Ignore:
Timestamp:
Mar 8, 2007, 11:31:57 AM (16 years ago)
Author:
gerson bicca
Message:

modified and fixed comments in heat exchangers equations

File:
1 edited

Legend:

Unmodified
Added
Removed

  • branches/newlanguage/eml/heat_exchangers/DoublePipe.mso

    r176 r197  
    6969SET
    7070
     71#"Component Molecular Weight"
    7172        M  = PP.MolecularWeight();
    7273       
     74#"Pi Number"
    7375        Pi      = 3.14159265;
    7476       
    … …  
    9395EQUATIONS
    9496
    95 "OuterStream Average Temperature"
     97"Outer  Stream Average Temperature"
    9698        Outer.Properties.Average.T = 0.5*InletOuter.T + 0.5*OutletOuter.T;
    9799
    … …  
    121123        then   
    122124
    123 "Heat Capacity Inner Stream"
     125"Average Heat Capacity Inner Stream"
    124126        Inner.Properties.Average.Cp             =       PP.LiquidCp(Inner.Properties.Average.T,Inner.Properties.Average.P,InletInner.z);
    125         Inner.Properties.Inlet.Cp               =       PP.LiquidCp(InletInner.T,InletInner.P,InletInner.z);
     127
     128"Inlet Heat Capacity Inner Stream"
     129        Inner.Properties.Inlet.Cp                       =       PP.LiquidCp(InletInner.T,InletInner.P,InletInner.z);
     130
     131"Outlet Heat Capacity Inner Stream"
    126132        Inner.Properties.Outlet.Cp              =       PP.LiquidCp(OutletInner.T,OutletInner.P,OutletInner.z);
    127133
    128 "Mass Density Inner Stream"
     134"Average Mass Density Inner Stream"
    129135        Inner.Properties.Average.rho    =       PP.LiquidDensity(Inner.Properties.Average.T,Inner.Properties.Average.P,InletInner.z);
     136
     137"Inlet Mass Density Inner Stream"
    130138        Inner.Properties.Inlet.rho              =       PP.LiquidDensity(InletInner.T,InletInner.P,InletInner.z);
    131         Inner.Properties.Outlet.rho             =       PP.LiquidDensity(OutletInner.T,OutletInner.P,OutletInner.z);
    132 
    133 "Viscosity Inner Stream"
     139
     140"Outlet Mass Density Inner Stream"
     141        Inner.Properties.Outlet.rho     =       PP.LiquidDensity(OutletInner.T,OutletInner.P,OutletInner.z);
     142
     143"Average Viscosity Inner Stream"
    134144        Inner.Properties.Average.Mu     =       PP.LiquidViscosity(Inner.Properties.Average.T,Inner.Properties.Average.P,InletInner.z);
     145
     146"Inlet  Viscosity Inner Stream"
    135147        Inner.Properties.Inlet.Mu               =       PP.LiquidViscosity(InletInner.T,InletInner.P,InletInner.z);
    136         Inner.Properties.Outlet.Mu              =       PP.LiquidViscosity(OutletInner.T,OutletInner.P,OutletInner.z);
    137 
    138 "Conductivity Inner Stream"
     148
     149"Outlet Viscosity Inner Stream"
     150        Inner.Properties.Outlet.Mu      =       PP.LiquidViscosity(OutletInner.T,OutletInner.P,OutletInner.z);
     151
     152"Average        Conductivity Inner Stream"
    139153        Inner.Properties.Average.K              =       PP.LiquidThermalConductivity(Inner.Properties.Average.T,Inner.Properties.Average.P,InletInner.z);
     154
     155"Inlet  Conductivity Inner Stream"
    140156        Inner.Properties.Inlet.K                =       PP.LiquidThermalConductivity(InletInner.T,InletInner.P,InletInner.z);
     157
     158"Outlet Conductivity Inner Stream"
    141159        Inner.Properties.Outlet.K               =       PP.LiquidThermalConductivity(OutletInner.T,OutletInner.P,OutletInner.z);
