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/HEX_Engine.mso

    r995 r1005  
    107107       
    108108VARIABLES
    109 TubeFriction    as press_delta  (Brief="Tube Pressure Drop due to friction", Symbol = "\Delta P_{tube}", Default=0.01, Lower=1E-10,DisplayUnit='kPa');
     109TubeFriction    as press_delta  (Brief="Tube Pressure Drop due to friction", Symbol = "\Delta P_{tube}", Default=0.01, Lower=0,DisplayUnit='kPa');
    110110InletNozzle     as press_delta  (Brief="Inlet Nozzle Pressure Drop", Symbol = "\Delta P_{Nozzle\_In}", Default=0.01, Lower=0,DisplayUnit='kPa');
    111111OutletNozzle    as press_delta  (Brief="Outlet Nozzle Pressure Drop", Symbol = "\Delta P_{Nozzle\_Out}", Default=0.01, Lower=0,DisplayUnit='kPa');
    112 Total                           as press_delta  (Brief="Total Pressure Drop", Symbol = "\Delta P_{total}", Default=0.01, Lower=1E-10,DisplayUnit='kPa');
    113 Vnozzle_in              as velocity             (Brief="Inlet Nozzle Velocity", Symbol = "V_{Nozzle\_In}", Default=1, Upper=1e5, Lower=0);
    114 Vnozzle_out     as velocity             (Brief="Outlet Nozzle Velocity", Symbol = "V_{Nozzle\_Out}", Default=1, Upper=1E5, Lower=0);
     112Total                           as press_delta  (Brief="Total Pressure Drop", Symbol = "\Delta P_{total}", Default=0.01, Lower=0,DisplayUnit='kPa');
     113Vnozzle_in              as velocity             (Brief="Inlet Nozzle Velocity", Symbol = "V_{Nozzle\_In}", Default=1, Upper=1e7, Lower=0);
     114Vnozzle_out     as velocity             (Brief="Outlet Nozzle Velocity", Symbol = "V_{Nozzle\_Out}", Default=1, Upper=1E7, Lower=0);
    115115FricFactor              as fricfactor           (Brief="Friction Factor", Symbol = "f_i", Default=0.05, Lower=1e-10, Upper=2000);
    116116
     
    130130       
    131131VARIABLES
    132 Re              as positive                             (Brief="Tube Side Reynolds Number",Default=1000,Lower=1);
     132Re              as positive                             (Brief="Tube Side Reynolds Number",Default=1000,Lower=1e-3);
    133133Nu              as positive                             (Brief="Nusselt Number",Default=0.5,Lower=1e-8);
    134134htube   as heat_trans_coeff (Brief="Tube Side Film Coefficient",Default=1,Lower=1e-12, Upper=1e6);
     
    248248VARIABLES
    249249
    250 DT0             as temp_delta   (Brief="Temperature Difference at Inlet",Lower=1e-6, Symbol ="\Delta T_0",Protected=true);
    251 DTL             as temp_delta   (Brief="Temperature Difference at Outlet",Lower=1e-6, Symbol ="\Delta T_L",Protected=true);
    252 LMTD    as temp_delta   (Brief="Logarithmic Mean Temperature Difference",Lower=1e-6,Protected=true);
     250DT0             as temp_delta   (Brief="Temperature Difference at Inlet",Lower=0, Symbol ="\Delta T_0",Protected=true);
     251DTL             as temp_delta   (Brief="Temperature Difference at Outlet",Lower=0, Symbol ="\Delta T_L",Protected=true);
     252LMTD    as temp_delta   (Brief="Logarithmic Mean Temperature Difference",Lower=0,Protected=true);
    253253Fc                      as positive             (Brief="LMTD Correction Factor",Lower=0.1,Protected=true);
    254254
     
    286286VARIABLES
    287287A               as area                                 (Brief="Exchange Surface Area");
    288 Q               as power                                (Brief="Heat Transfer", Default=7000, Lower=1e-6, Upper=1e10);
     288Q               as power                                (Brief="Heat Transfer", Default=7000, Lower=-1e10, Upper=1e10);
    289289Uc      as heat_trans_coeff (Brief="Overall Heat Transfer Coefficient Clean",Default=1,Lower=1e-6,Upper=1e10);
    290290Ud      as heat_trans_coeff (Brief="Overall Heat Transfer Coefficient Dirty",Default=1,Lower=1e-6,Upper=1e10);
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