Buildings.DHC.Loads.Combined
Package with models for loads
Information
This package contains models of building loads that are used to build example models of DHC systems.
Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
Package Content
| Name | Description |
|---|---|
 BuildingTimeSeriesWithETS
|
Model of a building with loads provided as time series, connected to an ETS |
| BuildingTimeSeriesWithETSWithDHWTank
|
Model of a building with loads provided as time series, connected to an ETS with domestic hot water storage tank |
 Examples
|
This package contains example models |
 BaseClasses
|
Package with base classes that are used by multiple models |
Buildings.DHC.Loads.Combined.BuildingTimeSeriesWithETS
Model of a building with loads provided as time series, connected to an ETS
Information
This model is composed of a heat pump based energy transfer station model Buildings.DHC.ETS.Combined.HeatPumpHeatExchanger connected to a simplified building model where the space heating, cooling and hot water loads are provided as time series.
Scaling
The parameter bui.facMul is the multiplier factor
applied to the building loads that are provided as time series.
It is used to represent multiple identical buildings served by
a unique energy transfer station.
The parameter facMul is the multiplier factor
applied to the whole system composed of the building(s) and the
energy transfer station.
It is used to represent multiple identical ETSs served by
the DHC system.
So, if for instance the overall heating and cooling efficiency is
equal to 1, then the load on the district loop
is the load provided as time series multiplied by facMul * bui.facMul.
Note that the parameters QCoo_flow_nominal, QHea_flow_nominal
and QHot_flow_nominal are the ETS design values. They include
the building loads multiplier factor bui.facMul but not
the building and ETS multiplier factor facMul.
Extends from Buildings.DHC.Loads.Combined.BaseClasses.PartialBuildingWithETS (Partial model with ETS model and partial building model).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package MediumSer | Water | Service side medium | |
| replaceable package MediumSerHea_a | Water | Service side medium at heating inlet | |
| replaceable package MediumBui | Water | Building side medium | |
| String | filNam | Library path of the file with thermal loads as time series | |
| Configuration | |||
| Integer | nPorts_heaWat | 1 | Number of heating water fluid ports |
| Integer | nPorts_chiWat | 1 | Number of chilled water fluid ports |
| Scaling | |||
| Real | facMul | 1 | Multiplier factor |
| ETS model parameters | |||
| Temperature | TDisWatMin | 6 + 273.15 | District water minimum temperature [K] |
| Temperature | TDisWatMax | 17 + 273.15 | District water maximum temperature [K] |
| TemperatureDifference | dT_nominal | 4 | Water temperature drop/increase accross load and source-side HX (always positive) [K] |
| Temperature | TChiWatSup_nominal | 18 + 273.15 | Chilled water supply temperature [K] |
| Temperature | THeaWatSup_nominal | 38 + 273.15 | Heating water supply temperature [K] |
| Temperature | THotWatSup_nominal | 63 + 273.15 | Domestic hot water supply temperature to fixtures [K] |
| Temperature | TColWat_nominal | 288.15 | Cold water temperature (for hot water production) [K] |
| Pressure | dp_nominal | 50000 | Pressure difference at nominal flow rate (for each flow leg) [Pa] |
| Real | COPHeaWat_nominal | 4.0 | COP of heat pump for heating water production [1] |
| Real | COPHotWat_nominal | 2.3 | COP of heat pump for hot water production [1] |
| Assumptions | |||
| Boolean | allowFlowReversalSer | false | Set to true to allow flow reversal on service side |
| Boolean | allowFlowReversalBui | false | Set to true to allow flow reversal on building side |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_aSerAmb | Fluid connector for ambient water service supply line |
| FluidPort_b | port_bSerAmb | Fluid connector for ambient water service return line |
| FluidPort_a | port_aSerHea | Fluid connector for heating service supply line |
| FluidPort_b | port_bSerHea | Fluid connector for heating service return line |
| FluidPort_a | port_aSerCoo | Fluid connector for cooling service supply line |
| FluidPort_b | port_bSerCoo | Fluid connector for cooling service return line |
| Bus | weaBus | Weather data bus |
