Buildings.Obsolete.DHC.ETS.Combined
Package with obsolete models for district heating and cooling systems
Information
Package with obsolete models for district heating and cooling systems.
Extends from Modelica.Icons.Package (Icon for standard packages).
Package Content
| Name | Description |
|---|---|
 ChillerBorefield
|
ETS model for 5GDHC systems with heat recovery chiller and optional borefield |
 Controls
|
Package with control models |
| Subsystems
|
Package with obsolete models for district heating and cooling sub-systems |
 Examples
|
Collection of models that illustrate model use and test models |
| Validation
|
Collection of validation models |
 BaseClasses
|
Package with base classes for Buildings.Obsolete.DHC.ETS.Combined |
Buildings.Obsolete.DHC.ETS.Combined.ChillerBorefield
ETS model for 5GDHC systems with heat recovery chiller and optional borefield
Information
This model represents an energy transfer station as illustrated in the schematics below.
- The heating and cooling functions are provided by a heat recovery chiller, see Buildings.Obsolete.DHC.ETS.Combined.Subsystems.Chiller for the operating principles and modeling assumptions. The condenser and evaporator loops are equipped with constant speed pumps.
- The supervisory controller ensures the load balancing between the condenser side and the evaporator side of the chiller by controlling in sequence an optional geothermal borefield (priority system), the district heat exchanger (second priority system), and ultimately the chiller, by resetting down the chilled water supply temperature, see Buildings.Obsolete.DHC.ETS.Combined.Controls.Supervisory for a detailed description. The borefield and district heat exchanger loops are equipped with variable speed pumps modulated by the supervisory controller.
Note that the heating and cooling enable signals (uHea and uCoo)
connected to this model should be switched to false when the
building has no corresponding demand (e.g., based on the requests yielded by
the terminal unit controllers, in conjunction with a schedule).
This will significantly improve the system performance as it is a
necessary condition for the chiller to be operated at a lower lift, see
Buildings.DHC.ETS.Combined.Controls.Reset.
Extends from Buildings.Obsolete.DHC.ETS.Combined.BaseClasses.PartialParallel (Partial ETS model with district heat exchanger and parallel connection of production systems).
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 | |
| Generic | fue[nFue] | Fuel type | |
| ConnectionConfiguration | conCon | Buildings.DHC.ETS.Types.Conn... | District connection configuration |
| Integer | nSysHea | 1 | Number of heating systems |
| Integer | nSysCoo | nSysHea | Number of cooling systems |
| Integer | nSouAmb | if have_borFie then 2 else 1 | Number of ambient sources |
| Boolean | have_borFie | false | Set to true in case a borefield is used in addition of the district HX |
| Boolean | have_WSE | false | Set to true in case a waterside economizer is used |
| Configuration | |||
| Boolean | have_hotWat | false | Set to true if the ETS supplies hot water |
| Boolean | have_fan | false | Set to true if fan power is computed |
| Boolean | have_eleHea | false | Set to true if the ETS has electric heating system |
| Integer | nFue | 0 | Number of fuel types (0 means no combustion system) |
| Boolean | have_eleCoo | true | Set to true if the ETS has electric cooling system |
| Boolean | have_weaBus | false | Set to true to use a weather bus |
| Nominal condition | |||
