FCSys.Chemistry

Chemical reactions and related models

Information

Extends from Icons.ChemistryPackage (Icon for packages containing chemical models).

Package Content

Name	Description
Examples	Examples
Electrochemistry	Models associated with electrochemical reactions
HOR	Hydrogen oxidation reaction
ORR	Oxygen reduction reaction
Capillary	Young-Laplace model for capillary pressure
CapillaryVolume	Volume with capillary pressure applied to the liquid

FCSys.Chemistry.HOR

Hydrogen oxidation reaction FCSys.Chemistry.HOR

Information

H₂ ⇌ 2e^- + 2H⁺

Extends from FCSys.Icons.Names.Top2.

Parameters

Type Name Default Description

Integer n_trans Number of components of translational momentum

Type	Name	Default	Description
Integer	n_trans		Number of components of translational momentum

Connectors

Type Name Description

Chemical 'cheme-' Connector for e-

Chemical 'chemH+' Connector for H+

Chemical chemH2 Connector for H2

Type	Name	Description
Chemical	'cheme-'	Connector for e-
Chemical	'chemH+'	Connector for H+
Chemical	chemH2	Connector for H2

Modelica definition

model HOR "Hydrogen oxidation reaction"
  extends FCSys.Icons.Names.Top2;

  constant Integer n_trans(min=0, max=3) 
    "Number of components of translational momentum";
  // Note:  This must be a constant rather than a parameter due to errors in
  // Dymola 2014.
  Conditions.Adapters.ChemicalReaction 'e-'(
    final n_trans=n_trans,
    m=Characteristics.'e-'.Gas.m,
    n=-2);
  Conditions.Adapters.ChemicalReaction 'H+'(
    final n_trans=n_trans,
    m=Characteristics.'H+'.Gas.m,
    n=-2);
  Conditions.Adapters.ChemicalReaction H2(
    final n_trans=n_trans,
    m=Characteristics.H2.Gas.m,
    n=1);

  Connectors.Chemical 'cheme-'(redeclare final constant Integer n_trans=n_trans)
    "Connector for e-";
  Connectors.Chemical 'chemH+'(redeclare final constant Integer n_trans=n_trans)
    "Connector for H+";
  Connectors.Chemical chemH2(redeclare final constant Integer n_trans=n_trans) 
    "Connector for H2";
  // Note:  These redeclarations are necessary due to errors in Dymola 2014.

equation 
  connect(chemH2, H2.chemical);
  connect('e-'.chemical, 'cheme-');
  connect('H+'.chemical, 'chemH+');
  connect(H2.reaction, 'e-'.reaction);
  connect('H+'.reaction, H2.reaction);
end HOR;

FCSys.Chemistry.ORR

Oxygen reduction reaction FCSys.Chemistry.ORR

Information

4e^- + 4H⁺ + O₂ ⇌ 2H₂O

Extends from FCSys.Icons.Names.Top2.

Parameters

Type Name Default Description

Integer n_trans Number of components of translational momentum

Type	Name	Default	Description
Integer	n_trans		Number of components of translational momentum

Connectors

Type Name Description

Chemical 'cheme-' Connector for e-

Chemical 'chemH+' Connector for H+

Chemical chemO2 Connector for O2

Chemical chemH2O Connector for H2O

Type	Name	Description
Chemical	'cheme-'	Connector for e-
Chemical	'chemH+'	Connector for H+
Chemical	chemO2	Connector for O2
Chemical	chemH2O	Connector for H2O

