modelPartialHeatPump

Partial base class for subsystems containing a heat pump
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Information

This model represents a water-to-water heat pump, as described in Buildings.Fluid.HeatPumps.Carnot_TCon, the condenser pump, and the evaporator side hydronics and control.

Evaporator Controls

The system is enabled when the input control signal uEna switches to true. When enabled,

  • the evaporator pump is commanded on and supplies the nominal mass flow rate,
  • a three-way diverging valve is used to bypass flow through the evaporator and is controlled by a PI controller to maintain dT_nominal across the district supply and return flows.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.MassFlowRatemCon_flow_nominalheaPum.m1_flow_nominalCondenser mass flow rate
Modelica.Units.SI.MassFlowRatemEva_flow_nominalheaPum.m2_flow_nominalEvaporator mass flow rate
Nominal condition
RealCOP_nominalHeat pump COP
Modelica.Units.SI.TemperatureTCon_nominalCondenser outlet temperature used to compute COP_nominal
Modelica.Units.SI.TemperatureTEva_nominalEvaporator outlet temperature used to compute COP_nominal
Modelica.Units.SI.TemperatureDifferencedT_nominal5Water temperature drop/increase accross load and source-side HX (always positive)
Modelica.Units.SI.Pressuredp1_nominalPressure difference over condenser
Modelica.Units.SI.Pressuredp2_nominalPressure difference over evaporator
Assumptions
BooleanallowFlowReversal1falseSet to true to allow flow reversal on condenser side
BooleanallowFlowReversal2falseSet to true to allow flow reversal on evaporator side

Connectors

TypeNameDefaultDescription
Modelica.Fluid.Interfaces.FluidPort_aport_a2Fluid port for entering evaporator water
Modelica.Fluid.Interfaces.FluidPort_bport_b2Fluid port for leaving evaporator water
Modelica.Fluid.Interfaces.FluidPort_aport_a1Fluid port for cold domestic water
Modelica.Fluid.Interfaces.FluidPort_bport_b1Fluid port for heated domestic hot water
Buildings.Controls.OBC.CDL.Interfaces.RealOutputPHeaHeat pump power
Buildings.Controls.OBC.CDL.Interfaces.RealOutputPPumPump power
Buildings.Controls.OBC.CDL.Interfaces.RealOutputmEva_flowEvaporator water mass flow rate
Buildings.Controls.OBC.CDL.Interfaces.BooleanInputuEnaEnable signal

Components

TypeNameDefaultDescription
Buildings.Fluid.HeatPumps.Carnot_TConheaPumDomestic hot water heat pump
Buildings.DHC.ETS.BaseClasses.Pump_m_flowpumConPump for heat pump condenser
Buildings.Fluid.Movers.Preconfigured.SpeedControlled_ypumEvaHeat pump evaporator water pump
Modelica.Blocks.Math.AddaddPPumElectricity use for pumps
Buildings.Controls.OBC.CDL.Conversions.BooleanToRealfloEvaEvaporator mass flow rate
Fluid.Actuators.Valves.ThreeWayEqualPercentageLinearvalHeaPumEvaValve at heat pump evaporator
Fluid.Sensors.TemperatureTwoPortsenTEvaRetEvaporator return temperature sensor
Fluid.Sensors.TemperatureTwoPortsenTDisSupDistrict supply temperature sensor
Buildings.Controls.OBC.CDL.Reals.SubtractdT_supRetTemperature difference over heat pump connection
Buildings.Controls.OBC.CDL.Reals.Sources.ConstantdTSetSet point for temperature difference over heat pump
Buildings.Controls.OBC.CDL.Reals.PIDWithResetconPIController to ensure dT_nominal over heat pump connection
Fluid.Sensors.MassFlowRatesenMasFloMass flow rate drawn from ETS
Buildings.DHC.ETS.BaseClasses.Junctionjunction

Contents

NameDescription
Medium1Medium model on condenser side
Medium2Medium model on evaporator side

Revisions

  • February 15, 2024, by Ettore Zanetti:
    Made heat pump model dynamic and added junction.
  • November 15, 2023, by David Blum:
    Changed to partial base class with evaporator hydronics and control.
  • November 16, 2022, by Michael Wetter:
    Set pumEva.dp_nominal to correct value.
  • February 23, 2021, by Antoine Gautier:
    First implementation.