Changeset 599 for branches/gui/eml/pressure_changers

Timestamp:

Aug 15, 2008, 10:31:59 PM (14 years ago)

Author:

gerson bicca

Message:

updated equations for compressor model

File:

• branches/gui/eml/pressure_changers/compressor.mso (modified) (6 diffs)

branches/gui/eml/pressure_changers/compressor.mso

@@ -21 +21 @@
 
 Model centrifugal_compressor
+        
+# Do Not Forget to Update The Losses by Mechanical Efficiency !!!! 
 
 ATTRIBUTES
@@ -38 +40 @@
 VARIABLES
 
-        PolyCoeff       as positive             (Brief = "Polytropic Coefficient", Lower=0);
-        IseCoeff        as positive     (Brief = "Isentropic Coefficient", Lower=1e-3); 
-        Cp              as cp_mol               (Brief = "Heat Capacity");
-        Cv                      as cv_mol               (Brief = "Heat Capacity");
+        PolyCoeff       as positive             (Brief = "Polytropic Coefficient", Lower=1E-6);
+        IseCoeff        as positive     (Brief = "Isentropic Coefficient", Lower=1E-6); 
+        Cp              as cp_mol               (Brief = "Heat Capacity at constant Pressure");
+        Cv                      as cv_mol               (Brief = "Heat Capacity at constant Volume");
         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", DisplayUnit = 'kPa', Symbol ="P_{incr}");
 
-        Head            as energy_mass  (Brief = "Isentropic Head");
+        Head            as energy_mass  (Brief = "Head");
         Tiso            as temperature  (Brief = "Isentropic Temperature"); 
         
@@ -86 +89 @@
         Outlet.P  = Inlet.P - Pdrop;
 
+"Pressure Increase"
+        Outlet.P  = Inlet.P + Pincrease;
+
 "Mass Density"
         rho = PP.VapourDensity(Inlet.T, Inlet.P, Inlet.z);
@@ -104 +110 @@
         IseCoeff * Cv = Cp;
 
-#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 switch CompressorType
         
@@ -110 +115 @@
         
 "Isentropic Head"
-        Head = (0.5*Zfac_in+0.5*Zfac_out)*(1/Mwm)*(IseCoeff/(IseCoeff-1))*Rgas*Inlet.T*((Outlet.P/Inlet.P)^((IseCoeff-1)/IseCoeff) - 1);
+        Head = (0.5*Zfac_in+0.5*Zfac_out)*(1/Mwm)*(IseCoeff/(IseCoeff-1.001))*Rgas*Inlet.T*((Outlet.P/Inlet.P)^((IseCoeff-1.001)/IseCoeff) - 1);
 
 "Fluid Power"
         FluidPower*IsentropicEff = Head*sum(Mw*Inlet.z)*Inlet.F;
 
+"Discharge Temperature"
+        Outlet.T = Inlet.T*((Outlet.P/Inlet.P)^((IseCoeff-1.001)/IseCoeff));
+
         case "Polytropic Operation":
         
 "Polytropic Head"
-        Head = (0.5*Zfac_in+0.5*Zfac_out)*(1/Mwm)*(PolyCoeff/(PolyCoeff-1))*Rgas*Inlet.T*((Outlet.P/Inlet.P)^((PolyCoeff-1)/PolyCoeff) - 1);
+        Head = (0.5*Zfac_in+0.5*Zfac_out)*(1/Mwm)*(PolyCoeff/(PolyCoeff-1.001))*Rgas*Inlet.T*((Outlet.P/Inlet.P)^((PolyCoeff-1.001)/PolyCoeff) - 1);
 
 "Fluid Power"
         FluidPower*PolytropicEff = Head*sum(Mw*Inlet.z)*Inlet.F;
+
+"Discharge Temperature"
+        Outlet.T = Inlet.T*((Outlet.P/Inlet.P)^((PolyCoeff-1.001)/PolyCoeff));
 
 end
@@ -128 +139 @@
         PP.VapourEntropy(Tiso, Outlet.P, Outlet.z) = PP.VapourEntropy(Inlet.T, Inlet.P, Inlet.z);
 
-"Discharge Temperature"
-        IsentropicEff * (Outlet.T- Inlet.T) = (Tiso - Inlet.T);
+#"Calculate Politropic Coefficient"
+        #PolyCoeff*(ln(Outlet.T/Inlet.T)) = (PolyCoeff-1)*(ln(Outlet.P/Inlet.P));
 
-"Calculate Politropic Coefficient"
-        PolyCoeff*(ln(Outlet.T/Inlet.T)) = (PolyCoeff-1)*(ln(Outlet.P/Inlet.P));
-
-#"Polytropic Efficiency"
-        #PolytropicEff * (PolyCoeff-1) * IseCoeff = PolyCoeff * (IseCoeff-1);
+"Polytropic Efficiency"
+        PolytropicEff * (PolyCoeff-1) * IseCoeff = PolyCoeff * (IseCoeff-1);
 
 "Fluid Power"