozzle_Shell as area (Brief="Shell Inlet Escape Area Under Nozzle",Lower=10e-6); Lcf as length (Brief="Bundle-to-Shell Clearance",Lower=10e-8); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Tubes Geometrical Parameters #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Ntt as Integer (Brief="Total Number of Tubes in Shell",Default=100,Lower=1); Pattern as Integer (Brief="Tube Layout Characteristic Angle",Lower=30); Ltube as length (Brief="Effective Tube Length",Lower=0.1); pitch as length (Brief="Tube Pitch",Lower=1e-8); Kwall as conductivity (Brief="Tube Wall Material Thermal Conductivity"); Dotube as length (Brief="Tube Outside Diameter",Lower=10e-6); Ditube as length (Brief="Tube Inside Diameter",Lower=10e-6); Donozzle_Tube as length (Brief="Tube Outlet Nozzle Diameter",Lower=10e-6); Dinozzle_Tube as length (Brief="Tube Inlett Nozzle Diameter",Lower=10e-6); Aonozzle_Tube as area (Brief="Tube Outlet Nozzle Area",Lower=10e-6); Ainozzle_Tube as area (Brief="Tube Inlet Nozzle Area",Lower=10e-6); Kinlet_Tube as positive (Brief="Tube Inlet Nozzle Pressure Loss Coeff",Default=1.1); Koutlet_Tube as positive (Brief="Tube Outlet Nozzle Pressure Loss Coeff",Default=0.7); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Baffles Geometrical Parameters #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Bc as Integer (Brief="Baffle Cut",Default=25,Lower=25); Nb as Real (Brief="Number of Baffles",Lower=1); Lcd as length (Brief="Baffle-to-Shell Clearance",Lower=10e-8); Ltd as length (Brief="Tube-to-Bafflehole Clearance",Lower=10e-8); #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# VARIABLES LMTD(Nshell) as temp_delta (Brief="Logarithmic Mean Temperature Difference",Lower=5); Fc(Nshell) as positive (Brief="LMTD Correction Factor",Lower=0.5); MTD(Nshell) as temp_delta (Brief="Mean Temperature Difference",Lower=5); Unity(Nshell) as HeatExchangerDetailed_Basic; SET #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# # Set Parameters for heatex Calculation #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# Pi = 3.14159265; HE.Tpass = Tpass; HE.Nss = Nss; HE.Ntt = Ntt; HE.Pattern = Pattern; HE.Bc = Bc; HE.Donozzle_Shell = Donozzle_Shell; HE.Dinozzle_Shell = Dinozzle_Shell; HE.Honozzle_Shell = Honozzle_Shell; HE.Hinozzle_Shell = Hinozzle_Shell; HE.Donozzle_Tube = Donozzle_Tube; HE.Dinozzle_Tube = Dinozzle_Tube; HE.Nb = Nb; HE.Dishell = Dishell; HE.Lcf = Lcf; HE.Ltube = Ltube; HE.pitch = pitch; HE.Dotube = Dotube; HE.Ditube = Ditube; HE.Lcd = Lcd; HE.Ltd = Ltd; side = HE.FluidAlocation(); #"Tube Side Inlet Nozzle Area" Ainozzle_Tube = (Pi*Dinozzle_Tube*Dinozzle_Tube)/4; #"Tube Side Outlet Nozzle Area" Aonozzle_Tube = (Pi*Donozzle_Tube*Donozzle_Tube)/4; #"Tube Inlet Nozzle Pressure Loss Coeff" Kinlet_Tube = 1.1; #"Tube Outlet Nozzle Pressure Loss Coeff" Koutlet_Tube = 0.7; #"Shell Outlet Nozzle Area" Aonozzle_Shell = (Pi*Donozzle_Shell*Donozzle_Shell)/4; #"Shell Inlet Nozzle Area" Ainozzle_Shell = (Pi*Dinozzle_Shell*Dinozzle_Shell)/4; #"Shell Outlet Escape Area Under Nozzle" Aeonozzle_Shell = Pi*Donozzle_Shell*Honozzle_Shell + 0.6*Aonozzle_Shell*(1-Dotube/pitch); #"Shell Inlet Escape Area Under Nozzle" Aeinozzle_Shell = Pi*Dinozzle_Shell*Hinozzle_Shell + 0.6*Ainozzle_Shell*(1-Dotube/pitch); CONNECTIONS Unity([1:Nshell-1]).Outlet.Hot to Unity([2:Nshell]).Inlet.Hot; Unity([2:Nshell]).Outlet.Cold to Unity([1:Nshell-1]).Inlet.Cold; EQUATIONS for i in [1:Nshell] "Shell Side Cross Flow Area" Unity(i).Shell.HeatTransfer.Sm = HE.CrossFlowArea(Unity(i).Baffles.Ls); "Ji Factor" Unity(i).Shell.HeatTransfer.Ji = HE.JiFactor(Unity(i).Shell.HeatTransfer.Re); "Jc Factor" Unity(i).Shell.HeatTransfer.Jc = HE.JcFactor(); "Jl Factor" Unity(i).Shell.HeatTransfer.Jl = HE.JlFactor(Unity(i).Shell.HeatTransfer.Sm); "Jb Factor" Unity(i).Shell.HeatTransfer.Jb = HE.JbFactor(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Ls,Unity(i).Shell.HeatTransfer.Sm); "Jr Factor" Unity(i).Shell.HeatTransfer.Jr = HE.JrFactor(Unity(i).Shell.HeatTransfer.Re); "Total J Factor" Unity(i).Shell.HeatTransfer.Jtotal=Unity(i).Shell.HeatTransfer.Jc*Unity(i).Shell.HeatTransfer.Jl*Unity(i).Shell.HeatTransfer.Jb*Unity(i).Shell.HeatTransfer.Jr*Unity(i).Shell.HeatTransfer.Js; if side equal 1 then "Tube Side Pressure Drop" Unity(i).Tubes.PressureDrop.PdTube = HE.DeltaPtube(Unity(i).Tubes.HeatTransfer.Re,Unity(i).Properties.Cold.Average.rho,Unity(i).Tubes.HeatTransfer.Vtube,Unity(i).Tubes.HeatTransfer.Phi); "Pressure Drop Tube Side Inlet Nozzle" Unity(i).Tubes.PressureDrop.Pdnozzle_in = 0.5*Kinlet_Tube*Unity(i).Properties.Cold.Inlet.rho*Unity(i).Tubes.PressureDrop.Vnozzle_in^2; "Velocity Tube Side Inlet Nozzle" Unity(i).Tubes.PressureDrop.Vnozzle_in = Unity(i).Properties.Cold.Inlet.Fw/(Unity(i).Properties.Cold.Inlet.rho*Ainozzle_Tube); "Pressure Drop Tube Side Outlet Nozzle" Unity(i).Tubes.PressureDrop.Pdnozzle_out = 0.5*Koutlet_Tube*Unity(i).Properties.Cold.Outlet.rho*Unity(i).Tubes.PressureDrop.Vnozzle_out^2; "Velocity Tube Side Outlet Nozzle" Unity(i).Tubes.PressureDrop.Vnozzle_out = Unity(i).Properties.Cold.Inlet.Fw/(Unity(i).Properties.Cold.Outlet.rho*Aonozzle_Tube); "Shell Pressure Drop Inlet Nozzle" Unity(i).Shell.PressureDrop.Pdnozzle_in = (0.5*Unity(i).Properties.Hot.Inlet.Fw^2/Unity(i).Properties.Hot.Inlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Inlet Nozzle" Unity(i).Shell.PressureDrop.Vnozzle_in = Unity(i).Properties.Hot.Inlet.Fw/(Unity(i).Properties.Hot.Inlet.rho*Ainozzle_Shell); "Shell Pressure Drop Outlet Nozzle" Unity(i).Shell.PressureDrop.Pdnozzle_out = (0.5*Unity(i).Properties.Hot.Outlet.Fw^2/Unity(i).Properties.Hot.Outlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Outlet Nozzle" Unity(i).Shell.PressureDrop.Vnozzle_out = Unity(i).Properties.Hot.Outlet.Fw/(Unity(i).Properties.Hot.Outlet.rho*Aonozzle_Shell); "Pressure Drop Hot Stream" Unity(i).Outlet.Hot.P = Unity(i).Inlet.Hot.P - Unity(i).Shell.PressureDrop.Pdtotal; "Pressure Drop Cold Stream" Unity(i).Outlet.Cold.P = Unity(i).Inlet.Cold.P - Unity(i).Tubes.PressureDrop.Pdtotal; else "Tube Side Pressure Drop" Unity(i).Tubes.PressureDrop.PdTube = HE.DeltaPtube(Unity(i).Tubes.HeatTransfer.Re,Unity(i).Properties.Hot.Average.rho,Unity(i).Tubes.HeatTransfer.Vtube,Unity(i).Tubes.HeatTransfer.Phi); "Pressure Drop Tube Side Inlet Nozzle" Unity(i).Tubes.PressureDrop.Pdnozzle_in = 0.5*Kinlet_Tube*Unity(i).Properties.Hot.Inlet.rho*Unity(i).Tubes.PressureDrop.Vnozzle_in^2; "Velocity Tube Side Inlet Nozzle" Unity(i).Tubes.PressureDrop.Vnozzle_in = Unity(i).Properties.Hot.Inlet.Fw/(Unity(i).Properties.Hot.Inlet.rho*Ainozzle_Tube); "Pressure Drop Tube Side Outlet Nozzle" Unity(i).Tubes.PressureDrop.Pdnozzle_out = 0.5*Koutlet_Tube*Unity(i).Properties.Hot.Outlet.rho*Unity(i).Tubes.PressureDrop.Vnozzle_out^2; "Velocity Tube Side Outlet Nozzle" Unity(i).Tubes.PressureDrop.Vnozzle_out = Unity(i).Properties.Hot.Inlet.Fw/(Unity(i).Properties.Hot.Outlet.rho*Aonozzle_Tube); "Shell Pressure Drop Inlet Nozzle" Unity(i).Shell.PressureDrop.Pdnozzle_in = (0.5*Unity(i).Properties.Cold.Inlet.Fw^2/Unity(i).Properties.Cold.Inlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Inlet Nozzle" Unity(i).Shell.PressureDrop.Vnozzle_in = Unity(i).Properties.Cold.Inlet.Fw/(Unity(i).Properties.Cold.Inlet.rho*Ainozzle_Shell); "Shell Pressure Drop Outlet Nozzle" Unity(i).Shell.PressureDrop.Pdnozzle_out = (0.5*Unity(i).Properties.Cold.Outlet.Fw^2/Unity(i).Properties.Cold.Outlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); "Velocity Shell Side Outlet Nozzle" Unity(i).Shell.PressureDrop.Vnozzle_out = Unity(i).Properties.Cold.Outlet.Fw/(Unity(i).Properties.Cold.Outlet.rho*Ainozzle_Shell); "Pressure Drop Hot Stream" Unity(i).Outlet.Hot.P = Unity(i).Inlet.Hot.P- Unity(i).Tubes.PressureDrop.Pdtotal; "Pressure Drop Cold Stream" Unity(i).Outlet.Cold.P = Unity(i).Inlet.Cold.P - Unity(i).Shell.PressureDrop.Pdtotal; end if side equal 1 then "Shell Side Phi correction for viscosity" Unity(i).Shell.HeatTransfer.Phi = HE.PhiCorrection(Unity(i).Properties.Hot.Average.Mu,Unity(i).Properties.Hot.Wall.Mu); "Tube Side Phi correction for viscosity" Unity(i).Tubes.HeatTransfer.Phi = HE.PhiCorrection(Unity(i).Properties.Cold.Average.Mu,Unity(i).Properties.Cold.Wall.Mu); else "Shell Side Phi correction for viscosity" Unity(i).Shell.HeatTransfer.Phi = HE.PhiCorrection(Unity(i).Properties.Cold.Average.Mu,Unity(i).Properties.Cold.Wall.Mu); "Tube Side Phi correction for viscosity" Unity(i).Tubes.HeatTransfer.Phi = HE.PhiCorrection(Unity(i).Properties.Hot.Average.Mu,Unity(i).Properties.Hot.Wall.Mu); end if side equal 1 then "Shell Side inlet Nozzle rho-V^2" Unity(i).Shell.PressureDrop.RVsquare_in = Unity(i).Properties.Hot.Inlet.rho*(Unity(i).Shell.PressureDrop.Vnozzle_in)^2; "Shell Side Outlet Nozzle rho-V^2" Unity(i).Shell.PressureDrop.RVsquare_out = Unity(i).Properties.Hot.Outlet.rho*(Unity(i).Shell.PressureDrop.Vnozzle_out)^2; else "Shell Side inlet Nozzle rho-V^2" Unity(i).Shell.PressureDrop.RVsquare_in = Unity(i).Properties.Cold.Inlet.rho*(Unity(i).Shell.PressureDrop.Vnozzle_in)^2; "Shell Side Outlet Nozzle rho-V^2" Unity(i).Shell.PressureDrop.RVsquare_out = Unity(i).Properties.Cold.Outlet.rho*(Unity(i).Shell.PressureDrop.Vnozzle_out)^2; end if side equal 1 then "Hot Wall Temperature" Unity(i).Properties.Hot.Wall.Twall = (Unity(i).Properties.Hot.Average.T+Unity(i).Properties.Cold.Average.T)/2; "ColdWall Temperature" Unity(i).Properties.Cold.Wall.Twall = (Unity(i).Properties.Hot.Average.T+Unity(i).Properties.Cold.Average.T)/2; "Tube Side Velocity" Unity(i).Tubes.HeatTransfer.Vtube = Unity(i).Properties.Cold.Inlet.Fw*Tpass/((Pi*Ditube*Ditube/4)*Unity(i).Properties.Cold.Average.rho*Ntt); "Tube Side Reynolds Number" Unity(i).Tubes.HeatTransfer.Re = (Unity(i).Properties.Cold.Average.rho*Unity(i).Tubes.HeatTransfer.Vtube*Ditube)/Unity(i).Properties.Cold.Average.Mu; "Tube Side Prandtl Number" Unity(i).Tubes.HeatTransfer.PR = ((Unity(i).Properties.Cold.Average.Cp/Unity(i).Properties.Cold.Average.Mw)*Unity(i).Properties.Cold.Average.Mu)/Unity(i).Properties.Cold.Average.K; "Tube Side Prandtl Number at Wall Temperature" Unity(i).Tubes.HeatTransfer.PRw = ((Unity(i).Properties.Cold.Wall.Cp/Unity(i).Properties.Cold.Average.Mw)*Unity(i).Properties.Cold.Wall.Mu)/Unity(i).Properties.Cold.Wall.K; "Tube Side Film Coefficient" Unity(i).Tubes.HeatTransfer.htube = HE.TubeFilmCoeff(Unity(i).Tubes.HeatTransfer.Re,Unity(i).Tubes.HeatTransfer.PR,Unity(i).Properties.Cold.Average.K)*Unity(i).Tubes.HeatTransfer.Phi; "Shell Side Prandtl Number" Unity(i).Shell.HeatTransfer.PR = ((Unity(i).Properties.Hot.Average.Cp/Unity(i).Properties.Hot.Average.Mw)*Unity(i).Properties.Hot.Average.Mu)/Unity(i).Properties.Hot.Average.K; "Shell Side Prandtl Number at Wall Temperature" Unity(i).Shell.HeatTransfer.PRw = ((Unity(i).Properties.Hot.Wall.Cp/Unity(i).Properties.Hot.Average.Mw)*Unity(i).Properties.Hot.Wall.Mu)/Unity(i).Properties.Hot.Wall.K; else "Hot Wall Temperature" Unity(i).Properties.Hot.Wall.Twall = (Unity(i).Properties.Hot.Average.T+Unity(i).Properties.Cold.Average.T)/2; "Cold Wall