modelSingleSpeed

Single speed water source DX coils

Extends from Buildings.Fluid.DXSystems.Cooling.BaseClasses.PartialWaterCooledDXCoil (Base class for water source DX coils).

Information

This model can be used to simulate a water source DX cooling coil with single speed compressor.

See Buildings.Fluid.DXSystems.Cooling.UsersGuide for an explanation of the model.

Parameters

Type	Name	Default	Description
Buildings.Fluid.DXSystems.Cooling.AirSource.Data.Generic.DXCoil	datCoi (from EssentialParameters)		Performance data
Boolean	homotopyInitialization (from PartialWaterCooledDXCoil)	true	= true, use homotopy method
Boolean	computeReevaporation (from PartialWaterCooledDXCoil)	true	Set to true to compute reevaporation of water that accumulated on coil
Assumptions
Boolean	allowFlowReversalEva (from PartialWaterCooledDXCoil)	true	= false to simplify equations, assuming, but not enforcing, no flow reversal for evaporator
Boolean	allowFlowReversalCon (from PartialWaterCooledDXCoil)	true	= false to simplify equations, assuming, but not enforcing, no flow reversal for condenser
Nominal condition
Modelica.Units.SI.PressureDifference	dpEva_nominal (from PartialWaterCooledDXCoil)		Pressure difference over evaporator at nominal flow rate
Modelica.Units.SI.PressureDifference	dpCon_nominal (from PartialWaterCooledDXCoil)		Pressure difference over condenser at nominal flow rate
Flow resistance › Evaporator
Boolean	from_dpEva (from PartialWaterCooledDXCoil)	false	= true, use m_flow = f(dp) else dp = f(m_flow)
Real	nEva (from PartialWaterCooledDXCoil)	2	Flow exponent, nEva=1 for laminar, nEva=2 for turbulent
Boolean	linearizeFlowResistanceEva (from PartialWaterCooledDXCoil)	false	= true, use linear relation between m_flow and dp for any flow rate
Real	deltaMEva (from PartialWaterCooledDXCoil)	0.1	Fraction of nominal flow rate where flow transitions to laminar
Flow resistance › Condenser
Boolean	from_dpCon (from PartialWaterCooledDXCoil)	false	= true, use m_flow = f(dp) else dp = f(m_flow)
Real	nCon (from PartialWaterCooledDXCoil)	2	Flow exponent, nCon=1 for laminar, nCon=2 for turbulent
Boolean	linearizeFlowResistanceCon (from PartialWaterCooledDXCoil)	false	= true, use linear relation between m_flow and dp for any flow rate
Real	deltaMCon (from PartialWaterCooledDXCoil)	0.1	Fraction of nominal flow rate where flow transitions to laminar
Dynamics › Evaporator
Modelica.Units.SI.Time	tauEva (from PartialWaterCooledDXCoil)	60	Time constant at nominal flow rate (used if energyDynamics <> Modelica.Fluid.Types.Dynamics.SteadyState)
Dynamics › Condenser
Modelica.Units.SI.Time	tauCon (from PartialWaterCooledDXCoil)	60	Time constant at nominal flow rate (used if energyDynamics <> Modelica.Fluid.Types.Dynamics.SteadyState)
Initialization › Evaporator
MediumEva.AbsolutePressure	pEva_start (from PartialWaterCooledDXCoil)	MediumEva.p_default	Start value of pressure
MediumEva.Temperature	TEva_start (from PartialWaterCooledDXCoil)	MediumEva.T_default	Start value of temperature
MediumEva.MassFraction[MediumEva.nX]	XEva_start (from PartialWaterCooledDXCoil)	MediumEva.X_default	Start value of mass fractions m_i/m
MediumEva.ExtraProperty[MediumEva.nC]	CEva_start (from PartialWaterCooledDXCoil)	fill(0, MediumEva.nC)	Start value of trace substances
MediumEva.ExtraProperty[MediumEva.nC]	CEva_nominal (from PartialWaterCooledDXCoil)	fill(1E-2, MediumEva.nC)	Nominal value of trace substances. (Set to typical order of magnitude.)
Initialization › Condenser
MediumCon.AbsolutePressure	pCon_start (from PartialWaterCooledDXCoil)	MediumCon.p_default	Start value of pressure
MediumCon.Temperature	TCon_start (from PartialWaterCooledDXCoil)	MediumCon.T_default	Start value of temperature
MediumCon.MassFraction[MediumCon.nX]	XCon_start (from PartialWaterCooledDXCoil)	MediumCon.X_default	Start value of mass fractions m_i/m
MediumCon.ExtraProperty[MediumCon.nC]	CCon_start (from PartialWaterCooledDXCoil)	fill(0, MediumCon.nC)	Start value of trace substances
MediumCon.ExtraProperty[MediumCon.nC]	CCon_nominal (from PartialWaterCooledDXCoil)	fill(1E-2, MediumCon.nC)	Nominal value of trace substances. (Set to typical order of magnitude.)
Dynamics › Conservation equations
Modelica.Fluid.Types.Dynamics	energyDynamics (from PartialWaterCooledDXCoil)	Modelica.Fluid.Types.Dynamics.DynamicFreeInitial	Type of energy balance: dynamic (3 initialization options) or steady state
Advanced › Diagnostics
Boolean	show_T (from PartialWaterCooledDXCoil)	false	= true, if actual temperature at port is computed