    142160
    143 "Viscosity Cold Stream"
     161"Viscosity Inner Stream at wall temperature"
    144162        Inner.Properties.Wall.Mu                =       PP.LiquidViscosity(Inner.Properties.Wall.Twall,Inner.Properties.Average.P,InletInner.z);
    145163
    146 
    147164        else
    148165
    149 "Heat Capacity Cold Stream"
     166"Average Heat Capacity InnerStream"
    150167        Inner.Properties.Average.Cp     =       PP.VapourCp(Inner.Properties.Average.T,Inner.Properties.Average.P,InletInner.z);
    151         Inner.Properties.Inlet.Cp       =       PP.VapourCp(InletInner.T,InletInner.P,InletInner.z);
     168
     169"Inlet Heat Capacity Inner Stream"
     170        Inner.Properties.Inlet.Cp               =       PP.VapourCp(InletInner.T,InletInner.P,InletInner.z);
     171
     172"Outlet Heat Capacity Inner Stream"
    152173        Inner.Properties.Outlet.Cp      =       PP.VapourCp(OutletInner.T,OutletInner.P,OutletInner.z);
    153174
    154 "Mass Density Cold Stream"
     175"Average Mass Density Inner Stream"
    155176        Inner.Properties.Average.rho    =       PP.VapourDensity(Inner.Properties.Average.T,Inner.Properties.Average.P,InletInner.z);
     177
     178"Inlet Mass Density Inner Stream"
    156179        Inner.Properties.Inlet.rho              =       PP.VapourDensity(InletInner.T,InletInner.P,InletInner.z);
    157         Inner.Properties.Outlet.rho             =       PP.VapourDensity(OutletInner.T,OutletInner.P,OutletInner.z);
    158 
    159 "Viscosity Cold Stream"
    160         Inner.Properties.Average.Mu             =       PP.VapourViscosity(Inner.Properties.Average.T,Inner.Properties.Average.P,InletInner.z);
     180       
     181"Outlet Mass Density Inner Stream"
     182        Inner.Properties.Outlet.rho     =       PP.VapourDensity(OutletInner.T,OutletInner.P,OutletInner.z);
     183
     184"Average Viscosity Inner Stream"
     185        Inner.Properties.Average.Mu     =       PP.VapourViscosity(Inner.Properties.Average.T,Inner.Properties.Average.P,InletInner.z);
     186
     187"Inlet Viscosity Inner Stream"
    161188        Inner.Properties.Inlet.Mu               =       PP.VapourViscosity(InletInner.T,InletInner.P,InletInner.z);
    162         Inner.Properties.Outlet.Mu              =       PP.VapourViscosity(OutletInner.T,OutletInner.P,OutletInner.z);
    163 
    164 "Conductivity Cold Stream"
     189
     190"Outlet Viscosity Inner Stream"
     191        Inner.Properties.Outlet.Mu      =       PP.VapourViscosity(OutletInner.T,OutletInner.P,OutletInner.z);
     192
     193"Average Conductivity Inner Stream"
    165194        Inner.Properties.Average.K              =       PP.VapourThermalConductivity(Inner.Properties.Average.T,Inner.Properties.Average.P,InletInner.z);
     195
     196"Inlet Conductivity Inner Stream"
    166197        Inner.Properties.Inlet.K                =       PP.VapourThermalConductivity(InletInner.T,InletInner.P,InletInner.z);
     198
     199"Outlet Conductivity Inner Stream"
    167200        Inner.Properties.Outlet.K               =       PP.VapourThermalConductivity(OutletInner.T,OutletInner.P,OutletInner.z);
    168201       
    169 "Viscosity Cold Stream"
     202"Viscosity Inner Stream at wall temperature"
    170203        Inner.Properties.Wall.Mu                =       PP.VapourViscosity(Inner.Properties.Wall.Twall,Inner.Properties.Average.P,InletInner.z);
    171204
    … …  
    176209        then
    177210
