FCSys.Characteristics.H2O

H₂O

Information

Extends from Modelica.Icons.Package (Icon for standard packages).

Package Content

Name	Description
Gas	H2O gas
Ionomer	H2O in ionomer
Liquid	H2O liquid
p_sat	Saturation pressure (psat) as a function of temperature
lambda_eq	Equilibrium hydration of ionomer in contact with vapor (λeq) as a function of relative humidity

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FCSys.Characteristics.H2O.p_sat

Saturation pressure (p_sat) as a function of temperature

Information

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Default	Description
TemperatureAbsolute	T		Temperature [L2.M/(N.T2)]

Outputs

Type	Name	Description
PressureAbsolute	p_sat	Saturation pressure [M/(L.T2)]

Modelica definition

function p_sat 
  "Saturation pressure (psat) as a function of temperature"
  extends Modelica.Icons.Function;

  input Q.TemperatureAbsolute T "Temperature";
  output Q.PressureAbsolute p_sat "Saturation pressure";

algorithm 
  p_sat := Modelica.Media.Air.MoistAir.saturationPressureLiquid(T/U.K)*U.Pa;
end p_sat;

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FCSys.Characteristics.H2O.lambda_eq

Equilibrium hydration of ionomer in contact with vapor (λ_eq) as a function of relative humidity

Information

This implements the correlation by Springer et al. [Springer1991] for the ratio of H₂O molecules to SO₃^- units of Nafion® EW 1100 series ionomer.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Default	Description
NumberAbsolute	RH		Relative humidity [1]

Outputs

Type	Name	Description
Real	lambda	Mole ratio of H2O to SO3-

Modelica definition

function lambda_eq 
  "Equilibrium hydration of ionomer in contact with vapor (λeq) as a function of relative humidity"
  extends Modelica.Icons.Function;

  input Q.NumberAbsolute RH "Relative humidity";
  output Real lambda 
    "Mole ratio of H2O to SO3-";

algorithm 
  lambda := 0.043 + 17.81*RH - 39.85*RH^2 + 36*RH^3;

end lambda_eq;