| output RealOutput | QHea_flow | Total heating heat flow rate transferred to the loads (>=0) [W] |
| output RealOutput | QCoo_flow | Total cooling heat flow rate transferred to the loads (<=0) [W] |
| output RealOutput | PHea | Power drawn by heating system [W] |
| output RealOutput | PCoo | Power drawn by cooling system [W] |
| output RealOutput | PFan | Power drawn by fan motors [W] |
| output RealOutput | PPum | Power drawn by pump motors [W] |
| output RealOutput | QFue_flow[nFue] | Fuel energy input rate [W] |
| input RealInput | TChiWatSupSet | Chilled water supply temperature set point [K] |
| input RealInput | THeaWatSupMaxSet | Heating water supply temperature set point - Maximum value [K] |
| input RealInput | THeaWatSupMinSet | Heating water supply temperature set point - Minimum value [K] |
| output RealOutput | PPumETS | ETS pump power [W] |
| input RealInput | THotWatSupSet | Service hot water supply temperature set point [K] |
| input RealInput | TColWat | Cold water temperature [K] |
Modelica definition
model BuildingTimeSeriesWithETS
"Model of a building with loads provided as time series, connected to an ETS"
extends Buildings.DHC.Loads.Combined.BaseClasses.PartialBuildingWithETS(
redeclare Buildings.DHC.Loads.BaseClasses.BuildingTimeSeries bui(
filNam=filNam,
have_hotWat=true,
T_aHeaWat_nominal=ets.THeaWatSup_nominal,
T_bHeaWat_nominal=ets.THeaWatRet_nominal,
T_aChiWat_nominal=ets.TChiWatSup_nominal,
T_bChiWat_nominal=ets.TChiWatRet_nominal),
redeclare Buildings.DHC.ETS.Combined.HeatPumpHeatExchanger
ets(
final dT_nominal=dT_nominal,
final TDisWatMin=TDisWatMin,
final TDisWatMax=TDisWatMax,
final TChiWatSup_nominal=TChiWatSup_nominal,
final THeaWatSup_nominal=THeaWatSup_nominal,
final THotWatSup_nominal=THotWatSup_nominal,
final TColWat_nominal=TColWat_nominal,
final dp_nominal=dp_nominal,
final COPHeaWat_nominal=COPHeaWat_nominal,
final COPHotWat_nominal=COPHotWat_nominal,
have_hotWat=true,
QChiWat_flow_nominal=QCoo_flow_nominal,
QHeaWat_flow_nominal=QHea_flow_nominal,
QHotWat_flow_nominal=QHot_flow_nominal));
parameter String filNam
"Library path of the file with thermal loads as time series";
final parameter Modelica.Units.SI.HeatFlowRate QCoo_flow_nominal(
max=-Modelica.Constants.eps)=
bui.facMul * bui.QCoo_flow_nominal
"Space cooling design load (<=0)";
final parameter Modelica.Units.SI.HeatFlowRate QHea_flow_nominal(
min=Modelica.Constants.eps)=
bui.facMul * bui.QHea_flow_nominal
"Space heating design load (>=0)";
final parameter Modelica.Units.SI.HeatFlowRate QHot_flow_nominal(
min=Modelica.Constants.eps)=
bui.facMul * Buildings.DHC.Loads.BaseClasses.getPeakLoad(
string="#Peak water heating load",
filNam=Modelica.Utilities.Files.loadResource(filNam))
"Hot water design load (>=0)";
Buildings.Controls.OBC.CDL.Interfaces.RealInput THotWatSupSet(
final unit="K",
displayUnit="degC")
"Service hot water supply temperature set point";
Buildings.Controls.OBC.CDL.Interfaces.RealInput TColWat(
final unit="K",
displayUnit="degC")
"Cold water temperature";
Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter loaHeaNor(
k=1/QHea_flow_nominal) "Normalized heating load";
Buildings.Controls.OBC.CDL.Reals.GreaterThreshold enaHeaCoo[2](each t=1e-4)
"Threshold comparison to enable heating and cooling";
Modelica.Blocks.Sources.BooleanConstant enaSHW(
final k=true) if have_hotWat
"SHW production enable signal";
Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter loaCooNor(k=1/
QCoo_flow_nominal) "Normalized cooling load";
equation
connect(bui.QReqHotWat_flow, ets.QReqHotWat_flow);
connect(THotWatSupSet, ets.THotWatSupSet);
connect(TColWat, ets.TColWat);
connect(enaHeaCoo[1].y, ets.uHea);
connect(enaHeaCoo[2].y, ets.uCoo);
connect(enaSHW.y, ets.uSHW);
connect(loaHeaNor.y, enaHeaCoo[1].u);
connect(loaCooNor.y, enaHeaCoo[2].u);
connect(bui.QReqHea_flow, loaHeaNor.u);
connect(bui.QReqCoo_flow, loaCooNor.u);
connect(loaHeaNor.y, resTHeaWatSup.u);
end BuildingTimeSeriesWithETS;
Buildings.DHC.Loads.Combined.BuildingTimeSeriesWithETSWithDHWTank
Model of a building with loads provided as time series, connected to an ETS with domestic hot water storage tank
Information
This model is the same as Buildings.DHC.Loads.Combined.BuildingTimeSeriesWithETS except that it implements an ETS that uses a heat pump with hot water storage tank for production of domestic hot water. That ETS model is Buildings.DHC.ETS.Combined.HeatPumpHeatExchangerDHWTank.
