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Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations

Package with correlations for cooling tower performance

Information

This package contains the performance curve for the Buildings.Fluid.HeatExchangers.CoolingTowers.YorkCalc cooling tower model.

Extends from Modelica.Icons.MaterialProperty (Icon for property classes).

Package Content

Name Description
Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations.yorkCalc yorkCalc Cooling tower performance correlation for YorkCalc model
Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations.BoundsYorkCalc BoundsYorkCalc Coefficient data record for properties of York cooling tower model
Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations.Examples Examples Collection of models that illustrate model use and test models
Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations.BaseClasses BaseClasses Package with base classes for Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations

Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations.yorkCalc

Cooling tower performance correlation for YorkCalc model

Information

Correlation for approach temperature for YorkCalc cooling tower model. See Examples/YorkCalc.mo for the graph.

Inputs

TypeNameDefaultDescription
TemperatureTWetBul Air wet-bulb inlet temperature [K]
MassFractionFRWat Ratio actual over design water mass flow ratio [1]
MassFractionFRAir Ratio actual over design air mass flow ratio [1]
Nominal condition
TemperatureDifferenceTRan Range temperature (water in - water out) [K]

Outputs

TypeNameDescription
TemperatureDifferenceTAppApproach temperature [K]

Modelica definition

function yorkCalc "Cooling tower performance correlation for YorkCalc model" input Modelica.SIunits.TemperatureDifference TRan "Range temperature (water in - water out)"; input Modelica.SIunits.Temperature TWetBul "Air wet-bulb inlet temperature"; input Modelica.SIunits.MassFraction FRWat "Ratio actual over design water mass flow ratio"; input Modelica.SIunits.MassFraction FRAir "Ratio actual over design air mass flow ratio"; output Modelica.SIunits.TemperatureDifference TApp "Approach temperature"; protected Modelica.SIunits.Conversions.NonSIunits.Temperature_degC TWetBul_degC "Air wet-bulb inlet temperature"; Modelica.SIunits.MassFraction liqGasRat "Liquid to gas mass flow ratio"; constant Real c[:] = {-0.359741205, -0.055053608, 0.0023850432, 0.173926877, -0.0248473764, 0.00048430224, -0.005589849456, 0.0005770079712, -0.00001342427256, 2.84765801111111, -0.121765149, 0.0014599242, 1.680428651, -0.0166920786, -0.0007190532, -0.025485194448, 0.0000487491696, 0.00002719234152, -0.0653766255555556, -0.002278167, 0.0002500254, -0.0910565458, 0.00318176316, 0.000038621772, -0.0034285382352, 0.00000856589904, -0.000001516821552} "Polynomial coefficients"; algorithm TWetBul_degC :=Modelica.SIunits.Conversions.to_degC(TWetBul); // smoothMax is added to the numerator and denominator so that // liqGasRat -> 1, as both FRWat -> 0 and FRAir -> 0 liqGasRat := Buildings.Utilities.Math.Functions.smoothMax(x1=1E-4, x2=FRWat, deltaX=1E-5)/ Buildings.Utilities.Math.Functions.smoothMax(x1=1E-4, x2=FRAir, deltaX=1E-5); TApp := c[1] + c[2] * TWetBul_degC + c[3] * TWetBul_degC * TWetBul_degC + c[4] * TRan + c[5] * TWetBul_degC * TRan + c[6] * TWetBul_degC * TWetBul_degC * TRan + c[7] * TRan * TRan + c[8] * TWetBul_degC * TRan * TRan + c[9] * TWetBul_degC * TWetBul_degC * TRan * TRan + c[10] * liqGasRat + c[11] * TWetBul_degC * liqGasRat + c[12] * TWetBul_degC * TWetBul_degC * liqGasRat + c[13] * TRan * liqGasRat + c[14] * TWetBul_degC * TRan * liqGasRat + c[15] * TWetBul_degC * TWetBul_degC * TRan * liqGasRat + c[16] * TRan * TRan * liqGasRat + c[17] * TWetBul_degC * TRan * TRan * liqGasRat + c[18] * TWetBul_degC * TWetBul_degC * TRan * TRan * liqGasRat + c[19] * liqGasRat * liqGasRat + c[20] * TWetBul_degC * liqGasRat * liqGasRat + c[21] * TWetBul_degC * TWetBul_degC * liqGasRat * liqGasRat + c[22] * TRan * liqGasRat * liqGasRat + c[23] * TWetBul_degC * TRan * liqGasRat * liqGasRat + c[24] * TWetBul_degC * TWetBul_degC * TRan * liqGasRat * liqGasRat + c[25] * TRan * TRan * liqGasRat * liqGasRat + c[26] * TWetBul_degC * TRan * TRan * liqGasRat * liqGasRat + c[27] * TWetBul_degC * TWetBul_degC * TRan * TRan * liqGasRat * liqGasRat; end yorkCalc;

Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations.BoundsYorkCalc Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations.BoundsYorkCalc

Coefficient data record for properties of York cooling tower model

Information

This data record contains the bounds for the YorkCalc cooling tower correlations.

Extends from Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations.BaseClasses.Bounds (Coefficient data record for properties of cooling tower model).

Parameters

TypeNameDefaultDescription
TemperatureTAirInWB_min273.15 - 34.4Minimum air inlet wet bulb temperature [K]
TemperatureTAirInWB_max273.15 + 26.7Maximum air inlet wet bulb temperature [K]
TemperatureTRan_min1.1Minimum range temperature [K]
TemperatureTRan_max22.2Minimum range temperature [K]
TemperatureTApp_min1.1Minimum approach temperature [K]
TemperatureTApp_max40Minimum approach temperature [K]
RealFRWat_min0.75Minimum water flow ratio
RealFRWat_max1.25Maximum water flow ratio
RealliqGasRat_max8Maximum liquid to gas ratio

Modelica definition

record BoundsYorkCalc "Coefficient data record for properties of York cooling tower model" extends Buildings.Fluid.HeatExchangers.CoolingTowers.Correlations.BaseClasses.Bounds (TAirInWB_min = 273.15-34.4, TAirInWB_max = 273.15+26.7, TRan_min = 1.1, TRan_max = 22.2, TApp_min = 1.1, TApp_max = 40, FRWat_min = 0.75, FRWat_max = 1.25, liqGasRat_max = 8); end BoundsYorkCalc;
Automatically generated Mon May 4 10:20:44 2015.