modelVolumeFlowRate

Ideal sensor for volume flow rate

Extends from Buildings.Fluid.Sensors.BaseClasses.PartialDynamicFlowSensor, Modelica.Icons.RoundSensor.

Information

This model outputs the volume flow rate flowing from port_a to port_b. The sensor is ideal, i.e., it does not influence the fluid. If the parameter tau is non-zero, then the measured density that is used to convert the mass flow rate into volumetric flow rate is computed using a first order differential equation. Setting tau=0 is not recommend. See Buildings.Fluid.Sensors.UsersGuide for an explanation.

Parameters

TypeNameDefaultDescription
Initialization
Medium.Densityd_startMedium.density(Medium.setState_pTX(p_start, T_start, X_start))Initial or guess value of density
Modelica.Units.SI.TemperatureT_startMedium.T_defaultTemperature used to compute d_start
Modelica.Units.SI.Pressurep_startMedium.p_defaultPressure used to compute d_start
Modelica.Units.SI.MassFraction[Medium.nX]X_startMedium.X_defaultMass fraction used to compute d_start

Components

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.RealOutputV_flowVolume flow rate from port_a to port_b

Revisions

  • October 19, 2020, by Antoine Gautier:
    Changed default value for tau from 1 to 0.
    This is for #1406.
  • February 25, 2020, by Michael Wetter:
    Changed icon to display its operating state.
    This is for #1294.
  • January 18, 2016 by Filip Jorissen:
    Using parameter tauInv since this now exists in Buildings.Fluid.Sensors.BaseClasses.PartialDynamicFlowSensor. This is for #372.
  • August 31, 2013, by Michael Wetter:
    Removed default value tau=0 as the base class already sets tau=1. This change was made so that all sensors use the same default value.
  • June 3, 2011 by Michael Wetter:
    Revised implementation to add dynamics in such a way that the time constant increases as the mass flow rate tends to zero. This significantly improves the numerics.
  • September 29, 2009, by Michael Wetter:
    First implementation. Implementation is based on Modelica.Fluid.