    178 "Heat Capacity Hot Stream"
     211"Average Heat Capacity Outer Stream"
    179212        Outer.Properties.Average.Cp     =               PP.LiquidCp(Outer.Properties.Average.T,Outer.Properties.Average.P,InletOuter.z);
    180         Outer.Properties.Inlet.Cp       =               PP.LiquidCp(InletOuter.T,InletOuter.P,InletOuter.z);
     213
     214"Inlet Heat Capacity Outer Stream"
     215        Outer.Properties.Inlet.Cp               =               PP.LiquidCp(InletOuter.T,InletOuter.P,InletOuter.z);
     216
     217"Outlet Heat Capacity Outer Stream"
    181218        Outer.Properties.Outlet.Cp      =               PP.LiquidCp(OutletOuter.T,OutletOuter.P,OutletOuter.z);
    182219
    183 "Mass Density Hot Stream"
    184         Outer.Properties.Average.rho    =               PP.LiquidDensity(Outer.Properties.Average.T,Outer.Properties.Average.P,InletOuter.z);
    185         Outer.Properties.Inlet.rho      =               PP.LiquidDensity(InletOuter.T,InletOuter.P,InletOuter.z);
     220"Average Mass Density Outer Stream"
     221        Outer.Properties.Average.rho =          PP.LiquidDensity(Outer.Properties.Average.T,Outer.Properties.Average.P,InletOuter.z);
     222
     223"Inlet Mass Density Outer Stream"
     224        Outer.Properties.Inlet.rho              =               PP.LiquidDensity(InletOuter.T,InletOuter.P,InletOuter.z);
     225
     226"Outlet Mass Density Outer Stream"
    186227        Outer.Properties.Outlet.rho     =               PP.LiquidDensity(OutletOuter.T,OutletOuter.P,OutletOuter.z);
    187228
    188 "Viscosity Hot Stream"
     229"Average Viscosity Outer Stream"
    189230        Outer.Properties.Average.Mu     =               PP.LiquidViscosity(Outer.Properties.Average.T,Outer.Properties.Average.P,InletOuter.z);
     231
     232"Inlet Viscosity Outer Stream"
    190233        Outer.Properties.Inlet.Mu       =               PP.LiquidViscosity(InletOuter.T,InletOuter.P,InletOuter.z);     
     234
     235"Outlet Viscosity Outer Stream"
    191236        Outer.Properties.Outlet.Mu      =               PP.LiquidViscosity(OutletOuter.T,OutletOuter.P,OutletOuter.z); 
    192237
    193 "Conductivity Hot Stream"
     238"Average Conductivity Outer Stream"
    194239        Outer.Properties.Average.K      =               PP.LiquidThermalConductivity(Outer.Properties.Average.T,Outer.Properties.Average.P,InletOuter.z);       
     240
     241"Inlet Conductivity Outer Stream"
    195242        Outer.Properties.Inlet.K                =               PP.LiquidThermalConductivity(InletOuter.T,InletOuter.P,InletOuter.z);   
     243
     244"Outlet Conductivity Outer Stream"
    196245        Outer.Properties.Outlet.K       =               PP.LiquidThermalConductivity(OutletOuter.T,OutletOuter.P,OutletOuter.z);       
    197246
    198 "Viscosity Hot Stream"
     247"Viscosity Outer Stream at wall temperature"
    199248        Outer.Properties.Wall.Mu                =               PP.LiquidViscosity(Outer.Properties.Wall.Twall,Outer.Properties.Average.P,InletOuter.z);       
    200249
    … …  
    202251        else
    203252
    204 "Heat Capacity Hot Stream"
     253"Average Heat Capacity Outer Stream"
    205254        Outer.Properties.Average.Cp     =               PP.VapourCp(Outer.Properties.Average.T,Outer.Properties.Average.P,InletOuter.z);
    206         Outer.Properties.Inlet.Cp       =               PP.VapourCp(InletOuter.T,InletOuter.P,InletOuter.z);
