Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses
Package with base classes for Buildings.Applications.DataCenters.ChillerCooled
Information
This package contains base classes that are used to construct the models in Buildings.Applications.DataCenters.ChillerCooled.Extends from Modelica.Icons.BasesPackage (Icon for packages containing base classes).
Package Content
| Name | Description |
|---|---|
 AHUParameters
|
Essential parameters for air handling unit |
 PartialChillerWSE
|
Partial model for chiller and WSE package |
 PartialChillerWSEInterface
|
Partial model that defines the interface for chiller and WSE package |
 PartialControllerInterface
|
Partial interface model for waterside economizer temperature controller |
 PartialCoolingCoilHumidifyingHeating
|
Partial AHU model |
 PartialHeatExchanger
|
Partial model for heat exchangers |
 PartialIntegratedPrimary
|
Integrated water-side economizer for primary-only chilled water system |
| PartialOperationSequenceInterface
|
Partial interface for operation sequence |
 PartialParallelElectricEIR
|
Partial model for electric chiller parallel |
 PartialPlantParallel
|
Partial source plant model with associated valves |
| PartialPlantParallelInterface
|
Partial model that implements the interface for parallel plants |
 PartialPumpParallel
|
Partial model for pump parallel |
| SignalFilter
|
Partial model that implements the filtered opening for valves and dampers |
| ThreeWayValveParameters
|
Model with parameters for a three-way valve |
| ValvesParameters
|
Model with parameters for multiple valves |
 FourPortResistanceChillerWSE
|
Flow resistance model for the chiller and WSE package |
| SignalFilterParameters
|
Record that contains the parameters of the filtered opening for multiple valves and dampers |
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.AHUParameters
Essential parameters for air handling unit
Information
This block declares parameters that are required by most classes in the package Buildings.Applications.DataCenters.ChillerCooled.Equipment.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Cooling coil | |||
| ThermalConductance | UA_nominal | Thermal conductance at nominal flow for sensible heat, used to compute time constant [W/K] | |
| Real | r_nominal | 2/3 | Ratio between air-side and water-side convective heat transfer coefficient |
| Time | tau1 | 20 | Time constant at nominal flow of medium 1 [s] |
| Time | tau2 | 1 | Time constant at nominal flow of medium 2 [s] |
| Time | tau_m | 20 | Time constant of metal at nominal UA value [s] |
| Integer | nEle | 4 | Number of pipe segments used for discretization in the cooling coil |
| Dynamics | |||
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
Modelica definition
partial model AHUParameters "Essential parameters for air handling unit"
parameter Modelica.SIunits.ThermalConductance UA_nominal
"Thermal conductance at nominal flow for sensible heat, used to compute time constant";
parameter Real r_nominal=2/3
"Ratio between air-side and water-side convective heat transfer coefficient";
parameter Modelica.SIunits.Time tau1 = 20 "Time constant at nominal flow of medium 1";
parameter Modelica.SIunits.Time tau2 = 1 "Time constant at nominal flow of medium 2";
parameter Modelica.SIunits.Time tau_m(min=0) = 20
"Time constant of metal at nominal UA value";
parameter Integer nEle(min=1) = 4
"Number of pipe segments used for discretization in the cooling coil";
parameter Modelica.Fluid.Types.Dynamics energyDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial
"Type of energy balance: dynamic (3 initialization options) or steady state";
parameter Modelica.Fluid.Types.Dynamics massDynamics=energyDynamics
"Type of mass balance: dynamic (3 initialization options) or steady state";
end AHUParameters;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialChillerWSE
Partial model for chiller and WSE package
Information
Partial model that can be extended to different configurations inclduing chillers and integrated/non-integrated water-side economizers.
Extends from Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialChillerWSEInterface (Partial model that defines the interface for chiller and WSE package), Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.FourPortResistanceChillerWSE (Flow resistance model for the chiller and WSE package), Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialControllerInterface (Partial interface model for waterside economizer temperature controller), Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ValvesParameters (Model with parameters for multiple valves), Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.SignalFilterParameters (Record that contains the parameters of the filtered opening for multiple valves and dampers), Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ThreeWayValveParameters (Model with parameters for a three-way valve).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium1 | PartialMedium | Medium 1 in the component | |
| replaceable package Medium2 | PartialMedium | Medium 2 in the component | |
| Integer | num | numChi + 1 | Total number of chillers and waterside economizer |
| Boolean | use_controller | true | Set to ture if the built-in controller is enabled to maintain the outlet temperature on the load side of a heat exchanger |
| Integer | numVal | 4 | Number of valves |
| Integer | numFil | 1 | Number of filters |
| Boolean | activate_ThrWayVal | use_controller | Activate the use of three-way valve: True-use three-way valve; False-not use the three-way valve |
| Chiller | |||
| MassFlowRate | m1_flow_chi_nominal | Nominal mass flow rate on the medium 1 side in the chiller [kg/s] | |
| MassFlowRate | m2_flow_chi_nominal | Nominal mass flow rate on the medium 2 side in the chiller [kg/s] | |
| PressureDifference | dp1_chi_nominal | Pressure difference on medium 1 side in the chillers [Pa] | |
| PressureDifference | dp2_chi_nominal | Pressure difference on medium 2 side in the chillers [Pa] | |
| Integer | numChi | Number of chillers | |
| Generic | perChi[numChi] | redeclare parameter Building... | Performance data for chillers |
| Waterside economizer | |||
| MassFlowRate | m1_flow_wse_nominal | Nominal mass flow rate on the medium 1 side in the waterside economizer [kg/s] | |
| MassFlowRate | m2_flow_wse_nominal | Nominal mass flow rate on the medium 2 side in the waterside economizer [kg/s] | |
| PressureDifference | dp1_wse_nominal | Pressure difference on medium 1 side in the waterside economizer [Pa] | |
| PressureDifference | dp2_wse_nominal | Pressure difference on medium 2 side in the waterside economizer [Pa] | |
| Efficiency | eta | 0.8 | Heat exchange effectiveness [1] |
| Two-way valve | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv[numVal] | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv[numVal] | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av[numVal] | Av (metric) flow coefficient [m2] | |
| MassFlowRate | m_flow_nominal[numVal] | Nominal mass flow rate [kg/s] | |
| PressureDifference | dpValve_nominal[numVal] | fill(6000, numVal) | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] |
| Real | lValChi[2] | {0.0001,0.0001} | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Real | lValWSE[2] | {0.0001,0.0001} | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Pressure-flow linearization | |||
| Real | deltaM | deltaM1 | Fraction of nominal flow rate where linearization starts, if y=1 |
| Three-way Valve | |||
| PressureDifference | dpThrWayVal_nominal | 6000 | Nominal pressure drop of fully open valve [Pa] |
| Real | fraK_ThrWayVal | 0.7 | Fraction Kv(port_3→port_2)/Kv(port_1→port_2)for the three-way valve |
| Real | l_ThrWayVal[2] | {0.0001,0.0001} | Bypass valve leakage, l=Kv(y=0)/Kv(y=1) |
| Real | R | 50 | Rangeability, R=50...100 typically for the three-way valve |
| Real | delta0 | 0.01 | Range of significant deviation from equal percentage law for the three-way valve |
| Assumptions | |||
| Boolean | allowFlowReversal1 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1 |
| Boolean | allowFlowReversal2 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2 |
| Advanced | |||
| MassFlowRate | m1_flow_small | 1E-4*abs(m1_flow_chi_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | m2_flow_small | 1E-4*abs(m2_flow_chi_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| PortFlowDirection | portFlowDirection_1 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_1 in the three-way valve |
| PortFlowDirection | portFlowDirection_2 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_2 in the three-way valve |
| PortFlowDirection | portFlowDirection_3 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_3 in the three-way valve |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Two-way valve | |||
| Density | rhoStd[numVal] | Inlet density for which valve coefficients are defined [kg/m3] | |
| Flow resistance | |||
| Medium 1 | |||
| Boolean | computeFlowResistance1 | true | =true, compute flow resistance. Set to false to assume no friction |
| Boolean | from_dp1 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance1 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM1 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Medium 2 | |||
| Boolean | computeFlowResistance2 | true | =true, compute flow resistance. Set to false to assume no friction |
| Boolean | from_dp2 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance2 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM2 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Controller | |||
| SimpleController | controllerType | Modelica.Blocks.Types.Simple... | Type of controller |
| Real | k | 1 | Gain of controller [1] |
| Time | Ti | 0.5 | Time constant of integrator block [s] |
| Time | Td | 0.1 | Time constant of derivative block [s] |
| Real | yMax | 1 | Upper limit of output |
| Real | yMin | 0 | Lower limit of output |
| Real | wp | 1 | Set-point weight for Proportional block (0..1) |
| Real | wd | 0 | Set-point weight for Derivative block (0..1) |
| Real | Ni | 0.9 | Ni*Ti is time constant of anti-windup compensation |
| Real | Nd | 10 | The higher Nd, the more ideal the derivative block |
| Boolean | reverseActing | false | Set to true for throttling the water flow rate through a cooling coil controller |
| Initialization | |||
| InitPID | initType | Modelica.Blocks.Types.InitPI... | Type of initialization (1: no init, 2: steady state, 3: initial state, 4: initial output) |
| Real | xi_start | 0 | Initial or guess value value for integrator output (= integrator state) |
| Real | xd_start | 0 | Initial or guess value for state of derivative block |
| Real | yCon_start | 0 | Initial value of output from the controller |
| Integrator reset | |||
| Reset | reset | Buildings.Types.Reset.Disabled | Type of controller output reset |
| Real | y_reset | xi_start | Value to which the controller output is reset if the boolean trigger has a rising edge, used if reset == Buildings.Types.Reset.Parameter |
| Dynamics | |||
| Filtered opening | |||
| Boolean | use_inputFilter | true | = true, if opening is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimeValve | 120 | Rise time of the filter (time to reach 99.6 % of an opening step) [s] |
| Init | initValve | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yValve_start[numFil] | {yValWSE_start} | Initial value of output:0-closed, 1-fully opened |
| Real | yValChi_start[numChi] | fill(0, numChi) | Initial value of output from on/off valves in chillers |
| Real | yValWSE_start | 0 | Initial value of output from on/off valve in WSE |
| Real | yThrWayValWSE_start | 0 | Initial value of output from three-way bypass valve in WSE |
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| Chiller | |||
| Time | tauChi1 | 30 | Time constant at nominal flow in chillers [s] |
| Time | tauChi2 | 30 | Time constant at nominal flow in chillers [s] |
| Waterside economizer | |||
| Time | tauWSE | 10 | Time constant at nominal flow for dynamic energy and momentum balance of the three-way valve [s] |
