modelPartialChiller

Interface class for chiller models

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

Information

This partial class provides a standard interface for chiller models.

Parameters

Type	Name	Default	Description
Buildings.Templates.Components.Data.Chiller	dat		Design and operating parameters
Modelica.Units.SI.MassFlowRate	mChiWat_flow_nominal	dat.mChiWat_flow_nominal	Design CHW mass flow rate
Modelica.Units.SI.MassFlowRate	mCon_flow_nominal	dat.mCon_flow_nominal	Design condenser cooling fluid mass flow rate
Modelica.Units.SI.HeatFlowRate	cap_nominal	dat.cap_nominal	Design cooling capacity
Modelica.Units.SI.HeatFlowRate	QChiWat_flow_nominal	-abs(cap_nominal)	Design cooling heat flow rate
Modelica.Units.SI.PressureDifference	dpChiWat_nominal	dat.dpChiWat_nominal	Design CHW pressure drop
Modelica.Units.SI.PressureDifference	dpCon_nominal	dat.dpCon_nominal	Design condenser cooling fluid pressure drop
Modelica.Units.SI.Temperature	TChiWatSup_nominal	dat.TChiWatSup_nominal	Design CHW supply temperature
Modelica.Units.SI.Temperature	TChiWatRet_nominal	TChiWatSup_nominal - QChiWat_flow_nominal/cpChiWat_default/mChiWat_flow_nominal	Design CHW return temperature
Modelica.Units.SI.HeatFlowRate	QCon_flow_nominal		Design condenser heat flow rate
Modelica.Units.SI.Temperature	TConEnt_nominal		Design condenser entering fluid temperature
Modelica.Units.SI.Temperature	TConLvg_nominal		Design condenser leaving fluid temperature
Modelica.Units.SI.Efficiency	COP_nominal		Coefficient of performance at design cooling conditions
MediumChiWat.SpecificHeatCapacity	cpChiWat_default	MediumChiWat.specificHeatCapacityCp(staChiWat_default)	CHW default specific heat capacity
MediumChiWat.ThermodynamicState	staChiWat_default	MediumChiWat.setState_pTX(T = TChiWatSup_nominal, p = MediumChiWat.p_default, X = MediumChiWat.X_default)	CHW default state
MediumCon.SpecificHeatCapacity	cpCon_default	MediumCon.specificHeatCapacityCp(staCon_default)	Condenser cooling fluid default specific heat capacity
MediumCon.ThermodynamicState	staCon_default	MediumCon.setState_pTX(T = dat.TCon_nominal, p = MediumCon.p_default, X = MediumCon.X_default)	Condenser cooling fluid default state
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
Boolean	have_dpChiWat	true	Set to true for CHW pressure drop computed by this model, false for external computation
Boolean	have_dpCon	true	Set to true for condenser cooling fluid pressure drop computed by this model, false for external computation
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
Configuration
Buildings.Templates.Components.Types.Chiller	typ		Type of chiller
Boolean	have_switchover	false	Set to true for heat recovery chiller with built-in switchover
Boolean	use_TChiWatSupForCtl	true	Set to true for CHW supply temperature control, false for CHW return temperature control
Dynamics › Nominal condition
Modelica.Units.SI.Time	tau	30	Time constant at 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.Components.Interfaces.Bus	bus	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

Name	Description
MediumChiWat
MediumCon

Revisions

April 17, 2025, by Antoine Gautier:
Refactored for load-dependent 2D table data chiller model.
November 18, 2022, by Antoine Gautier:
First implementation.