Buildings.Experimental.DistrictHeatingCooling.Plants
Package with plant models
Information
This package contains component models for district heating and cooling plants.Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
Package Content
| Name | Description |
|---|---|
 HeatingCoolingCarnot_T
|
Ideal heating and cooling plant with leaving temperature as set point and vapor compression engines that are approximated by Carnot cycles |
 Ideal_T
|
Ideal heating and cooling plant with leaving temperature as set point |
 LakeWaterHeatExchanger_T
|
Heat exchanger with lake, ocean or river water |
 Validation
|
Collection of validation models |
Buildings.Experimental.DistrictHeatingCooling.Plants.HeatingCoolingCarnot_T
Ideal heating and cooling plant with leaving temperature as set point and vapor compression engines that are approximated by Carnot cycles
Information
Model of an ideal heating and cooling plant that takes as a parameter the set point for the leaving fluid temperature. The power consumptions are modeled using a vapor compression engine for heating and for cooling. The efficiency of these vapor compression engines varies using the Carnot cycle analogy.
Extends from Buildings.Fluid.Interfaces.PartialTwoPortInterface (Partial model transporting fluid between two ports without storing mass or energy).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| TemperatureDifference | dTEva_nominal | -10 | Temperature difference evaporator outlet-inlet of heat pump [K] |
| TemperatureDifference | dTCon_nominal | 10 | Temperature difference condenser outlet-inlet of chiller [K] |
| Nominal condition | |||
| MassFlowRate | m_flow_nominal | Nominal mass flow rate [kg/s] | |
| Design parameter | |||
| Pressure | dp_nominal | 30000 | Pressure difference at nominal flow rate [Pa] |
| 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] |
| Boolean | linearizeFlowResistance | false | = true, use linear relation between m_flow and dp for any flow rate |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
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 | TSetHea | Temperature set point for heating [K] |
| input RealInput | TSetCoo | Temperature set point for cooling [K] |
| input RealInput | TSink | Temperature of heat sink [K] |
| output RealOutput | PComHea | Compressor energy for heating [W] |
| output RealOutput | PComCoo | Compressor energy for cooling [W] |
| output RealOutput | QHea_flow | Heat input into fluid [W] |
| output RealOutput | QCoo_flow | Heat extracted from fluid [W] |
| output RealOutput | QAmbHea_flow | Heat from ambient to heat pump evaporator [W] |
| output RealOutput | QAmbChi_flow | Heat from chiller condensor to ambient [W] |
Modelica definition
model HeatingCoolingCarnot_T
"Ideal heating and cooling plant with leaving temperature as set point and vapor compression engines that are approximated by Carnot cycles"
extends Buildings.Fluid.Interfaces.PartialTwoPortInterface(
final m_flow(start=0),
final allowFlowReversal = true,
final dp(start=0));
parameter Modelica.SIunits.TemperatureDifference dTEva_nominal=-10
"Temperature difference evaporator outlet-inlet of heat pump";
parameter Modelica.SIunits.TemperatureDifference dTCon_nominal=10
"Temperature difference condenser outlet-inlet of chiller";
parameter Modelica.SIunits.Pressure dp_nominal(displayUnit="Pa")=30000
"Pressure difference at nominal flow rate";
parameter Boolean linearizeFlowResistance=false
"= true, use linear relation between m_flow and dp for any flow rate";
Modelica.Blocks.Interfaces.RealInput TSetHea(unit="K")
"Temperature set point for heating";
Modelica.Blocks.Interfaces.RealInput TSetCoo(unit="K")
"Temperature set point for cooling";
Modelica.Blocks.Interfaces.RealInput TSink(unit="K")
"Temperature of heat sink";
Modelica.Blocks.Interfaces.RealOutput PComHea(unit="W")
"Compressor energy for heating";
