modelZonalFlow_ACS

Zonal flow with input air change per second

Extends from Buildings.Airflow.Multizone.BaseClasses.ZonalFlow (Flow across zonal boundaries of a room).

Information

This model computes the air exchange between volumes.

Input is the air change per seconds. The volume flow rate is computed as

  V_flow = ACS * V

where ACS is an input and the volume V is a parameter.

Parameters

TypeNameDefaultDescription
BooleanuseDefaultPropertiesfalseSet to true to use constant density
Modelica.Units.SI.VolumeVVolume of room
Assumptions
BooleanallowFlowReversal1 (from PartialFourPort)true= false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1
BooleanallowFlowReversal2 (from PartialFourPort)true= false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2
Nominal condition
Modelica.Units.SI.MassFlowRatem1_flow_nominal (from PartialFourPortInterface)Nominal mass flow rate
Modelica.Units.SI.MassFlowRatem2_flow_nominal (from PartialFourPortInterface)Nominal mass flow rate
Advanced
Medium1.MassFlowRatem1_flow_small (from PartialFourPortInterface)1E-4*abs(m1_flow_nominal)Small mass flow rate for regularization of zero flow
Medium2.MassFlowRatem2_flow_small (from PartialFourPortInterface)1E-4*abs(m2_flow_nominal)Small mass flow rate for regularization of zero flow
Advanced › Diagnostics
Booleanshow_T (from PartialFourPortInterface)false= true, if actual temperature at port is computed

Connectors

TypeNameDefaultDescription
Modelica.Fluid.Interfaces.FluidPort_aport_a1 (from PartialFourPort)Fluid connector a1 (positive design flow direction is from port_a1 to port_b1)
Modelica.Fluid.Interfaces.FluidPort_bport_b1 (from PartialFourPort)Fluid connector b1 (positive design flow direction is from port_a1 to port_b1)
Modelica.Fluid.Interfaces.FluidPort_aport_a2 (from PartialFourPort)Fluid connector a2 (positive design flow direction is from port_a2 to port_b2)
Modelica.Fluid.Interfaces.FluidPort_bport_b2 (from PartialFourPort)Fluid connector b2 (positive design flow direction is from port_a2 to port_b2)
Modelica.Blocks.Interfaces.RealInputACSAir change per seconds, relative to the smaller of the two volumes

Components

TypeNameDefaultDescription
Medium1.MassFlowRatem1_flow (from PartialFourPortInterface)port_a1.m_flowMass flow rate from port_a1 to port_b1 (m1_flow > 0 is design flow direction)
Modelica.Units.SI.PressureDifferencedp1 (from PartialFourPortInterface)port_a1.p - port_b1.pPressure difference between port_a1 and port_b1
Medium2.MassFlowRatem2_flow (from PartialFourPortInterface)port_a2.m_flowMass flow rate from port_a2 to port_b2 (m2_flow > 0 is design flow direction)
Modelica.Units.SI.PressureDifferencedp2 (from PartialFourPortInterface)port_a2.p - port_b2.pPressure difference between port_a2 and port_b2
Medium1.ThermodynamicStatesta_a1 (from PartialFourPortInterface)if allowFlowReversal1 then Medium1.setState_phX(port_a1.p, noEvent(actualStream(port_a1.h_outflow)), noEvent(actualStream(port_a1.Xi_outflow))) else Medium1.setState_phX(port_a1.p, inStream(port_a1.h_outflow), inStream(port_a1.Xi_outflow))Medium properties in port_a1
Medium1.ThermodynamicStatesta_b1 (from PartialFourPortInterface)if allowFlowReversal1 then Medium1.setState_phX(port_b1.p, noEvent(actualStream(port_b1.h_outflow)), noEvent(actualStream(port_b1.Xi_outflow))) else Medium1.setState_phX(port_b1.p, port_b1.h_outflow, port_b1.Xi_outflow)Medium properties in port_b1
Medium2.ThermodynamicStatesta_a2 (from PartialFourPortInterface)if allowFlowReversal2 then Medium2.setState_phX(port_a2.p, noEvent(actualStream(port_a2.h_outflow)), noEvent(actualStream(port_a2.Xi_outflow))) else Medium2.setState_phX(port_a2.p, inStream(port_a2.h_outflow), inStream(port_a2.Xi_outflow))Medium properties in port_a2
Medium2.ThermodynamicStatesta_b2 (from PartialFourPortInterface)if allowFlowReversal2 then Medium2.setState_phX(port_b2.p, noEvent(actualStream(port_b2.h_outflow)), noEvent(actualStream(port_b2.Xi_outflow))) else Medium2.setState_phX(port_b2.p, port_b2.h_outflow, port_b2.Xi_outflow)Medium properties in port_b2

Revisions

  • August 18, 2014, by Michael Wetter:
    Removed parameter forceErrorControlOnFlow as it was not used. Changed message of assert statement to avoid an error in OpenModelica.
  • October 8, 2013 by Michael Wetter:
    Changed the parameter useConstantDensity to useDefaultProperties to use consistent names within this package. A conversion script can be used to update this parameter.
  • December 14, 2012 by Michael Wetter:
    Renamed protected parameters for consistency with the naming conventions.
  • July 20, 2010 by Michael Wetter:
    Migrated model to Modelica 3.1 and integrated it into the Buildings library.
  • January 4, 2006 by Michael Wetter:
    Implemented first version.