| Temperature Sensor | |||
| Time | tauSenT | 1 | Time constant at nominal flow rate (use tau=0 for steady-state sensor, but see user guide for potential problems) [s] |
| Init | initTSenor | Modelica.Blocks.Types.Init.I... | Type of initialization of the temperature sensor (InitialState and InitialOutput are identical) |
| Initialization | |||
| Medium 1 | |||
| AbsolutePressure | p1_start | Medium1.p_default | Start value of pressure [Pa] |
| Temperature | T1_start | Medium1.T_default | Start value of temperature [K] |
| MassFraction | X1_start[Medium1.nX] | Medium1.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C1_start[Medium1.nC] | fill(0, Medium1.nC) | Start value of trace substances |
| ExtraProperty | C1_nominal[Medium1.nC] | fill(1E-2, Medium1.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
| Medium 2 | |||
| AbsolutePressure | p2_start | Medium2.p_default | Start value of pressure [Pa] |
| Temperature | T2_start | Medium2.T_default | Start value of temperature [K] |
| MassFraction | X2_start[Medium2.nX] | Medium2.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C2_start[Medium2.nC] | fill(0, Medium2.nC) | Start value of trace substances |
| ExtraProperty | C2_nominal[Medium2.nC] | fill(1E-2, Medium2.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a1 | Fluid connector a1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_b | port_b1 | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_a | port_a2 | Fluid connector a2 (positive design flow direction is from port_a2 to port_b2) |
| FluidPort_b | port_b2 | Fluid connector b2 (positive design flow direction is from port_a2 to port_b2) |
| input RealInput | TSet | Set point for leaving water temperature [K] |
| input BooleanInput | on[num] | Set to true to enable equipment, or false to disable equipment |
| input BooleanInput | trigger | Resets the controller output when trigger becomes true |
| input RealInput | y_reset_in | Input signal for state to which integrator is reset, enabled if reset = Buildings.Types.Reset.Input |
| output RealOutput | TCHWSupWSE | Chilled water supply temperature in the waterside economizer [K] |
| output RealOutput | powChi[numChi] | Electric power consumed by chiller compressor [W] |
Modelica definition
partial model PartialChillerWSE
"Partial model for chiller and WSE package"
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialChillerWSEInterface
(final num=numChi+1);
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.FourPortResistanceChillerWSE
(final computeFlowResistance1=true,
final computeFlowResistance2=true);
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialControllerInterface
(final reverseActing=false);
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ValvesParameters
(numVal=4,
final deltaM=deltaM1);
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.SignalFilterParameters
(final numFil=1,
final yValve_start={yValWSE_start});
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ThreeWayValveParameters
(final activate_ThrWayVal=use_controller);
constant Boolean homotopyInitialization = true "= true, use homotopy method";
//Chiller
parameter Integer numChi(min=1) "Number of chillers";
replaceable parameter Buildings.Fluid.Chillers.Data.ElectricEIR.Generic perChi[numChi]
"Performance data for chillers";
parameter Real[2] lValChi(each min=1e-10, each max=1) = {0.0001,0.0001}
"Valve leakage, l=Kv(y=0)/Kv(y=1)";
parameter Real[numChi] yValChi_start=fill(0,numChi)
"Initial value of output from on/off valves in chillers";
//WSE
parameter Modelica.SIunits.Efficiency eta(min=0,max=1)=0.8
"Heat exchange effectiveness";
parameter Real[2] lValWSE(each min=1e-10, each max=1) = {0.0001,0.0001}
"Valve leakage, l=Kv(y=0)/Kv(y=1)";
parameter Real yValWSE_start=0
"Initial value of output from on/off valve in WSE";
parameter Real yThrWayValWSE_start=0
"Initial value of output from three-way bypass valve in WSE";
// Dynamics
parameter Modelica.Fluid.Types.Dynamics energyDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial
"Type of energy balance: dynamic (3 initialization options) or steady state";
parameter Modelica.Fluid.Types.Dynamics massDynamics=energyDynamics
"Type of mass balance: dynamic (3 initialization options) or steady state";
parameter Modelica.SIunits.Time tauChi1 = 30
"Time constant at nominal flow in chillers";
parameter Modelica.SIunits.Time tauChi2 = 30
"Time constant at nominal flow in chillers";
parameter Modelica.SIunits.Time tauWSE = 10
"Time constant at nominal flow for dynamic energy and momentum balance of the three-way valve";
// Initialization
parameter Medium1.AbsolutePressure p1_start = Medium1.p_default
"Start value of pressure";
parameter Medium1.Temperature T1_start = Medium1.T_default
"Start value of temperature";
parameter Medium1.MassFraction X1_start[Medium1.nX] = Medium1.X_default
"Start value of mass fractions m_i/m";
parameter Medium1.ExtraProperty C1_start[Medium1.nC](
final quantity=Medium1.extraPropertiesNames)=fill(0, Medium1.nC)
"Start value of trace substances";
parameter Medium1.ExtraProperty C1_nominal[Medium1.nC](
final quantity=Medium1.extraPropertiesNames) = fill(1E-2, Medium1.nC)
"Nominal value of trace substances. (Set to typical order of magnitude.)";
parameter Medium2.AbsolutePressure p2_start = Medium2.p_default
"Start value of pressure";
parameter Medium2.Temperature T2_start = Medium2.T_default
"Start value of temperature";
parameter Medium2.MassFraction X2_start[Medium2.nX] = Medium2.X_default
"Start value of mass fractions m_i/m";
parameter Medium2.ExtraProperty C2_start[Medium2.nC](
final quantity=Medium2.extraPropertiesNames)=fill(0, Medium2.nC)
"Start value of trace substances";
parameter Medium2.ExtraProperty C2_nominal[Medium2.nC](
final quantity=Medium2.extraPropertiesNames) = fill(1E-2, Medium2.nC)
"Nominal value of trace substances. (Set to typical order of magnitude.)";
// Temperature sensor
parameter Modelica.SIunits.Time tauSenT=1
"Time constant at nominal flow rate (use tau=0 for steady-state sensor,
but see user guide for potential problems)";
parameter Modelica.Blocks.Types.Init initTSenor = Modelica.Blocks.Types.Init.InitialState
"Type of initialization of the temperature sensor (InitialState and InitialOutput are identical)";
Modelica.Blocks.Interfaces.RealOutput TCHWSupWSE(
final quantity="ThermodynamicTemperature",
final unit="K",
displayUnit="degC",
min=200,
start=T2_start)
"Chilled water supply temperature in the waterside economizer";
Modelica.Blocks.Interfaces.RealOutput powChi[numChi](
each final quantity="Power",
each final unit="W")
"Electric power consumed by chiller compressor";
Buildings.Applications.DataCenters.ChillerCooled.Equipment.ElectricChillerParallel
chiPar(
redeclare final replaceable package Medium1 = Medium1,
redeclare final replaceable package Medium2 = Medium2,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final allowFlowReversal1=allowFlowReversal1,
final allowFlowReversal2=allowFlowReversal2,
final m1_flow_small=m1_flow_small,
final m2_flow_small=m2_flow_small,
final show_T=show_T,
final from_dp1=from_dp1,
final linearizeFlowResistance1=linearizeFlowResistance1,
final deltaM1=deltaM1,
final from_dp2=from_dp2,
final linearizeFlowResistance2=linearizeFlowResistance2,
final deltaM2=deltaM2,
final num=numChi,
final per=perChi,
final homotopyInitialization=homotopyInitialization,
final use_inputFilter=use_inputFilter,
final riseTimeValve=riseTimeValve,
final initValve=initValve,
final m1_flow_nominal=m1_flow_chi_nominal,
final m2_flow_nominal=m2_flow_chi_nominal,
final dp1_nominal=dp1_chi_nominal,
final tau1=tauChi1,
final tau2=tauChi2,
final energyDynamics=energyDynamics,
final massDynamics=massDynamics,
final p1_start=p1_start,
final T1_start=T1_start,
final X1_start=X1_start,
final C1_start=C1_start,
final C1_nominal=C1_nominal,
final p2_start=p2_start,
final T2_start=T2_start,
final X2_start=X2_start,
final C2_start=C2_start,
final C2_nominal=C2_nominal,
final l=lValChi,
final dp2_nominal=dp2_chi_nominal,
final dpValve_nominal=dpValve_nominal[1:2],
final rhoStd=rhoStd[1:2],
final yValve_start=yValChi_start)
"Chillers with identical nominal parameters but different performance curves";
Buildings.Applications.DataCenters.ChillerCooled.Equipment.WatersideEconomizer
wse(
redeclare final replaceable package Medium1 = Medium1,
redeclare final replaceable package Medium2 = Medium2,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final allowFlowReversal1=allowFlowReversal1,
final allowFlowReversal2=allowFlowReversal2,
final m1_flow_nominal=m1_flow_wse_nominal,
final m2_flow_nominal=m2_flow_wse_nominal,
final m1_flow_small=m1_flow_small,
final m2_flow_small=m2_flow_small,
final from_dp1=from_dp1,
final dp1_nominal=dp1_wse_nominal,
final linearizeFlowResistance1=linearizeFlowResistance1,
final deltaM1=deltaM1,
final from_dp2=from_dp2,
final dp2_nominal=dp2_wse_nominal,
final linearizeFlowResistance2=linearizeFlowResistance2,
final deltaM2=deltaM2,
final homotopyInitialization=homotopyInitialization,
final l=lValWSE,
final use_inputFilter=use_inputFilter,
final riseTimeValve=riseTimeValve,
final initValve=initValve,
final energyDynamics=energyDynamics,
final massDynamics=massDynamics,
final p_start=p2_start,
final T_start=T2_start,
final X_start=X2_start,
final C_start=C2_start,
final C_nominal=C2_nominal,
final controllerType=controllerType,
final k=k,
final Ti=Ti,
final Td=Td,
final yMax=yMax,
final yMin=yMin,
final wp=wp,
final wd=wd,
final Ni=Ni,
final Nd=Nd,
final initType=initType,
final xi_start=xi_start,
final xd_start=xd_start,
final yCon_start=yCon_start,
final reset=reset,
final y_reset=y_reset,
final eta=eta,
final fraK_ThrWayVal=fraK_ThrWayVal,
final l_ThrWayVal=l_ThrWayVal,
final R=R,
final delta0=delta0,
final dpValve_nominal=dpValve_nominal[3:4],
final rhoStd=rhoStd[3:4],
final yThrWayVal_start=yThrWayValWSE_start,
final yValWSE_start=yValWSE_start,
final tauThrWayVal=tauWSE,
final use_controller=use_controller,
final reverseActing=reverseActing,
final show_T=show_T,
final portFlowDirection_1=portFlowDirection_1,
final portFlowDirection_2=portFlowDirection_2,
final portFlowDirection_3=portFlowDirection_3)
"Waterside economizer";
Buildings.Fluid.Sensors.TemperatureTwoPort senTem(
redeclare final replaceable package Medium = Medium2,
final m_flow_nominal=m2_flow_wse_nominal,
final tau=tauSenT,
final initType=initTSenor,
final T_start=T2_start,
final allowFlowReversal=allowFlowReversal2,
final m_flow_small=m2_flow_small)
"Temperature sensor";
Fluid.FixedResistances.Junction spl1(
redeclare package Medium = Medium1,
energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState,
m_flow_nominal={numChi*m1_flow_chi_nominal,-m1_flow_wse_nominal,-numChi*
m1_flow_chi_nominal},
dp_nominal={0,0,0}) "Splitter";
Fluid.FixedResistances.Junction jun1(
redeclare package Medium = Medium1,
energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState,
m_flow_nominal={numChi*m1_flow_chi_nominal,-numChi*m1_flow_chi_nominal,
m1_flow_wse_nominal},
dp_nominal={0,0,0}) "Junction";
initial equation
assert(homotopyInitialization, "In " + getInstanceName() +
": The constant homotopyInitialization has been modified from its default value. This constant will be removed in future releases.",
level = AssertionLevel.warning);
equation
for i in 1:numChi loop
connect(chiPar.on[i], on[i]);
end for;
connect(on[numChi+1], wse.on[1]);
connect(chiPar.TSet, TSet);
connect(TSet, wse.TSet);
connect(y_reset_in, wse.y_reset_in);
connect(trigger, wse.trigger);
connect(senTem.T,TCHWSupWSE);
connect(wse.port_b2, senTem.port_a);
connect(chiPar.P, powChi);
connect(port_a1, spl1.port_1);
connect(spl1.port_3, chiPar.port_a1);
connect(spl1.port_2, wse.port_a1);
connect(port_b1, jun1.port_2);
connect(jun1.port_3, wse.port_b1);
connect(chiPar.port_b1, jun1.port_1);
end PartialChillerWSE;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialChillerWSEInterface
Partial model that defines the interface for chiller and WSE package
Information
This model implements an interface for chillers and integrated/nonitegrated water-side economizers.