Modelica.Blocks.Interfaces.RealOutput PComCoo(unit="W")
"Compressor energy for cooling";
Modelica.Blocks.Interfaces.RealOutput QHea_flow(unit="W")
"Heat input into fluid";
Modelica.Blocks.Interfaces.RealOutput QCoo_flow(unit="W")
"Heat extracted from fluid";
Modelica.Blocks.Interfaces.RealOutput QAmbHea_flow(unit="W")
"Heat from ambient to heat pump evaporator";
Modelica.Blocks.Interfaces.RealOutput QAmbChi_flow(unit="W")
"Heat from chiller condensor to ambient";
protected
replaceable package MediumSin =
Buildings.Media.Air "Medium model for the heat sink";
parameter Modelica.SIunits.TemperatureDifference dTSin = 2
"Temperature difference over heat source or sink";
final parameter Medium.ThermodynamicState staSin_default = Medium.setState_pTX(
T=MediumSin.T_default,
p=MediumSin.p_default,
X=MediumSin.X_default[1:MediumSin.nXi])
"Medium state at default properties";
final parameter Modelica.SIunits.SpecificHeatCapacity cpSin_default=
Medium.specificHeatCapacityCp(staSin_default)
"Specific heat capacity of the fluid";
final parameter Medium.ThermodynamicState sta_default = Medium.setState_pTX(
T=Medium.T_default,
p=Medium.p_default,
X=Medium.X_default[1:Medium.nXi]) "Medium state at default properties";
final parameter Modelica.SIunits.SpecificHeatCapacity cp_default=
Medium.specificHeatCapacityCp(sta_default)
"Specific heat capacity of the fluid";
Buildings.Fluid.Chillers.Carnot_TEva coo(
show_T=true,
redeclare package Medium1 = MediumSin,
redeclare package Medium2 = Medium,
m2_flow_nominal=m_flow_nominal,
QEva_flow_nominal=m_flow_nominal*cp_default*dTEva_nominal,
use_eta_Carnot_nominal=true,
etaCarnot_nominal=0.3,
dp1_nominal=6000,
dp2_nominal=0,
dTEva_nominal=-dTSin,
dTCon_nominal=dTCon_nominal,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
allowFlowReversal1=false) "Chiller";
Buildings.Fluid.HeatPumps.Carnot_TCon hea(
redeclare package Medium1 = Medium,
redeclare package Medium2 = MediumSin,
show_T=true,
m1_flow_nominal=m_flow_nominal,
QCon_flow_nominal=m_flow_nominal*cp_default*dTCon_nominal,
dp2_nominal=6000,
use_eta_Carnot_nominal=true,
etaCarnot_nominal=0.3,
dTEva_nominal=dTEva_nominal,
dTCon_nominal=dTSin,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
allowFlowReversal2=false,
dp1_nominal=dp_nominal) "Heat pump for heating";
Buildings.Fluid.Sources.FixedBoundary sinHea(
redeclare package Medium = MediumSin,
nPorts=1) "Pressure source";
Buildings.Fluid.Sources.MassFlowSource_T souHea(
redeclare package Medium = MediumSin,
use_m_flow_in=true,
use_T_in=true,
nPorts=1) "Mass flow source";
Modelica.Blocks.Math.Gain mHeaSin_flow(k=1/(cpSin_default*dTSin))
"Mass flow rate for heat source";
Modelica.Blocks.Math.Add addHea(k2=-1) "Adder for energy balance";
Modelica.Blocks.Math.Add addCoo "Adder for energy balance";
Modelica.Blocks.Math.Gain mCooSin_flow(k=-1/(cpSin_default*dTSin))
"Mass flow rate for heat sink";
Buildings.Fluid.Sources.MassFlowSource_T sou2(
redeclare package Medium = MediumSin,
use_m_flow_in=true,
use_T_in=true,
nPorts=1) "Mass flow source";
Buildings.Fluid.Sources.FixedBoundary sinCoo(
redeclare package Medium = MediumSin,
nPorts=1) "Pressure source";
equation
connect(hea.TSet, TSetHea);
connect(port_a, hea.port_a1);
connect(hea.QCon_flow, addHea.u1);
connect(hea.P, addHea.u2);
connect(mHeaSin_flow.u, addHea.y);
connect(coo.P, addCoo.u2);
connect(addCoo.y, mCooSin_flow.u);
connect(sinHea.ports[1], hea.port_b2);
connect(mHeaSin_flow.y, souHea.m_flow_in);
connect(TSink, souHea.T_in);
connect(souHea.ports[1], hea.port_a2);
connect(mCooSin_flow.y, sou2.m_flow_in);
connect(sou2.T_in, TSink);
connect(hea.P, PComHea);
connect(coo.P, PComCoo);
connect(hea.QCon_flow, QHea_flow);
connect(TSetCoo, coo.TSet);
connect(sou2.ports[1], coo.port_a1);
connect(coo.port_b1, sinCoo.ports[1]);
connect(port_b, coo.port_a2);
connect(addCoo.u1, coo.QEva_flow);
connect(coo.QEva_flow, QCoo_flow);
