Ignore:
Timestamp:
Jun 12, 2017, 10:29:43 AM (5 years ago)
Author:
Argimiro Resende Secchi
Message:

Fixed convergence problem in detailed heat exchanger.

File:
1 edited

Legend:

Unmodified
Added
Removed
  • trunk/eml/heat_exchangers/HeatExchangerDetailed.mso

    r737 r1005  
    107107#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++#
    108108Pi                                                      as constant   (Brief="Pi Number", Hidden = true, Default=3.14159265, Symbol = "\pi");
     109pi                                                      as constant   (Brief="Pi Number", Unit = 'rad', Default=3.14159265, Symbol = "\pi");
    109110Aonozzle_Shell          as area                 (Brief="Shell Outlet Nozzle Area", Hidden = true, Lower=1E-6 ,  Symbol ="A_{nozzle\_out }^{shell}");
    110111Ainozzle_Shell          as area                 (Brief="Shell Inlet Nozzle Area", Hidden = true, Lower=1E-6 ,  Symbol ="A_{nozzle\_in }^{shell}");
     
    130131#"Pi Number"
    131132        Pi      = 3.14159265;
     133        pi = Pi * 'rad';
    132134
    133135#"Baffle cut angle in degrees"
    134         Ods     = (360/Pi)*acos(1-0.02*Baffles.BaffleCut);
     136        Ods     = (360/pi)*acos(1-0.02*Baffles.BaffleCut);
    135137
    136138#"Baffle cut angle relative to the centerline"
    137         Octl    = (360/Pi)*acos((Shell.ShellID/(Shell.ShellID - Clearances.BundleToShell - Tubes.TubeOD))*(1-0.02*Baffles.BaffleCut));
     139        Octl    = (360/pi)*acos((Shell.ShellID/(Shell.ShellID - Clearances.BundleToShell - Tubes.TubeOD))*(1-0.02*Baffles.BaffleCut));
    138140
    139141#"Fraction of number of tubes in baffle window"
    140         Ftw     = (Octl/360)-sin(Octl*Pi/180)/(2*Pi);
     142        Ftw     = (Octl/360)-sin(Octl*pi/180)/(2*Pi);
    141143
    142144#"Shell to baffle leakage area"
     
    150152
    151153#"comments"
    152         Dw      = (4*abs((Pi*Shell.ShellID*Shell.ShellID*((Ods/360)-sin(Ods*Pi/180)/(2*Pi))/4)-(Tubes.NumberOfTubes*Pi*Tubes.TubeOD*Tubes.TubeOD*Ftw/4)))/(Pi*Tubes.TubeOD*Tubes.NumberOfTubes*Ftw+ Pi*Shell.ShellID*Ods/360);
     154        Dw      = (4*abs((Pi*Shell.ShellID*Shell.ShellID*((Ods/360)-sin(Ods*pi/180)/(2*Pi))/4)-(Tubes.NumberOfTubes*Pi*Tubes.TubeOD*Tubes.TubeOD*Ftw/4)))/(Pi*Tubes.TubeOD*Tubes.NumberOfTubes*Ftw+ Pi*Shell.ShellID*Ods/360);
    153155
    154156#"Tube Side Inlet Nozzle Area"
     
    180182"Shell Stream Average Temperature"
    181183        Shell.Properties.Average.T = 0.5*InletShell.T + 0.5*OutletShell.T;
     184#       Shell.Properties.Average.T = InletShell.T;
    182185       
    183186"Tube Stream Average Temperature"
    184187        Tubes.Properties.Average.T = 0.5*InletTube.T + 0.5*OutletTube.T;
     188#       Tubes.Properties.Average.T = InletTube.T;
    185189       
    186190"Shell Stream Average Pressure"
    187         Shell.Properties.Average.P = 0.5*InletShell.P+0.5*OutletShell.P;
     191#       Shell.Properties.Average.P = 0.5*InletShell.P+0.5*OutletShell.P;
     192        Shell.Properties.Average.P = InletShell.P;
    188193       
    189194"Tube Stream Average Pressure"
    190         Tubes.Properties.Average.P = 0.5*InletTube.P+0.5*OutletTube.P;
     195#       Tubes.Properties.Average.P = 0.5*InletTube.P+0.5*OutletTube.P;
     196        Tubes.Properties.Average.P = InletTube.P;
    191197       
    192198"Shell Stream Average Molecular Weight"
     
    355361
    356362"Mass Velocity in Window Zone"
    357         mw      = Shell.Properties.Inlet.Fw/sqrt(abs(Sm*abs((Pi*Shell.ShellID*Shell.ShellID*((Ods/360)-sin(Ods*Pi/180)/(2*Pi))/4)-(Tubes.NumberOfTubes*Pi*Tubes.TubeOD*Tubes.TubeOD*Ftw/4))));
     363        mw      = Shell.Properties.Inlet.Fw/sqrt(abs(Sm*abs((Pi*Shell.ShellID*Shell.ShellID*((Ods/360)-sin(Ods*pi/180)/(2*Pi))/4)-(Tubes.NumberOfTubes*Pi*Tubes.TubeOD*Tubes.TubeOD*Ftw/4))));
    358364
    359365switch TubeFlowRegime
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