Annex60.Fluid.Chillers.Examples

This package contains examples for the use of models that can be found in Annex60.Fluid.Chillers.

Package Content

Name	Description
Carnot_TEva	Test model for chiller based on Carnot efficiency and evaporator outlet temperature control signal
Carnot_y	Test model for chiller based on Carnot_y efficiency

Annex60.Fluid.Chillers.Examples.Carnot_TEva

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

Annex60.Fluid.Chillers.Examples.Carnot_TEva

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.

Parameters

Modelica definition

Type	Name	Default	Description
TemperatureDifference	dTEva_nominal	-10	Temperature difference evaporator outlet-inlet [K]
TemperatureDifference	dTCon_nominal	10	Temperature difference condenser outlet-inlet [K]
Real	COPc_nominal	3	Chiller COP
HeatFlowRate	QEva_flow_nominal	-100E3	Evaporator heat flow rate [W]
MassFlowRate	m2_flow_nominal	QEva_flow_nominal/dTEva_nomi...	Nominal mass flow rate at chilled water side [kg/s]

model Carnot_TEva "Test model for chiller based on Carnot efficiency and evaporator outlet temperature control signal" extends Modelica.Icons.Example; package Medium1 = Annex60.Media.Water "Medium model"; package Medium2 = Annex60.Media.Water "Medium model"; parameter Modelica.SIunits.TemperatureDifference dTEva_nominal=-10 "Temperature difference evaporator outlet-inlet"; 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"; Annex60.Fluid.Chillers.Carnot_TEva chi( redeclare package Medium1 = Medium1, redeclare package Medium2 = Medium2, dTEva_nominal=dTEva_nominal, dTCon_nominal=dTCon_nominal, m2_flow_nominal=m2_flow_nominal, show_T=true, QEva_flow_nominal=QEva_flow_nominal, allowFlowReversal1=false, allowFlowReversal2=false, use_eta_Carnot_nominal=true, etaCarnot_nominal=0.3, dp1_nominal=6000, dp2_nominal=6000) "Chiller model"; Annex60.Fluid.Sources.MassFlowSource_T sou1(nPorts=1, redeclare package Medium = Medium1, use_T_in=false, use_m_flow_in=true, T=298.15); Annex60.Fluid.Sources.MassFlowSource_T sou2(nPorts=1, redeclare package Medium = Medium2, m_flow=m2_flow_nominal, use_T_in=false, T=295.15); Annex60.Fluid.Sources.FixedBoundary sin1( redeclare package Medium = Medium1, nPorts=1); Annex60.Fluid.Sources.FixedBoundary sin2(nPorts=1, redeclare package Medium = Medium2); Modelica.Blocks.Sources.Ramp TEvaLvg( duration=60, startTime=1800, offset=273.15 + 6, height=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"; 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]); end Carnot_TEva;

Annex60.Fluid.Chillers.Examples.Carnot_y

Information

Example that simulates a chiller whose efficiency is scaled based on the Carnot cycle. The chiller control signal is the compressor speed.

Parameters

Modelica definition

Type	Name	Default	Description
Power	P_nominal	10E3	Nominal compressor power (at y=1) [W]
TemperatureDifference	dTEva_nominal	-10	Temperature difference evaporator outlet-inlet [K]
TemperatureDifference	dTCon_nominal	10	Temperature difference condenser outlet-inlet [K]
Real	COPc_nominal	3	Chiller COP
MassFlowRate	m2_flow_nominal	-P_nominal*COPc_nominal/dTEv...	Nominal mass flow rate at chilled water side [kg/s]
MassFlowRate	m1_flow_nominal	m2_flow_nominal*(COPc_nomina...	Nominal mass flow rate at condenser water wide [kg/s]

model Carnot_y "Test model for chiller based on Carnot_y efficiency" extends Modelica.Icons.Example; package Medium1 = Annex60.Media.Water "Medium model"; package Medium2 = Annex60.Media.Water "Medium model"; parameter Modelica.SIunits.Power P_nominal=10E3 "Nominal compressor power (at y=1)"; parameter Modelica.SIunits.TemperatureDifference dTEva_nominal=-10 "Temperature difference evaporator outlet-inlet"; parameter Modelica.SIunits.TemperatureDifference dTCon_nominal=10 "Temperature difference condenser outlet-inlet"; parameter Real COPc_nominal = 3 "Chiller COP"; parameter Modelica.SIunits.MassFlowRate m2_flow_nominal= -P_nominal*COPc_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"; Annex60.Fluid.Chillers.Carnot_y chi( redeclare package Medium1 = Medium1, redeclare package Medium2 = Medium2, P_nominal=P_nominal, dTEva_nominal=dTEva_nominal, dTCon_nominal=dTCon_nominal, use_eta_Carnot_nominal=true, etaCarnot_nominal=0.3, dp1_nominal=6000, dp2_nominal=6000, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial, show_T=true, T1_start=303.15, T2_start=278.15) "Chiller model"; Annex60.Fluid.Sources.MassFlowSource_T sou1(nPorts=1, redeclare package Medium = Medium1, use_T_in=true, m_flow=m1_flow_nominal, T=298.15); Annex60.Fluid.Sources.MassFlowSource_T sou2(nPorts=1, redeclare package Medium = Medium2, use_T_in=true, m_flow=m2_flow_nominal, T=291.15); Annex60.Fluid.Sources.FixedBoundary sin1( nPorts=1, redeclare package Medium = Medium1); Annex60.Fluid.Sources.FixedBoundary sin2( nPorts=1, redeclare package Medium = Medium2); Modelica.Blocks.Sources.Ramp uCom( height=-1, duration=60, offset=1, startTime=1800) "Compressor control signal"; Modelica.Blocks.Sources.Ramp TCon_in( height=10, duration=60, offset=273.15 + 20, startTime=60) "Condenser inlet temperature"; Modelica.Blocks.Sources.Ramp TEva_in( height=10, duration=60, startTime=900, offset=273.15 + 15) "Evaporator inlet temperature"; equation connect(sou1.ports[1], chi.port_a1); connect(sou2.ports[1], chi.port_a2); connect(chi.port_b1, sin1.ports[1]); connect(sin2.ports[1], chi.port_b2); connect(TCon_in.y, sou1.T_in); connect(TEva_in.y, sou2.T_in); connect(uCom.y, chi.y); end Carnot_y;