connect(hea.port_b1, coo.port_b2);
connect(hea.QEva_flow, QAmbHea_flow);
connect(coo.QCon_flow, QAmbChi_flow);
end HeatingCoolingCarnot_T;
Buildings.Experimental.DistrictHeatingCooling.Plants.Ideal_T
Ideal heating and cooling plant with leaving temperature as set point
Information
Model of an ideal heating and cooling plant that takes as a parameter the set point for the leaving fluid temperature.
Extends from Buildings.Fluid.Interfaces.PartialTwoPortInterface (Partial model transporting fluid between two ports without storing mass or energy).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Nominal condition | |||
| MassFlowRate | m_flow_nominal | Nominal mass flow rate [kg/s] | |
| Design parameter | |||
| Pressure | dp_nominal | 30000 | Pressure difference at nominal flow rate [Pa] |
| 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] |
| Boolean | linearizeFlowResistance | false | = true, use linear relation between m_flow and dp for any flow rate |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
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) |
| output RealOutput | QHea_flow | Heat input into fluid [W] |
| output RealOutput | QCoo_flow | Heat extracted from fluid [W] |
| input RealInput | TSetHea | Temperature set point for heating [K] |
| input RealInput | TSetCoo | Temperature set point for cooling [K] |
Modelica definition
model Ideal_T
"Ideal heating and cooling plant with leaving temperature as set point"
extends Buildings.Fluid.Interfaces.PartialTwoPortInterface(
final m_flow(start=0),
final allowFlowReversal = true,
final dp(start=0));
parameter Modelica.SIunits.Pressure dp_nominal(displayUnit="Pa")=30000
"Pressure difference at nominal flow rate";
parameter Boolean linearizeFlowResistance=false
"= true, use linear relation between m_flow and dp for any flow rate";
Modelica.Blocks.Interfaces.RealOutput QHea_flow(unit="W")
"Heat input into fluid";
Modelica.Blocks.Interfaces.RealOutput QCoo_flow(unit="W")
"Heat extracted from fluid";
protected
final parameter Medium.ThermodynamicState sta_default = Medium.setState_pTX(
T=Medium.T_default,
p=Medium.p_default,
X=Medium.X_default[1:Medium.nXi]) "Medium state at default properties";
final parameter Modelica.SIunits.SpecificHeatCapacity cp_default=
Medium.specificHeatCapacityCp(sta_default)
"Specific heat capacity of the fluid";
Buildings.Fluid.HeatExchangers.HeaterCooler_T coo(
redeclare package Medium = Medium,
allowFlowReversal=allowFlowReversal,
m_flow_nominal=m_flow_nominal,
show_T=true,
Q_flow_maxHeat=0,
dp_nominal=0,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
tau=60) "Cooling supply";
Buildings.Fluid.HeatExchangers.HeaterCooler_T hea(
redeclare package Medium = Medium,
allowFlowReversal=allowFlowReversal,
m_flow_nominal=m_flow_nominal,
from_dp=false,
show_T=true,
Q_flow_maxCool=0,
dp_nominal=dp_nominal,
linearizeFlowResistance=linearizeFlowResistance,
energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
tau=60) "Heat supply";
Buildings.Fluid.Sensors.TemperatureTwoPort senTem(
redeclare package Medium = Medium,
m_flow_nominal=m_flow_nominal,
tau=0) "Temperature sensor";
public
Modelica.Blocks.Interfaces.RealInput TSetHea(unit="K")
"Temperature set point for heating";
Modelica.Blocks.Interfaces.RealInput TSetCoo(unit="K")
"Temperature set point for cooling";
equation
connect(QHea_flow, hea.Q_flow);
connect(coo.Q_flow, QCoo_flow);
connect(port_a, hea.port_a);
connect(coo.port_a, port_b);
connect(hea.port_b, senTem.port_a);
connect(senTem.port_b, coo.port_b);
connect(hea.TSet, TSetHea);
connect(TSetCoo, coo.TSet);
end Ideal_T;
Buildings.Experimental.DistrictHeatingCooling.Plants.LakeWaterHeatExchanger_T
Heat exchanger with lake, ocean or river water
Information
Model for a heat exchanger that uses water such as from a lake, the ocean or a river,
or the ambient air to either provide heating or cooling.