Extends from Buildings.Fluid.Interfaces.PartialFourPort (Partial model with four ports).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium1 | PartialMedium | Medium 1 in the component | |
| replaceable package Medium2 | PartialMedium | Medium 2 in the component | |
| Integer | num | 2 | Total number of chillers and waterside economizer |
| Chiller | |||
| MassFlowRate | m1_flow_chi_nominal | Nominal mass flow rate on the medium 1 side in the chiller [kg/s] | |
| MassFlowRate | m2_flow_chi_nominal | Nominal mass flow rate on the medium 2 side in the chiller [kg/s] | |
| Waterside economizer | |||
| MassFlowRate | m1_flow_wse_nominal | Nominal mass flow rate on the medium 1 side in the waterside economizer [kg/s] | |
| MassFlowRate | m2_flow_wse_nominal | Nominal mass flow rate on the medium 2 side in the waterside economizer [kg/s] | |
| Assumptions | |||
| Boolean | allowFlowReversal1 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1 |
| Boolean | allowFlowReversal2 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2 |
| Advanced | |||
| MassFlowRate | m1_flow_small | 1E-4*abs(m1_flow_chi_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | m2_flow_small | 1E-4*abs(m2_flow_chi_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a1 | Fluid connector a1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_b | port_b1 | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_a | port_a2 | Fluid connector a2 (positive design flow direction is from port_a2 to port_b2) |
| FluidPort_b | port_b2 | Fluid connector b2 (positive design flow direction is from port_a2 to port_b2) |
| input RealInput | TSet | Set point for leaving water temperature [K] |
| input BooleanInput | on[num] | Set to true to enable equipment, or false to disable equipment |
Modelica definition
partial model PartialChillerWSEInterface
"Partial model that defines the interface for chiller and WSE package"
extends Buildings.Fluid.Interfaces.PartialFourPort;
// Nominal conditions
parameter Modelica.SIunits.MassFlowRate m1_flow_chi_nominal(min=0)
"Nominal mass flow rate on the medium 1 side in the chiller";
parameter Modelica.SIunits.MassFlowRate m2_flow_chi_nominal(min=0)
"Nominal mass flow rate on the medium 2 side in the chiller";
parameter Modelica.SIunits.MassFlowRate m1_flow_wse_nominal(min=0)
"Nominal mass flow rate on the medium 1 side in the waterside economizer";
parameter Modelica.SIunits.MassFlowRate m2_flow_wse_nominal(min=0)
"Nominal mass flow rate on the medium 2 side in the waterside economizer";
// Advanced
parameter Medium1.MassFlowRate m1_flow_small(min=0) = 1E-4*abs(m1_flow_chi_nominal)
"Small mass flow rate for regularization of zero flow";
parameter Medium2.MassFlowRate m2_flow_small(min=0) = 1E-4*abs(m2_flow_chi_nominal)
"Small mass flow rate for regularization of zero flow";
// Diagnostics
parameter Boolean show_T = false
"= true, if actual temperature at port is computed";
parameter Integer num(min=1)=2 "Total number of chillers and waterside economizer";
Modelica.Blocks.Interfaces.RealInput TSet(
final unit="K",
final quantity="ThermodynamicTemperature",
displayUnit="degC")
"Set point for leaving water temperature";
Modelica.Blocks.Interfaces.BooleanInput on[num]
"Set to true to enable equipment, or false to disable equipment";
Medium1.MassFlowRate m1_flow = port_a1.m_flow
"Mass flow rate from port_a1 to port_b1 (m1_flow > 0 is design flow direction)";
Modelica.SIunits.PressureDifference dp1(displayUnit="Pa") = port_a1.p - port_b1.p
"Pressure difference between port_a1 and port_b1";
Medium2.MassFlowRate m2_flow = port_a2.m_flow
"Mass flow rate from port_a2 to port_b2 (m2_flow > 0 is design flow direction)";
Modelica.SIunits.PressureDifference dp2(displayUnit="Pa") = port_a2.p - port_b2.p
"Pressure difference between port_a2 and port_b2";
Medium1.ThermodynamicState sta_a1=
Medium1.setState_phX(port_a1.p,
noEvent(actualStream(port_a1.h_outflow)),
noEvent(actualStream(port_a1.Xi_outflow)))
if show_T "Medium properties in port_a1";
Medium1.ThermodynamicState sta_b1=
Medium1.setState_phX(port_b1.p,
noEvent(actualStream(port_b1.h_outflow)),
noEvent(actualStream(port_b1.Xi_outflow)))
if show_T "Medium properties in port_b1";
Medium2.ThermodynamicState sta_a2=
Medium2.setState_phX(port_a2.p,
noEvent(actualStream(port_a2.h_outflow)),
noEvent(actualStream(port_a2.Xi_outflow)))
if show_T "Medium properties in port_a2";
Medium2.ThermodynamicState sta_b2=
Medium2.setState_phX(port_b2.p,
noEvent(actualStream(port_b2.h_outflow)),
noEvent(actualStream(port_b2.Xi_outflow)))
if show_T "Medium properties in port_b2";
protected
Medium1.ThermodynamicState state_a1_inflow=
Medium1.setState_phX(port_a1.p, inStream(port_a1.h_outflow), inStream(port_a1.Xi_outflow))
"state for medium inflowing through port_a1";
Medium1.ThermodynamicState state_b1_inflow=
Medium1.setState_phX(port_b1.p, inStream(port_b1.h_outflow), inStream(port_b1.Xi_outflow))
"state for medium inflowing through port_b1";
Medium2.ThermodynamicState state_a2_inflow=
Medium2.setState_phX(port_a2.p, inStream(port_a2.h_outflow), inStream(port_a2.Xi_outflow))
"state for medium inflowing through port_a2";
Medium2.ThermodynamicState state_b2_inflow=
Medium2.setState_phX(port_b2.p, inStream(port_b2.h_outflow), inStream(port_b2.Xi_outflow))
"state for medium inflowing through port_b2";
end PartialChillerWSEInterface;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialControllerInterface
Partial interface model for waterside economizer temperature controller
Information
This module implements a PID controller interface.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | use_controller | true | Set to ture if the built-in controller is enabled to maintain the outlet temperature on the load side of a heat exchanger |
| Controller | |||
| SimpleController | controllerType | Modelica.Blocks.Types.Simple... | Type of controller |
| Real | k | 1 | Gain of controller [1] |
| Time | Ti | 0.5 | Time constant of integrator block [s] |
| Time | Td | 0.1 | Time constant of derivative block [s] |
| Real | yMax | 1 | Upper limit of output |
| Real | yMin | 0 | Lower limit of output |
| Real | wp | 1 | Set-point weight for Proportional block (0..1) |
| Real | wd | 0 | Set-point weight for Derivative block (0..1) |
| Real | Ni | 0.9 | Ni*Ti is time constant of anti-windup compensation |
| Real | Nd | 10 | The higher Nd, the more ideal the derivative block |
| Boolean | reverseActing | false | Set to true for throttling the water flow rate through a cooling coil controller |
| Initialization | |||
| InitPID | initType | Modelica.Blocks.Types.InitPI... | Type of initialization (1: no init, 2: steady state, 3: initial state, 4: initial output) |
| Real | xi_start | 0 | Initial or guess value value for integrator output (= integrator state) |
| Real | xd_start | 0 | Initial or guess value for state of derivative block |
| Real | yCon_start | 0 | Initial value of output from the controller |
| Integrator reset | |||
| Reset | reset | Buildings.Types.Reset.Disabled | Type of controller output reset |
| Real | y_reset | xi_start | Value to which the controller output is reset if the boolean trigger has a rising edge, used if reset == Buildings.Types.Reset.Parameter |
Connectors
| Type | Name | Description |
|---|---|---|
| input BooleanInput | trigger | Resets the controller output when trigger becomes true |
| input RealInput | y_reset_in | Input signal for state to which integrator is reset, enabled if reset = Buildings.Types.Reset.Input |
Modelica definition
partial model PartialControllerInterface
"Partial interface model for waterside economizer temperature controller"
parameter Boolean use_controller=true
"Set to ture if the built-in controller is enabled to maintain the outlet
temperature on the load side of a heat exchanger";
// Controller
parameter Modelica.Blocks.Types.SimpleController controllerType=
Modelica.Blocks.Types.SimpleController.PID
"Type of controller";
parameter Real k(min=0, unit="1") = 1
"Gain of controller";
parameter Modelica.SIunits.Time Ti(min=Modelica.Constants.small)=0.5
"Time constant of integrator block";
parameter Modelica.SIunits.Time Td(min=0)=0.1
"Time constant of derivative block";
parameter Real yMax(start=1)=1
"Upper limit of output";
parameter Real yMin=0
"Lower limit of output";
parameter Real wp(min=0) = 1
"Set-point weight for Proportional block (0..1)";
parameter Real wd(min=0) = 0
"Set-point weight for Derivative block (0..1)";
parameter Real Ni(min=100*Modelica.Constants.eps) = 0.9
"Ni*Ti is time constant of anti-windup compensation";
parameter Real Nd(min=100*Modelica.Constants.eps) = 10
"The higher Nd, the more ideal the derivative block";
parameter Modelica.Blocks.Types.InitPID initType=
Modelica.Blocks.Types.InitPID.DoNotUse_InitialIntegratorState
"Type of initialization (1: no init, 2: steady state, 3: initial state, 4: initial output)";
parameter Real xi_start=0
"Initial or guess value value for integrator output (= integrator state)";
parameter Real xd_start=0
"Initial or guess value for state of derivative block";
parameter Real yCon_start=0
"Initial value of output from the controller";
parameter Boolean reverseActing=false
"Set to true for throttling the water flow rate through a cooling coil controller";
parameter Buildings.Types.Reset reset = Buildings.Types.Reset.Disabled
"Type of controller output reset";
parameter Real y_reset=xi_start
"Value to which the controller output is reset if the boolean trigger
has a rising edge, used if reset == Buildings.Types.Reset.Parameter";
Modelica.Blocks.Interfaces.BooleanInput trigger
if reset <> Buildings.Types.Reset.Disabled
"Resets the controller output when trigger becomes true";
Modelica.Blocks.Interfaces.RealInput y_reset_in
if reset == Buildings.Types.Reset.Input
"Input signal for state to which integrator is reset,
enabled if reset = Buildings.Types.Reset.Input";
end PartialControllerInterface;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialCoolingCoilHumidifyingHeating
Partial AHU model
Information
This model describes a partial air handling unit model, which contains a water-side valve, a cooling coil and a fan model.
The valve and fan are partial models, and should be redeclared when used in the air handling unit model.
Extends from Buildings.Fluid.Interfaces.PartialFourPortInterface (Partial model transporting fluid between two ports without storing mass or energy), Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.AHUParameters (Essential parameters for air handling unit), Buildings.Fluid.Actuators.BaseClasses.ValveParameters (Model with parameters for valves), Buildings.Fluid.Interfaces.FourPortFlowResistanceParameters (Parameters for flow resistance for models with four ports).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium1 | PartialMedium | Medium 1 in the component | |
| replaceable package Medium2 | PartialMedium | Medium 2 in the component | |
| Generic | perFan | redeclare parameter Building... | Performance data for the fan |
| PartialFlowMachine | fan | redeclare Buildings.Fluid.Mo... | Fan |
| PartialTwoWayValveKv | watVal | redeclare Buildings.Fluid.Ac... | Two-way valve |
| Nominal condition | |||
| MassFlowRate | m1_flow_nominal | Nominal mass flow rate [kg/s] | |
| MassFlowRate | m2_flow_nominal | Nominal mass flow rate [kg/s] | |
| MassFlowRate | m_flow_nominal | m1_flow_nominal | Nominal mass flow rate [kg/s] |
| PressureDifference | dpValve_nominal | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] | |
| PressureDifference | dp1_nominal | Pressure difference [Pa] | |
| PressureDifference | dp2_nominal | Pressure difference [Pa] | |
| Cooling coil | |||
| ThermalConductance | UA_nominal | Thermal conductance at nominal flow for sensible heat, used to compute time constant [W/K] | |
| Real | r_nominal | 2/3 | Ratio between air-side and water-side convective heat transfer coefficient |
| Time | tau1 | 20 | Time constant at nominal flow of medium 1 [s] |
| Time | tau2 | 1 | Time constant at nominal flow of medium 2 [s] |
| Time | tau_m | 20 | Time constant of metal at nominal UA value [s] |
| Integer | nEle | 4 | Number of pipe segments used for discretization in the cooling coil |
| Flow Coefficient | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av | Av (metric) flow coefficient [m2] | |
| Pressure-flow linearization | |||
| Real | deltaM | deltaM2 | Fraction of nominal flow rate where linearization starts, if y=1 |
| Valve | |||
| Real | l | 0.0001 | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Fan | |||
| InputType | inputType | Buildings.Fluid.Types.InputT... | Control input type |
| Boolean | addPowerToMedium | true | Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations) |
| Assumptions | |||
| Boolean | allowFlowReversal1 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1 |
| Boolean | allowFlowReversal2 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2 |
| Advanced | |||
| MassFlowRate | m1_flow_small | 1E-4*abs(m1_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | m2_flow_small | 1E-4*abs(m2_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | true | = true, if actual temperature at port is computed |
| Nominal condition | |||
| Density | rhoStd | Medium1.density_pTX(101325, ... | Inlet density for which valve coefficients are defined [kg/m3] |
| Dynamics | |||
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| Valve | |||
| Boolean | use_inputFilterValve | true | = true, if opening is filtered with a 2nd order CriticalDamping filter for the water-side valve |
| Time | riseTimeValve | 120 | Rise time of the filter for the water-side valve (time to reach 99.6 % of an opening step) [s] |
| Init | initValve | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yValve_start | 1 | Initial value of output |
| Fan | |||
| Time | tauFan | 1 | Time constant at nominal flow (if energyDynamics <> SteadyState) [s] |
| Boolean | use_inputFilterFan | true | = true, if speed is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimeFan | 30 | Rise time of the filter (time to reach 99.6 % of the speed) [s] |
| Init | initFan | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yFan_start | 0 | Initial value of speed [1] |
| Flow resistance | |||
| Medium 1 | |||
| Boolean | computeFlowResistance1 | true | =true, compute flow resistance. Set to false to assume no friction |
| Boolean | from_dp1 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance1 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM1 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Medium 2 | |||
| Boolean | computeFlowResistance2 | true | =true, compute flow resistance. Set to false to assume no friction |
| Boolean | from_dp2 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance2 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM2 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Heat transfer | |||
| Cooling coil | |||
| Boolean | waterSideFlowDependent | true | Set to false to make water-side hA independent of mass flow rate |
| Boolean | airSideFlowDependent | true | Set to false to make air-side hA independent of mass flow rate |
| Boolean | waterSideTemperatureDependent | false | Set to false to make water-side hA independent of temperature |
| Boolean | airSideTemperatureDependent | false | Set to false to make air-side hA independent of temperature |
| Initialization | |||
| AbsolutePressure | p_start | Medium2.p_default | Start value of pressure [Pa] |
| Temperature | T_start | Medium2.T_default | Start value of temperature [K] |
| MassFraction | X_start[Medium2.nX] | Medium2.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C_start[Medium2.nC] | fill(0, Medium2.nC) | Start value of trace substances |
| ExtraProperty | C_nominal[Medium2.nC] | fill(1E-2, Medium2.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a1 | Fluid connector a1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_b | port_b1 | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_a | port_a2 | Fluid connector a2 (positive design flow direction is from port_a2 to port_b2) |
| FluidPort_b | port_b2 | Fluid connector b2 (positive design flow direction is from port_a2 to port_b2) |
| input RealInput | uVal | Actuator position (0: closed, 1: open) on water side [1] |
| input RealInput | uFan | Continuous input signal for the fan |
| output RealOutput | PFan | Electrical power consumed by the fan [W] |