| HeatFlowRate | QHeaWat_flow_nominal | 0 | Nominal capacity of heating system (>=0) [W] |
| HeatFlowRate | QHotWat_flow_nominal | 0 | Nominal capacity of hot water production system (>=0) [W] |
| HeatFlowRate | QChiWat_flow_nominal | 0 | Nominal capacity of cooling system (<=0) [W] |
| PressureDifference | dpValIso_nominal | 2E3 | Nominal pressure drop of ambient circuit isolation valves [Pa] |
| District heat exchanger | |||
| PressureDifference | dp1Hex_nominal | Nominal pressure drop across heat exchanger on district side [Pa] | |
| PressureDifference | dp2Hex_nominal | Nominal pressure drop across heat exchanger on building side [Pa] | |
| HeatFlowRate | QHex_flow_nominal | Nominal heat flow rate through heat exchanger (from district to building) [W] | |
| Temperature | T_a1Hex_nominal | Nominal water inlet temperature on district side [K] | |
| Temperature | T_b1Hex_nominal | Nominal water outlet temperature on district side [K] | |
| Temperature | T_a2Hex_nominal | Nominal water inlet temperature on building side [K] | |
| Temperature | T_b2Hex_nominal | Nominal water outlet temperature on building side [K] | |
| Real | spePum1HexMin | 0.1 | Heat exchanger primary pump minimum speed (fractional) [1] |
| Real | spePum2HexMin | 0.1 | Heat exchanger secondary pump minimum speed (fractional) [1] |
| Buffer Tank | |||
| Volume | VTanHeaWat | datChi.PLRMin*datChi.mCon_fl... | Heating water tank volume [m3] |
| Length | hTanHeaWat | (VTanHeaWat*16/Modelica.Cons... | Heating water tank height (assuming twice the diameter) [m] |
| Length | dInsTanHeaWat | 0.1 | Heating water tank insulation thickness [m] |
| Volume | VTanChiWat | datChi.PLRMin*datChi.mEva_fl... | Chilled water tank volume [m3] |
| Length | hTanChiWat | (VTanChiWat*16/Modelica.Cons... | Chilled water tank height (without insulation) [m] |
| Length | dInsTanChiWat | 0.1 | Chilled water tank insulation thickness [m] |
| Integer | nSegTan | 3 | Number of volume segments for tanks |
| Chiller | |||
| PressureDifference | dpCon_nominal | Nominal pressure drop accross condenser [Pa] | |
| PressureDifference | dpEva_nominal | Nominal pressure drop accross evaporator [Pa] | |
| Generic | datChi | redeclare parameter Building... | Chiller performance data |
| Chiller | chi | chi(redeclare final package ... | Chiller |
| Waterside economizer | |||
| PressureDifference | dp1WSE_nominal | 40E3 | Nominal pressure drop across heat exchanger on district side [Pa] |
| PressureDifference | dp2WSE_nominal | 40E3 | Nominal pressure drop across heat exchanger on building side [Pa] |
| HeatFlowRate | QWSE_flow_nominal | 0 | Nominal heat flow rate through heat exchanger (<=0) [W] |
| Temperature | T_a1WSE_nominal | 279.15 | Nominal water inlet temperature on district side [K] |
| Temperature | T_b1WSE_nominal | 284.15 | Nominal water outlet temperature on district side [K] |
| Temperature | T_a2WSE_nominal | 288.15 | Nominal water inlet temperature on building side [K] |
| Temperature | T_b2WSE_nominal | 281.15 | Nominal water outlet temperature on building side [K] |
| Real | y1WSEMin | 0.05 | Minimum pump flow rate or valve opening for temperature measurement (fractional) [1] |
| Borefield | |||
| Temperature | TBorWatEntMax | 313.15 | Maximum value of borefield water entering temperature [K] |
| Real | spePumBorMin | 0.1 | Borefield pump minimum speed [1] |
| Pressure | dpBorFie_nominal | 5E4 | Pressure losses for the entire borefield (control valve excluded) [Pa] |
| Example | datBorFie | redeclare parameter Building... | Borefield parameters |