The model has built-in controls in order to exchange heat,
up to a maximum approach temperature difference
set by TApp.
There are three input signals for the heat or cold source:
-
TSouWatis the temperature of the ocean, lake or river to which heat is rejected, or from which heat is extracted from. -
TSouHeais the temperature used to heat the water. This could be set to the outdoor drybulb temperature if there is an air-to-water heat exchanger, or else to the same value as is used forTSouWatbelow. -
TSouCoois the temperature used to cool the water. This could be set to the outdoor wet bulb temperature if there is a wet cooling tower, to the outdoor dry-bulb temperature if there is a dry cooling tower, or else toTSouWat.
The parameters TLooMin and TLooMax are used to avoid
that the water of the district heating/cooling
is below or above a maximum threshold.
Implementation
The pressure drop of the heat exchanger is implemented in the valve
instances valCoo and valHea.
Extends from Buildings.Fluid.Interfaces.PartialFourPortInterface (Partial model transporting fluid between two ports without storing mass or energy).
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 | Modelica.Media.Interfaces.Pa... | Medium in the component | |
| Boolean | disableHeatExchanger | false | Set to true to disable the heat exchanger |
| TemperatureDifference | TApp | 0.5 | Approach temperature difference [K] |
| Nominal condition | |||
| MassFlowRate | m1_flow_nominal | m_flow_nominal | Nominal mass flow rate [kg/s] |
| MassFlowRate | m2_flow_nominal | m_flow_nominal | Nominal mass flow rate [kg/s] |
| MassFlowRate | m_flow_nominal | Nominal mass flow rate [kg/s] | |
| PressureDifference | dpValve_nominal | 1000 | Nominal pressure drop of fully open valve [Pa] |
| PressureDifference | dpHex_nominal | Pressure drop of heat exchanger pipe and other resistances in the heat exchanger flow leg that are in series with the 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] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| 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 |
| Real | deltaM | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable package Medium1 | Medium 1 in the component | |
| replaceable package Medium2 | Medium 2 in the component | |
| 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 | |
| input RealInput | TSouWat | Temperature of ocean, lake or river [K] |
| input RealInput | TSouHea | Source temperature to add heat the loop water (such as outdoor drybulb temperature) [K] |
| input RealInput | TSouCoo | Source temperature to reject heat, such as outdoor wet bulb, outdoor drybulb, or else TSouWat [K] |
| input RealInput | TSetHea | Temperature set point for heating [K] |
| input RealInput | TSetCoo | Temperature set point for cooling [K] |
| output RealOutput | QWat_flow | Heat exchanged with water reservoir (positive if added to reservoir) [W] |
Modelica definition
model LakeWaterHeatExchanger_T "Heat exchanger with lake, ocean or river water"
extends Buildings.Fluid.Interfaces.PartialFourPortInterface(
redeclare final package Medium1 = Medium,
redeclare final package Medium2 = Medium,
final allowFlowReversal1 = true,