Extends from Buildings.DHC.Loads.Combined.BaseClasses.PartialBuildingWithETS (Partial model with ETS model and partial building model).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package MediumSer | Water | Service side medium | |
| replaceable package MediumSerHea_a | Water | Service side medium at heating inlet | |
| replaceable package MediumBui | Water | Building side medium | |
| String | filNam | Library path of the file with thermal loads as time series | |
| GenericDomesticHotWaterWithHeatExchanger | datWatHea | Performance data | |
| Configuration | |||
| Integer | nPorts_heaWat | 1 | Number of heating water fluid ports |
| Integer | nPorts_chiWat | 1 | Number of chilled water fluid ports |
| Scaling | |||
| Real | facMul | 1 | Multiplier factor |
| ETS model parameters | |||
| Temperature | TDisWatMin | 6 + 273.15 | District water minimum temperature [K] |
| Temperature | TDisWatMax | 17 + 273.15 | District water maximum temperature [K] |
| TemperatureDifference | dT_nominal | 4 | Water temperature drop/increase accross load and source-side HX (always positive) [K] |
| Temperature | TChiWatSup_nominal | 18 + 273.15 | Chilled water supply temperature [K] |
| Temperature | THeaWatSup_nominal | 38 + 273.15 | Heating water supply temperature [K] |
| Temperature | THotWatSup_nominal | 63 + 273.15 | Domestic hot water supply temperature to fixtures [K] |
| Temperature | TColWat_nominal | 288.15 | Cold water temperature (for hot water production) [K] |
| Pressure | dp_nominal | 50000 | Pressure difference at nominal flow rate (for each flow leg) [Pa] |
| Real | COPHeaWat_nominal | 4.0 | COP of heat pump for heating water production [1] |
| Real | COPHotWat_nominal | 2.3 | COP of heat pump for hot water production [1] |
| Assumptions | |||
| Boolean | allowFlowReversalSer | false | Set to true to allow flow reversal on service side |
| Boolean | allowFlowReversalBui | false | Set to true to allow flow reversal on building side |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_aSerAmb | Fluid connector for ambient water service supply line |
| FluidPort_b | port_bSerAmb | Fluid connector for ambient water service return line |
| FluidPort_a | port_aSerHea | Fluid connector for heating service supply line |
| FluidPort_b | port_bSerHea | Fluid connector for heating service return line |
| FluidPort_a | port_aSerCoo | Fluid connector for cooling service supply line |
| FluidPort_b | port_bSerCoo | Fluid connector for cooling service return line |
| Bus | weaBus | Weather data bus |
| output RealOutput | QHea_flow | Total heating heat flow rate transferred to the loads (>=0) [W] |
| output RealOutput | QCoo_flow | Total cooling heat flow rate transferred to the loads (<=0) [W] |
| output RealOutput | PHea | Power drawn by heating system [W] |
| output RealOutput | PCoo | Power drawn by cooling system [W] |
| output RealOutput | PFan | Power drawn by fan motors [W] |
| output RealOutput | PPum | Power drawn by pump motors [W] |
| output RealOutput | QFue_flow[nFue] | Fuel energy input rate [W] |
| input RealInput | TChiWatSupSet | Chilled water supply temperature set point [K] |
| input RealInput | THeaWatSupMaxSet | Heating water supply temperature set point - Maximum value [K] |
| input RealInput | THeaWatSupMinSet | Heating water supply temperature set point - Minimum value [K] |