| output RealOutput | yVal | Actual valve position [1] |
| input IntegerInput | stage | Stage input signal for the pressure head |
Modelica definition
partial model PartialCoolingCoilHumidifyingHeating "Partial AHU model "
extends Buildings.Fluid.Interfaces.PartialFourPortInterface(
final show_T=true);
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.AHUParameters;
extends Buildings.Fluid.Actuators.BaseClasses.ValveParameters(
final m_flow_nominal=m1_flow_nominal,
final rhoStd=Medium1.density_pTX(101325, 273.15+4, Medium1.X_default),
final deltaM = deltaM2);
extends Buildings.Fluid.Interfaces.FourPortFlowResistanceParameters(
final computeFlowResistance1=true,
final computeFlowResistance2=true);
constant Boolean homotopyInitialization = true "= true, use homotopy method";
// Cooling coil
parameter Boolean waterSideFlowDependent=true
"Set to false to make water-side hA independent of mass flow rate";
parameter Boolean airSideFlowDependent=true
"Set to false to make air-side hA independent of mass flow rate";
parameter Boolean waterSideTemperatureDependent=false
"Set to false to make water-side hA independent of temperature";
parameter Boolean airSideTemperatureDependent=false
"Set to false to make air-side hA independent of temperature";
// Initialization of the fan
parameter Medium2.AbsolutePressure p_start = Medium2.p_default
"Start value of pressure";
parameter Medium2.Temperature T_start=Medium2.T_default
"Start value of temperature";
parameter Medium2.MassFraction X_start[Medium2.nX](
quantity=Medium2.substanceNames) = Medium2.X_default
"Start value of mass fractions m_i/m";
parameter Medium2.ExtraProperty C_start[Medium2.nC](
quantity=Medium2.extraPropertiesNames)=fill(0, Medium2.nC)
"Start value of trace substances";
parameter Medium2.ExtraProperty C_nominal[Medium2.nC](
quantity=Medium2.extraPropertiesNames) = fill(1E-2, Medium2.nC)
"Nominal value of trace substances. (Set to typical order of magnitude.)";
// valve parameters
parameter Real l(min=1e-10, max=1) = 0.0001
"Valve leakage, l=Kv(y=0)/Kv(y=1)";
parameter Boolean use_inputFilterValve=true
"= true, if opening is filtered with a 2nd order CriticalDamping filter for the water-side valve";
parameter Modelica.SIunits.Time riseTimeValve=120
"Rise time of the filter for the water-side valve (time to reach 99.6 % of an opening step)";
parameter Modelica.Blocks.Types.Init initValve=Modelica.Blocks.Types.Init.InitialOutput
"Type of initialization (no init/steady state/initial state/initial output)";
parameter Real yValve_start=1 "Initial value of output";
// fan parameters
parameter Buildings.Fluid.Types.InputType inputType = Buildings.Fluid.Types.InputType.Continuous
"Control input type";
parameter Boolean addPowerToMedium=true
"Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations)";
parameter Modelica.SIunits.Time tauFan = 1
"Time constant at nominal flow (if energyDynamics <> SteadyState)";
parameter Boolean use_inputFilterFan=true
"= true, if speed is filtered with a 2nd order CriticalDamping filter";
parameter Modelica.SIunits.Time riseTimeFan=30
"Rise time of the filter (time to reach 99.6 % of the speed)";
parameter Modelica.Blocks.Types.Init initFan=Modelica.Blocks.Types.Init.InitialOutput
"Type of initialization (no init/steady state/initial state/initial output)";
parameter Real yFan_start(min=0, max=1, unit="1")=0 "Initial value of speed";
replaceable parameter Buildings.Fluid.Movers.Data.Generic perFan "Performance data for the fan";
Modelica.Blocks.Interfaces.RealInput uVal(min=0,max=1,unit="1")
"Actuator position (0: closed, 1: open) on water side";
Modelica.Blocks.Interfaces.RealInput uFan
if not inputType == Buildings.Fluid.Types.InputType.Stages
"Continuous input signal for the fan";
Modelica.Blocks.Interfaces.RealOutput PFan(
final quantity="Power",
final unit="W")
"Electrical power consumed by the fan";
Modelica.Blocks.Interfaces.RealOutput yVal(
min=0,
max=1,
final unit="1") "Actual valve position";
Modelica.Blocks.Interfaces.IntegerInput stage
if inputType == Buildings.Fluid.Types.InputType.Stages
"Stage input signal for the pressure head";
Buildings.Fluid.HeatExchangers.WetCoilCounterFlow cooCoi(
redeclare final package Medium1 = Medium1,
redeclare final package Medium2 = Medium2,
final UA_nominal=UA_nominal,
final r_nominal=r_nominal,
final nEle=nEle,
final tau1=tau1,
final tau2=tau2,
final tau_m=tau_m,
final allowFlowReversal1=allowFlowReversal1,
final allowFlowReversal2=allowFlowReversal2,
final show_T=show_T,
final m1_flow_small=m1_flow_small,
final m2_flow_small=m2_flow_small,
final waterSideFlowDependent=waterSideFlowDependent,
final airSideFlowDependent=airSideFlowDependent,
final waterSideTemperatureDependent=waterSideTemperatureDependent,
final airSideTemperatureDependent=airSideTemperatureDependent,
final energyDynamics=energyDynamics,
final m1_flow_nominal=m1_flow_nominal,
final m2_flow_nominal=m2_flow_nominal,
final dp1_nominal=0,
final dp2_nominal=dp2_nominal)
"Cooling coil";
replaceable Buildings.Fluid.Movers.BaseClasses.PartialFlowMachine fan
constrainedby Buildings.Fluid.Movers.BaseClasses.PartialFlowMachine(
redeclare final package Medium = Medium2,
final per=perFan,
final allowFlowReversal=allowFlowReversal2,
final show_T=show_T,
final energyDynamics=energyDynamics,
final massDynamics=massDynamics,
final inputType=inputType,
final tau=tauFan,
final addPowerToMedium=addPowerToMedium,
final use_inputFilter=use_inputFilterFan,
final riseTime=riseTimeFan,
final init=initFan,
final y_start=yFan_start,
final p_start=p_start,
final T_start=T_start,
final X_start=X_start,
final C_start=C_start,
final C_nominal=C_nominal,
final m_flow_small=m2_flow_small)
"Fan";
replaceable Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValveKv watVal
constrainedby Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValveKv(
redeclare final package Medium = Medium1,
final allowFlowReversal=allowFlowReversal1,
final show_T=show_T,
final l=l,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final from_dp=from_dp1,
final homotopyInitialization=homotopyInitialization,
final linearized=linearizeFlowResistance1,
final rhoStd=rhoStd,
final use_inputFilter=use_inputFilterValve,
final riseTime=riseTimeValve,
final init=initValve,
final y_start=yValve_start,
final dpValve_nominal=dpValve_nominal,
final m_flow_nominal=m_flow_nominal,
final deltaM=deltaM1,
final dpFixed_nominal=dp1_nominal)
"Two-way valve";
initial equation
assert(homotopyInitialization, "In " + getInstanceName() +
": The constant homotopyInitialization has been modified from its default value. This constant will be removed in future releases.",
level = AssertionLevel.warning);
equation
connect(port_a1, cooCoi.port_a1);
connect(cooCoi.port_a2, port_a2);
connect(cooCoi.port_b1, watVal.port_a);
connect(watVal.port_b, port_b1);
connect(fan.P, PFan);
connect(watVal.y, uVal);
connect(port_b2, fan.port_b);
connect(fan.stage, stage);
connect(yVal, watVal.y_actual);
end PartialCoolingCoilHumidifyingHeating;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialHeatExchanger
Partial model for heat exchangers
Information
This module simulates a heat exchanger with a three-way bypass used to modulate water flow rate.
Extends from Buildings.Fluid.Interfaces.PartialFourPortInterface (Partial model transporting fluid between two ports without storing mass or energy), Buildings.Fluid.Interfaces.FourPortFlowResistanceParameters (Parameters for flow resistance for models with four ports), Buildings.Fluid.Interfaces.LumpedVolumeDeclarations (Declarations for lumped volumes), Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ThreeWayValveParameters (Model with parameters for a three-way valve).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium1 | PartialMedium | Medium 1 in the component | |
| replaceable package Medium2 | PartialMedium | Medium 2 in the component | |
| replaceable package Medium | PartialMedium | Medium in the component | |
| Boolean | activate_ThrWayVal | Activate the use of three-way valve: True-use three-way valve; False-not use the three-way valve | |
| Efficiency | eta | constant effectiveness [1] | |
| Nominal condition | |||
| MassFlowRate | m1_flow_nominal | Nominal mass flow rate [kg/s] | |
| MassFlowRate | m2_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dp1_nominal | Pressure difference [Pa] | |
| PressureDifference | dp2_nominal | Pressure difference [Pa] | |
| Three-way Valve | |||
| PressureDifference | dpThrWayVal_nominal | 6000 | Nominal pressure drop of fully open valve [Pa] |
| Real | fraK_ThrWayVal | 0.7 | Fraction Kv(port_3→port_2)/Kv(port_1→port_2)for the three-way valve |
| Real | l_ThrWayVal[2] | {0.0001,0.0001} | Bypass valve leakage, l=Kv(y=0)/Kv(y=1) |
| Real | R | 50 | Rangeability, R=50...100 typically for the three-way valve |
| Real | delta0 | 0.01 | Range of significant deviation from equal percentage law for the three-way valve |
| PressureDifference | dpValve_nominal | 6000 | Nominal pressure drop of fully open valve [Pa] |
| Assumptions | |||
| Boolean | allowFlowReversal1 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1 |
| Boolean | allowFlowReversal2 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2 |
| Advanced | |||
| MassFlowRate | m1_flow_small | 1E-4*abs(m1_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | m2_flow_small | 1E-4*abs(m2_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| PortFlowDirection | portFlowDirection_1 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_1 in the three-way valve |
| PortFlowDirection | portFlowDirection_2 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_2 in the three-way valve |
| PortFlowDirection | portFlowDirection_3 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_3 in the three-way valve |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Nominal condition | |||
| Density | rhoStd | Medium2.density_pTX(101325, ... | Inlet density for which valve coefficients are defined [kg/m3] |
| Flow resistance | |||
| Medium 1 | |||
| Boolean | computeFlowResistance1 | (dp1_nominal > Modelica.Cons... | =true, compute flow resistance. Set to false to assume no friction |
| Boolean | from_dp1 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance1 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM1 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Medium 2 | |||
| Boolean | computeFlowResistance2 | (dp2_nominal > Modelica.Cons... | =true, compute flow resistance. Set to false to assume no friction |
| Boolean | from_dp2 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance2 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM2 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Dynamics | |||
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| Real | mSenFac | 1 | Factor for scaling the sensible thermal mass of the volume |
| Filtered opening | |||
| Boolean | use_inputFilter | true | = true, if opening is filtered with a 2nd order CriticalDamping filter |
| Time | riseTime | 120 | Rise time of the filter (time to reach 99.6 % of an opening step) [s] |
| Init | init | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yThrWayVal_start | 1 | Initial value of output from the filter in the bypass valve |
| Nominal condition | |||
| Time | tauThrWayVal | 10 | Time constant at nominal flow for dynamic energy and momentum balance of the three-way valve [s] |
| Initialization | |||
| AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
| Temperature | T_start | Medium.T_default | Start value of temperature [K] |
| MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a1 | Fluid connector a1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_b | port_b1 | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_a | port_a2 | Fluid connector a2 (positive design flow direction is from port_a2 to port_b2) |
| FluidPort_b | port_b2 | Fluid connector b2 (positive design flow direction is from port_a2 to port_b2) |
| replaceable package Medium | Medium in the component | |
Modelica definition
partial model PartialHeatExchanger "Partial model for heat exchangers "
extends Buildings.Fluid.Interfaces.PartialFourPortInterface;
extends Buildings.Fluid.Interfaces.FourPortFlowResistanceParameters(
final computeFlowResistance1=(dp1_nominal > Modelica.Constants.eps),
final computeFlowResistance2=(dp2_nominal > Modelica.Constants.eps));
extends Buildings.Fluid.Interfaces.LumpedVolumeDeclarations(
final mSenFac=1,
redeclare final package Medium=Medium2);
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ThreeWayValveParameters;
constant Boolean homotopyInitialization = true "= true, use homotopy method";
parameter Modelica.SIunits.Efficiency eta(min=0,max=1,start=0.8)
"constant effectiveness";
// Filter opening
parameter Boolean use_inputFilter=true
"= true, if opening is filtered with a 2nd order CriticalDamping filter";
parameter Modelica.SIunits.Time riseTime=120
"Rise time of the filter (time to reach 99.6 % of an opening step)";
parameter Modelica.Blocks.Types.Init init=Modelica.Blocks.Types.Init.InitialOutput
"Type of initialization (no init/steady state/initial state/initial output)";
parameter Real yThrWayVal_start=1
"Initial value of output from the filter in the bypass valve";
parameter Modelica.SIunits.PressureDifference dpValve_nominal(
displayUnit="Pa",
min=0,
fixed=true)= 6000
"Nominal pressure drop of fully open valve";
// Time constant
parameter Modelica.SIunits.Time tauThrWayVal=10
"Time constant at nominal flow for dynamic energy and momentum balance of the three-way valve";
// Advanced
parameter Modelica.SIunits.Density rhoStd = Medium2.density_pTX(101325, 273.15+4, Medium2.X_default)
"Inlet density for which valve coefficients are defined";
Buildings.Fluid.Actuators.Valves.ThreeWayEqualPercentageLinear thrWayVal(
redeclare package Medium = Medium2,
final from_dp=from_dp2,
final linearized={linearizeFlowResistance2,linearizeFlowResistance2},
final rhoStd=rhoStd,
final homotopyInitialization=homotopyInitialization,
final use_inputFilter=use_inputFilter,
final riseTime=riseTime,
final init=init,
final R=R,
final delta0=delta0,
final fraK=fraK_ThrWayVal,
final dpFixed_nominal={dp2_nominal,0},
final energyDynamics=energyDynamics,
final massDynamics=massDynamics,
final p_start=p_start,
final T_start=T_start,
final C_start=C_start,
final C_nominal=C_nominal,
final X_start=X_start,
final y_start=yThrWayVal_start,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final l=l_ThrWayVal,
final dpValve_nominal=dpValve_nominal,
final deltaM=deltaM2,
final m_flow_nominal=m2_flow_nominal,
final portFlowDirection_1=portFlowDirection_1,
final portFlowDirection_2=portFlowDirection_2,
final portFlowDirection_3=portFlowDirection_3,
final tau=tauThrWayVal) if activate_ThrWayVal
"Three-way valve used to control the outlet temperature ";
Buildings.Fluid.HeatExchangers.ConstantEffectiveness hex(
redeclare package Medium1 = Medium1,
redeclare package Medium2 = Medium2,
final allowFlowReversal1=allowFlowReversal1,
final allowFlowReversal2=allowFlowReversal2,
final m1_flow_nominal=m1_flow_nominal,
final m2_flow_nominal=m2_flow_nominal,
final m1_flow_small=m1_flow_small,
final m2_flow_small=m2_flow_small,
final show_T=show_T,
final from_dp1=from_dp1,
final dp1_nominal=dp1_nominal,
final linearizeFlowResistance1=linearizeFlowResistance1,
final deltaM1=deltaM1,
final from_dp2=from_dp2,
final linearizeFlowResistance2=linearizeFlowResistance2,
final deltaM2=deltaM2,
final eps=eta,
final homotopyInitialization=homotopyInitialization,
final dp2_nominal=if activate_ThrWayVal then 0 else dp2_nominal)
"Heat exchanger";
initial equation
assert(homotopyInitialization, "In " + getInstanceName() +
": The constant homotopyInitialization has been modified from its default value. This constant will be removed in future releases.",
level = AssertionLevel.warning);
equation
connect(port_a1, hex.port_a1);
connect(hex.port_b1, port_b1);
connect(hex.port_a2, port_a2);
if activate_ThrWayVal then
connect(hex.port_b2, thrWayVal.port_1);
connect(port_a2, thrWayVal.port_3);
connect(thrWayVal.port_2, port_b2);
else
connect(port_b2, hex.port_b2);
end if;
end PartialHeatExchanger;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialIntegratedPrimary
Integrated water-side economizer for primary-only chilled water system
Information
Partial model that implements integrated waterside economizer in primary-ony chilled water system.