Modelica definition

model ORR "Oxygen reduction reaction"
  extends FCSys.Icons.Names.Top2;

  constant Integer n_trans(min=0, max=3) 
    "Number of components of translational momentum";
  // Note:  This must be a constant rather than a parameter due to errors in
  // Dymola 2014.
  Conditions.Adapters.ChemicalReaction 'e-'(
    final n_trans=n_trans,
    m=Characteristics.'e-'.Gas.m,
    reaction(Ndot(stateSelect=StateSelect.prefer)),
    n=4);
  Conditions.Adapters.ChemicalReaction 'H+'(
    final n_trans=n_trans,
    m=Characteristics.'H+'.Gas.m,
    n=4);
  Conditions.Adapters.ChemicalReaction O2(
    final n_trans=n_trans,
    m=Characteristics.O2.Gas.m,
    n=1);
  Conditions.Adapters.ChemicalReaction H2O(
    final n_trans=n_trans,
    m=Characteristics.H2O.Gas.m,
    n=-2);

  Connectors.Chemical 'cheme-'(redeclare final constant Integer n_trans=n_trans)
    "Connector for e-";
  Connectors.Chemical 'chemH+'(redeclare final constant Integer n_trans=n_trans)
    "Connector for H+";
  Connectors.Chemical chemO2(redeclare final constant Integer n_trans=n_trans) 
    "Connector for O2";
  Connectors.Chemical chemH2O(redeclare final constant Integer n_trans=n_trans)
    "Connector for H2O";
  // Note:  These redeclarations are necessary due to errors in Dymola 2014.

equation 
  connect('H+'.chemical, 'chemH+');
  connect('e-'.chemical, 'cheme-');
  connect(O2.chemical, chemO2);
  connect(H2O.chemical, chemH2O);
  connect('e-'.reaction, H2O.reaction);
  connect('H+'.reaction, H2O.reaction);
  connect(O2.reaction, H2O.reaction);
end ORR;

FCSys.Chemistry.Capillary

Young-Laplace model for capillary pressure FCSys.Chemistry.Capillary

Information

The characteristic radius (R) is the harmonic mean of the (2) principle radii of the liquid volume.

The default surface tension (γ = 0.0663 N/m) is for saturated water at 60 °C, interpolated from [Incropera2002, pp. 924]. Note that the surface tension in [Wang2001] is incorrect (likely unit conversion error).

Extends from FCSys.Icons.Names.Top2.

Parameters

Type Name Default Description

Geometry

Length R U.um Effective radius [L]

Material properties

SurfaceTension gamma 0.0663*U.N/U.m Surface tension [M/T2]

Angle theta 140*U.degree Contact angle [A]

Type	Name	Default	Description
Geometry
Length	R	U.um	Effective radius [L]
Material properties
SurfaceTension	gamma	0.0663*U.N/U.m	Surface tension [M/T2]
Angle	theta	140*U.degree	Contact angle [A]

Connectors

Type Name Description

Amagat wetting Interface to the wetting phase

Amagat nonwetting Interface to the nonwetting phase

Type	Name	Description
Amagat	wetting	Interface to the wetting phase
Amagat	nonwetting	Interface to the nonwetting phase

Modelica definition

model Capillary "Young-Laplace model for capillary pressure"

  extends FCSys.Icons.Names.Top2;

  // Geometry
  parameter Q.Length R=U.um "Effective radius";

  // Material properties
  parameter Q.SurfaceTension gamma=0.0663*U.N/U.m "Surface tension";
  parameter Q.Angle theta=140*U.degree "Contact angle";

  // Auxiliary variables (for analysis only)
  Q.Pressure Deltap=wetting.p - nonwetting.p if environment.analysis 
    "Pressure difference due to surface tension";

  Connectors.Amagat wetting "Interface to the wetting phase";
  Connectors.Amagat nonwetting "Interface to the nonwetting phase";

protected 
  outer Conditions.Environment environment "Environmental conditions";

equation 
  // Pressure relation
  nonwetting.p = wetting.p + 2*gamma*cos(theta)/R "Young-Laplace equation";

  // Conservation (without storage)
  0 = wetting.V + nonwetting.V "Volume";

end Capillary;

FCSys.Chemistry.CapillaryVolume

Volume with capillary pressure applied to the liquid FCSys.Chemistry.CapillaryVolume

Information

The default permeability (κ = 6.46×10^-5 mm²) is based on the air permeability of SGL Carbon Group Sigracet® 10 BA [SGL2007]. Wang et al. use κ = 10^-5 mm² [Wang2001].

