Buildings.DHC.Examples.Combined.BaseClasses
Package with base classes that are used by multiple models
Information
This package contains base classes that are used to construct the classes in Buildings.DHC.Examples.Combined.
Extends from Modelica.Icons.BasesPackage (Icon for packages containing base classes).
Package Content
| Name | Description |
|---|---|
 Borefield
|
Geothermal borefield model |
 PartialSeries
|
Partial model for series network |
 DesignDataSeries
|
Record with design data for series network |
| Zurich
|
Zurich |
Buildings.DHC.Examples.Combined.BaseClasses.Borefield
Geothermal borefield model
Information
This model represents a borefield composed of 350 boreholes, with the following main assumptions.
- The soil is made of sandstone.
- The boreholes are filled with a bentonite grout.
- The boreholes have a height of 300 m and a diameter of 190 mm. They are discretized vertically in five segments.
- A distance of 10 m between each borehole is considered.
- HDPE pipes with a diameter of 40 mm are considered, in a double U-tube parallel configuration.
Extends from Buildings.Fluid.Geothermal.Borefields.TwoUTubes (Borefield model containing double U-tube boreholes).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Integer | nCel | 5 | Number of cells per aggregation level |
| Integer | nSeg | 5 | Number of segments to use in vertical discretization of the boreholes |
| Integer | nBor | borFieDat.conDat.nBor | Number of boreholes |
| Real | dxyBor | 10 | Distance between boreholes |
| 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 | true | = true, if actual temperature at port is computed |
| g-function | |||
| Boolean | forceGFunCalc | false | Set to true to force the thermal response to be calculated at the start instead of checking whether this has been pre-computed |
| Integer | nSegGFun | 12 | Number of segments to use in the calculation of the g-function |
| Integer | nClu | 5 | Number of borehole clusters to use in the calculation of the g-function |
| 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 |
| Dynamics | |||
| Conservation equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Boolean | dynFil | true | Set to false to remove the dynamics of the filling material. |
| Initialization | |||
| AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
| Temperature | TFlu_start[nSeg] | TGro_start | Start value of fluid temperature [K] |
| Soil | |||
| Temperature | TExt0_start | 282.55 | Initial far field temperature [K] |
| Temperature | TExt_start[nSeg] | {if z[i] >= z0 then TExt0_st... | Temperature of the undisturbed ground [K] |
| Filling material | |||
| Temperature | TGro_start[nSeg] | TExt_start | Start value of grout temperature [K] |
| Temperature profile | |||
| Height | z0 | 10 | Depth below which the temperature gradient starts [m] |
| Real | dT_dz | 0.02 | Vertical temperature gradient of the undisturbed soil for h below z0 [K/m] |
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 | TBorAve | Average borehole wall temperature in the borefield [K] |
| output RealOutput | Q_flow | Rate at which heat is extracted from soil [W] |
Modelica definition
model Borefield "Geothermal borefield model"
extends Buildings.Fluid.Geothermal.Borefields.TwoUTubes(
final energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
final tLoaAgg(displayUnit="h") = 3600,
final nSeg=5,
TExt0_start=282.55,
final z0=10,
final dT_dz=0.02,
final dynFil=true,
borFieDat(
filDat=Buildings.Fluid.Geothermal.Borefields.Data.Filling.Bentonite(
kFil=2.0,
cFil=3040,
dFil=1450),
soiDat=Buildings.Fluid.Geothermal.Borefields.Data.Soil.SandStone(
kSoi=2.3,
cSoi=1000,
dSoi=2600),
conDat=Buildings.Fluid.Geothermal.Borefields.Data.Configuration.Example(
borCon=Buildings.Fluid.Geothermal.Borefields.Types.BoreholeConfiguration.DoubleUTubeParallel,
dp_nominal=35000,
hBor=300,
rBor=0.095,
nBor=350,
cooBor=cooBor,
dBor=1,
rTub=0.02,
kTub=0.5,
eTub=0.0037,
xC=0.05)),
show_T=true);
/*
Some parameters (such as nBor) cannot be propagated down to
borFieDat.conDat otherwise Dymola fails to expand.
We assign them literally within borFieDat.conDat and propagate them up here
to compute dependent parameters.
