modelHeatRecoveryChiller

Heat recovery chiller for sidestream integration

Extends from Buildings.Fluid.Interfaces.PartialFourPortInterface (Partial model with four ports and declaration of quantities that are used by many models).

Information

Model of a heat recovery chiller with constant speed CHW and HW pumps. The model is intended to represent the sidestream integration of a HRC into a heating and cooling plant. In such a configuration, the condenser is connected to the HW return and the evaporator is connected to the CHW return.

Control points

The following input and output points are available.

Chiller: Refer to the documentation of Buildings.Templates.Components.Chillers.Compression considering have_switchover=true and typ=Buildings.Templates.Components.Types.Chiller.WaterCooled.
CHW pump or HW pump: Refer to the documentation of Buildings.Templates.Components.Pumps.Single.

Parameters

Type	Name	Default	Description
Buildings.Templates.Components.Data.PumpSingle	datPumChiWat		HRC CHW pump parameters
Buildings.Templates.Components.Data.PumpSingle	datPumHeaWat		HRC HW pump parameters
Buildings.Templates.Components.Data.Chiller	datHrc		HRC parameters
Modelica.Units.SI.MassFlowRate	mChiWat_flow_nominal	hrc.mChiWat_flow_nominal	Design CHW mass flow rate
Modelica.Units.SI.MassFlowRate	mCon_flow_nominal	hrc.mCon_flow_nominal	Design condenser cooling fluid mass flow rate
Modelica.Units.SI.HeatFlowRate	QChiWat_flow_nominal	hrc.QChiWat_flow_nominal	Design cooling heat flow rate
Modelica.Units.SI.PressureDifference	dpChiWat_nominal	hrc.dpChiWat_nominal	Design CHW pressure drop
Modelica.Units.SI.PressureDifference	dpCon_nominal	hrc.dpCon_nominal	Design condenser cooling fluid pressure drop
Modelica.Units.SI.Temperature	TChiWatSup_nominal	hrc.TChiWatSup_nominal	Design CHW supply temperature
Modelica.Units.SI.Temperature	TChiWatRet_nominal	hrc.TChiWatRet_nominal	Design CHW return temperature
Modelica.Units.SI.HeatFlowRate	QCon_flow_nominal	hrc.QCon_flow_nominal	Design condenser heat flow rate
Modelica.Units.SI.Temperature	TConEnt_nominal	hrc.TConEnt_nominal	Design condenser entering fluid temperature
Modelica.Units.SI.Temperature	TConLvg_nominal	hrc.TConLvg_nominal	Design condenser leaving fluid temperature
Assumptions
Boolean	allowFlowReversal1 (from PartialFourPort)	true	= false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1
Boolean	allowFlowReversal2 (from PartialFourPort)	true	= false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2
Nominal condition
Modelica.Units.SI.MassFlowRate	m1_flow_nominal (from PartialFourPortInterface)		Nominal mass flow rate
Modelica.Units.SI.MassFlowRate	m2_flow_nominal (from PartialFourPortInterface)		Nominal mass flow rate
Advanced
Medium1.MassFlowRate	m1_flow_small (from PartialFourPortInterface)	1E-4*abs(m1_flow_nominal)	Small mass flow rate for regularization of zero flow
Medium2.MassFlowRate	m2_flow_small (from PartialFourPortInterface)	1E-4*abs(m2_flow_nominal)	Small mass flow rate for regularization of zero flow
Advanced › Diagnostics
Boolean	show_T (from PartialFourPortInterface)	false	= true, if actual temperature at port is computed
Dynamics › Nominal condition
Modelica.Units.SI.Time	tauHrc	30	HRC – Time constant at nominal flow, used if energy or mass balance is dynamic
Modelica.Units.SI.Time	tauPum	1	Pump – Time constant of fluid volume for nominal flow, used if energy or mass balance is dynamic
Dynamics › Conservation equations
Modelica.Fluid.Types.Dynamics	energyDynamics	Modelica.Fluid.Types.Dynamics.DynamicFreeInitial	Type of energy balance: dynamic (3 initialization options) or steady state