Extends from Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialChillerWSE (Partial model for chiller and WSE package).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium1 | PartialMedium | Medium 1 in the component | |
| replaceable package Medium2 | PartialMedium | Medium 2 in the component | |
| Boolean | use_controller | true | Set to ture if the built-in controller is enabled to maintain the outlet temperature on the load side of a heat exchanger |
| Integer | numVal | 6 | Number of valves |
| Chiller | |||
| MassFlowRate | m1_flow_chi_nominal | Nominal mass flow rate on the medium 1 side in the chiller [kg/s] | |
| MassFlowRate | m2_flow_chi_nominal | Nominal mass flow rate on the medium 2 side in the chiller [kg/s] | |
| PressureDifference | dp1_chi_nominal | Pressure difference on medium 1 side in the chillers [Pa] | |
| PressureDifference | dp2_chi_nominal | Pressure difference on medium 2 side in the chillers [Pa] | |
| Integer | numChi | Number of chillers | |
| Generic | perChi[numChi] | redeclare parameter Building... | Performance data for chillers |
| Waterside economizer | |||
| MassFlowRate | m1_flow_wse_nominal | Nominal mass flow rate on the medium 1 side in the waterside economizer [kg/s] | |
| MassFlowRate | m2_flow_wse_nominal | Nominal mass flow rate on the medium 2 side in the waterside economizer [kg/s] | |
| PressureDifference | dp1_wse_nominal | Pressure difference on medium 1 side in the waterside economizer [Pa] | |
| PressureDifference | dp2_wse_nominal | Pressure difference on medium 2 side in the waterside economizer [Pa] | |
| Efficiency | eta | 0.8 | Heat exchange effectiveness [1] |
| Two-way valve | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv[numVal] | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv[numVal] | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av[numVal] | Av (metric) flow coefficient [m2] | |
| MassFlowRate | m_flow_nominal[numVal] | Nominal mass flow rate [kg/s] | |
| PressureDifference | dpValve_nominal[numVal] | fill(6000, numVal) | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] |
| Real | lValChi[2] | {0.0001,0.0001} | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Real | lValWSE[2] | {0.0001,0.0001} | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Real | lVal5 | 0.0001 | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Real | lVal6 | 0.0001 | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Three-way Valve | |||
| PressureDifference | dpThrWayVal_nominal | 6000 | Nominal pressure drop of fully open valve [Pa] |
| Real | fraK_ThrWayVal | 0.7 | Fraction Kv(port_3→port_2)/Kv(port_1→port_2)for the three-way valve |
| Real | l_ThrWayVal[2] | {0.0001,0.0001} | Bypass valve leakage, l=Kv(y=0)/Kv(y=1) |
| Real | R | 50 | Rangeability, R=50...100 typically for the three-way valve |
| Real | delta0 | 0.01 | Range of significant deviation from equal percentage law for the three-way valve |
| Assumptions | |||
| Boolean | allowFlowReversal1 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1 |
| Boolean | allowFlowReversal2 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2 |
| Advanced | |||
| MassFlowRate | m1_flow_small | 1E-4*abs(m1_flow_chi_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | m2_flow_small | 1E-4*abs(m2_flow_chi_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| PortFlowDirection | portFlowDirection_1 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_1 in the three-way valve |
| PortFlowDirection | portFlowDirection_2 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_2 in the three-way valve |
| PortFlowDirection | portFlowDirection_3 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_3 in the three-way valve |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Two-way valve | |||
| Density | rhoStd[numVal] | Inlet density for which valve coefficients are defined [kg/m3] | |
| Flow resistance | |||
| Medium 1 | |||
| Boolean | from_dp1 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance1 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM1 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Medium 2 | |||
| Boolean | from_dp2 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance2 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM2 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Controller | |||
| SimpleController | controllerType | Modelica.Blocks.Types.Simple... | Type of controller |
| Real | k | 1 | Gain of controller [1] |
| Time | Ti | 0.5 | Time constant of integrator block [s] |
| Time | Td | 0.1 | Time constant of derivative block [s] |
| Real | yMax | 1 | Upper limit of output |
| Real | yMin | 0 | Lower limit of output |
| Real | wp | 1 | Set-point weight for Proportional block (0..1) |
| Real | wd | 0 | Set-point weight for Derivative block (0..1) |
| Real | Ni | 0.9 | Ni*Ti is time constant of anti-windup compensation |
| Real | Nd | 10 | The higher Nd, the more ideal the derivative block |
| Initialization | |||
| InitPID | initType | Modelica.Blocks.Types.InitPI... | Type of initialization (1: no init, 2: steady state, 3: initial state, 4: initial output) |
| Real | xi_start | 0 | Initial or guess value value for integrator output (= integrator state) |
| Real | xd_start | 0 | Initial or guess value for state of derivative block |
| Real | yCon_start | 0 | Initial value of output from the controller |
| Integrator reset | |||
| Reset | reset | Buildings.Types.Reset.Disabled | Type of controller output reset |
| Real | y_reset | xi_start | Value to which the controller output is reset if the boolean trigger has a rising edge, used if reset == Buildings.Types.Reset.Parameter |
| Dynamics | |||
| Filtered opening | |||
| Boolean | use_inputFilter | true | = true, if opening is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimeValve | 120 | Rise time of the filter (time to reach 99.6 % of an opening step) [s] |
| Init | initValve | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yValChi_start[numChi] | fill(0, numChi) | Initial value of output from on/off valves in chillers |
| Real | yValWSE_start | 0 | Initial value of output from on/off valve in WSE |
| Real | yThrWayValWSE_start | 0 | Initial value of output from three-way bypass valve in WSE |
| Real | yVal5_start | 0 | Initial value of output:0-closed, 1-fully opened |
| Real | yVal6_start | 1 - yVal5_start | Initial value of output:0-closed, 1-fully opened |
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| Chiller | |||
| Time | tauChi1 | 30 | Time constant at nominal flow in chillers [s] |
| Time | tauChi2 | 30 | Time constant at nominal flow in chillers [s] |
| Waterside economizer | |||
| Time | tauWSE | 10 | Time constant at nominal flow for dynamic energy and momentum balance of the three-way valve [s] |
| Temperature Sensor | |||
| Time | tauSenT | 1 | Time constant at nominal flow rate (use tau=0 for steady-state sensor, but see user guide for potential problems) [s] |
| Init | initTSenor | Modelica.Blocks.Types.Init.I... | Type of initialization of the temperature sensor (InitialState and InitialOutput are identical) |
| Initialization | |||
| Medium 1 | |||
| AbsolutePressure | p1_start | Medium1.p_default | Start value of pressure [Pa] |
| Temperature | T1_start | Medium1.T_default | Start value of temperature [K] |
| MassFraction | X1_start[Medium1.nX] | Medium1.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C1_start[Medium1.nC] | fill(0, Medium1.nC) | Start value of trace substances |
| ExtraProperty | C1_nominal[Medium1.nC] | fill(1E-2, Medium1.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
| Medium 2 | |||
| AbsolutePressure | p2_start | Medium2.p_default | Start value of pressure [Pa] |
| Temperature | T2_start | Medium2.T_default | Start value of temperature [K] |
| MassFraction | X2_start[Medium2.nX] | Medium2.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C2_start[Medium2.nC] | fill(0, Medium2.nC) | Start value of trace substances |
| ExtraProperty | C2_nominal[Medium2.nC] | fill(1E-2, Medium2.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a1 | Fluid connector a1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_b | port_b1 | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_a | port_a2 | Fluid connector a2 (positive design flow direction is from port_a2 to port_b2) |
| FluidPort_b | port_b2 | Fluid connector b2 (positive design flow direction is from port_a2 to port_b2) |
| input RealInput | TSet | Set point for leaving water temperature [K] |
| input BooleanInput | on[num] | Set to true to enable equipment, or false to disable equipment |
| input BooleanInput | trigger | Resets the controller output when trigger becomes true |
| input RealInput | y_reset_in | Input signal for state to which integrator is reset, enabled if reset = Buildings.Types.Reset.Input |
| output RealOutput | TCHWSupWSE | Chilled water supply temperature in the waterside economizer [K] |
| output RealOutput | powChi[numChi] | Electric power consumed by chiller compressor [W] |
| input RealInput | yVal6 | Actuator position for valve 6 (0: closed, 1: open) [1] |
| input RealInput | yVal5 | Actuator position for valve 5(0: closed, 1: open) [1] |
Modelica definition
model PartialIntegratedPrimary
"Integrated water-side economizer for primary-only chilled water system"
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialChillerWSE
(
final numVal=6);
//Parameters for the valve used in free cooling mode
parameter Real lVal5(min=1e-10,max=1) = 0.0001
"Valve leakage, l=Kv(y=0)/Kv(y=1)";
parameter Real lVal6(min=1e-10,max=1) = 0.0001
"Valve leakage, l=Kv(y=0)/Kv(y=1)";
parameter Real yVal5_start(min=0,max=1) = 0
"Initial value of output:0-closed, 1-fully opened";
parameter Real yVal6_start(min=0,max=1) = 1-yVal5_start
"Initial value of output:0-closed, 1-fully opened";
Modelica.Blocks.Interfaces.RealInput yVal6(
final unit = "1",
min=0,
max=1)
"Actuator position for valve 6 (0: closed, 1: open)";
Modelica.Blocks.Interfaces.RealInput yVal5(
final unit= "1",
min=0,
max=1)
"Actuator position for valve 5(0: closed, 1: open)";
Buildings.Fluid.Actuators.Valves.TwoWayLinear val5(
redeclare final package Medium = Medium2,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final allowFlowReversal=allowFlowReversal2,
final m_flow_nominal=numChi*m2_flow_chi_nominal,
final show_T=show_T,
final from_dp=from_dp2,
final homotopyInitialization=homotopyInitialization,
final linearized=linearizeFlowResistance2,
final deltaM=deltaM2,
final use_inputFilter=use_inputFilter,
final riseTime=riseTimeValve,
final init=initValve,
final dpFixed_nominal=0,
final dpValve_nominal=dpValve_nominal[5],
final l=lVal5,
final rhoStd=rhoStd[5],
final y_start=yVal5_start)
"Bypass valve: closed when fully mechanic cooling is activated;
open when fully mechanic cooling is activated";
Buildings.Fluid.Actuators.Valves.TwoWayLinear val6(
redeclare final package Medium = Medium2,
final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
final m_flow_nominal=m2_flow_wse_nominal,
final allowFlowReversal=allowFlowReversal2,
final show_T=show_T,
final from_dp=from_dp2,
final homotopyInitialization=homotopyInitialization,
final linearized=linearizeFlowResistance2,
final deltaM=deltaM2,
final use_inputFilter=use_inputFilter,
final riseTime=riseTimeValve,
final init=initValve,
final dpFixed_nominal=0,
final dpValve_nominal=dpValve_nominal[6],
final l=lVal6,
final rhoStd=rhoStd[6],
final y_start=yVal6_start)
"Bypass valve: closed when free cooling mode is deactivated;
open when free cooling is activated";
Fluid.FixedResistances.Junction spl2(
redeclare package Medium = Medium2,
energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState,
m_flow_nominal={numChi*m2_flow_chi_nominal,-numChi*m2_flow_chi_nominal,
-m2_flow_wse_nominal},
dp_nominal={0,0,0}) "Splitter";
Fluid.FixedResistances.Junction jun2(
redeclare package Medium = Medium2,
energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState,
m_flow_nominal={m2_flow_wse_nominal,-numChi*m2_flow_chi_nominal,numChi*
m2_flow_chi_nominal},
dp_nominal={0,0,0}) "Junction";
equation
connect(val5.y, yVal5);
connect(yVal6, val6.y);
connect(port_a2, spl2.port_1);
connect(spl2.port_3, wse.port_a2);
connect(spl2.port_2, val5.port_a);
connect(val6.port_b, jun2.port_1);
connect(jun2.port_2, port_b2);
connect(chiPar.port_b2, jun2.port_3);
end PartialIntegratedPrimary;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialOperationSequenceInterface
Partial interface for operation sequence
Information
Partial model that transforms the valve signal.
