blockAirFlowRateSplit

Air flow rate ratios and unit conversion

Extends from Modelica.Blocks.Icons.Block.

Information

This model splits a given volume flow in m3/s (e.g. for an Air Handling Unit) into several flows for one zone each based on:

  • Which zone is supplied by the AHU
  • A minimal volume flow (minAHU) in m3/(m2*h) per zone
  • A maxmial volume flow (maxAHU = deltaAHU + minAHU) in m3/(m2*h) per zone
  • A given profile or relative occupation per zone

A vector of AixLib.DataBase.ThermalZones.ZoneBaseRecord records is necessary to evaluate which zones are supplied by an AHU. The model calculates the single ratios of each zone of the ingoing volume flow into the AHU and weights the outcoming volume flow of the AHU correspondingly. As thermal zones as consumer typically use 1/h, this model converts m3/s to 1/h.

Typical use and important parameters

The governing equations are:

airFlow[nZones] = (minAHU + deltaAHU * (profile OR relative Occupation)) * AZone * 3600^-1

airFlowShareZones[nZones] = airFow[nZones] * isSuppliedByAHU[nZones]

airFlowOut[nZones] = airFlowShareZones[nZones] .* airFlowIn

All parameter come from the vector of AixLib.DataBase.ThermalZones.ZoneBaseRecord records. The model is typically used as output adapter for AHU model in AixLib.ThermalZones.ReducedOrder.Multizone.MultizoneEquipped.

  • September 27, 2016, by Moritz Lauster:
    Moved to fit to new Annex60 structure.
  • October 30, 2015, by Moritz Lauster:
    Moved and adapted to AixLib. Some renaming and adding units.
  • March 3, 2015, by Ole Odendahl:
    Added documentation and formatted appropriately

Parameters

TypeNameDefaultDescription
IntegerdimensionNumber of Zones
BooleanwithProfilefalseProfile or occupancy as control value for AHU
AixLib.DataBase.ThermalZones.ZoneBaseRecord[dimension]zoneParamRecords of zones

Components

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.RealInputprofileInput profile for AHU operation
Modelica.Blocks.Interfaces.RealInput[dimension]relOccupationInput for relative occupation
Modelica.Blocks.Interfaces.RealInputairFlowInAggregated air flow rate
Modelica.Blocks.Interfaces.RealOutput[dimension]airFlowOutSplitted air flow rate