Temperature" Unity(i).Properties.Cold.Wall.Twall = (Unity(i).Properties.Hot.Average.T+Unity(i).Properties.Cold.Average.T)/2; "Tube Side Velocity" Unity(i).Tubes.HeatTransfer.Vtube = Unity(i).Properties.Hot.Inlet.Fw*Tpass/((Pi*Ditube*Ditube/4)*Unity(i).Properties.Hot.Average.rho*Ntt); "Tube Side Reynolds Number" Unity(i).Tubes.HeatTransfer.Re = (Unity(i).Properties.Hot.Average.rho*Unity(i).Tubes.HeatTransfer.Vtube*Ditube)/Unity(i).Properties.Hot.Average.Mu; "Tube Side Prandtl Number" Unity(i).Tubes.HeatTransfer.PR = ((Unity(i).Properties.Hot.Average.Cp/Unity(i).Properties.Hot.Average.Mw)*Unity(i).Properties.Hot.Average.Mu)/Unity(i).Properties.Hot.Average.K; "Tube Side Prandtl Number at Wall" Unity(i).Tubes.HeatTransfer.PRw = ((Unity(i).Properties.Hot.Wall.Cp/Unity(i).Properties.Hot.Average.Mw)*Unity(i).Properties.Hot.Wall.Mu)/Unity(i).Properties.Hot.Wall.K; "Tube Side Film Coefficient" Unity(i).Tubes.HeatTransfer.htube= HE.TubeFilmCoeff(Unity(i).Tubes.HeatTransfer.Re,Unity(i).Tubes.HeatTransfer.PR,Unity(i).Properties.Hot.Average.K)*Unity(i).Tubes.HeatTransfer.Phi; "Shell Side Prandtl Number" Unity(i).Shell.HeatTransfer.PR = ((Unity(i).Properties.Cold.Average.Cp/Unity(i).Properties.Cold.Average.Mw)*Unity(i).Properties.Cold.Average.Mu)/Unity(i).Properties.Cold.Average.K; "Shell Side Prandtl Number at Wall" Unity(i).Shell.HeatTransfer.PRw=((Unity(i).Properties.Cold.Wall.Cp/Unity(i).Properties.Cold.Average.Mw)*Unity(i).Properties.Cold.Wall.Mu)/Unity(i).Properties.Cold.Wall.K; end "Tube Resistance" Unity(i).Resistances.Rtube*(Unity(i).Tubes.HeatTransfer.htube*Ditube) = Dotube; "Wall Resistance" Unity(i).Resistances.Rwall=Dotube*ln(Dotube/Ditube)/(2*Kwall); "Shell Resistance" Unity(i).Resistances.Rshell*(Unity(i).Shell.HeatTransfer.hshell)=1; "Overall Heat Transfer Coefficient Clean" Unity(i).Details.Uc*(Dotube/(Unity(i).Tubes.HeatTransfer.htube*Ditube)+(Dotube*ln(Dotube/Ditube)/(2*Kwall))+(1/(Unity(i).Shell.HeatTransfer.hshell)))=1; "Overall Heat Transfer Coefficient Dirty" (1/Unity(i).Details.Ud)=(1/Unity(i).Details.Uc)+Unity(i).Resistances.Rfo+Unity(i).Resistances.Rfi*(Dotube/Ditube); "Exchange Surface Area" Unity(i).Details.A=Pi*Dotube*Ntt*Ltube; "Baffles Spacing" Ltube = Unity(i).Baffles.Lsi+Unity(i).Baffles.Lso+Unity(i).Baffles.Ls*(Nb-1); "LMTD Correction Factor" Fc(i) = HE.EshellCorrectionFactor(Unity(i).Inlet.Hot.T,Unity(i).Outlet.Hot.T,Unity(i).Inlet.Cold.T,Unity(i).Outlet.Cold.T); "Counter Flow LMTD" LMTD(i) = HE.CounterLMTD(Unity(i).Inlet.Hot.T,Unity(i).Outlet.Hot.T,Unity(i).Inlet.Cold.T,Unity(i).Outlet.Cold.T); "Js Factor" Unity(i).Shell.HeatTransfer.Js = HE.JsFactor(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Lsi,Unity(i).Baffles.Lso,Unity(i).Baffles.Ls); if side equal 1 then "Shell Side Reynolds