1 | #*---------------------------------------------------------------------------- |
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2 | * This file is property of the author and cannot be used, copyed |
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3 | * or modified without permission. |
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4 | * |
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5 | * Copyright (C) 2002-2006 the author |
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6 | *----------------------------------------------------------------------------- |
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7 | * Author: Marcos L. Alencastro Date:03/03/2006 |
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8 | * $Id:$ Estefane da S. Horn |
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9 | *----------------------------------------------------------------------------- |
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10 | * -> Steady State |
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11 | * -> Only Vapour |
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12 | * -> Adiabatic |
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13 | *# |
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14 | |
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15 | using "streams"; |
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16 | using "pressure_changers/flux_machine_basic"; |
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17 | |
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18 | Model centrifugal_compressor as flux_machine_basic_TP |
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19 | |
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20 | PARAMETERS |
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21 | ext PP as CalcObject (Brief = "External Physical Properties"); |
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22 | ext NComp as Integer (Brief = "Number of chemical components", Lower = 1); |
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23 | Effs as positive (Default = 0.72, Brief = "Isentropic efficiency", Lower = 0, Upper = 1); |
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24 | R as positive (Default = 8.31451, Brief = "Constant of Gases", Unit= "kJ/kmol/K"); |
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25 | Mw(NComp) as molweight (Brief = "Molar Weight"); |
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26 | |
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27 | VARIABLES |
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28 | n as positive (Brief = "Politropic Coefficient"); |
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29 | k as positive (Brief = "Isentropic Coefficient"); |
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30 | Cp as cp_mol (Brief = "Heat Capacity", Unit = "kJ/(kmol*K)"); |
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31 | Cv as cv_mol (Brief = "Heat Capacity", Unit = "kJ/(kmol*K)"); |
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32 | Pdiff as press_delta (Brief = "Pressure Increase", Unit="kPa"); |
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33 | Pratio as positive (Brief = "Pressure Ratio"); |
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34 | Wp as energy_mol (Brief = "Politropic Head", Unit = "kJ/kmol"); |
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35 | Ws as energy_mol (Brief = "Isentropic Head", Unit = "kJ/kmol"); |
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36 | Tiso as temperature (Brief = "Isentropic Temperature"); |
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37 | Effp as positive (Brief = "Politropic efficiency", Lower = 0, Upper = 1); |
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38 | FPower as power (Brief = "Fluid Power", Unit="kW"); |
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39 | Mwm as molweight (Brief = "Mixture Molar Weight"); |
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40 | |
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41 | SET |
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42 | Mw = PP.MolecularWeight(); |
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43 | |
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44 | EQUATIONS |
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45 | |
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46 | "Calculate Mwm for Inlet Mixture" |
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47 | Mwm = sum(Mw([1:NComp])*Inlet.z([1:NComp])); |
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48 | |
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49 | "Calculate Outlet Stream Pressure" |
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50 | Outlet.P = Inlet.P + Pdiff; |
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51 | |
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52 | "Pratio Definition" |
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53 | Outlet.P = Inlet.P * Pratio; |
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54 | |
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55 | "Calculate Cp Using a External Physical Properties Routine" |
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56 | Cp = PP.VapourCp(Inlet.T,Inlet.P,Inlet.z); |
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57 | |
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58 | "Calculate Cv Using a External Physical Properties Routine" |
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59 | Cv = PP.VapourCv(Inlet.T,Inlet.P,Inlet.z); |
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60 | |
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61 | "Calculate Isentropic Coeficient" |
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62 | k = Cp/Cv; |
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63 | |
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64 | "Calculate Isentropic Head" |
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65 | Ws = (k/(k-1))*R*Inlet.T*((Outlet.P/Inlet.P)^((k-1)/k) - 1); |
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66 | |
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67 | "Calculate Isentropic Outlet Temperature" |
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68 | Tiso = Inlet.T * (Outlet.P/Inlet.P)^((k-1)/k); |
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69 | |
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70 | "Calculate Real Outlet Temperature" |
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71 | Effs * (Outlet.T- Inlet.T) = (Tiso - Inlet.T); |
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72 | |
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73 | "Calculate Politropic Coefficient" |
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74 | Outlet.T = Inlet.T * (Outlet.P/Inlet.P)^((n-1)/n); |
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75 | |
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76 | "Calculate Politropic Efficiency" |
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77 | Effp = (n/(n-1))/(k/(k-1)); |
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78 | |
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79 | "Calculate Politropic Head" |
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80 | Ws*Effp = Wp*Effs; |
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81 | |
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82 | "Calculate Fluid Power" |
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83 | FPower*Effs = Inlet.F*Ws; |
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84 | |
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85 | "Molar Balance" |
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86 | Outlet.F = Inlet.F; |
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87 | |
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88 | Outlet.z = Inlet.z; |
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89 | |
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90 | |
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91 | end |
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