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Buildings.Fluid.Chillers.Validation

Collection of models that validate the chiller models

Information

This package contains models that validate the chiller models. The examples plot various outputs, which have been verified against analytical solutions. These model outputs are stored as reference data to allow continuous validation whenever models in the library change.

Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).

Package Content

Name Description
Buildings.Fluid.Chillers.Validation.Carnot_TEva_HighTemperature Carnot_TEva_HighTemperature Test model for Carnot_TEva with high evaporator temperature
Buildings.Fluid.Chillers.Validation.Carnot_TEva_LimitedCapacity Carnot_TEva_LimitedCapacity Test model for Carnot_TEva with limited heating capacity
Buildings.Fluid.Chillers.Validation.Carnot_TEva_etaPL Carnot_TEva_etaPL Test model for the part load efficiency curve with evaporator leaving temperature as input signal
Buildings.Fluid.Chillers.Validation.Carnot_TEva_reverseFlow Carnot_TEva_reverseFlow Test model for chiller based on Carnot efficiency and evaporator outlet temperature control signal
Buildings.Fluid.Chillers.Validation.Carnot_y_etaPL Carnot_y_etaPL Test model for the part load efficiency curve with compressor speed as input signal

Buildings.Fluid.Chillers.Validation.Carnot_TEva_HighTemperature Buildings.Fluid.Chillers.Validation.Carnot_TEva_HighTemperature

Test model for Carnot_TEva with high evaporator temperature

Buildings.Fluid.Chillers.Validation.Carnot_TEva_HighTemperature

Information

This example extends from Buildings.Fluid.Chillers.Examples.Carnot_TEva but increases the set point for the leaving evaporator temperature to be above its inlet temperature, in which case the model provide no cooling. Towards the end of the simulation, the inlet temperature of the evaporator is increased to be above the condenser temperature. In this domain, the model requires cooling again. While this is not a meaningful operating point for the model, the example verifies that it robustly simulates this regime.

Extends from Examples.Carnot_TEva (Test model for chiller based on Carnot efficiency and evaporator outlet temperature control signal).

Parameters

TypeNameDefaultDescription
TemperatureDifferencedTEva_nominal-10Temperature difference evaporator outlet-inlet [K]
TemperatureDifferencedTCon_nominal10Temperature difference condenser outlet-inlet [K]
RealCOPc_nominal3Chiller COP
HeatFlowRateQEva_flow_nominal-100E3Evaporator heat flow rate [W]
MassFlowRatem2_flow_nominalQEva_flow_nominal/dTEva_nomi...Nominal mass flow rate at chilled water side [kg/s]

Modelica definition

model Carnot_TEva_HighTemperature "Test model for Carnot_TEva with high evaporator temperature" extends Examples.Carnot_TEva(TEvaLvg(height=34), sou2(use_T_in=true)); Modelica.Blocks.Sources.Ramp TEvaEnt( startTime=3000, height=38, offset=273.15 + 22, duration=60) "Control signal for evaporator entering temperature"; equation connect(TEvaEnt.y, sou2.T_in); end Carnot_TEva_HighTemperature;

Buildings.Fluid.Chillers.Validation.Carnot_TEva_LimitedCapacity Buildings.Fluid.Chillers.Validation.Carnot_TEva_LimitedCapacity

Test model for Carnot_TEva with limited heating capacity

Buildings.Fluid.Chillers.Validation.Carnot_TEva_LimitedCapacity

Information

This example extends from Buildings.Fluid.Chillers.Examples.Carnot_TEva but limits the cooling capacity.

Extends from Examples.Carnot_TEva (Test model for chiller based on Carnot efficiency and evaporator outlet temperature control signal).