Modelica definition
partial model PartialOperationSequenceInterface
"Partial interface for operation sequence "
Modelica.Blocks.Math.BooleanToReal booToRea(
final realTrue=1,
final realFalse=0)
"Boolean to real (if true then 1 else 0)";
Modelica.Blocks.Math.Feedback inv
"Inversion of the control signal";
protected
Modelica.Blocks.Sources.Constant uni(final k=1)
"Unitary signal";
equation
connect(uni.y, inv.u1);
connect(booToRea.y, inv.u2);
end PartialOperationSequenceInterface;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialParallelElectricEIR
Partial model for electric chiller parallel
Information
Partial model that implements parallel electric chillers with associated valves.
The model has num identical chillers.
Extends from Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPlantParallel (Partial source plant model with associated valves).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium1 | PartialMedium | Medium 1 in the component | |
| replaceable package Medium2 | PartialMedium | Medium 2 in the component | |
| Integer | num | 2 | Number of equipment |
| PartialElectric | chi[num] | redeclare Buildings.Fluid.Ch... | Chillers with identical nominal parameters but different performance curves |
| Nominal condition | |||
| MassFlowRate | m1_flow_nominal | Nominal mass flow rate [kg/s] | |
| MassFlowRate | m2_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dp1_nominal | Pressure difference [Pa] | |
| PressureDifference | dp2_nominal | Pressure difference [Pa] | |
| Two-way valve | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv[numVal] | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv[numVal] | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av[numVal] | Av (metric) flow coefficient [m2] | |
| PressureDifference | dpValve_nominal[numVal] | fill(6000, numVal) | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] |
| Real | l[2] | {0.0001,0.0001} | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Assumptions | |||
| Boolean | allowFlowReversal1 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1 |
| Boolean | allowFlowReversal2 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2 |
| Advanced | |||
| MassFlowRate | m1_flow_small | 1E-4*abs(m1_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | m2_flow_small | 1E-4*abs(m2_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Two-way valve | |||
| Density | rhoStd[numVal] | {Medium1.density_pTX(101325,... | Inlet density for which valve coefficients are defined [kg/m3] |
| Flow resistance | |||
| Medium 1 | |||
| Boolean | from_dp1 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance1 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM1 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Medium 2 | |||
| Boolean | from_dp2 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance2 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM2 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Dynamics | |||
| Filtered opening | |||
| Boolean | use_inputFilter | true | = true, if opening is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimeValve | 120 | Rise time of the filter (time to reach 99.6 % of an opening step) [s] |
| Init | initValve | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yValve_start[numFil] | fill(1, numFil) | Initial value of output:0-closed, 1-fully opened |
| Nominal condition | |||
| Time | tau1 | 30 | Time constant at nominal flow in chillers [s] |
| Time | tau2 | 30 | Time constant at nominal flow in chillers [s] |
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| Initialization | |||
| Medium 1 | |||
| AbsolutePressure | p1_start | Medium1.p_default | Start value of pressure [Pa] |
| Temperature | T1_start | Medium1.T_default | Start value of temperature [K] |
| MassFraction | X1_start[Medium1.nX] | Medium1.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C1_start[Medium1.nC] | fill(0, Medium1.nC) | Start value of trace substances |
| ExtraProperty | C1_nominal[Medium1.nC] | fill(1E-2, Medium1.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
| Medium 2 | |||
| AbsolutePressure | p2_start | Medium2.p_default | Start value of pressure [Pa] |
| Temperature | T2_start | Medium2.T_default | Start value of temperature [K] |
| MassFraction | X2_start[Medium2.nX] | Medium2.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C2_start[Medium2.nC] | fill(0, Medium2.nC) | Start value of trace substances |
| ExtraProperty | C2_nominal[Medium2.nC] | fill(1E-2, Medium2.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a1 | Fluid connector a1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_b | port_b1 | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_a | port_a2 | Fluid connector a2 (positive design flow direction is from port_a2 to port_b2) |
| FluidPort_b | port_b2 | Fluid connector b2 (positive design flow direction is from port_a2 to port_b2) |
| input BooleanInput | on[num] | Set to true to enable equipment, or false to disable equipment |
| input RealInput | TSet | Set point for leaving water temperature [K] |
| output RealOutput | P[num] | Electric power consumed by chiller compressor [W] |
Modelica definition
partial model PartialParallelElectricEIR
"Partial model for electric chiller parallel"
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPlantParallel
(
val2(each final dpFixed_nominal=dp2_nominal),
val1(each final dpFixed_nominal=dp1_nominal));
parameter Modelica.SIunits.Time tau1 = 30
"Time constant at nominal flow in chillers";
parameter Modelica.SIunits.Time tau2 = 30
"Time constant at nominal flow in chillers";
// Assumptions
parameter Modelica.Fluid.Types.Dynamics energyDynamics=
Modelica.Fluid.Types.Dynamics.FixedInitial
"Type of energy balance: dynamic (3 initialization options) or steady state";
parameter Modelica.Fluid.Types.Dynamics massDynamics=energyDynamics
"Type of mass balance: dynamic (3 initialization options) or steady state";
// Initialization
parameter Medium1.AbsolutePressure p1_start = Medium1.p_default
"Start value of pressure";
parameter Medium1.Temperature T1_start = Medium1.T_default
"Start value of temperature";
parameter Medium1.MassFraction X1_start[Medium1.nX] = Medium1.X_default
"Start value of mass fractions m_i/m";
parameter Medium1.ExtraProperty C1_start[Medium1.nC](
final quantity=Medium1.extraPropertiesNames)=fill(0, Medium1.nC)
"Start value of trace substances";
parameter Medium1.ExtraProperty C1_nominal[Medium1.nC](
final quantity=Medium1.extraPropertiesNames) = fill(1E-2, Medium1.nC)
"Nominal value of trace substances. (Set to typical order of magnitude.)";
parameter Medium2.AbsolutePressure p2_start = Medium2.p_default
"Start value of pressure";
parameter Medium2.Temperature T2_start = Medium2.T_default
"Start value of temperature";
parameter Medium2.MassFraction X2_start[Medium2.nX] = Medium2.X_default
"Start value of mass fractions m_i/m";
parameter Medium2.ExtraProperty C2_start[Medium2.nC](
final quantity=Medium2.extraPropertiesNames)=fill(0, Medium2.nC)
"Start value of trace substances";
parameter Medium2.ExtraProperty C2_nominal[Medium2.nC](
final quantity=Medium2.extraPropertiesNames) = fill(1E-2, Medium2.nC)
"Nominal value of trace substances. (Set to typical order of magnitude.)";
Modelica.Blocks.Interfaces.BooleanInput on[num]
"Set to true to enable compressor, or false to disable compressor";
Modelica.Blocks.Interfaces.RealInput TSet(
final quantity="ThermodynamicTemperature",
final unit="K",
displayUnit="degC")
"Set point for leaving water temperature";
Modelica.Blocks.Interfaces.RealOutput P[num](
each final quantity="Power",
each final unit="W")
"Electric power consumed by chiller compressor";
replaceable Buildings.Fluid.Chillers.BaseClasses.PartialElectric chi[num]
constrainedby Buildings.Fluid.Chillers.BaseClasses.PartialElectric(
redeclare each final package Medium1 = Medium1,
redeclare each final package Medium2 = Medium2,
each final allowFlowReversal1=allowFlowReversal1,
each final allowFlowReversal2=allowFlowReversal2,
each final show_T=show_T,
each final from_dp1=from_dp1,
each final dp1_nominal=0,
each final linearizeFlowResistance1=linearizeFlowResistance1,
each final deltaM1=deltaM1,
each final from_dp2=from_dp2,
each final dp2_nominal=0,
each final linearizeFlowResistance2=linearizeFlowResistance2,
each final deltaM2=deltaM2,
each final homotopyInitialization=homotopyInitialization,
each final m1_flow_nominal=m1_flow_nominal,
each final m2_flow_nominal=m2_flow_nominal,
each final m1_flow_small=m1_flow_small,
each final m2_flow_small=m2_flow_small,
each final tau1=tau1,
each final tau2=tau2,
each final energyDynamics=energyDynamics,
each final massDynamics=massDynamics,
each final p1_start=p1_start,
each final T1_start=T1_start,
each final X1_start=X1_start,
each final C1_start=C1_start,
each final C1_nominal=C1_nominal,
each final p2_start=p2_start,
each final T2_start=T2_start,
each final X2_start=X2_start,
each final C2_start=C2_start,
each final C2_nominal=C2_nominal)
"Chillers with identical nominal parameters but different performance curves";
equation
for i in 1:num loop
connect(TSet, chi[i].TSet);
connect(chi[i].port_a1, port_a1);
connect(chi[i].port_a2, port_a2);
end for;
connect(chi.port_b2, val2.port_a);
connect(chi.port_b1, val1.port_a);
connect(on, chi.on);
connect(chi.P, P);
end PartialParallelElectricEIR;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPlantParallel
Partial source plant model with associated valves
Information
Partial model that can be extended to construct parallel chillers such as Buildings.Applications.DataCenters.ChillerCooled.Equipment.ElectricChillerParallel and water-side economizers Buildings.Applications.DataCenters.ChillerCooled.Equipment.WatersideEconomizer.
The associated valve group val1 and val2
on medium 1 and medium 2 side are for on/off use only.
The number of valves in each group is specified by the parameter n.
The valve parameters can be specified differently.
The signal filter is used to smoothe the on/off signal for the valves.
Extends from Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPlantParallelInterface (Partial model that implements the interface for parallel plants), Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ValvesParameters (Model with parameters for multiple valves), Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.SignalFilter (Partial model that implements the filtered opening for valves and dampers).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium1 | PartialMedium | Medium 1 in the component | |
| replaceable package Medium2 | PartialMedium | Medium 2 in the component | |
| Integer | num | 2 | Number of equipment |
| Integer | numVal | 2 | Number of valves |
| Integer | numFil | num | Number of filters |
| Nominal condition | |||
| MassFlowRate | m1_flow_nominal | Nominal mass flow rate [kg/s] | |
| MassFlowRate | m2_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dp1_nominal | Pressure difference [Pa] | |
| PressureDifference | dp2_nominal | Pressure difference [Pa] | |
| Two-way valve | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv[numVal] | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv[numVal] | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av[numVal] | Av (metric) flow coefficient [m2] | |
| MassFlowRate | m_flow_nominal[numVal] | {m1_flow_nominal,m2_flow_nom... | Nominal mass flow rate [kg/s] |
| PressureDifference | dpValve_nominal[numVal] | fill(6000, numVal) | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] |
| Real | l[2] | {0.0001,0.0001} | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Pressure-flow linearization | |||
| Real | deltaM | deltaM1 | Fraction of nominal flow rate where linearization starts, if y=1 |
| Assumptions | |||
| Boolean | allowFlowReversal1 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1 |
| Boolean | allowFlowReversal2 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2 |
| Advanced | |||
| MassFlowRate | m1_flow_small | 1E-4*abs(m1_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | m2_flow_small | 1E-4*abs(m2_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Two-way valve | |||
| Density | rhoStd[numVal] | {Medium1.density_pTX(101325,... | Inlet density for which valve coefficients are defined [kg/m3] |
| Flow resistance | |||
| Medium 1 | |||
| Boolean | from_dp1 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance1 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM1 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Medium 2 | |||
| Boolean | from_dp2 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance2 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM2 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Dynamics | |||
| Filtered opening | |||
| Boolean | use_inputFilter | true | = true, if opening is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimeValve | 120 | Rise time of the filter (time to reach 99.6 % of an opening step) [s] |
| Init | initValve | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yValve_start[numFil] | fill(1, numFil) | Initial value of output:0-closed, 1-fully opened |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a1 | Fluid connector a1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_b | port_b1 | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_a | port_a2 | Fluid connector a2 (positive design flow direction is from port_a2 to port_b2) |
| FluidPort_b | port_b2 | Fluid connector b2 (positive design flow direction is from port_a2 to port_b2) |
| input BooleanInput | on[num] | Set to true to enable equipment, or false to disable equipment |
Modelica definition
partial model PartialPlantParallel
"Partial source plant model with associated valves"
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPlantParallelInterface;
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ValvesParameters
(
final numVal = 2,
final m_flow_nominal = {m1_flow_nominal,m2_flow_nominal},
rhoStd = {Medium1.density_pTX(101325, 273.15+4, Medium1.X_default),
Medium2.density_pTX(101325, 273.15+4, Medium2.X_default)},
final deltaM=deltaM1);
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.SignalFilter
(
final numFil=num);
constant Boolean homotopyInitialization = true "= true, use homotopy method";
// Isolation valve parameters
parameter Real l[2](each min=1e-10, each max=1) = {0.0001,0.0001}
"Valve leakage, l=Kv(y=0)/Kv(y=1)";
Buildings.Fluid.Actuators.Valves.TwoWayLinear val2[num](
redeclare each replaceable package Medium = Medium2,
each final allowFlowReversal=allowFlowReversal2,
each final m_flow_nominal=m2_flow_nominal,
each dpFixed_nominal=dp2_nominal,
each final show_T=show_T,
each final homotopyInitialization=homotopyInitialization,
each final riseTime=riseTimeValve,
each final init=initValve,
each final use_inputFilter=false,
each final deltaM=deltaM2,
each final l=l[2],
final y_start=yValve_start,
each final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
each final from_dp=from_dp2,
each final linearized=linearizeFlowResistance2,
each final rhoStd=rhoStd[2],
each final dpValve_nominal=dpValve_nominal[2])
"Isolation valves on medium 2 side for on/off use";
Buildings.Fluid.Actuators.Valves.TwoWayLinear val1[num](
redeclare each replaceable package Medium = Medium1,
each final allowFlowReversal=allowFlowReversal1,
each final m_flow_nominal=m1_flow_nominal,
each dpFixed_nominal=dp1_nominal,
each final show_T=show_T,
each final homotopyInitialization=homotopyInitialization,
each final use_inputFilter=false,
each final riseTime=riseTimeValve,
each final init=initValve,
final y_start=yValve_start,
each final deltaM=deltaM1,
each final l=l[1],
each final dpValve_nominal=dpValve_nominal[1],
each final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
each final from_dp=from_dp1,
each final linearized=linearizeFlowResistance1,
each final rhoStd=rhoStd[1])
"Isolation valves on medium 1 side for on/off use";
initial equation
assert(homotopyInitialization, "In " + getInstanceName() +
": The constant homotopyInitialization has been modified from its default value. This constant will be removed in future releases.",
level = AssertionLevel.warning);
equation
for i in 1:num loop
connect(val1[i].port_b, port_b1);
connect(val2[i].port_b, port_b2);
end for;
if use_inputFilter then
connect(booToRea.y, filter.u);
else
connect(booToRea.y, y_actual);
end if;
connect(on, booToRea.u);
connect(y_actual, val1.y);
connect(y_actual, val2.y);
end PartialPlantParallel;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPlantParallelInterface
Partial model that implements the interface for parallel plants
Information
This model implements the interface for the parallel plants in the Buildings.Applications.DataCenters.ChillerCooled package. The parallel plants containnum identical plants
that share the same temperature setpoint at port_b2.