| Borefield | borFie | borFie(redeclare final packa... | Borefield |
| Supervisory controller | |||
| SimpleController | controllerType | Buildings.Controls.OBC.CDL.T... | Type of controller |
| Real | kHot | 0.05 | Gain of controller on hot side |
| Real | kCol | 0.1 | Gain of controller on cold side |
| Time | TiHot | 300 | Time constant of integrator block on hot side [s] |
| Time | TiCol | 120 | Time constant of integrator block on cold side [s] |
| Temperature | THeaWatSupSetMin | datChi.TConEntMin + 5 | Minimum value of heating water supply temperature set point [K] |
| Temperature | TChiWatSupSetMin | datChi.TEvaLvgMin | Minimum value of chilled water supply temperature set point [K] |
| Temperature | TChiWatSupSetMax | datChi.TEvaLvgMax | Minimum value of chilled water supply temperature set point [K] |
| 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 |
|---|---|---|
| FluidPorts_a | ports_aHeaWat[nPorts_aHeaWat] | Fluid connectors for heating water return (from building) |
| FluidPorts_b | ports_bHeaWat[nPorts_bHeaWat] | Fluid connectors for heating water supply (to building) |
| FluidPorts_a | ports_aChiWat[nPorts_aChiWat] | Fluid connectors for chilled water return (from building) |
| FluidPorts_b | ports_bChiWat[nPorts_bChiWat] | Fluid connectors for chilled water supply (to building) |
| 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 |
| 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] |
| Bus | weaBus | Weather data bus |
| input BooleanInput | uHea | Heating enable signal |
| input BooleanInput | uCoo | Cooling enable signal |
| input RealInput | THeaWatSupSet | Heating water supply temperature set point [K] |
| input RealInput | TChiWatSupSet | Chilled water supply temperature set point [K] |
| output RealOutput | dHHeaWat_flow | Heating water distributed energy flow rate [W] |
| output RealOutput | dHChiWat_flow | Chilled water distributed energy flow rate [W] |
Modelica definition
model ChillerBorefield "ETS model for 5GDHC systems with heat recovery chiller and optional borefield"
extends Buildings.Obsolete.DHC.ETS.Combined.BaseClasses.PartialParallel(
final have_eleCoo=true,
final have_fan=false,
redeclare replaceable Buildings.Obsolete.DHC.ETS.Combined.Controls.Supervisory
conSup
constrainedby Buildings.Obsolete.DHC.ETS.Combined.Controls.Supervisory(
final controllerType=controllerType,
final kHot=kHot,
final kCol=kCol,
final TiHot=TiHot,
final TiCol=TiCol,
final THeaWatSupSetMin=THeaWatSupSetMin,
final TChiWatSupSetMin=TChiWatSupSetMin,
final TChiWatSupSetMax=TChiWatSupSetMax),
nSysHea=1,
nSouAmb=
if have_borFie then
2
else
1,
VTanHeaWat=datChi.PLRMin*datChi.mCon_flow_nominal*5*60/1000,
VTanChiWat=datChi.PLRMin*datChi.mEva_flow_nominal*5*60/1000,
colChiWat(
mCon_flow_nominal={colAmbWat.mDis_flow_nominal,datChi.mEva_flow_nominal}),
colHeaWat(
mCon_flow_nominal={colAmbWat.mDis_flow_nominal,datChi.mCon_flow_nominal}),
colAmbWat(
mCon_flow_nominal=
if have_borFie then
{hex.m2_flow_nominal,datBorFie.conDat.mBorFie_flow_nominal}
else
{hex.m2_flow_nominal}),
totPPum(
nin=3),
totPHea(
nin=1),
totPCoo(
nin=1),
nPorts_bChiWat=1,
nPorts_aHeaWat=1,
nPorts_aChiWat=1,
nPorts_bHeaWat=1);
parameter Boolean have_borFie=false
"Set to true in case a borefield is used in addition of the district HX";
parameter Boolean have_WSE=false
"Set to true in case a waterside economizer is used";
parameter Modelica.Units.SI.PressureDifference dpCon_nominal(displayUnit="Pa")
"Nominal pressure drop accross condenser";
parameter Modelica.Units.SI.PressureDifference dpEva_nominal(displayUnit="Pa")