     255
     256"Inlet Heat Capacity Outer Stream"
     257        Outer.Properties.Inlet.Cp               =               PP.VapourCp(InletOuter.T,InletOuter.P,InletOuter.z);
     258
     259"Outlet Heat Capacity Outer Stream"
    207260        Outer.Properties.Outlet.Cp      =               PP.VapourCp(OutletOuter.T,OutletOuter.P,OutletOuter.z);
    208261
    209 "Mass Density Hot Stream"
    210         Outer.Properties.Average.rho    =               PP.VapourDensity(Outer.Properties.Average.T,Outer.Properties.Average.P,InletOuter.z);
    211         Outer.Properties.Inlet.rho      =               PP.VapourDensity(InletOuter.T,InletOuter.P,InletOuter.z);
     262"Average Mass Density Outer Stream"
     263        Outer.Properties.Average.rho =          PP.VapourDensity(Outer.Properties.Average.T,Outer.Properties.Average.P,InletOuter.z);
     264
     265"Inlet Mass Density Outer Stream"
     266        Outer.Properties.Inlet.rho              =               PP.VapourDensity(InletOuter.T,InletOuter.P,InletOuter.z);
     267       
     268"Outlet Mass Density Outer Stream"
    212269        Outer.Properties.Outlet.rho     =               PP.VapourDensity(OutletOuter.T,OutletOuter.P,OutletOuter.z);
    213270
    214 "Viscosity Hot Stream"
     271"Average Viscosity Outer Stream"
    215272        Outer.Properties.Average.Mu     =               PP.VapourViscosity(Outer.Properties.Average.T,Outer.Properties.Average.P,InletOuter.z);
     273
     274"Inlet Viscosity Outer Stream"
    216275        Outer.Properties.Inlet.Mu       =               PP.VapourViscosity(InletOuter.T,InletOuter.P,InletOuter.z);
     276
     277"Outlet Viscosity Outer Stream"
    217278        Outer.Properties.Outlet.Mu      =               PP.VapourViscosity(OutletOuter.T,OutletOuter.P,OutletOuter.z);
    218279
    219 "Conductivity Hot Stream"
     280"Average Conductivity Outer Stream"
    220281        Outer.Properties.Average.K      =               PP.VapourThermalConductivity(Outer.Properties.Average.T,Outer.Properties.Average.P,InletOuter.z);       
     282
     283"Inlet Conductivity Outer Stream"
    221284        Outer.Properties.Inlet.K                =               PP.VapourThermalConductivity(InletOuter.T,InletOuter.P,InletOuter.z);   
     285
     286"Outlet Conductivity Outer Stream"
    222287        Outer.Properties.Outlet.K       =               PP.VapourThermalConductivity(OutletOuter.T,OutletOuter.P,OutletOuter.z);       
    223288
    224 "Viscosity Hot Stream"
     289"Viscosity Outer Stream at wall temperature"
    225290        Outer.Properties.Wall.Mu                =               PP.VapourViscosity(Outer.Properties.Wall.Twall,Outer.Properties.Average.P,InletOuter.z);
    226291
    … …  
    251316end
    252317
    253 "Flow Mass Inlet Cold Stream"
     318"Flow Mass Inlet Inner Stream"
    254319        Inner.Properties.Inlet.Fw       =  sum(M*InletInner.z)*InletInner.F;
    255320
    256 "Flow Mass Outlet Cold Stream"
     321"Flow Mass Outlet Inner Stream"
    257322        Inner.Properties.Outlet.Fw      =  sum(M*OutletInner.z)*OutletInner.F;
    258323
    259 "Flow Mass Inlet Hot Stream"
     324"Flow Mass Inlet Outer Stream"
    260325        Outer.Properties.Inlet.Fw               =  sum(M*InletOuter.z)*InletOuter.F;
    261326
    262 "Flow Mass Outlet Hot Stream"   
     327"Flow Mass Outlet Outer Stream"
    263328        Outer.Properties.Outlet.Fw      =  sum(M*OutletOuter.z)*OutletOuter.F;
    264329
