Buildings.Fluids.Sources

Package with source models for species

Information

This package contains source models for species.

Package Content

Name Description

Examples Collection of models that illustrate model use and test models

PrescribedExtraPropertyFlowRate Source with mass flow that does not take part in medium mass balance (such as CO2)

Name	Description
Examples	Collection of models that illustrate model use and test models
PrescribedExtraPropertyFlowRate	Source with mass flow that does not take part in medium mass balance (such as CO2)

Buildings.Fluids.Sources.PrescribedExtraPropertyFlowRate

Source with mass flow that does not take part in medium mass balance (such as CO2)

Buildings.Fluids.Sources.PrescribedExtraPropertyFlowRate

Information

This model adds a mass flow rate to the port for an auxiliary medium that does not take part in the mass balance of the medium model. Instead, this mass transfer is tracked separately. A typical use of this source is to add carbon dioxide to a room, since the carbon dioxide concentration is typically so small that it need not be added to the room mass balance.

Extends from Modelica_Fluid.Sources.BaseClasses.PartialSource (Partial component source with one fluid connector).

Parameters

Type Name Default Description

replaceable package Medium PartialMedium Medium model within the source

String substanceName "CO2" Name of trace substance

Boolean use_m_flow_in false Get the trace substance mass flow rate from the input connector

MassFlowRate m_flow 0 Fixed mass flow rate going out of the fluid port [kg/s]

Type	Name	Default	Description
replaceable package Medium	PartialMedium	Medium model within the source
String	substanceName	"CO2"	Name of trace substance
Boolean	use_m_flow_in	false	Get the trace substance mass flow rate from the input connector
MassFlowRate	m_flow	0	Fixed mass flow rate going out of the fluid port [kg/s]

Connectors

Type Name Description

FluidPorts_b ports[nPorts]

input RealInput m_flow_in Prescribed mass flow rate for extra property

Type	Name	Description
FluidPorts_b	ports[nPorts]
input RealInput	m_flow_in	Prescribed mass flow rate for extra property

Modelica definition

model PrescribedExtraPropertyFlowRate 
  "Source with mass flow that does not take part in medium mass balance (such as CO2)"
  extends Modelica_Fluid.Sources.BaseClasses.PartialSource(nPorts=1);


  parameter String substanceName = "CO2" "Name of trace substance";
  parameter Boolean use_m_flow_in = false 
    "Get the trace substance mass flow rate from the input connector";

  parameter Medium.MassFlowRate m_flow = 0 
    "Fixed mass flow rate going out of the fluid port";
  Modelica.Blocks.Interfaces.RealInput m_flow_in if 
       use_m_flow_in "Prescribed mass flow rate for extra property";

protected 
  Modelica.Blocks.Interfaces.RealInput m_flow_in_internal 
    "Needed to connect to conditional connector";
  parameter Medium.ExtraProperty C_in_internal[Medium.nC](
       fixed=false,
       quantity=Medium.extraPropertiesNames)=fill(0, Medium.nC) 
    "Boundary trace substances";
initial algorithm 
  for i in 1:Medium.nC loop
    if ( Modelica.Utilities.Strings.isEqual(Medium.extraPropertiesNames[i], substanceName)) then
      C_in_internal[i] := 1;
    else
      C_in_internal[i] := 0;
    end if;
  end for;
  assert(sum(C_in_internal) > 0, "Trace substance '" + substanceName + "' is not present in medium '"
         + Medium.mediumName + "'.\n"
         + "Check source parameter and medium model.");
equation 
  connect(m_flow_in, m_flow_in_internal);
  if not use_m_flow_in then
    m_flow_in_internal = m_flow;
  end if;

  assert(sum(m_flow_in_internal) >= 0, "Reverse flow for species source is not yet implemented.");
  sum(ports.m_flow) = -m_flow_in_internal;
  medium.T = Medium.T_default;
  medium.Xi = Medium.X_default[1:Medium.nXi];
  ports.C_outflow = fill(C_in_internal, nPorts);
end PrescribedExtraPropertyFlowRate;

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