"Nominal pressure drop accross evaporator";
replaceable parameter Buildings.Fluid.Chillers.Data.ElectricEIR.Generic datChi
"Chiller performance data";
parameter Modelica.Units.SI.PressureDifference dp1WSE_nominal(displayUnit=
"Pa") = 40E3
"Nominal pressure drop across heat exchanger on district side";
parameter Modelica.Units.SI.PressureDifference dp2WSE_nominal(displayUnit=
"Pa") = 40E3
"Nominal pressure drop across heat exchanger on building side";
parameter Modelica.Units.SI.HeatFlowRate QWSE_flow_nominal=0
"Nominal heat flow rate through heat exchanger (<=0)";
parameter Modelica.Units.SI.Temperature T_a1WSE_nominal=279.15
"Nominal water inlet temperature on district side";
parameter Modelica.Units.SI.Temperature T_b1WSE_nominal=284.15
"Nominal water outlet temperature on district side";
parameter Modelica.Units.SI.Temperature T_a2WSE_nominal=288.15
"Nominal water inlet temperature on building side";
parameter Modelica.Units.SI.Temperature T_b2WSE_nominal=281.15
"Nominal water outlet temperature on building side";
parameter Real y1WSEMin(unit="1")=0.05
"Minimum pump flow rate or valve opening for temperature measurement (fractional)";
final parameter Modelica.Units.SI.MassFlowRate m1WSE_flow_nominal=abs(
QWSE_flow_nominal/4200/(T_b1WSE_nominal - T_a1WSE_nominal))
"WSE primary mass flow rate";
parameter Modelica.Units.SI.Temperature TBorWatEntMax=313.15
"Maximum value of borefield water entering temperature";
parameter Real spePumBorMin(unit="1")=0.1
"Borefield pump minimum speed";
parameter Modelica.Units.SI.Pressure dpBorFie_nominal(displayUnit="Pa") = 5E4
"Pressure losses for the entire borefield (control valve excluded)";
replaceable parameter Buildings.Fluid.Geothermal.Borefields.Data.Borefield.Example
datBorFie
constrainedby Buildings.Fluid.Geothermal.Borefields.Data.Borefield.Template
"Borefield parameters";
parameter Buildings.Controls.OBC.CDL.Types.SimpleController controllerType=
Buildings.Controls.OBC.CDL.Types.SimpleController.PI
"Type of controller";
parameter Real kHot(
min=0)=0.05
"Gain of controller on hot side";
parameter Real kCol(
min=0)=0.1
"Gain of controller on cold side";
parameter Modelica.Units.SI.Time TiHot(min=Buildings.Controls.OBC.CDL.Constants.small)
= 300 "Time constant of integrator block on hot side";
parameter Modelica.Units.SI.Time TiCol(min=Buildings.Controls.OBC.CDL.Constants.small)
= 120 "Time constant of integrator block on cold side";
parameter Modelica.Units.SI.Temperature THeaWatSupSetMin(displayUnit="degC")
= datChi.TConEntMin + 5
"Minimum value of heating water supply temperature set point";
parameter Modelica.Units.SI.Temperature TChiWatSupSetMin(displayUnit="degC")
= datChi.TEvaLvgMin
"Minimum value of chilled water supply temperature set point";
parameter Modelica.Units.SI.Temperature TChiWatSupSetMax(displayUnit="degC")
= datChi.TEvaLvgMax
"Minimum value of chilled water supply temperature set point";
replaceable Buildings.Obsolete.DHC.ETS.Combined.Subsystems.Chiller
chi(
redeclare final package Medium = MediumBui,
final dpCon_nominal=dpCon_nominal,
final dpEva_nominal=dpEva_nominal,
final dat=datChi) "Chiller";
replaceable Buildings.Obsolete.DHC.ETS.Combined.Subsystems.Borefield
borFie(
redeclare final package Medium = MediumBui,
final datBorFie=datBorFie,
final TBorWatEntMax=TBorWatEntMax,
final spePumBorMin=spePumBorMin,
final dp_nominal=dpBorFie_nominal) if have_borFie "Borefield";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant zerPPum(
final k=0) if not have_borFie
"Zero power";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant zerPHea(