Connectors

Type	Name	Description
Modelica.Fluid.Interfaces.FluidPort_a	port_a1 (from PartialFourPort)	Fluid connector a1 (positive design flow direction is from port_a1 to port_b1)
Modelica.Fluid.Interfaces.FluidPort_b	port_b1 (from PartialFourPort)	Fluid connector b1 (positive design flow direction is from port_a1 to port_b1)
Modelica.Fluid.Interfaces.FluidPort_a	port_a2 (from PartialFourPort)	Fluid connector a2 (positive design flow direction is from port_a2 to port_b2)
Modelica.Fluid.Interfaces.FluidPort_b	port_b2 (from PartialFourPort)	Fluid connector b2 (positive design flow direction is from port_a2 to port_b2)
Buildings.Templates.Plants.HeatPumps.Interfaces.Bus	bus	Plant control bus

Components

Type	Name	Default	Description
Medium1.MassFlowRate	m1_flow (from PartialFourPortInterface)	port_a1.m_flow	Mass flow rate from port_a1 to port_b1 (m1_flow > 0 is design flow direction)
Modelica.Units.SI.PressureDifference	dp1 (from PartialFourPortInterface)	port_a1.p - port_b1.p	Pressure difference between port_a1 and port_b1
Medium2.MassFlowRate	m2_flow (from PartialFourPortInterface)	port_a2.m_flow	Mass flow rate from port_a2 to port_b2 (m2_flow > 0 is design flow direction)
Modelica.Units.SI.PressureDifference	dp2 (from PartialFourPortInterface)	port_a2.p - port_b2.p	Pressure difference between port_a2 and port_b2
Medium1.ThermodynamicState	sta_a1 (from PartialFourPortInterface)	if allowFlowReversal1 then Medium1.setState_phX(port_a1.p, noEvent(actualStream(port_a1.h_outflow)), noEvent(actualStream(port_a1.Xi_outflow))) else Medium1.setState_phX(port_a1.p, inStream(port_a1.h_outflow), inStream(port_a1.Xi_outflow))	Medium properties in port_a1
Medium1.ThermodynamicState	sta_b1 (from PartialFourPortInterface)	if allowFlowReversal1 then Medium1.setState_phX(port_b1.p, noEvent(actualStream(port_b1.h_outflow)), noEvent(actualStream(port_b1.Xi_outflow))) else Medium1.setState_phX(port_b1.p, port_b1.h_outflow, port_b1.Xi_outflow)	Medium properties in port_b1
Medium2.ThermodynamicState	sta_a2 (from PartialFourPortInterface)	if allowFlowReversal2 then Medium2.setState_phX(port_a2.p, noEvent(actualStream(port_a2.h_outflow)), noEvent(actualStream(port_a2.Xi_outflow))) else Medium2.setState_phX(port_a2.p, inStream(port_a2.h_outflow), inStream(port_a2.Xi_outflow))	Medium properties in port_a2
Medium2.ThermodynamicState	sta_b2 (from PartialFourPortInterface)	if allowFlowReversal2 then Medium2.setState_phX(port_b2.p, noEvent(actualStream(port_b2.h_outflow)), noEvent(actualStream(port_b2.Xi_outflow))) else Medium2.setState_phX(port_b2.p, port_b2.h_outflow, port_b2.Xi_outflow)	Medium properties in port_b2
Buildings.Templates.Components.Chillers.Compression	hrc		Heat recovery chiller
Buildings.Templates.Components.Pumps.Single	pumChiWat		HRC CHW pump
Buildings.Templates.Components.Pumps.Single	pumHeaWat		HRC HW pump

Name	Description
MediumChiWat
MediumHeaWat

Revisions

April 18, 2025, by Antoine Gautier:
Refactored with load-dependent 2D table data heat recovery chiller model.
This is for #4152.
May 31, 2024, by Antoine Gautier:
First implementation.