final allowFlowReversal2 = true,
final m1_flow_nominal = m_flow_nominal,
final m2_flow_nominal = m_flow_nominal);
replaceable package Medium =
Modelica.Media.Interfaces.PartialMedium "Medium in the component";
parameter Boolean disableHeatExchanger = false
"Set to true to disable the heat exchanger";
parameter Modelica.SIunits.TemperatureDifference TApp(
min=0,
displayUnit="K") = 0.5
"Approach temperature difference";
parameter Modelica.SIunits.MassFlowRate m_flow_nominal
"Nominal mass flow rate";
parameter Modelica.SIunits.PressureDifference dpValve_nominal(
displayUnit="Pa",
min=0) = 1000 "Nominal pressure drop of fully open valve";
parameter Modelica.SIunits.PressureDifference dpHex_nominal(
displayUnit="Pa",
min=0)
"Pressure drop of heat exchanger pipe and other resistances in the heat exchanger flow leg that are in series with the valve";
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 deltaM = 0.1
"Fraction of nominal flow rate where flow transitions to laminar";
Modelica.Blocks.Interfaces.RealInput TSouWat(
unit="K",
displayUnit="degC")
"Temperature of ocean, lake or river";
Modelica.Blocks.Interfaces.RealInput TSouHea(
unit="K",
displayUnit="degC")
"Source temperature to add heat the loop water (such as outdoor drybulb temperature)";
Modelica.Blocks.Interfaces.RealInput TSouCoo(
unit="K",
displayUnit="degC")
"Source temperature to reject heat, such as outdoor wet bulb, outdoor drybulb, or else TSouWat";
Modelica.Blocks.Interfaces.RealInput TSetHea(unit="K")
"Temperature set point for heating";
Modelica.Blocks.Interfaces.RealInput TSetCoo(unit="K")
"Temperature set point for cooling";
Modelica.Blocks.Interfaces.RealOutput QWat_flow(unit="W")
"Heat exchanged with water reservoir (positive if added to reservoir)";
Buildings.Fluid.Actuators.Valves.ThreeWayLinear valCoo(
redeclare final package Medium = Medium,
final m_flow_nominal=m_flow_nominal,
dpValve_nominal=1000,
use_inputFilter=false,
final energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyStateInitial,
final dpFixed_nominal={if disableHeatExchanger then 0 else dpHex_nominal,0})
"Switching valve for cooling";
Buildings.Fluid.Actuators.Valves.ThreeWayLinear valHea(
redeclare final package Medium = Medium,
final m_flow_nominal=m_flow_nominal,
dpValve_nominal=1000,
use_inputFilter=false,
final energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyStateInitial,
final dpFixed_nominal={if disableHeatExchanger then 0 else dpHex_nominal,0})
"Switching valve for heating";
protected
Buildings.Fluid.HeatExchangers.HeaterCooler_T coo(
redeclare final package Medium = Medium,
final m_flow_nominal=m_flow_nominal,
final dp_nominal=0,
final Q_flow_maxHeat=0,
final allowFlowReversal=true,
final show_T=false,
final from_dp=from_dp,
final linearizeFlowResistance=linearizeFlowResistance,
final deltaM=deltaM,
final energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState,
Q_flow_maxCool=if disableHeatExchanger then 0 else -Modelica.Constants.inf)
"Heat exchanger effect for mode in which water is cooled";
Modelica.Blocks.Sources.RealExpression TWarIn(y=
Medium.temperature_phX(
p=port_b1.p,
h=inStream(port_b1.h_outflow),
X=cat(1,inStream(port_b1.Xi_outflow),