final k=0)
"Zero power";
Buildings.DHC.Networks.BaseClasses.DifferenceEnthalpyFlowRate dHFloHeaWat(
redeclare final package Medium1 = MediumBui,
final m_flow_nominal=colHeaWat.mDis_flow_nominal)
"Variation of enthalpy flow rate";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput dHHeaWat_flow(final unit="W")
"Heating water distributed energy flow rate";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput dHChiWat_flow(final unit="W")
"Chilled water distributed energy flow rate";
Buildings.DHC.Networks.BaseClasses.DifferenceEnthalpyFlowRate dHFloChiWat(
redeclare final package Medium1 = MediumBui,
final m_flow_nominal=colChiWat.mDis_flow_nominal)
"Variation of enthalpy flow rate";
Buildings.DHC.ETS.Combined.Subsystems.WatersideEconomizer
WSE(
redeclare final package Medium1 = MediumSer,
redeclare final package Medium2 = MediumBui,
final allowFlowReversal1=allowFlowReversalSer,
final allowFlowReversal2=allowFlowReversalBui,
final conCon=conCon,
final dp1Hex_nominal=dp1WSE_nominal,
final dp2Hex_nominal=dp2WSE_nominal,
final Q_flow_nominal=QWSE_flow_nominal,
final T_a1_nominal=T_a1WSE_nominal,
final T_b1_nominal=T_b1WSE_nominal,
final T_a2_nominal=T_a2WSE_nominal,
final T_b2_nominal=T_b2WSE_nominal,
final y1Min=y1WSEMin) if have_WSE "Waterside economizer";
Buildings.DHC.ETS.BaseClasses.Junction splWSE(
redeclare final package Medium = MediumSer,
final m_flow_nominal={
hex.m1_flow_nominal + m1WSE_flow_nominal,
-hex.m1_flow_nominal,
-m1WSE_flow_nominal})
"Flow splitter for WSE";
Buildings.DHC.ETS.BaseClasses.Junction mixWSE(
redeclare final package Medium = MediumSer,
final m_flow_nominal={
hex.m1_flow_nominal,
-hex.m1_flow_nominal - m1WSE_flow_nominal,
m1WSE_flow_nominal})
"Flow mixer for WSE";
equation
if not have_WSE then
connect(tanChiWat.port_aTop, dHFloChiWat.port_b2);
end if;
connect(chi.port_bHeaWat,colHeaWat.ports_aCon[2]);
connect(chi.port_aHeaWat,colHeaWat.ports_bCon[2]);
connect(chi.port_bChiWat,colChiWat.ports_aCon[2]);
connect(colChiWat.ports_bCon[2],chi.port_aChiWat);
connect(conSup.TChiWatSupSet,chi.TChiWatSupSet);
connect(chi.PPum,totPPum.u[2]);
connect(colAmbWat.ports_aCon[2],borFie.port_b);
connect(colAmbWat.ports_bCon[2],borFie.port_a);
connect(conSup.yAmb[1],borFie.u);
connect(valIsoCon.y_actual,borFie.yValIso_actual[1]);
connect(valIsoEva.y_actual,borFie.yValIso_actual[2]);
connect(borFie.PPum,totPPum.u[3]);
connect(zerPPum.y,totPPum.u[3]);
connect(zerPHea.y,totPHea.u[1]);
connect(chi.PChi,totPCoo.u[1]);
connect(uHea,conSup.uHea);
connect(conSup.yHea,chi.uHea);
connect(conSup.yCoo,chi.uCoo);
connect(valIsoCon.y_actual,conSup.yValIsoCon_actual);
connect(valIsoEva.y_actual,conSup.yValIsoEva_actual);
connect(dHFloHeaWat.dH_flow,dHHeaWat_flow);
connect(dHFloChiWat.dH_flow,dHChiWat_flow);
connect(dHFloChiWat.port_a1, tanChiWat.port_bBot);
connect(dHFloChiWat.port_b1, ports_bChiWat[1]);
connect(tanHeaWat.port_bTop, dHFloHeaWat.port_a1);
connect(tanHeaWat.port_aBot, dHFloHeaWat.port_b2);
connect(dHFloHeaWat.port_a2, ports_aHeaWat[1]);
connect(ports_aChiWat[1], dHFloChiWat.port_a2);
connect(dHFloHeaWat.port_b1, ports_bHeaWat[1]);
connect(splWSE.port_2, hex.port_a1);
connect(dHFloChiWat.port_b2, WSE.port_a2);
connect(WSE.port_b2, tanChiWat.port_aTop);
connect(mixWSE.port_2, port_bSerAmb);
connect(splWSE.port_3, WSE.port_a1);
connect(WSE.port_b1, mixWSE.port_3);
connect(hex.port_b1, mixWSE.port_1);
connect(conSup.yCoo, WSE.uCoo);
connect(valIsoEva.y_actual, WSE.yValIsoEva_actual);
connect(port_aSerAmb, splWSE.port_1);
end ChillerBorefield;