Parameters

TypeNameDefaultDescription
TemperatureDifferencedTEva_nominal-10Temperature difference evaporator outlet-inlet [K]
TemperatureDifferencedTCon_nominal10Temperature difference condenser outlet-inlet [K]
RealCOPc_nominal3Chiller COP
HeatFlowRateQEva_flow_nominal-100E3Evaporator heat flow rate [W]
MassFlowRatem2_flow_nominalQEva_flow_nominal/dTEva_nomi...Nominal mass flow rate at chilled water side [kg/s]

Modelica definition

model Carnot_TEva_LimitedCapacity "Test model for Carnot_TEva with limited heating capacity" extends Examples.Carnot_TEva( chi(QEva_flow_min=-100000)); end Carnot_TEva_LimitedCapacity;

Buildings.Fluid.Chillers.Validation.Carnot_TEva_etaPL Buildings.Fluid.Chillers.Validation.Carnot_TEva_etaPL

Test model for the part load efficiency curve with evaporator leaving temperature as input signal

Buildings.Fluid.Chillers.Validation.Carnot_TEva_etaPL

Information

This example extends from Buildings.Fluid.Chillers.Examples.Carnot_TEva but has a part load efficiency that varies with the load.

Extends from Examples.Carnot_TEva (Test model for chiller based on Carnot efficiency and evaporator outlet temperature control signal).

Parameters

TypeNameDefaultDescription
TemperatureDifferencedTEva_nominal-10Temperature difference evaporator outlet-inlet [K]
TemperatureDifferencedTCon_nominal10Temperature difference condenser outlet-inlet [K]
RealCOPc_nominal3Chiller COP
HeatFlowRateQEva_flow_nominal-100E3Evaporator heat flow rate [W]
MassFlowRatem2_flow_nominalQEva_flow_nominal/dTEva_nomi...Nominal mass flow rate at chilled water side [kg/s]

Modelica definition

model Carnot_TEva_etaPL "Test model for the part load efficiency curve with evaporator leaving temperature as input signal" extends Examples.Carnot_TEva( chi(a={0.7,0.3}, QEva_flow_min=-100000)); end Carnot_TEva_etaPL;

Buildings.Fluid.Chillers.Validation.Carnot_TEva_reverseFlow Buildings.Fluid.Chillers.Validation.Carnot_TEva_reverseFlow

Test model for chiller based on Carnot efficiency and evaporator outlet temperature control signal

Buildings.Fluid.Chillers.Validation.Carnot_TEva_reverseFlow

Information

Example that simulates a chiller whose efficiency is scaled based on the Carnot cycle. The chiller takes as an input the evaporator leaving water temperature. The condenser mass flow rate is computed in such a way that it has a temperature difference equal to dTEva_nominal.

This example checks the correct behavior if a mass flow rate attains zero.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Parameters

TypeNameDefaultDescription
TemperatureDifferencedTEva_nominal-10Temperature difference evaporator inlet-outlet [K]
TemperatureDifferencedTCon_nominal10Temperature difference condenser outlet-inlet [K]
RealCOPc_nominal3Chiller COP
HeatFlowRateQEva_flow_nominal-100E3Evaporator heat flow rate [W]
MassFlowRatem2_flow_nominalQEva_flow_nominal/dTEva_nomi...Nominal mass flow rate at chilled water side [kg/s]
MassFlowRatem1_flow_nominalm2_flow_nominal*(COPc_nomina...Nominal mass flow rate at condenser water wide [kg/s]