{1-sum(inStream(port_b1.Xi_outflow))})))
"Warm water inlet temperature";
Buildings.Fluid.HeatExchangers.HeaterCooler_T hea(
redeclare final package Medium = Medium,
final m_flow_nominal=m_flow_nominal,
final dp_nominal=0,
final allowFlowReversal=true,
final show_T=false,
final from_dp=from_dp,
final linearizeFlowResistance=linearizeFlowResistance,
final deltaM=deltaM,
final energyDynamics=Modelica.Fluid.Types.Dynamics.SteadyState,
Q_flow_maxCool=0,
Q_flow_maxHeat=if disableHeatExchanger then 0 else Modelica.Constants.inf)
"Heat exchanger effect for mode in which water is heated";
Modelica.Blocks.Sources.RealExpression TColIn(y=
Medium.temperature_phX(
p=port_a2.p,
h=inStream(port_a2.h_outflow),
X=cat(1, inStream(port_a2.Xi_outflow),
{1-sum(inStream(port_a2.Xi_outflow))}))) "Cold water inlet temperature";
Utilities.Math.SmoothMax maxHeaLea(deltaX=0.1) "Maximum leaving temperature";
Utilities.Math.SmoothMin minHeaLvg(deltaX=0.1) "Minimum leaving temperature";
Utilities.Math.SmoothMax maxCooLea(deltaX=0.1) "Maximum leaving temperature";
Utilities.Math.SmoothMin minCooLvg(deltaX=0.1) "Minimum leaving temperature";
Modelica.Blocks.Sources.Constant TAppHex(k=TApp)
"Approach temperature difference";
Modelica.Blocks.Math.Add TWatHea(k2=-1)
"Heat exchanger outlet, taking into account approach";
Modelica.Blocks.Math.Add TWatCoo
"Heat exchanger outlet, taking into account approach";
Modelica.Blocks.Math.Add QExc_flow(k1=-1) "Heat added to water reservoir";
Utilities.Math.SmoothMax smoothMax(deltaX=0.1);
Utilities.Math.SmoothMin smoothMin(deltaX=0.1);
Controller conCoo(final m_flow_nominal=m_flow_nominal)
"Controller for hex for cooling";
Buildings.Fluid.Sensors.MassFlowRate senMasFloCoo(redeclare package Medium = Medium)
"Mass flow sensor used for cooling control";
Buildings.Fluid.Sensors.MassFlowRate senMasFloHea(redeclare package Medium = Medium)
"Mass flow sensor used for heating control";
Controller conHea(final m_flow_nominal=m_flow_nominal)
"Controller for hex for heating";
equation
connect(TColIn.y, maxHeaLea.u2);
connect(maxHeaLea.y, minHeaLvg.u2);
connect(minHeaLvg.y, hea.TSet);
connect(TWarIn.y, minCooLvg.u1);
connect(minCooLvg.y, maxCooLea.u2);
connect(maxCooLea.y, coo.TSet);
connect(TAppHex.y, TWatHea.u2);
connect(TAppHex.y, TWatCoo.u2);
connect(TWatCoo.y, minCooLvg.u2);
connect(TWatHea.y, maxHeaLea.u1);
connect(coo.Q_flow, QExc_flow.u1);
connect(hea.Q_flow, QExc_flow.u2);
connect(QExc_flow.y, QWat_flow);
connect(smoothMax.y, TWatHea.u1);
connect(smoothMin.y, TWatCoo.u1);
connect(TSetCoo, maxCooLea.u1);
connect(valCoo.port_2, port_b1);
connect(conCoo.y, valCoo.y);
protected
model Controller "Controller for bay water heat exchanger"
parameter Modelica.SIunits.MassFlowRate m_flow_nominal
"Nominal mass flow rate";
Modelica.Blocks.Nonlinear.Limiter limTem(
uMax=1,
uMin=0,
limitsAtInit=false,
strict=true)
"Signal limiter for switching valve";
Modelica.Blocks.Math.Gain gaiTem(k=4) "Control gain for dT";
Modelica.Blocks.Math.Feedback feeBac "Control error";
Modelica.Blocks.Interfaces.RealInput u1;
Modelica.Blocks.Interfaces.RealInput u2;
Modelica.Blocks.Interfaces.RealOutput y
"Control signal (0: bypass hex, 1: use hex)";