These plants can be operated individually by specifying different on/off signals.
Extends from Buildings.Fluid.Interfaces.PartialFourPortInterface (Partial model transporting fluid between two ports without storing mass or energy), Buildings.Fluid.Interfaces.FourPortFlowResistanceParameters (Parameters for flow resistance for models with four ports).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium1 | PartialMedium | Medium 1 in the component | |
| replaceable package Medium2 | PartialMedium | Medium 2 in the component | |
| Integer | num | 2 | Number of equipment |
| Nominal condition | |||
| MassFlowRate | m1_flow_nominal | Nominal mass flow rate [kg/s] | |
| MassFlowRate | m2_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dp1_nominal | Pressure difference [Pa] | |
| PressureDifference | dp2_nominal | Pressure difference [Pa] | |
| Assumptions | |||
| Boolean | allowFlowReversal1 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 1 |
| Boolean | allowFlowReversal2 | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for medium 2 |
| Advanced | |||
| MassFlowRate | m1_flow_small | 1E-4*abs(m1_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| MassFlowRate | m2_flow_small | 1E-4*abs(m2_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Flow resistance | |||
| Medium 1 | |||
| Boolean | computeFlowResistance1 | true | =true, compute flow resistance. Set to false to assume no friction |
| Boolean | from_dp1 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance1 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM1 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Medium 2 | |||
| Boolean | computeFlowResistance2 | true | =true, compute flow resistance. Set to false to assume no friction |
| Boolean | from_dp2 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance2 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM2 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a1 | Fluid connector a1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_b | port_b1 | Fluid connector b1 (positive design flow direction is from port_a1 to port_b1) |
| FluidPort_a | port_a2 | Fluid connector a2 (positive design flow direction is from port_a2 to port_b2) |
| FluidPort_b | port_b2 | Fluid connector b2 (positive design flow direction is from port_a2 to port_b2) |
| input BooleanInput | on[num] | Set to true to enable equipment, or false to disable equipment |
Modelica definition
partial model PartialPlantParallelInterface "Partial model that implements the interface for parallel plants"
extends Buildings.Fluid.Interfaces.PartialFourPortInterface;
extends Buildings.Fluid.Interfaces.FourPortFlowResistanceParameters(
final computeFlowResistance1=true,
final computeFlowResistance2=true);
parameter Integer num(min=1)=2 "Number of equipment";
Modelica.Blocks.Math.BooleanToReal booToRea[num](
each final realTrue=1,
each final realFalse=0)
"Boolean to real (if true then 1 else 0)";
Modelica.Blocks.Interfaces.BooleanInput on[num]
"Set to true to enable equipment, or false to disable equipment";
equation
connect(on, booToRea.u);
end PartialPlantParallelInterface;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.PartialPumpParallel
Partial model for pump parallel
Information
Partial model for num parallel pumps, each with an isolation valve to
avoid recirculation.
Extends from Buildings.Fluid.Interfaces.PartialTwoPortInterface (Partial model transporting fluid between two ports without storing mass or energy), Buildings.Fluid.Actuators.BaseClasses.ValveParameters (Model with parameters for valves).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Generic | per[num] | per(each motorCooledByFluid=... | Record with performance data |
| Integer | num | 2 | The number of pumps |
| Real | threshold | 0.05 | Hysteresis threshold |
| PartialFlowMachine | pum[num] | redeclare Buildings.Fluid.Mo... | Pumps |
| Nominal condition | |||
| MassFlowRate | m_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dpValve_nominal | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] | |
| Flow Coefficient | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av | Av (metric) flow coefficient [m2] | |
| Pressure-flow linearization | |||
| Real | deltaM | 0.02 | Fraction of nominal flow rate where linearization starts, if y=1 |
| Pump | |||
| Boolean | addPowerToMedium | false | Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations) |
| Two-way valve | |||
| Real | l | 0.0001 | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Assumptions | |||
| Boolean | allowFlowReversal | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
| Advanced | |||
| MassFlowRate | m_flow_small | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Nominal condition | |||
| Density | rhoStd | Inlet density for which valve coefficients are defined [kg/m3] | |
| Dynamics | |||
| Pump | |||
| Time | tau | 1 | Time constant at nominal flow (if energyDynamics <> SteadyState) [s] |
| Boolean | use_inputFilter | true | = true, if speed is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimePump | 30 | Rise time of the filter (time to reach 99.6 % of the speed) [s] |
| Init | init | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yPump_start[num] | fill(0, num) | Initial value of pump signals |
| Valve | |||
| Time | riseTimeValve | 120 | Rise time of the filter (time to reach 99.6 % of the speed) [s] |
| Real | yValve_start[num] | fill(0, num) | Initial value of pump signals |
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| Initialization | |||
| AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
| Temperature | T_start | Medium.T_default | Start value of temperature [K] |
| MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
| Flow resistance | |||
| Boolean | from_dp | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance | false | = true, use linear relation between m_flow and dp for any flow rate |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a | Fluid connector a (positive design flow direction is from port_a to port_b) |
| FluidPort_b | port_b | Fluid connector b (positive design flow direction is from port_a to port_b) |
| input RealInput | u[num] | Continuous input signal for the flow machine [1] |
| output RealOutput | P[num] | Electrical power consumed by the pumps [W] |
Modelica definition
partial model PartialPumpParallel "Partial model for pump parallel"
extends Buildings.Fluid.Interfaces.PartialTwoPortInterface;
extends Buildings.Fluid.Actuators.BaseClasses.ValveParameters;
replaceable parameter Buildings.Fluid.Movers.Data.Generic per[num](
each motorCooledByFluid=false)
constrainedby Buildings.Fluid.Movers.Data.Generic
"Record with performance data";
constant Boolean homotopyInitialization = true "= true, use homotopy method";
// Pump parameters
parameter Integer num=2 "The number of pumps";
parameter Boolean addPowerToMedium=false
"Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations)";
parameter Modelica.SIunits.Time tau = 1
"Time constant at nominal flow (if energyDynamics <> SteadyState)";
parameter Boolean use_inputFilter=true
"= true, if speed is filtered with a 2nd order CriticalDamping filter";
parameter Modelica.SIunits.Time riseTimePump= 30
"Rise time of the filter (time to reach 99.6 % of the speed)";
parameter Modelica.Blocks.Types.Init init=Modelica.Blocks.Types.Init.InitialOutput
"Type of initialization (no init/steady state/initial state/initial output)";
parameter Real[num] yPump_start=fill(0,num) "Initial value of pump signals";
// Valve parameters
parameter Real l=0.0001 "Valve leakage, l=Kv(y=0)/Kv(y=1)";
parameter Modelica.SIunits.Time riseTimeValve = 120
"Rise time of the filter (time to reach 99.6 % of the speed)";
parameter Real[num] yValve_start = fill(0,num)
"Initial value of pump signals";
// Dynamics
parameter Modelica.Fluid.Types.Dynamics energyDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial
"Type of energy balance: dynamic (3 initialization options) or steady state";
parameter Modelica.Fluid.Types.Dynamics massDynamics=energyDynamics
"Type of mass balance: dynamic (3 initialization options) or steady state";
// Initialization
parameter Medium.AbsolutePressure p_start = Medium.p_default
"Start value of pressure";
parameter Medium.Temperature T_start = Medium.T_default
"Start value of temperature";
parameter Medium.MassFraction X_start[Medium.nX] = Medium.X_default
"Start value of mass fractions m_i/m";
parameter Medium.ExtraProperty C_start[Medium.nC](
final quantity=Medium.extraPropertiesNames)=fill(0, Medium.nC)
"Start value of trace substances";
parameter Medium.ExtraProperty C_nominal[Medium.nC](
final quantity=Medium.extraPropertiesNames) = fill(1E-2, Medium.nC)
"Nominal value of trace substances. (Set to typical order of magnitude.)";
parameter Boolean from_dp = false
"= true, use m_flow = f(dp) else dp = f(m_flow)";
parameter Boolean linearizeFlowResistance = false
"= true, use linear relation between m_flow and dp for any flow rate";
parameter Real threshold(min = 0.01) = 0.05
"Hysteresis threshold";
Modelica.Blocks.Interfaces.RealInput u[num](
each final unit="1",
each max=1,
each min=0)
"Continuous input signal for the flow machine";
Modelica.Blocks.Interfaces.RealOutput P[num](
each final quantity="Power",
each final unit="W")
"Electrical power consumed by the pumps";
replaceable Buildings.Fluid.Movers.BaseClasses.PartialFlowMachine pum[num]
constrainedby Buildings.Fluid.Movers.BaseClasses.PartialFlowMachine(
redeclare each final replaceable package Medium = Medium,
each final inputType=Buildings.Fluid.Types.InputType.Continuous,
final per=per,
each final addPowerToMedium=addPowerToMedium,
each final allowFlowReversal=allowFlowReversal,
each final m_flow_small=m_flow_small,
each final show_T=show_T,
each final tau=tau,
each final use_inputFilter=use_inputFilter,
each final riseTime=riseTimePump,
each final init=init,
final y_start= yPump_start,
each final energyDynamics=energyDynamics,
each final massDynamics=massDynamics,
each final p_start=p_start,
each final T_start=T_start,
each final X_start=X_start,
each final C_start=C_start,
each final C_nominal=C_nominal)
"Pumps";
Buildings.Fluid.Actuators.Valves.TwoWayLinear val[num](
redeclare each final replaceable package Medium = Medium,
each final dpFixed_nominal=0,
each final l=l,
each final CvData=Buildings.Fluid.Types.CvTypes.OpPoint,
each final allowFlowReversal=allowFlowReversal,
each final show_T=show_T,
each final rhoStd=rhoStd,
each final use_inputFilter=use_inputFilter,
each final riseTime=riseTimeValve,
each final init=init,
final y_start=yValve_start,
each final dpValve_nominal=dpValve_nominal,
each final m_flow_nominal=m_flow_nominal,
each final deltaM=deltaM,
each final from_dp=from_dp,
each final linearized=linearizeFlowResistance,
each final homotopyInitialization=homotopyInitialization)
"Isolation valves";
Buildings.Controls.OBC.CDL.Continuous.Hysteresis hys[num](
each final uLow=threshold,
each final uHigh=2*threshold) "Hysteresis for isolation valves";
Buildings.Controls.OBC.CDL.Conversions.BooleanToReal booToRea[num]
"Boolean to real conversion for isolation valves";
initial equation
assert(homotopyInitialization, "In " + getInstanceName() +
": The constant homotopyInitialization has been modified from its default value. This constant will be removed in future releases.",
level = AssertionLevel.warning);
equation
connect(pum.port_b, val.port_a);
for i in 1:num loop
connect(val[i].port_b, port_b);
connect(port_a, pum[i].port_a);
end for;
connect(pum.P, P);
connect(booToRea.y, val.y);
connect(hys.y, booToRea.u);
connect(hys.u, u);
end PartialPumpParallel;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.SignalFilter
Partial model that implements the filtered opening for valves and dampers
Information
Partial model that implements the filters that are used to approximate the travel time of the actuators.
The signal y_actual is used to obtain the current position of the actuators.
