modelLosslessPipe

Pipe with no flow friction and no heat transfer

Extends from Buildings.Fluid.Interfaces.PartialTwoPortInterface (Partial model with two ports and declaration of quantities that are used by many models).

Information

Model of a pipe with no flow resistance, no heat loss and no transport delay. This model can be used to replace a replaceable pipe model in flow legs in which no friction should be modeled. This is for example done in the outlet port of the base class for three way valves, Buildings.Fluid.Actuators.BaseClasses.PartialThreeWayValve.

Parameters

TypeNameDefaultDescription
Booleanfrom_dptrueUsed to satisfy replaceable models
Assumptions
BooleanallowFlowReversal (from PartialTwoPort)true= false to simplify equations, assuming, but not enforcing, no flow reversal
Nominal condition
Modelica.Units.SI.MassFlowRatem_flow_nominal (from PartialTwoPortInterface)Nominal mass flow rate
Advanced
Modelica.Units.SI.MassFlowRatem_flow_small (from PartialTwoPortInterface)1E-4*abs(m_flow_nominal)Small mass flow rate for regularization of zero flow
Advanced › Diagnostics
Booleanshow_T (from PartialTwoPortInterface)false= true, if actual temperature at port is computed

Connectors

TypeNameDefaultDescription
Modelica.Fluid.Interfaces.FluidPort_aport_a (from PartialTwoPort)Fluid connector a (positive design flow direction is from port_a to port_b)
Modelica.Fluid.Interfaces.FluidPort_bport_b (from PartialTwoPort)Fluid connector b (positive design flow direction is from port_a to port_b)

Components

TypeNameDefaultDescription
Modelica.Units.SI.MassFlowRatem_flow (from PartialTwoPortInterface)port_a.m_flowMass flow rate from port_a to port_b (m_flow > 0 is design flow direction)
Modelica.Units.SI.PressureDifferencedp (from PartialTwoPortInterface)port_a.p - port_b.pPressure difference between port_a and port_b
Medium.ThermodynamicStatesta_a (from PartialTwoPortInterface)if allowFlowReversal then Medium.setState_phX(port_a.p, noEvent(actualStream(port_a.h_outflow)), noEvent(actualStream(port_a.Xi_outflow))) else Medium.setState_phX(port_a.p, noEvent(inStream(port_a.h_outflow)), noEvent(inStream(port_a.Xi_outflow)))Medium properties in port_a
Medium.ThermodynamicStatesta_b (from PartialTwoPortInterface)if allowFlowReversal then Medium.setState_phX(port_b.p, noEvent(actualStream(port_b.h_outflow)), noEvent(actualStream(port_b.Xi_outflow))) else Medium.setState_phX(port_b.p, noEvent(port_b.h_outflow), noEvent(port_b.Xi_outflow))Medium properties in port_b

Revisions

  • June 23, 2018, by Filip Jorissen:
    Implementation is now more efficient for allowFlowReversal=false. See #949.
  • October 8, 2013, by Michael Wetter:
    Removed parameter show_V_flow.
  • June 13, 2008 by Michael Wetter:
    First implementation.