modelVAVBranch

Supply branch of a VAV system

Information

Model for a VAV supply branch. The terminal VAV box has a pressure independent damper and a water reheat coil. The pressure independent damper model includes an idealized flow rate controller and requires a discharge air flow rate set-point (normalized to the nominal value) as a control signal.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.PressureDifferencedpFixed_nominal0Pressure drop of duct and other resistances that are in series
Modelica.Units.SI.MassFlowRatem_flow_nominalMass flow rate of this thermal zone
Modelica.Units.SI.VolumeVRooRoom volume

Components

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Interfaces.RealInputTRooHeaSetSetpoint temperature for room for heating
Buildings.Controls.OBC.CDL.Interfaces.RealInputTRooCooSetSetpoint temperature for room for cooling
Modelica.Blocks.Interfaces.RealInputTRooMeasured room temperature
Modelica.Fluid.Interfaces.FluidPort_aport_aFluid connector a1 (positive design flow direction is from port_a1 to port_b1)
Modelica.Fluid.Interfaces.FluidPort_aport_bFluid connector b (positive design flow direction is from port_a1 to port_b1)
Modelica.Blocks.Interfaces.RealOutputyDamActual VAV damper position
Fluid.Actuators.Dampers.PressureIndependentvavVAV box for room
Buildings.Fluid.HeatExchangers.DryCoilEffectivenessNTUterHeaHeat exchanger of terminal box
Buildings.Fluid.Sources.Boundary_pTsinTerSink for terminal box
Buildings.Examples.VAVReheat.BaseClasses.Controls.RoomVAVconRoom temperature controller
Buildings.Fluid.Sensors.MassFlowRatesenMasFloSensor for mass flow rate
Modelica.Blocks.Math.GainfraMasFloFraction of mass flow rate, relative to nominal flow
Buildings.Fluid.Sensors.TemperatureTwoPortTSupSupply air temperature
Modelica.Blocks.Math.GainACHAir change per hour
Buildings.Fluid.Actuators.Valves.TwoWayLinearvalHeaValve at reaheat coil
Buildings.Fluid.Sources.Boundary_pTsouTerSource for terminal box

Contents

NameDescription
MediumAMedium model for air
MediumWMedium model for water

Revisions

  • February 25, 2021 by Baptiste Ravache:
    Inverse the sign of terHea.Q_flow_nominal to respect the heat flow convention.
  • June 6, 2017 by Jianjun Hu:
    First implementation, based on Buildings library.