Modelica.Blocks.Interfaces.RealInput m_flow "Mass flow rate";
Modelica.Blocks.Math.Gain norFlo(final k=1/m_flow_nominal)
"Normalized flow rate";
Modelica.Blocks.Nonlinear.Limiter limFlo(
uMax=1,
uMin=0,
limitsAtInit=false,
strict=true)
"Signal limiter for switching valve";
Modelica.Blocks.Math.Gain gaiFlo(k=100) "Control gain for flow rate";
Modelica.Blocks.Math.Product product;
equation
connect(feeBac.y, gaiTem.u);
connect(gaiTem.y, limTem.u);
connect(u1, feeBac.u1);
connect(u2, feeBac.u2);
connect(m_flow, norFlo.u);
connect(norFlo.y, gaiFlo.u);
connect(gaiFlo.y, limFlo.u);
connect(limFlo.y, product.u1);
connect(limTem.y, product.u2);
connect(product.y, y);
end Controller;
equation
connect(valCoo.port_1, coo.port_a);
connect(senMasFloCoo.m_flow, conCoo.m_flow);
connect(senMasFloCoo.port_b, port_a1);
connect(port_b2, senMasFloHea.port_b);
connect(conHea.m_flow, senMasFloHea.m_flow);
connect(valHea.port_2, port_a2);
connect(valHea.port_1, hea.port_a);
connect(conHea.y, valHea.y);
connect(TColIn.y, conHea.u2);
connect(conHea.u1, minHeaLvg.y);
connect(TWarIn.y, conCoo.u1);
connect(maxCooLea.y, conCoo.u2);
connect(coo.port_b, senMasFloCoo.port_a);
connect(valCoo.port_3, senMasFloCoo.port_a);
connect(senMasFloHea.port_a, hea.port_b);
connect(senMasFloHea.port_a, valHea.port_3);
connect(smoothMin.u2, TSouWat);
connect(smoothMax.u2, TSouWat);
connect(smoothMax.u1, TSouHea);
connect(smoothMin.u1, TSouCoo);
connect(minHeaLvg.u1, TSetHea);
end LakeWaterHeatExchanger_T;
Buildings.Experimental.DistrictHeatingCooling.Plants.LakeWaterHeatExchanger_T.Controller
Controller for bay water heat exchanger
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Nominal condition | |||
| MassFlowRate | m_flow_nominal | Nominal mass flow rate [kg/s] | |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | u1 | |
| input RealInput | u2 | |
| output RealOutput | y | Control signal (0: bypass hex, 1: use hex) |
| input RealInput | m_flow | Mass flow rate |
Modelica definition
model Controller "Controller for bay water heat exchanger"
parameter Modelica.SIunits.MassFlowRate m_flow_nominal
"Nominal mass flow rate";
Modelica.Blocks.Nonlinear.Limiter limTem(
uMax=1,
uMin=0,
limitsAtInit=false,
strict=true)
"Signal limiter for switching valve";
Modelica.Blocks.Math.Gain gaiTem(k=4) "Control gain for dT";
Modelica.Blocks.Math.Feedback feeBac "Control error";
Modelica.Blocks.Interfaces.RealInput u1;
Modelica.Blocks.Interfaces.RealInput u2;
Modelica.Blocks.Interfaces.RealOutput y
"Control signal (0: bypass hex, 1: use hex)";
Modelica.Blocks.Interfaces.RealInput m_flow "Mass flow rate";
Modelica.Blocks.Math.Gain norFlo(final k=1/m_flow_nominal)
"Normalized flow rate";
Modelica.Blocks.Nonlinear.Limiter limFlo(
uMax=1,
uMin=0,
limitsAtInit=false,
strict=true)
"Signal limiter for switching valve";
Modelica.Blocks.Math.Gain gaiFlo(k=100) "Control gain for flow rate";
Modelica.Blocks.Math.Product product;
equation
connect(feeBac.y, gaiTem.u);
connect(gaiTem.y, limTem.u);
connect(u1, feeBac.u1);
connect(u2, feeBac.u2);
connect(m_flow, norFlo.u);
connect(norFlo.y, gaiFlo.u);
connect(gaiFlo.y, limFlo.u);
connect(limFlo.y, product.u1);
connect(limTem.y, product.u2);
connect(product.y, y);
end Controller;