Connectors

Type	Name	Description
Modelica.Blocks.Interfaces.RealOutput	P (from PartialWaterCooledDXCoil)	Electrical power consumed by the unit
Modelica.Blocks.Interfaces.RealOutput	QEvaSen_flow (from PartialWaterCooledDXCoil)	Sensible heat flow rate in evaporators
Modelica.Blocks.Interfaces.RealOutput	QEvaLat_flow (from PartialWaterCooledDXCoil)	Latent heat flow rate in evaporators
Modelica.Fluid.Interfaces.FluidPort_a	port_a (from PartialWaterCooledDXCoil)	Fluid connector for evaporator inlet (positive design flow direction is from port_a1 to port_b1)
Modelica.Fluid.Interfaces.FluidPort_b	port_b (from PartialWaterCooledDXCoil)	Fluid connector b1 (positive design flow direction is from port_a1 to port_b1)
Modelica.Fluid.Interfaces.FluidPort_a	portCon_a (from PartialWaterCooledDXCoil)	Fluid connector a of condenser (positive design flow direction is from port_a2 to port_b2)
Modelica.Fluid.Interfaces.FluidPort_b	portCon_b (from PartialWaterCooledDXCoil)	Fluid connector b of condenser (positive design flow direction is from port_a2 to port_b2)
Modelica.Blocks.Interfaces.BooleanInput	on	Set to true to enable compressor, or false to disable compressor

Components

Type	Name	Default	Description
Buildings.Fluid.DXSystems.Cooling.BaseClasses.PartialDXCoolingCoil	eva (from PartialWaterCooledDXCoil)
Buildings.Fluid.HeatExchangers.HeaterCooler_u	watCooCon (from PartialWaterCooledDXCoil)		Water source condenser
Modelica.Units.SI.Temperature	TConEnt (from PartialWaterCooledDXCoil)	MediumCon.temperature(MediumCon.setState_phX(portCon_a.p, inStream(portCon_a.h_outflow)))	Temperature of fluid entering the condenser
MediumEva.ThermodynamicState	sta_a1 (from PartialWaterCooledDXCoil)	MediumEva.setState_phX(port_a.p, noEvent(actualStream(port_a.h_outflow)), noEvent(actualStream(port_a.Xi_outflow)))	Medium properties in port_a1
MediumEva.ThermodynamicState	sta_b1 (from PartialWaterCooledDXCoil)	MediumEva.setState_phX(port_b.p, noEvent(actualStream(port_b.h_outflow)), noEvent(actualStream(port_b.Xi_outflow)))	Medium properties in port_b1
MediumCon.ThermodynamicState	sta_a2 (from PartialWaterCooledDXCoil)	MediumCon.setState_phX(portCon_a.p, noEvent(actualStream(portCon_a.h_outflow)), noEvent(actualStream(portCon_a.Xi_outflow)))	Medium properties in port_a2
MediumCon.ThermodynamicState	sta_b2 (from PartialWaterCooledDXCoil)	MediumCon.setState_phX(portCon_b.p, noEvent(actualStream(portCon_b.h_outflow)), noEvent(actualStream(portCon_b.Xi_outflow)))	Medium properties in port_b2

Revisions

April 5, 2023, by Xing Lu:
Updated air-source cooling coil class being extended from SingleSpeed to Buildings.Fluid.DXSystems.Cooling.AirSource.SingleSpeed.
March 7, 2022, by Michael Wetter:
Set final massDynamics=energyDynamics.
This is for #1542.
March 21, 2017, by Michael Wetter:
Moved assignment of evaporator data datCoi from the constrainedBy declaration in the base class to the instantiation to work around a limitation of JModelica.
March 7, 2017, by Michael Wetter:
Refactored implementation to avoid code duplication and to propagate parameters.
February 16, 2017 by Yangyang Fu:
First implementation.