LBL logo

Buildings.Fluid.HeatPumps.Examples

Collection of models that illustrate model use and test models

Information

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

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

Package Content

Name Description
Buildings.Fluid.HeatPumps.Examples.Carnot_TCon Carnot_TCon Test model for heat pump based on Carnot efficiency and condenser outlet temperature control signal
Buildings.Fluid.HeatPumps.Examples.Carnot_y Carnot_y Test model for heat pump based on Carnot efficiency

Buildings.Fluid.HeatPumps.Examples.Carnot_TCon Buildings.Fluid.HeatPumps.Examples.Carnot_TCon

Test model for heat pump based on Carnot efficiency and condenser outlet temperature control signal

Buildings.Fluid.HeatPumps.Examples.Carnot_TCon

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.

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

Parameters

TypeNameDefaultDescription
TemperatureDifferencedTEva_nominal-5Temperature difference evaporator inlet-outlet [K]
TemperatureDifferencedTCon_nominal10Temperature difference condenser outlet-inlet [K]
HeatFlowRateQCon_flow_nominal100E3Evaporator heat flow rate [W]
MassFlowRatem1_flow_nominalQCon_flow_nominal/dTCon_nomi...Nominal mass flow rate at condenser [kg/s]

Modelica definition

model Carnot_TCon "Test model for heat pump based on Carnot efficiency and condenser 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=-5 "Temperature difference evaporator inlet-outlet"; parameter Modelica.SIunits.TemperatureDifference dTCon_nominal=10 "Temperature difference condenser outlet-inlet"; parameter Modelica.SIunits.HeatFlowRate QCon_flow_nominal = 100E3 "Evaporator heat flow rate"; parameter Modelica.SIunits.MassFlowRate m1_flow_nominal= QCon_flow_nominal/dTCon_nominal/4200 "Nominal mass flow rate at condenser"; Buildings.Fluid.HeatPumps.Carnot_TCon heaPum( redeclare package Medium1 = Medium1, redeclare package Medium2 = Medium2, dTEva_nominal=dTEva_nominal, dTCon_nominal=dTCon_nominal, m1_flow_nominal=m1_flow_nominal, show_T=true, allowFlowReversal1=false, allowFlowReversal2=false, use_eta_Carnot_nominal=true, etaCarnot_nominal=0.3, QCon_flow_nominal=QCon_flow_nominal, dp1_nominal=6000, dp2_nominal=6000) "Heat pump"; Buildings.Fluid.Sources.MassFlowSource_T sou1(nPorts=1, redeclare package Medium = Medium1, m_flow=m1_flow_nominal, T=293.15); Buildings.Fluid.Sources.MassFlowSource_T sou2(nPorts=1, redeclare package Medium = Medium2, use_T_in=false, use_m_flow_in=true, T=288.15); 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.Ramp TConLvg( duration=60, startTime=1800, height=15, offset=273.15 + 35) "Control signal for condenser leaving temperature"; Modelica.Blocks.Math.Gain mEva_flow(k=-1/cp2_default/dTEva_nominal) "Evaporator mass flow rate"; Modelica.Blocks.Math.Add QEva_flow(k2=-1) "Evaporator heat flow rate"; final parameter Modelica.SIunits.SpecificHeatCapacity cp2_default= Medium2.specificHeatCapacityCp(Medium2.setState_pTX( Medium2.p_default, Medium2.T_default, Medium2.X_default)) "Specific heat capacity of medium 2 at default medium state"; equation connect(sou1.ports[1], heaPum.port_a1); connect(sou2.ports[1], heaPum.port_a2); connect(sin2.ports[1], heaPum.port_b2); connect(QEva_flow.y,mEva_flow. u); connect(heaPum.port_b1, sin1.ports[1]); connect(TConLvg.y, heaPum.TSet); connect(mEva_flow.y, sou2.m_flow_in); connect(QEva_flow.u1, heaPum.QCon_flow); connect(QEva_flow.u2, heaPum.P); end Carnot_TCon;

Buildings.Fluid.HeatPumps.Examples.Carnot_y Buildings.Fluid.HeatPumps.Examples.Carnot_y

Test model for heat pump based on Carnot efficiency

Buildings.Fluid.HeatPumps.Examples.Carnot_y

Information

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

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

Parameters

TypeNameDefaultDescription
RealCOP_nominal6Nominal COP
PowerP_nominal10E3Nominal compressor power (at y=1) [W]
TemperatureDifferencedTEva_nominal-10Temperature difference evaporator outlet-inlet [K]
TemperatureDifferencedTCon_nominal10Temperature difference condenser outlet-inlet [K]
MassFlowRatem2_flow_nominal-P_nominal*(COP_nominal - 1)...Nominal mass flow rate at chilled water side [kg/s]
MassFlowRatem1_flow_nominalP_nominal*COP_nominal/cp1_de...Nominal mass flow rate at condenser water wide [kg/s]

Modelica definition

model Carnot_y "Test model for heat pump based on Carnot efficiency" extends Modelica.Icons.Example; package Medium1 = Buildings.Media.Water "Medium model"; package Medium2 = Buildings.Media.Water "Medium model"; parameter Real COP_nominal = 6 "Nominal COP"; 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 Modelica.SIunits.MassFlowRate m2_flow_nominal= -P_nominal*(COP_nominal-1)/cp2_default/dTEva_nominal "Nominal mass flow rate at chilled water side"; parameter Modelica.SIunits.MassFlowRate m1_flow_nominal= P_nominal*COP_nominal/cp1_default/dTCon_nominal "Nominal mass flow rate at condenser water wide"; Buildings.Fluid.HeatPumps.Carnot_y heaPum( redeclare package Medium1 = Medium1, redeclare package Medium2 = Medium2, P_nominal=P_nominal, dTEva_nominal=dTEva_nominal, dTCon_nominal=dTCon_nominal, dp1_nominal=6000, dp2_nominal=6000, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial, show_T=true, use_eta_Carnot_nominal=false, COP_nominal=COP_nominal, TCon_nominal=303.15, TEva_nominal=278.15) "Heat pump model"; Buildings.Fluid.Sources.MassFlowSource_T sou1(nPorts=1, redeclare package Medium = Medium1, use_T_in=true, m_flow=m1_flow_nominal, T=298.15); Buildings.Fluid.Sources.MassFlowSource_T sou2(nPorts=1, redeclare package Medium = Medium2, use_T_in=true, m_flow=m2_flow_nominal, T=291.15); Buildings.Fluid.Sources.FixedBoundary sin1( nPorts=1, redeclare package Medium = Medium1); Buildings.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"; 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 2 at default medium state"; final parameter Modelica.SIunits.SpecificHeatCapacity cp2_default= Medium2.specificHeatCapacityCp(Medium2.setState_pTX( Medium2.p_default, Medium2.T_default, Medium2.X_default)) "Specific heat capacity of medium 2 at default medium state"; equation connect(sou1.ports[1], heaPum.port_a1); connect(sou2.ports[1], heaPum.port_a2); connect(heaPum.port_b1, sin1.ports[1]); connect(sin2.ports[1], heaPum.port_b2); connect(TCon_in.y, sou1.T_in); connect(TEva_in.y, sou2.T_in); connect(uCom.y, heaPum.y); end Carnot_y;
http://simulationresearch.lbl.gov/modelica