Modelica definition

model Carnot_TEva_reverseFlow "Test model for chiller based on Carnot efficiency and evaporator outlet temperature control signal" extends Modelica.Icons.Example; package Medium1 = Buildings.Media.Water "Medium model"; package Medium2 = Buildings.Media.Water "Medium model"; parameter Modelica.SIunits.TemperatureDifference dTEva_nominal=-10 "Temperature difference evaporator inlet-outlet"; parameter Modelica.SIunits.TemperatureDifference dTCon_nominal=10 "Temperature difference condenser outlet-inlet"; parameter Real COPc_nominal = 3 "Chiller COP"; parameter Modelica.SIunits.HeatFlowRate QEva_flow_nominal = -100E3 "Evaporator heat flow rate"; parameter Modelica.SIunits.MassFlowRate m2_flow_nominal= QEva_flow_nominal/dTEva_nominal/4200 "Nominal mass flow rate at chilled water side"; parameter Modelica.SIunits.MassFlowRate m1_flow_nominal= m2_flow_nominal*(COPc_nominal+1)/COPc_nominal "Nominal mass flow rate at condenser water wide"; Buildings.Fluid.Chillers.Carnot_TEva chi( redeclare package Medium1 = Medium1, redeclare package Medium2 = Medium2, dTEva_nominal=dTEva_nominal, dTCon_nominal=dTCon_nominal, use_eta_Carnot_nominal=true, etaCarnot_nominal=0.3, m1_flow_nominal=m1_flow_nominal, m2_flow_nominal=m2_flow_nominal, show_T=true, QEva_flow_nominal=QEva_flow_nominal, allowFlowReversal1=true, allowFlowReversal2=true, dp1_nominal=6000, dp2_nominal=6000) "Chiller model"; Buildings.Fluid.Sources.MassFlowSource_T sou1(nPorts=1, redeclare package Medium = Medium1, m_flow=m1_flow_nominal, use_T_in=false, use_m_flow_in=true, T=298.15); Buildings.Fluid.Sources.MassFlowSource_T sou2(nPorts=1, redeclare package Medium = Medium2, m_flow=m2_flow_nominal, use_T_in=false, use_m_flow_in=true, T=295.15); Buildings.Fluid.Sources.FixedBoundary sin1( redeclare package Medium = Medium1, nPorts=1); Buildings.Fluid.Sources.FixedBoundary sin2(nPorts=1, redeclare package Medium = Medium2); Modelica.Blocks.Sources.Constant TEvaLvg(k=273.15 + 10) "Control signal for evaporator leaving temperature"; Modelica.Blocks.Math.Gain mCon_flow(k=-1/cp1_default/dTEva_nominal) "Condenser mass flow rate"; Modelica.Blocks.Math.Add QCon_flow(k2=-1) "Condenser heat flow rate"; final parameter Modelica.SIunits.SpecificHeatCapacity cp1_default= Medium1.specificHeatCapacityCp(Medium1.setState_pTX( Medium1.p_default, Medium1.T_default, Medium1.X_default)) "Specific heat capacity of medium 1 at default medium state"; Modelica.Blocks.Sources.Ramp mEva_flow( duration=60, startTime=1800, height=-2*m2_flow_nominal, offset=m2_flow_nominal) "Mass flow rate for evaporater"; equation connect(sou1.ports[1], chi.port_a1); connect(sou2.ports[1], chi.port_a2); connect(sin2.ports[1], chi.port_b2); connect(TEvaLvg.y, chi.TSet); connect(chi.P, QCon_flow.u1); connect(chi.QEva_flow, QCon_flow.u2); connect(QCon_flow.y, mCon_flow.u); connect(mCon_flow.y, sou1.m_flow_in); connect(chi.port_b1, sin1.ports[1]); connect(mEva_flow.y, sou2.m_flow_in); end Carnot_TEva_reverseFlow;

Buildings.Fluid.Chillers.Validation.Carnot_y_etaPL Buildings.Fluid.Chillers.Validation.Carnot_y_etaPL

Test model for the part load efficiency curve with compressor speed as input signal

Buildings.Fluid.Chillers.Validation.Carnot_y_etaPL

Information

This example extends from Buildings.Fluid.Chillers.Examples.Carnot_y but uses a part load efficiency curve that is different from 1.

Extends from Examples.Carnot_y (Test model for chiller based on Carnot_y efficiency).

Parameters

TypeNameDefaultDescription
PowerP_nominal10E3Nominal compressor power (at y=1) [W]
TemperatureDifferencedTEva_nominal-10Temperature difference evaporator outlet-inlet [K]
TemperatureDifferencedTCon_nominal10Temperature difference condenser outlet-inlet [K]
RealCOPc_nominal3Chiller COP
MassFlowRatem2_flow_nominal-P_nominal*COPc_nominal/dTEv...Nominal mass flow rate at chilled water side [kg/s]
MassFlowRatem1_flow_nominalm2_flow_nominal*(COPc_nomina...Nominal mass flow rate at condenser water wide [kg/s]

Modelica definition

model Carnot_y_etaPL "Test model for the part load efficiency curve with compressor speed as input signal" extends Examples.Carnot_y(chi(a={0.7,0.3})); end Carnot_y_etaPL;
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