    265 "Molar Balance Hot Stream"
     330"Molar Balance Outer Stream"
    266331        OutletOuter.F = InletOuter.F;
    267332       
    268 "Molar Balance Cold Stream"
     333"Molar Balance Inner Stream"
    269334        OutletInner.F = InletInner.F;
    270335
    271 "Hot Stream Molar Fraction Constraint"
     336"Outer Stream Molar Fraction Constraint"
    272337        OutletOuter.z=InletOuter.z;
    273338       
    274 "Cold Stream Molar Fraction Constraint"
     339"InnerStream Molar Fraction Constraint"
    275340        OutletInner.z=InletInner.z;
    276341
    … …  
    340405       
    341406        case "Hausen":
     407
     408"Nusselt Number"
    342409        Inner.HeatTransfer.Nu = 3.665 + ((0.19*((DiInner/Lpipe)*Inner.HeatTransfer.Re*Inner.HeatTransfer.PR)^0.8)/(1+0.117*((DiInner/Lpipe)*Inner.HeatTransfer.Re*Inner.HeatTransfer.PR)^0.467));
    343410       
    344411        case "Schlunder":
     412
     413"Nusselt Number"
    345414        Inner.HeatTransfer.Nu = (49.027896+4.173281*Inner.HeatTransfer.Re*Inner.HeatTransfer.PR*(DiInner/Lpipe))^(1/3);
    346415
    … …  
    351420        case "transition":
    352421       
     422"Inner Side Friction Factor for Heat Transfer - transition Flow"
    353423        Inner.HeatTransfer.fi   = 1/(0.79*ln(Inner.HeatTransfer.Re)-1.64)^2;
    354424       
    … …  
    356426       
    357427        case "Gnielinski":
     428       
     429"Nusselt Number"
    358430        Inner.HeatTransfer.Nu*(1+(12.7*sqrt(0.125*Inner.HeatTransfer.fi)*((Inner.HeatTransfer.PR)^(2/3) -1))) = 0.125*Inner.HeatTransfer.fi*(Inner.HeatTransfer.Re-1000)*Inner.HeatTransfer.PR;
    359431
    360432        case "ESDU":
     433
     434"Nusselt Number"
    361435        Inner.HeatTransfer.Nu =1;#to be implemented
    362436       
    … …  
    371445       
    372446        case "Petukhov":
     447       
     448"Inner Side Friction Factor for Heat Transfer - turbulent Flow"
    373449        Inner.HeatTransfer.fi   = 1/(1.82*log(Inner.HeatTransfer.Re)-1.64)^2;
     450
     451"Nusselt Number"
    374452        Inner.HeatTransfer.Nu*(1.07+(12.7*sqrt(0.125*Inner.HeatTransfer.fi)*((Inner.HeatTransfer.PR)^(2/3) -1))) = 0.125*Inner.HeatTransfer.fi*Inner.HeatTransfer.Re*Inner.HeatTransfer.PR;
    375453       
    376454        case "SiederTate":
     455
     456"Nusselt Number"
    377457        Inner.HeatTransfer.Nu = 0.027*(Inner.HeatTransfer.PR)^(1/3)*(Inner.HeatTransfer.Re)^(4/5);
     458
     459"Inner Side Friction Factor for Heat Transfer - turbulent Flow"
    378460        Inner.HeatTransfer.fi   = 1/(1.82*log(Inner.HeatTransfer.Re)-1.64)^2;
    379461       
    … …  
    388470        case "laminar":
    389471       
     472"Outer Side Friction Factor for Heat Transfer - laminar Flow"
    390473        Outer.HeatTransfer.fi   = 1/(0.79*ln(Outer.HeatTransfer.Re)-1.64)^2;
     474       
    391475switch OuterLaminarCorrelation
    392476       
    393477        case "Hausen":
     478
     479"Nusselt Number"
    394480        Outer.HeatTransfer.Nu = 3.665 + ((0.19*((Outer.HeatTransfer.Dh/Lpipe)*Outer.HeatTransfer.Re*Outer.HeatTransfer.PR)^0.8)/(1+0.117*((Outer.HeatTransfer.Dh/Lpipe)*Outer.HeatTransfer.Re*Outer.HeatTransfer.PR)^0.467));
    395481       
    396482        case "Schlunder":
     483
     484"Nusselt Number"
    397485        Outer.HeatTransfer.Nu = (49.027896+4.173281*Outer.HeatTransfer.Re*Outer.HeatTransfer.PR*(Outer.HeatTransfer.Dh/Lpipe))^(1/3);
