modelPredictLeavingTemperature

Block that predicts heat exchanger leaving water temperature
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Information

This block computes the predicted heat exchanger leaving water temperature as used in Buildings.DHC.ETS.Combined.Controls.WatersideEconomizer.

The predicted heat exchanger approach is computed as

dTApp = dTApp_nominal * m2_flow / m2_flow_nominal,

which gives the predicted heat exchanger leaving water temperature as

T2WatLvg = T1WatEnt + dTApp.

Parameters

TypeNameDefaultDescription
Nominal condition
RealdTApp_nominalHeat exchanger approach
Realm2_flow_nominalHeat exchanger secondary mass flow rate

Connectors

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Interfaces.RealInputm2_flowHeat exchanger secondary mass flow rate
Buildings.Controls.OBC.CDL.Interfaces.RealInputT1WatEntHeat exchanger primary water entering temperature
Buildings.Controls.OBC.CDL.Interfaces.RealOutputT2WatLvgHeat exchanger secondary water leaving temperature

Components

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Reals.Dividediv1Calculate flow ratio
Buildings.Controls.OBC.CDL.Reals.Sources.ConstantconHeat exchanger secondary nominal mass flow rate
Buildings.Controls.OBC.CDL.Reals.Minmin1Output the smaller input
Buildings.Controls.OBC.CDL.Reals.Absabs1Output the absolute value
Buildings.Controls.OBC.CDL.Reals.Sources.Constantcon1One
Buildings.Controls.OBC.CDL.Reals.Sources.Constantcon2Heat exchanger approach
Buildings.Controls.OBC.CDL.Reals.MultiplymulOutput product
Buildings.Controls.OBC.CDL.Reals.Addadd2Calculate the leaving water temperature

Revisions

  • February 5, 2025, by Jianjun Hu:
    Reimplemented it to comply with CDL specification. This is for Buildings, issue 4110.
  • July 14, 2021, by Antoine Gautier:
    First implementation.