Changeset 860

Timestamp:

Oct 9, 2009, 5:53:03 PM (13 years ago)

Author:

gerson bicca

Message:

updates

File:

• trunk/eml/pressure_changers/pump.mso (modified) (1 diff)

trunk/eml/pressure_changers/pump.mso

@@ -21 +21 @@
 
 Model centrifugal_pump
-        ATTRIBUTES
+ATTRIBUTES
+
         Pallete         = true;
-        Icon            = "icon/CentrifugalPump"; 
+
+        Icon            = "icon/Pump"; 
+
         Brief           = "Model of a centrifugal pump.";
+
         Info            =
+
 "== Assumptions ==
+
 * Steady State;
+
 * Only Liquid;
+
 * Adiabatic;
+
 * Isentropic.
-        
-== Specify == 
-* the inlet stream;
-* the Pressure Increase Pdiff.
+
 ";
-        
-        PARAMETERS
-        outer PP        as Plugin                       (Brief = "External Physical Properties", Type="PP");
+
+        
+
+PARAMETERS
+
+        outer PP                        as Plugin                       (Brief = "External Physical Properties", Type="PP");
+
         outer NComp     as Integer                      (Brief = "Number of chemical components", Lower = 1);
-        Mw(NComp)       as molweight            (Brief = "Molar Weight");
-        Eff             as positive             (Default = 0.72, Brief = "Pump Efficiency");
-        Meff            as positive             (Default = 0.95, Brief = "Brake Efficiency");
-        Beta            as positive             (Default = 0, Brief = "Volumetric Expansivity", Unit = '1/K');
-        g                       as acceleration         (Brief = "Gravity Acceleration", Default = 9.81);
-        N                       as vel_angular          (Brief = "Rotation", Default = 100);
-        Lev                     as length                       (Brief = "Loss Friction", Default = 0);
-        
-        VARIABLES
-        rho               as dens_mass          (Brief = "Specific Mass");
-        Cp        as cp_mol                     (Brief = "Heat Capacity");
-        FPower    as power                      (Brief = "Fluid Power");
-        BPower    as power                      (Brief = "Brake Power");
-        EPower    as power                      (Brief = "Eletrical Potency");
-        Pratio    as positive           (Brief = "Pressure Ratio", Symbol ="P_{ratio}");        
-        Pdrop     as press_delta        (Brief = "Pressure Drop", DisplayUnit = 'kPa', Symbol ="\Delta P");
-        Head      as head                       (Brief = "Head Developed"); 
-        Head_is   as head                       (Brief = "Isoentripic Head"); 
-        Mwm       as molweight          (Brief = "Mixture Molar Weight");
-        pvm               as pressure           (Brief = "Mixture Vapour Pressure");                    
-        NPSHa     as length                     (Brief = "Available Net Positive Suction Head");
-        NS                as positive           (Brief = "Specific Speed");
-        Q                 as flow_vol           (Brief = "Volumetric Flow Rate");
-        vm                as vol_mol            (Brief = "Mixture Molar Volume");
-in      Inlet     as stream                     (Brief = "Inlet stream", PosX=1, PosY=0.4025, Symbol="_{in}");
-out     Outlet    as stream                     (Brief = "Outlet stream", PosX=0, PosY=0, Symbol="_{out}");
-
-        SET
-        Mw = PP.MolecularWeight();
-        
-        EQUATIONS
-        #Mixtures Properties
-        "Calculate Mwm for Inlet Mixture"
-        Mwm = sum(Mw([1:NComp])*Inlet.z([1:NComp]));
-
-        "Calculate Cp Using a External Physical Properties Routine"
-        Cp = PP.LiquidCp(Inlet.T,Inlet.P,Inlet.z);
-        
-        "Calculate rho using a External Physical Properties Routine"
-        rho = PP.LiquidDensity(Inlet.T,Inlet.P,Inlet.z);
-
-        "Calculate Mixture Vapour Pressure"
-        [pvm] = PP.BubbleP(Inlet.T,Inlet.z); 
-        
-        "Calculate Outlet Vapour Fraction"
-        Outlet.v = PP.VapourFraction(Outlet.T, Outlet.P, Outlet.z);
-        
-        "Calculate Liquid Molar Volume"
-        vm = PP.LiquidVolume(Inlet.T,Inlet.P,Inlet.z);
-        
-        "Pressure Ratio"
+