    398486
    … …  
    406494       
    407495        case "Gnielinski":
     496
     497"Outer Side Friction Factor for Heat Transfer - transition Flow"
    408498        Outer.HeatTransfer.fi   = 1/(0.79*ln(Outer.HeatTransfer.Re)-1.64)^2;
     499
     500"Nusselt Number"
    409501        Outer.HeatTransfer.Nu*(1+(12.7*sqrt(0.125*Outer.HeatTransfer.fi)*((Outer.HeatTransfer.PR)^(2/3) -1))) = 0.125*Outer.HeatTransfer.fi*(Outer.HeatTransfer.Re-1000)*Outer.HeatTransfer.PR;
    410502
    411503        case "ESDU":
     504
     505"Nusselt Number"
    412506        Outer.HeatTransfer.Nu =1;#to be implemented
     507
     508"Outer Side Friction Factor for Heat Transfer - transition Flow"
    413509        Outer.HeatTransfer.fi   = 1/(0.79*ln(Outer.HeatTransfer.Re)-1.64)^2;
    414510       
    … …  
    423519       
    424520        case "Petukhov":
     521
     522"Outer Side Friction Factor for Heat Transfer - turbulent Flow"
    425523        Outer.HeatTransfer.fi   = 1/(1.82*log(Outer.HeatTransfer.Re)-1.64)^2;
     524       
     525"Nusselt Number"
    426526        Outer.HeatTransfer.Nu*(1.07+(12.7*sqrt(0.125*Outer.HeatTransfer.fi)*((Outer.HeatTransfer.PR)^(2/3) -1))) = 0.125*Outer.HeatTransfer.fi*Outer.HeatTransfer.Re*Outer.HeatTransfer.PR;
    427527       
    428528        case "SiederTate":
     529
     530"Nusselt Number"
    429531        Outer.HeatTransfer.Nu = 0.027*(Outer.HeatTransfer.PR)^(1/3)*(Outer.HeatTransfer.Re)^(4/5);
     532
     533"Outer Side Friction Factor for Heat Transfer - turbulent Flow"
    430534        Outer.HeatTransfer.fi   = 1/(1.82*log(Outer.HeatTransfer.Re)-1.64)^2;
    431535       
    … …  
    442546        Outer.HeatTransfer.hcoeff= (Outer.HeatTransfer.Nu*Outer.Properties.Average.K/Outer.HeatTransfer.Dh)*Outer.HeatTransfer.Phi;
    443547
    444 "Pressure Drop Hot Stream"
     548"Pressure Drop Outer Stream"
    445549        OutletOuter.P  = InletOuter.P - Outer.PressureDrop.Pdrop;
    446550
    447 "Pressure Drop Cold Stream"
     551"Pressure Drop Inner Stream"
    448552        OutletInner.P  = InletInner.P - Inner.PressureDrop.Pdrop;
    449553       
    450 "Outer Pipe Pressure Drop"
     554"Outer Pipe Pressure Drop for friction"
    451555        Outer.PressureDrop.Pdrop = (2*Outer.PressureDrop.fi*Lpipe*Outer.Properties.Average.rho*Outer.HeatTransfer.Vmean^2)/(Outer.PressureDrop.Dh*Outer.HeatTransfer.Phi);
    452556       
    453 "Inner Pipe Pressure Drop"
     557"Inner Pipe Pressure Drop for friction"
    454558        Inner.PressureDrop.Pdrop = (2*Inner.PressureDrop.fi*Lpipe*Inner.Properties.Average.rho*Inner.HeatTransfer.Vmean^2)/(DiInner*Inner.HeatTransfer.Phi);
    455559
    … …  
    507611VARIABLES
    508612
    509 Method as NTU_Basic;
     613Method as NTU_Basic     (Brief="NTU Method of Calculation");
    510614
    511615EQUATIONS
    … …  
    546650       
    547651        then
     652       
    548653"Effectiveness in Counter Flow"
    549654        Method.Eft = Method.NTU/(1+Method.NTU);
    550655       
    551656        else
     657       
    552658"Effectiveness in Counter Flow"
    553659        Method.Eft = (1-exp(-Method.NTU*(1-Method.Cr)))/(1-Method.Cr*exp(-Method.NTU*(1-Method.Cr)));
    … …  
    606712VARIABLES
    607713
    608 Method as LMTD_Basic;
     714Method as LMTD_Basic    (Brief="LMTD Method of Calculation");
    609715
    610716EQUATIONS
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