Number" Unity(i).Shell.HeatTransfer.Re=(Dotube*Unity(i).Properties.Hot.Inlet.Fw/Unity(i).Shell.HeatTransfer.Sm)/Unity(i).Properties.Hot.Average.Mu; "Shell Heat Transfer Coefficient" Unity(i).Shell.HeatTransfer.hshell=Unity(i).Shell.HeatTransfer.Ji*(Unity(i).Properties.Hot.Average.Cp/Unity(i).Properties.Hot.Average.Mw)*(Unity(i).Properties.Hot.Inlet.Fw/Unity(i).Shell.HeatTransfer.Sm)*(Unity(i).Shell.HeatTransfer.PR^(-2/3))*Unity(i).Shell.HeatTransfer.Jtotal*Unity(i).Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Unity(i).Shell.PressureDrop.PdCross = HE.DeltaPcross(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Ls,Unity(i).Baffles.Lso,Unity(i).Baffles.Lsi,Unity(i).Properties.Hot.Inlet.Fw,Unity(i).Shell.HeatTransfer.Phi,Unity(i).Properties.Hot.Average.rho); "Shell Pressure Baffle Window" Unity(i).Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Unity(i).Properties.Hot.Inlet.Fw,Unity(i).Shell.HeatTransfer.Sm,Unity(i).Properties.Hot.Average.rho,Unity(i).Properties.Hot.Average.Mu,Unity(i).Baffles.Ls); "Shell Pressure End Zones" Unity(i).Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Ls,Unity(i).Baffles.Lso,Unity(i).Baffles.Lsi,Unity(i).Properties.Hot.Inlet.Fw,Unity(i).Shell.HeatTransfer.Phi,Unity(i).Properties.Hot.Average.rho); else "Shell Side Reynolds Number" Unity(i).Shell.HeatTransfer.Re=(Dotube*Unity(i).Properties.Cold.Inlet.Fw/Unity(i).Shell.HeatTransfer.Sm)/Unity(i).Properties.Cold.Average.Mu; "Shell Heat Transfer Coefficient" Unity(i).Shell.HeatTransfer.hshell=Unity(i).Shell.HeatTransfer.Ji*(Unity(i).Properties.Cold.Average.Cp/Unity(i).Properties.Cold.Average.Mw)*(Unity(i).Properties.Cold.Inlet.Fw/Unity(i).Shell.HeatTransfer.Sm)*(Unity(i).Shell.HeatTransfer.PR^(-2/3))*Unity(i).Shell.HeatTransfer.Jtotal*Unity(i).Shell.HeatTransfer.Phi; "Shell Pressure Drop Cross Flow" Unity(i).Shell.PressureDrop.PdCross = HE.DeltaPcross(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Ls,Unity(i).Baffles.Lso,Unity(i).Baffles.Lsi,Unity(i).Properties.Cold.Inlet.Fw,Unity(i).Shell.HeatTransfer.Phi,Unity(i).Properties.Cold.Average.rho); "Shell Pressure Baffle Window" Unity(i).Shell.PressureDrop.Pdwindow = HE.DeltaPwindow(Unity(i).Properties.Cold.Inlet.Fw,Unity(i).Shell.HeatTransfer.Sm,Unity(i).Properties.Cold.Average.rho,Unity(i).Properties.Cold.Average.Mu,Unity(i).Baffles.Ls); "Shell Pressure End Zones" Unity(i).Shell.PressureDrop.PdEndZones = HE.DeltaPendZones(Unity(i).Shell.HeatTransfer.Re,Unity(i).Baffles.Ls,Unity(i).Baffles.Lso,Unity(i).Baffles.Lsi,Unity(i).Properties.Cold.Inlet.Fw,Unity(i).Shell.HeatTransfer.Phi,Unity(i).Properties.Cold.Average.rho); end "Exchange Surface Area" Unity(i).Details.Q = Unity(i).Details.Ud*Pi*Dotube*Ntt*Ltube*Fc(i)*LMTD(i); "Mean Temperature Difference" MTD(i) = Fc(i)*LMTD(i); end end