| output RealOutput | PPumETS | ETS pump power [W] |
| input RealInput | THotWatSupSet | Service hot water supply temperature set point [K] |
| input RealInput | TColWat | Cold water temperature [K] |
Modelica definition
model BuildingTimeSeriesWithETSWithDHWTank
"Model of a building with loads provided as time series, connected to an ETS with domestic hot water storage tank"
extends Buildings.DHC.Loads.Combined.BaseClasses.PartialBuildingWithETS(
redeclare Buildings.DHC.Loads.BaseClasses.BuildingTimeSeries bui(
filNam=filNam,
have_hotWat=true,
T_aHeaWat_nominal=ets.THeaWatSup_nominal,
T_bHeaWat_nominal=ets.THeaWatRet_nominal,
T_aChiWat_nominal=ets.TChiWatSup_nominal,
T_bChiWat_nominal=ets.TChiWatRet_nominal),
redeclare Buildings.DHC.ETS.Combined.HeatPumpHeatExchangerDHWTank
ets(
final dT_nominal=dT_nominal,
final TDisWatMin=TDisWatMin,
final TDisWatMax=TDisWatMax,
final TChiWatSup_nominal=TChiWatSup_nominal,
final THeaWatSup_nominal=THeaWatSup_nominal,
final THotWatSup_nominal=THotWatSup_nominal,
final TColWat_nominal=TColWat_nominal,
final dp_nominal=dp_nominal,
final COPHeaWat_nominal=COPHeaWat_nominal,
final COPHotWat_nominal=COPHotWat_nominal,
have_hotWat=true,
QChiWat_flow_nominal=QCoo_flow_nominal,
QHeaWat_flow_nominal=QHea_flow_nominal,
QHotWat_flow_nominal=QHot_flow_nominal,
datWatHea=datWatHea));
parameter String filNam
"Library path of the file with thermal loads as time series";
final parameter Modelica.Units.SI.HeatFlowRate QCoo_flow_nominal(
max=-Modelica.Constants.eps)=
bui.facMul * bui.QCoo_flow_nominal
"Space cooling design load (<=0)";
final parameter Modelica.Units.SI.HeatFlowRate QHea_flow_nominal(
min=Modelica.Constants.eps)=
bui.facMul * bui.QHea_flow_nominal
"Space heating design load (>=0)";
final parameter Modelica.Units.SI.HeatFlowRate QHot_flow_nominal(
min=Modelica.Constants.eps)=
bui.facMul * Buildings.DHC.Loads.BaseClasses.getPeakLoad(
string="#Peak water heating load",
filNam=Modelica.Utilities.Files.loadResource(filNam))
"Hot water design load (>=0)";
Buildings.Controls.OBC.CDL.Interfaces.RealInput THotWatSupSet(
final unit="K",
displayUnit="degC")
"Service hot water supply temperature set point";
Buildings.Controls.OBC.CDL.Interfaces.RealInput TColWat(
final unit="K",
displayUnit="degC")
"Cold water temperature";
Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter loaHeaNor(
k=1/QHea_flow_nominal) "Normalized heating load";
Buildings.Controls.OBC.CDL.Reals.GreaterThreshold enaHeaCoo[2](each t=1e-4)
"Threshold comparison to enable heating and cooling";
Modelica.Blocks.Sources.BooleanConstant enaSHW(
final k=true) if have_hotWat
"SHW production enable signal";
Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter loaCooNor(k=1/
QCoo_flow_nominal) "Normalized cooling load";
parameter HotWater.Data.GenericDomesticHotWaterWithHeatExchanger datWatHea
"Performance data";
equation
connect(bui.QReqHotWat_flow, ets.QReqHotWat_flow);
connect(THotWatSupSet, ets.THotWatSupSet);
connect(TColWat, ets.TColWat);
connect(enaHeaCoo[1].y, ets.uHea);
connect(enaHeaCoo[2].y, ets.uCoo);
connect(enaSHW.y, ets.uSHW);
connect(loaHeaNor.y, enaHeaCoo[1].u);
connect(loaCooNor.y, enaHeaCoo[2].u);
connect(bui.QReqHea_flow, loaHeaNor.u);
connect(bui.QReqCoo_flow, loaCooNor.u);
connect(loaHeaNor.y, resTHeaWatSup.u);
end BuildingTimeSeriesWithETSWithDHWTank;