blockSumZone

Output the sum, maximum and minimum from the zone level calculation
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Information

This sequence sums up the zone level minimum outdoor airflow setpoints, finds the maximum zone outdoor air fraction and the minimum zone ventilation efficiency. It collects zone level outputs and prepares inputs for specifying AHU level minimum outdoor air setpoint.

It requires following inputs from zone level calculation,

  • Design zone peak occupancy, uDesZonPeaOcc,
  • Population component of the breathing zone design outdoor airflow, VDesPopBreZon_flow,
  • Area component of the breathing zone design outdoor airflow, VDesAreBreZon_flow,
  • Design zone primary outdoor air fraction, uDesPriOutAirFra,
  • Uncorrected outdoor airflow rate, VUncOutAir_flow,
  • Primary outdoor air fraction, uPriOutAirFra,
  • Primary airflow rate, VPriAir_flow,

and following input from AHU level calculation,

  • Average AHU level outdoor air flow fraction plus 1, yAveOutAirFraPlu.

The sequence gives following outputs for AHU level calculation:

  • Sum of the design population of the zones, ySumDesZonPop,
  • Sum of the population component of the design breathing zone flow rate, VSumDesPopBreZon_flow,
  • Sum of the area component of the design breathing zone flow rate, VSumDesAreBreZon_flow,
  • Design system ventilation efficiency, yDesSysVenEff,

    First, compute the zone ventilation efficiency zonVenEff, for design purpose, as 

        zonVenEff[i] = yAveOutAirFraPlu - uDesPriOutAirFra[i]

    where the uDesPriOutAirFra is the design zone outdoor airflow fraction. Then the design system ventilation efficiency yDesSysVenEff is 

        yDesSysVenEff = min(zonVenEff[i]).
  • Sum of the required uncorrected outdoor airflow rate, VSumUncOutAir_flow,
  • Maximum zone outdoor air fraction, uOutAirFra_max,
  • AHU level primary airflow rate, VSumSysPriAir_flow.

Parameters

TypeNameDefaultDescription
IntegernumZonTotal number of zones that the system serves

Connectors

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Interfaces.RealInput[numZon]uDesZonPeaOccDesign zone peak occupancy
Buildings.Controls.OBC.CDL.Interfaces.RealInput[numZon]VDesPopBreZon_flowPopulation component breathing zone design outdoor airflow
Buildings.Controls.OBC.CDL.Interfaces.RealInput[numZon]VDesAreBreZon_flowArea component breathing zone design outdoor airflow
Buildings.Controls.OBC.CDL.Interfaces.RealInputyAveOutAirFraPluAverage system outdoor air flow fraction plus 1
Buildings.Controls.OBC.CDL.Interfaces.RealInput[numZon]uDesPriOutAirFraDesign zone primary outdoor air fraction
Buildings.Controls.OBC.CDL.Interfaces.RealInput[numZon]VUncOutAir_flowUncorrected outdoor airflow rate
Buildings.Controls.OBC.CDL.Interfaces.RealInput[numZon]uPriOutAirFraPrimary outdoor air fraction
Buildings.Controls.OBC.CDL.Interfaces.RealInput[numZon]VPriAir_flowPrimary airflow rate
Buildings.Controls.OBC.CDL.Interfaces.RealOutputySumDesZonPopSum of the design population of the zones in the group
Buildings.Controls.OBC.CDL.Interfaces.RealOutputVSumDesPopBreZon_flowSum of the population component design breathing zone flow rate
Buildings.Controls.OBC.CDL.Interfaces.RealOutputVSumDesAreBreZon_flowSum of the area component design breathing zone flow rate
Buildings.Controls.OBC.CDL.Interfaces.RealOutputyDesSysVenEffDesign system ventilation efficiency, equals to the minimum of all zones ventilation efficiency
Buildings.Controls.OBC.CDL.Interfaces.RealOutputVSumUncOutAir_flowSum of the required uncorrected outdoor airflow rate
Buildings.Controls.OBC.CDL.Interfaces.RealOutputuOutAirFra_maxMaximum zone outdoor air fraction, equals to the maximum of primary outdoor air fraction of all zones
Buildings.Controls.OBC.CDL.Interfaces.RealOutputVSumSysPriAir_flowAHU level primary airflow rate, equals to the sum of the measured discharged flow rate of all terminal units

Revisions

  • March 13, 2020, by Jianjun Hu:
    Separated from original sequence of finding the system minimum outdoor air setpoint.
    This is for #1829.