modelNoAHU

No AHU

Extends from AixLib.Airflow.AirHandlingUnit.BaseClasses.PartialAHU (Defines necessary parameters and connectors).

Information

This model can be seen as a dummy. Connectors exist due to partialAHU but outputs are zero and inputs do not have any effect. As a conclusion it is easier to choose whether an AHU exist in a building or not. For an example see AixLib.Building.LowOrder.Examples.MultizoneExample.

Parameters

TypeNameDefaultDescription
Settings for State Machines
RealclockPeriodGeneric (from PartialAHU)1800time period in s for sampling (= converting time-continous into time-discrete) input variables. Recommendation: half of the duration of one simulation interval
AHU Modes
Booleanheating (from PartialAHU)trueHeating Function of AHU
Booleancooling (from PartialAHU)trueCooling Function of AHU
BooleandehumidificationSet (from PartialAHU)if heating and cooling then true else falseDehumidification Function of AHU (Cooling and Heating must be enabled)
BooleanhumidificationSet (from PartialAHU)if heating and cooling then true else falseHumidification Function of AHU (Cooling and Heating must be enabled)
BooleanHRS (from PartialAHU)trueIs a HeatRecoverySystem physically integrated in the AHU?
Booleanuse_Vflow_in_extractAir (from PartialAHU)falseIf incoming volume flow of outdoor/supply air should not equal the volume flow of extract air, set this parameter to true
Settings AHU Value
RealBPF_DeHu (from PartialAHU)0.2By-pass factor of cooling coil during dehumidification. Necessary to calculate the real outgoing enthalpy flow of heat exchanger in dehumidification mode taking the surface enthalpy of the cooling coil into account
RealefficiencyHRS_enabled (from PartialAHU)0.8efficiency of HRS in the AHU modes when HRS is enabled
RealefficiencyHRS_disabled (from PartialAHU)0.2taking a little heat transfer into account although HRS is disabled (in case that a HRS is physically installed in the AHU)
Fans › Constant Assumptions
Modelica.Units.SI.Pressuredp_sup (from PartialAHU)800pressure difference over supply fan
Modelica.Units.SI.Pressuredp_eta (from PartialAHU)800pressure difference over extract fan
Modelica.Units.SI.Efficiencyeta_sup (from PartialAHU)0.7efficiency of supply fan
Modelica.Units.SI.Efficiencyeta_eta (from PartialAHU)0.7efficiency of extract fan

Connectors

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.RealInputVflow_in (from PartialAHU)m3/s
Modelica.Blocks.Interfaces.RealInputT_outdoorAir (from PartialAHU)K
Modelica.Blocks.Interfaces.RealInputX_outdoorAir (from PartialAHU)kg of water/kg of dry air
Modelica.Blocks.Interfaces.RealInputT_extractAir (from PartialAHU)K
Modelica.Blocks.Interfaces.RealInputphi_extractAir (from PartialAHU)relativ Humidity [Range: 0...1]
Modelica.Blocks.Interfaces.RealOutputphi_supply (from PartialAHU)relativ Humidity [Range: 0...1]
Modelica.Blocks.Interfaces.RealInputT_supplyAir (from PartialAHU)K (use as PortIn)
Modelica.Blocks.Interfaces.RealInput[2]phi_supplyAir (from PartialAHU)relativ Humidity [Range: 0...1] (Vector: [1] min, [2] max)
Modelica.Blocks.Interfaces.RealOutputQflowC (from PartialAHU)The absorbed cooling power supplied from a cooling circuit [W]
Modelica.Blocks.Interfaces.RealOutputQflowH (from PartialAHU)The absorbed heating power supplied from a heating circuit [W]
Modelica.Blocks.Interfaces.RealOutputPel (from PartialAHU)The consumed electrical power supplied from the mains [W]
Modelica.Blocks.Interfaces.RealOutputVflow_out (from PartialAHU)supply volume flow in m3/s
Modelica.Blocks.Interfaces.RealOutputT_supplyAirOut (from PartialAHU)K (use as PortOut)
Modelica.Blocks.Interfaces.RealInputVflow_in_extractAir (from PartialAHU)Volume flow of extract air

Components

TypeNameDefaultDescription
Booleandehumidification (from PartialAHU)
Booleanhumidification (from PartialAHU)
Modelica.Blocks.Sources.ConstantdummyPhi_supply
Modelica.Blocks.Sources.ConstantzeroVFlowOut
Modelica.Blocks.Sources.ConstantdummyT_supplyAirOut
Modelica.Blocks.Sources.CombiTimeTablezeroPowerElAndHeat1

Revisions

  • February, 2016  by Philipp Mehrfeld:
    Model implemented