+        Mw(NComp)               as molweight    (Brief = "Molar Weight");
+
+        
+
+        PumpEfficiency          as positive             (Brief = "Pump Efficiency", Default = 0.75, Lower=1E-3);
+
+        MechanicalEff           as positive             (Brief = "Mechanical efficiency", Default = 0.95, Lower=1E-3);
+
+        NPSH_Options       as Switcher          (Brief = "NPSH Options", Valid = ["Default","Include Kinetic Head"], Default = "Default");
+
+        g                                                       as acceleration (Brief = "Gravity Acceleration", Default = 9.81,Hidden = true);
+
+        SuctionArea                     as area                         (Brief = "Inlet Nozzle Suction Area", Default = 0.001);
+
+        
+
+VARIABLES
+
+        Fvol                            as flow_vol             (Brief = "Volumetric Flow Rate" ,Protected=true);
+
+        Fw_in                   as flow_mass    (Brief = "Inlet Mass Flow Rate" ,Protected=true);
+
+        Fw_out                  as flow_mass    (Brief = "Outlet Mass Flow Rate", Protected=true);
+
+        rho_in                  as dens_mass    (Brief = "Mass Density at inlet conditions", Lower = 1E-6, Protected=true);
+
+        rho_out                 as dens_mass    (Brief = "Mass Density at outlet conditions", Lower = 1E-6, Protected=true);
+
+        Mwm                     as molweight    (Brief = "Mixture Molar Weight" ,Protected=true);
+
+        Pvapor                  as pressure             (Brief = "Mixture Vapour Pressure" ,Protected=true);    
+
+        
+
+        FluidPower        as power                      (Brief = "Fluid Power");
+
+        BrakePower       as power                       (Brief = "Brake Power");
+
+        EletricPower      as power                      (Brief = "Eletrical Potency");
+
+        
+
+        Pratio          as positive             (Brief = "Pressure Ratio", Symbol ="P_{ratio}");        
+
+        Pdrop           as press_delta  (Brief = "Pressure Drop", DisplayUnit = 'kPa', Symbol ="\Delta P");
+
+        Pincrease       as press_delta  (Brief = "Pressure Increase",Lower = 0,  DisplayUnit = 'kPa', Symbol ="P_{incr}");
+
+        
+
+        StaticHead                      as length                               (Brief = "Static Head");
+
+        Head                                    as energy_mass  (Brief = "Actual Head", Protected=true);
+
+        HeadIsentropic          as energy_mass  (Brief = "Isentropic Head", Protected=true);
+
+        NPSH_available          as length                               (Brief = "Available Net Positive Suction Head" ,Protected=true);
+
+
+
+        VelocityHead                    as length                       (Brief = "Velocity Head",Protected=true);
+
+        NozzleVelocity          as velocity                     (Brief = "Velocity Inlet Nozzle",Hidden=true);
+
+
+
+        
+
+in              Inlet           as stream                       (Brief = "Inlet stream", PosX=0, PosY=0.4025, Symbol="_{in}");
+
+out     Outlet  as streamPH             (Brief = "Outlet stream", PosX=1, PosY=0.20, Symbol="_{out}");
+
+
+
+in      WorkIn  as work_stream  (Brief = "Work Inlet", PosX=0.5, PosY=1, Protected=true);
+
+
+
+SET
+
+        Mw      = PP.MolecularWeight();
+
+        g               = 9.81*'m/s^2';
+
+        
+
+EQUATIONS
+
+
+
+ "Velocity Inlet Nozzle"
+
+        Fvol = NozzleVelocity*SuctionArea;
+
+
+
+"Velocity Head"
+
+        VelocityHead = 0.5*NozzleVelocity^2/g;
+
+
+
+"Average Molecular Weight"
+
+        Mwm = sum(Mw*Inlet.z);
+
+
+
+"Mass Density at inlet conditions"
+
+        rho_in = PP.LiquidDensity(Inlet.T, Inlet.P, Inlet.z);
+
+
+
+"Mass Density at outlet conditions"
+
+        rho_out= PP.LiquidDensity(Outlet.T, Outlet.P, Outlet.z);
+
+
+
+"Inlet Flow Mass"
+
+        Fw_in   =  Mwm*Inlet.F;
+
+
+
+"Outlet Flow Mass"
+
+        Fw_out  =  Fw_in;
+
+        
+
+"Pressure Increase"
+
+        Outlet.P  = Inlet.P + Pincrease;
+
+        
+
+"Mixture Vapour Pressure"
+
+        Pvapor = PP.BubbleP(Inlet.T,Inlet.z); 
+
+        
+
+"Pressure Ratio"
+
         Outlet.P = Inlet.P * Pratio;
 
