modelPartialAHU

Defines necessary parameters and connectors
Diagram of PartialAHUOpen the diagram

Information

Base class to provide connectors. Thus, it is possible to declare parameters in a general way in superior building model and give the opportunity whether an AHU exist or does not.

Parameters

TypeNameDefaultDescription
Settings for State Machines
RealclockPeriodGeneric1800time period in s for sampling (= converting time-continous into time-discrete) input variables. Recommendation: half of the duration of one simulation interval
AHU Modes
BooleanheatingtrueHeating Function of AHU
BooleancoolingtrueCooling Function of AHU
BooleandehumidificationSetif heating and cooling then true else falseDehumidification Function of AHU (Cooling and Heating must be enabled)
BooleanhumidificationSetif heating and cooling then true else falseHumidification Function of AHU (Cooling and Heating must be enabled)
BooleanHRStrueIs a HeatRecoverySystem physically integrated in the AHU?
Booleanuse_Vflow_in_extractAirfalseIf 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_DeHu0.2By-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_enabled0.8efficiency of HRS in the AHU modes when HRS is enabled
RealefficiencyHRS_disabled0.2taking 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_sup800pressure difference over supply fan
Modelica.Units.SI.Pressuredp_eta800pressure difference over extract fan
Modelica.Units.SI.Efficiencyeta_sup0.7efficiency of supply fan
Modelica.Units.SI.Efficiencyeta_eta0.7efficiency of extract fan

Connectors

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.RealInputVflow_inm3/s
Modelica.Blocks.Interfaces.RealInputT_outdoorAirK
Modelica.Blocks.Interfaces.RealInputX_outdoorAirkg of water/kg of dry air
Modelica.Blocks.Interfaces.RealInputT_extractAirK
Modelica.Blocks.Interfaces.RealInputphi_extractAirrelativ Humidity [Range: 0...1]
Modelica.Blocks.Interfaces.RealOutputphi_supplyrelativ Humidity [Range: 0...1]
Modelica.Blocks.Interfaces.RealInputT_supplyAirK (use as PortIn)
Modelica.Blocks.Interfaces.RealInput[2]phi_supplyAirrelativ Humidity [Range: 0...1] (Vector: [1] min, [2] max)
Modelica.Blocks.Interfaces.RealOutputQflowCThe absorbed cooling power supplied from a cooling circuit [W]
Modelica.Blocks.Interfaces.RealOutputQflowHThe absorbed heating power supplied from a heating circuit [W]
Modelica.Blocks.Interfaces.RealOutputPelThe consumed electrical power supplied from the mains [W]
Modelica.Blocks.Interfaces.RealOutputVflow_outsupply volume flow in m3/s
Modelica.Blocks.Interfaces.RealOutputT_supplyAirOutK (use as PortOut)
Modelica.Blocks.Interfaces.RealInputVflow_in_extractAirVolume flow of extract air

Components

TypeNameDefaultDescription
Booleandehumidification
Booleanhumidification

Revisions

  • February, 2016  by Philipp Mehrfeld:
    Model implemented