Extends from Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.SignalFilterParameters (Record that contains the parameters of the filtered opening for multiple valves and dampers).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | numFil | 4 | Number of filters |
| Dynamics | |||
| Filtered opening | |||
| Boolean | use_inputFilter | true | = true, if opening is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimeValve | 120 | Rise time of the filter (time to reach 99.6 % of an opening step) [s] |
| Init | initValve | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yValve_start[numFil] | fill(1, numFil) | Initial value of output:0-closed, 1-fully opened |
Modelica definition
partial model SignalFilter "Partial model that implements the filtered opening for valves and dampers"
extends Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.SignalFilterParameters;
protected
Modelica.Blocks.Interfaces.RealOutput[numFil] y_actual "Actual valve position";
Modelica.Blocks.Continuous.Filter[numFil] filter(
each order=2,
each f_cut=5/(2*Modelica.Constants.pi*riseTimeValve),
each final init=initValve,
final y_start=yValve_start,
each final analogFilter=Modelica.Blocks.Types.AnalogFilter.CriticalDamping,
each final filterType=Modelica.Blocks.Types.FilterType.LowPass,
x(each stateSelect=StateSelect.always)) if use_inputFilter
"Second order filters to approximate valve opening time, and to improve numerics";
Modelica.Blocks.Interfaces.RealOutput[numFil] y_filtered if use_inputFilter
"Filtered valve positions in the range 0..1";
equation
connect(filter.y,y_filtered);
if use_inputFilter then
connect(filter.y, y_actual);
end if;
end SignalFilter;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ThreeWayValveParameters
Model with parameters for a three-way valve
Information
Partial model that decribes the parameters of a three-way valve.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | activate_ThrWayVal | Activate the use of three-way valve: True-use three-way valve; False-not use the three-way valve | |
| Three-way Valve | |||
| PressureDifference | dpThrWayVal_nominal | 6000 | Nominal pressure drop of fully open valve [Pa] |
| Real | fraK_ThrWayVal | 0.7 | Fraction Kv(port_3→port_2)/Kv(port_1→port_2)for the three-way valve |
| Real | l_ThrWayVal[2] | {0.0001,0.0001} | Bypass valve leakage, l=Kv(y=0)/Kv(y=1) |
| Real | R | 50 | Rangeability, R=50...100 typically for the three-way valve |
| Real | delta0 | 0.01 | Range of significant deviation from equal percentage law for the three-way valve |
| Advanced | |||
| PortFlowDirection | portFlowDirection_1 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_1 in the three-way valve |
| PortFlowDirection | portFlowDirection_2 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_2 in the three-way valve |
| PortFlowDirection | portFlowDirection_3 | Modelica.Fluid.Types.PortFlo... | Flow direction for port_3 in the three-way valve |
Modelica definition
partial model ThreeWayValveParameters
"Model with parameters for a three-way valve"
parameter Boolean activate_ThrWayVal
"Activate the use of three-way valve: True-use three-way valve; False-not use the three-way valve";
parameter Modelica.SIunits.PressureDifference dpThrWayVal_nominal(
displayUnit="Pa",
min=0,
fixed=true)= 6000
"Nominal pressure drop of fully open valve";
parameter Real fraK_ThrWayVal(
min=0,
max=1) = 0.7
"Fraction Kv(port_3→port_2)/Kv(port_1→port_2)for the three-way valve";
parameter Real l_ThrWayVal[2](
each min=1e-10,
each max=1) = {0.0001,0.0001}
"Bypass valve leakage, l=Kv(y=0)/Kv(y=1)";
parameter Real R=50
"Rangeability, R=50...100 typically for the three-way valve";
parameter Real delta0=0.01
"Range of significant deviation from equal percentage law for the three-way valve";
//Advanced
parameter Modelica.Fluid.Types.PortFlowDirection portFlowDirection_1=
Modelica.Fluid.Types.PortFlowDirection.Bidirectional
"Flow direction for port_1 in the three-way valve";
parameter Modelica.Fluid.Types.PortFlowDirection portFlowDirection_2=
Modelica.Fluid.Types.PortFlowDirection.Bidirectional
"Flow direction for port_2 in the three-way valve";
parameter Modelica.Fluid.Types.PortFlowDirection portFlowDirection_3=
Modelica.Fluid.Types.PortFlowDirection.Bidirectional
"Flow direction for port_3 in the three-way valve";
end ThreeWayValveParameters;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.ValvesParameters
Model with parameters for multiple valves
Information
Model that computes the flow coefficients of vectored valves. The number of vectored valves is
defined by the parameter numVal.
Note that the numVal valves have the same modelling option that can specify the valve
flow coefficient in fully open conditions. Details can be found in
Buildings.Fluid.Actuators.BaseClasses.ValveParameters.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | numVal | Number of valves | |
| Two-way valve | |||
| CvTypes | CvData | Buildings.Fluid.Types.CvType... | Selection of flow coefficient |
| Real | Kv[numVal] | Kv (metric) flow coefficient [m3/h/(bar)^(1/2)] | |
| Real | Cv[numVal] | Cv (US) flow coefficient [USG/min/(psi)^(1/2)] | |
| Area | Av[numVal] | Av (metric) flow coefficient [m2] | |
| MassFlowRate | m_flow_nominal[numVal] | Nominal mass flow rate [kg/s] | |
| PressureDifference | dpValve_nominal[numVal] | fill(6000, numVal) | Nominal pressure drop of fully open valve, used if CvData=Buildings.Fluid.Types.CvTypes.OpPoint [Pa] |
| Pressure-flow linearization | |||
| Real | deltaM | 0.02 | Fraction of nominal flow rate where linearization starts, if y=1 |
| Advanced | |||
| Two-way valve | |||
| Density | rhoStd[numVal] | Inlet density for which valve coefficients are defined [kg/m3] | |
Modelica definition
partial model ValvesParameters "Model with parameters for multiple valves"
parameter Integer numVal "Number of valves";
parameter Buildings.Fluid.Types.CvTypes CvData=Buildings.Fluid.Types.CvTypes.OpPoint
"Selection of flow coefficient";
parameter Real[numVal] Kv(
each fixed= if CvData==Buildings.Fluid.Types.CvTypes.Kv then true else false)
"Kv (metric) flow coefficient [m3/h/(bar)^(1/2)]";
parameter Real[numVal] Cv(
each fixed= if CvData==Buildings.Fluid.Types.CvTypes.Cv then true else false)
"Cv (US) flow coefficient [USG/min/(psi)^(1/2)]";
parameter Modelica.SIunits.Area[numVal] Av(
each fixed= if CvData==Buildings.Fluid.Types.CvTypes.Av then true else false)
"Av (metric) flow coefficient";
parameter Real deltaM = 0.02
"Fraction of nominal flow rate where linearization starts, if y=1";
parameter Modelica.SIunits.MassFlowRate[numVal] m_flow_nominal
"Nominal mass flow rate";
parameter Modelica.SIunits.PressureDifference[numVal] dpValve_nominal(
each displayUnit="Pa",
each min=0,
each fixed= if CvData==Buildings.Fluid.Types.CvTypes.OpPoint then true else false)=
fill(6000,numVal)
"Nominal pressure drop of fully open valve, used if
CvData=Buildings.Fluid.Types.CvTypes.OpPoint";
parameter Modelica.SIunits.Density[numVal] rhoStd
"Inlet density for which valve coefficients are defined";
protected
parameter Real[numVal] Kv_SI(
each min=0,
each fixed= false)
"Flow coefficient for fully open valve in SI units, Kv=m_flow/sqrt(dp) [kg/s/(Pa)^(1/2)]";
initial equation
if CvData == Buildings.Fluid.Types.CvTypes.OpPoint then
Kv_SI = m_flow_nominal./sqrt(dpValve_nominal);
Kv = Kv_SI./(rhoStd/3600/sqrt(1E5));
Cv = Kv_SI./(rhoStd*0.0631/1000/sqrt(6895));
Av = Kv_SI./sqrt(rhoStd);
elseif CvData == Buildings.Fluid.Types.CvTypes.Kv then
Kv_SI = Kv.*rhoStd/3600/sqrt(1E5)
"Unit conversion m3/(h*sqrt(bar)) to kg/(s*sqrt(Pa))";
Cv = Kv_SI./(rhoStd*0.0631/1000/sqrt(6895));
Av = Kv_SI./sqrt(rhoStd);
dpValve_nominal = (m_flow_nominal./Kv_SI).^2;
elseif CvData == Buildings.Fluid.Types.CvTypes.Cv then
Kv_SI = Cv.*rhoStd*0.0631/1000/sqrt(6895)
"Unit conversion USG/(min*sqrt(psi)) to kg/(s*sqrt(Pa))";
Kv = Kv_SI./(rhoStd/3600/sqrt(1E5));
Av = Kv_SI./sqrt(rhoStd);
dpValve_nominal = (m_flow_nominal./Kv_SI).^2;
else
assert(CvData == Buildings.Fluid.Types.CvTypes.Av, "Invalid value for CvData.
Obtained CvData = " + String(CvData) + ".");
Kv_SI = Av.*sqrt(rhoStd);
Kv = Kv_SI./(rhoStd/3600/sqrt(1E5));
Cv = Kv_SI./(rhoStd*0.0631/1000/sqrt(6895));
dpValve_nominal = (m_flow_nominal./Kv_SI).^2;
end if;
end ValvesParameters;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.FourPortResistanceChillerWSE
Flow resistance model for the chiller and WSE package
Information
This class contains parameters that are used to compute the pressure drop in the Buildings.Applications.DataCenters.ChillerCooled package.Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Chiller | |||
| PressureDifference | dp1_chi_nominal | Pressure difference on medium 1 side in the chillers [Pa] | |
| PressureDifference | dp2_chi_nominal | Pressure difference on medium 2 side in the chillers [Pa] | |
| Waterside economizer | |||
| PressureDifference | dp1_wse_nominal | Pressure difference on medium 1 side in the waterside economizer [Pa] | |
| PressureDifference | dp2_wse_nominal | Pressure difference on medium 2 side in the waterside economizer [Pa] | |
| Flow resistance | |||
| Medium 1 | |||
| Boolean | computeFlowResistance1 | true | =true, compute flow resistance. Set to false to assume no friction |
| Boolean | from_dp1 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance1 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM1 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Medium 2 | |||
| Boolean | computeFlowResistance2 | true | =true, compute flow resistance. Set to false to assume no friction |
| Boolean | from_dp2 | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearizeFlowResistance2 | false | = true, use linear relation between m_flow and dp for any flow rate |
| Real | deltaM2 | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
Modelica definition
record FourPortResistanceChillerWSE
"Flow resistance model for the chiller and WSE package"
parameter Boolean computeFlowResistance1 = true
"=true, compute flow resistance. Set to false to assume no friction";
parameter Boolean from_dp1 = false
"= true, use m_flow = f(dp) else dp = f(m_flow)";
parameter Modelica.SIunits.PressureDifference dp1_chi_nominal(
min=0,displayUnit="Pa")
"Pressure difference on medium 1 side in the chillers";
parameter Modelica.SIunits.PressureDifference dp1_wse_nominal(
min=0,displayUnit="Pa")
"Pressure difference on medium 1 side in the waterside economizer";
parameter Boolean linearizeFlowResistance1 = false
"= true, use linear relation between m_flow and dp for any flow rate";
parameter Real deltaM1 = 0.1
"Fraction of nominal flow rate where flow transitions to laminar";
parameter Boolean computeFlowResistance2 = true
"=true, compute flow resistance. Set to false to assume no friction";
parameter Boolean from_dp2 = false
"= true, use m_flow = f(dp) else dp = f(m_flow)";
parameter Modelica.SIunits.PressureDifference dp2_chi_nominal(
min=0,displayUnit="Pa")
"Pressure difference on medium 2 side in the chillers";
parameter Modelica.SIunits.PressureDifference dp2_wse_nominal(
min=0,displayUnit="Pa")
"Pressure difference on medium 2 side in the waterside economizer";
parameter Boolean linearizeFlowResistance2 = false
"= true, use linear relation between m_flow and dp for any flow rate";
parameter Real deltaM2 = 0.1
"Fraction of nominal flow rate where flow transitions to laminar";
end FourPortResistanceChillerWSE;
Buildings.Applications.DataCenters.ChillerCooled.Equipment.BaseClasses.SignalFilterParameters
Record that contains the parameters of the filtered opening for multiple valves and dampers
Information
Record that contains essential parameters for the vectored signal filters. The number of filters is specified bynFilter.
Note that all the signal filters have the same on/off control signal, rising time, and initialization type,
which are specified by use_inputFilter, riseTimeValve and initValve respectively.
However, they can have different initial valves, specified by yValve_start.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | numFil | 4 | Number of filters |
| Dynamics | |||
| Filtered opening | |||
| Boolean | use_inputFilter | true | = true, if opening is filtered with a 2nd order CriticalDamping filter |
| Time | riseTimeValve | 120 | Rise time of the filter (time to reach 99.6 % of an opening step) [s] |
| Init | initValve | Modelica.Blocks.Types.Init.I... | Type of initialization (no init/steady state/initial state/initial output) |
| Real | yValve_start[numFil] | fill(1, numFil) | Initial value of output:0-closed, 1-fully opened |
Modelica definition
record SignalFilterParameters
"Record that contains the parameters of the filtered opening for multiple valves and dampers"
parameter Integer numFil(min=1)=4 "Number of filters";
parameter Boolean use_inputFilter=true
"= true, if opening is filtered with a 2nd order CriticalDamping filter";
parameter Modelica.SIunits.Time riseTimeValve=120
"Rise time of the filter (time to reach 99.6 % of an opening step)";
parameter Modelica.Blocks.Types.Init initValve=Modelica.Blocks.Types.Init.InitialOutput
"Type of initialization (no init/steady state/initial state/initial output)";
parameter Real[numFil] yValve_start=fill(1,numFil)
"Initial value of output:0-closed, 1-fully opened";
end SignalFilterParameters;