-        "Pressure Drop"
+
+
+"Pressure Drop"
+
         Outlet.P  = Inlet.P - Pdrop;
 
-        "Calculate Isentropic Head"
-        Head_is = -Pdrop * Mwm/rho;
-
-        "Calculate Real Head"
-        Head = Head_is/(Eff*Meff); 
-        
-        "Calculate Outlet Enthalpy"
-        Outlet.h - Inlet.h = Head;
-        
-        "Calculate Fluid Power"
-        FPower = Head_is * Inlet.F;
-
-        "Calculate Brake Power"
-        BPower * Eff = FPower;
-
-        "Calculate Eletric Power"
-        BPower = EPower * Meff;
-        
-        "Calculate Outlet Temperature"
-        (Outlet.T - Inlet.T) * Cp = (Outlet.h - Inlet.h) + Pdrop * Mwm / rho * (1 - Beta * Inlet.T);
-        
-        "Molar Balance"
+
+
+"Isentropic Head"
+
+        HeadIsentropic = -Pdrop/rho_in;
+
+
+
+"Pump Efficiency"
+
+        Head = HeadIsentropic/PumpEfficiency; 
+
+        
+
+"Actual Head"
+
+        Head*Mwm = (Outlet.h-Inlet.h);
+
+        
+
+"Fluid Power"
+
+        FluidPower = HeadIsentropic *Mwm* Inlet.F;
+
+
+
+"Brake Power"
+
+        BrakePower * PumpEfficiency = FluidPower;
+
+
+
+"Eletric Power"
+
+        EletricPower = -WorkIn.Work;
+
+
+
+"Eletric Power"
+
+        BrakePower = EletricPower * MechanicalEff;
+
+        
+
+"Molar Balance"
+
         Outlet.F = Inlet.F;
 
-        "Calculate Outlet Composition"
+
+
+"Outlet Composition"
+
         Outlet.z = Inlet.z;
-        
-        "Calculate Net Positive Suction Head"
-        NPSHa = - Lev + (Inlet.P - pvm)/(g*rho); #If Inlet.P is the suction pump pressure, Lev is 0.
-        
-        "Calculate Volumetric Flow Rate"
-        Q = Inlet.F*vm;
-
-        "Calculate Specific Speed"
-        NS = N*(Q^0.5)/((Head/Mwm)^(3/4));
+
+
+
+"Volumetric Flow Rate"
+
+        Fvol = Fw_in/rho_in;
+
+
+
+switch NPSH_Options
+
+        
+
+        case "Default":
+
+        
+
+"Net Positive Suction Head Available - Without Velocity Head"
+
+        NPSH_available = (Inlet.P - Pvapor)/(rho_in*g) + StaticHead;    
+
+        
+
+        case "Include Kinetic Head":
+
+        
+
+"Net Positive Suction Head Available - Included Velocity Head"
+
+        NPSH_available = (Inlet.P - Pvapor)/(rho_in*g)+VelocityHead+StaticHead;
+
+
+end
 
 end