The default contact angle (θ = 140°) is typical of the GDL measurements listed at http://www.chem.mtu.edu/cnlm/research/Movement_of_Water-in_Fuel_Cell_Electrodes.htm (accessed Nov. 22, 2103).

Extends from FCSys.Icons.Names.Top3.

Parameters

Type Name Default Description

Capillary capillary Capillary model

Geometry

Volume V Volume [L3]

Included phases

Boolean inclGas true Gas

Boolean inclLiquid true Liquid

Boolean inclSolid true Solid

Capillary pressure

Boolean inclCapillary false Include capillary pressure

Type	Name	Default	Description
Capillary	capillary		Capillary model
Geometry
Volume	V		Volume [L3]
Included phases
Boolean	inclGas	true	Gas
Boolean	inclLiquid	true	Liquid
Boolean	inclSolid	true	Solid
Capillary pressure
Boolean	inclCapillary	false	Include capillary pressure

Connectors

Type Name Description

Dalton gas Interface to the gas phase

Amagat liquid Interface to the liquid phase

Amagat solid Interface to the solid phase

Type	Name	Description
Dalton	gas	Interface to the gas phase
Amagat	liquid	Interface to the liquid phase
Amagat	solid	Interface to the solid phase

Modelica definition

model CapillaryVolume 
  "Volume with capillary pressure applied to the liquid"
  extends FCSys.Icons.Names.Top3;

  // Material properties
  parameter Q.Volume V "Volume";

  // Material properties
  parameter Boolean inclGas=true "Gas";
  parameter Boolean inclLiquid=true "Liquid";
  parameter Boolean inclSolid=true "Solid";

  // Capillary pressure
  parameter Boolean inclCapillary=false "Include capillary pressure";
  Capillary capillary if inclLiquid and inclCapillary "Capillary model";

  // Alias variables (for common terms)
  Q.Volume V_pore "Pore volume";

  // Auxiliary variables (for analysis)
  output Q.NumberAbsolute x(final stateSelect=StateSelect.never) = liquid.V/(
    gas.V + liquid.V) if inclLiquid and inclGas and environment.analysis 
    "Liquid saturation";

  Connectors.Dalton gas if inclGas "Interface to the gas phase";
  Connectors.Amagat liquid if inclLiquid "Interface to the liquid phase";
  Connectors.Amagat solid "Interface to the solid phase";

  Conditions.ByConnector.Amagat.VolumeFixed volume(final V=V) if inclGas or 
    inclLiquid "Fixed volume";

protected 
  Conditions.Adapters.AmagatDalton amagatDalton if inclGas or (inclSolid and 
    not inclLiquid) 
    "Adapter between additivity of volume and additivity of gas pressure";

  outer Conditions.Environment environment "Environmental conditions";

equation 
  // Aliases
  V = V_pore + solid.V;

  if not inclCapillary then
    connect(liquid, volume.amagat) 
      "Directly connect liquid to the volume (not shown in diagram)";
  end if;

  connect(capillary.wetting, liquid);
  connect(solid, amagatDalton.amagat);
  connect(volume.amagat, amagatDalton.amagat);
  connect(gas, amagatDalton.dalton);
  connect(capillary.nonwetting, volume.amagat);
end CapillaryVolume;

FCSys

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FCSys.Chemistry

Information

Package Content

FCSys.Chemistry.HOR

Information

Parameters

Connectors

Modelica definition

FCSys.Chemistry.ORR

Information

Parameters

Connectors

Modelica definition

FCSys.Chemistry.Capillary

Information

Parameters

Connectors

Modelica definition

FCSys.Chemistry.CapillaryVolume

Information

Parameters

Connectors

Modelica definition