*/
parameter Integer nBor = borFieDat.conDat.nBor
"Number of boreholes";
parameter Real dxyBor = 10
"Distance between boreholes";
final parameter Modelica.Units.SI.Length cooBor[nBor,2]={dxyBor*{mod(i - 1,
10),floor((i - 1)/10)} for i in 1:nBor}
"Cartesian coordinates of the boreholes in meters";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput Q_flow(final unit="W")
"Rate at which heat is extracted from soil";
equation
connect(gaiQ_flow.y, Q_flow);
end Borefield;
Buildings.DHC.Examples.Combined.BaseClasses.PartialSeries
Partial model for series network
Information
Partial model that is used by the reservoir network models. The reservoir network models extend this model, add controls, and configure some component sizes.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | dpDis_length_nominal | 250 | Pressure drop per pipe length at nominal flow rate - Distribution line [Pa/m] |
| Real | dpCon_length_nominal | 250 | Pressure drop per pipe length at nominal flow rate - Connection line [Pa/m] |
| Length | dhSto | Hydraulic diameter of the distribution pipe before each connection [m] | |
| Length | dhPla | Hydraulic diameter of the distribution pipe before each connection [m] | |
| Integer | nBui | datDes.nBui | Number of buildings connected to DHC system |
| DesignDataSeries | datDes | datDes(final mCon_flow_nomin... | Design data |
| PartialBuildingWithETS | bui[nBui] | redeclare Buildings.DHC.Load... | Building and ETS |
| Assumptions | |||
| Boolean | allowFlowReversalSer | true | Set to true to allow flow reversal in the service lines |
| Boolean | allowFlowReversalBui | false | Set to true to allow flow reversal for in-building systems |
Modelica definition
partial model PartialSeries "Partial model for series network"
extends Modelica.Icons.Example;
package Medium = Buildings.Media.Water "Medium model";
constant Real facMul = 10
"Building loads multiplier factor";
parameter Real dpDis_length_nominal(final unit="Pa/m") = 250
"Pressure drop per pipe length at nominal flow rate - Distribution line";
parameter Real dpCon_length_nominal(final unit="Pa/m") = 250
"Pressure drop per pipe length at nominal flow rate - Connection line";
parameter Boolean allowFlowReversalSer = true
"Set to true to allow flow reversal in the service lines";
parameter Boolean allowFlowReversalBui = false
"Set to true to allow flow reversal for in-building systems";
parameter Modelica.Units.SI.Length dhSto(fixed=false,start=0.05,min=0.01)
"Hydraulic diameter of the distribution pipe before each connection";
parameter Modelica.Units.SI.Length dhPla(fixed=false,start=0.05,min=0.01)
"Hydraulic diameter of the distribution pipe before each connection";
parameter Integer nBui = datDes.nBui
"Number of buildings connected to DHC system";
inner parameter Buildings.DHC.Examples.Combined.BaseClasses.DesignDataSeries
datDes(final mCon_flow_nominal=bui.ets.mSerWat_flow_nominal, lEnd=100)
"Design data";
// COMPONENTS
Buildings.DHC.Examples.Combined.BaseClasses.Borefield borFie(
redeclare final package Medium = Medium) "Bore field";
Buildings.DHC.ETS.BaseClasses.Pump_m_flow pumDis(
redeclare final package Medium = Medium,
final m_flow_nominal=datDes.mPumDis_flow_nominal,
final allowFlowReversal=allowFlowReversalSer,
dp_nominal=150E3)
"Distribution pump";
Buildings.Fluid.Sources.Boundary_pT bou(
redeclare final package Medium=Medium, nPorts=1)
"Boundary pressure condition representing the expansion vessel";
Buildings.DHC.ETS.BaseClasses.Pump_m_flow pumSto(
redeclare final package Medium = Medium,
m_flow_nominal=datDes.mSto_flow_nominal)
"Bore field pump";
Buildings.DHC.Networks.Connections.Connection1Pipe_R conPla(
redeclare final package Medium = Medium,
final mDis_flow_nominal=datDes.mPipDis_flow_nominal,
final mCon_flow_nominal=datDes.mPla_flow_nominal,
lDis=50,
final allowFlowReversal=allowFlowReversalSer,
dhDis=dhPla)
"Connection to the plant (pressure drop lumped in plant and network model)";
Buildings.DHC.Networks.Connections.Connection1Pipe_R conSto(
redeclare final package Medium = Medium,
final mDis_flow_nominal=datDes.mPipDis_flow_nominal,
final mCon_flow_nominal=datDes.mSto_flow_nominal,
lDis=50,
final allowFlowReversal=allowFlowReversalSer,
dhDis=dhSto)
"Connection to the bore field (pressure drop lumped in plant and network model)";
Buildings.DHC.Plants.Heating.SewageHeatRecovery
pla(
redeclare final package Medium = Medium,
final mSew_flow_nominal=datDes.mPla_flow_nominal,
final mDis_flow_nominal=datDes.mPla_flow_nominal,
final dpSew_nominal=datDes.dpPla_nominal,
final dpDis_nominal=datDes.dpPla_nominal,
final epsHex=datDes.epsPla) "Sewage heat recovery plant";
Fluid.Sensors.TemperatureTwoPort TDisWatSup(
redeclare final package Medium = Medium,
final m_flow_nominal=datDes.mPumDis_flow_nominal)
"District water supply temperature";
Fluid.Sensors.TemperatureTwoPort TDisWatRet(
redeclare final package Medium = Medium,
final m_flow_nominal=datDes.mPumDis_flow_nominal)
"District water return temperature";
Fluid.Sensors.TemperatureTwoPort TDisWatBorLvg(
redeclare final package Medium = Medium,
final m_flow_nominal=datDes.mPumDis_flow_nominal)
"District water borefield leaving temperature";
replaceable Buildings.DHC.Loads.Combined.BaseClasses.PartialBuildingWithETS
bui[nBui] constrainedby Buildings.DHC.Loads.Combined.BaseClasses.PartialBuildingWithETS
(
bui(each final facMul=facMul),
redeclare each final package MediumBui = Medium,
redeclare each final package MediumSer = Medium,
each final allowFlowReversalBui=allowFlowReversalBui,
each final allowFlowReversalSer=allowFlowReversalSer,
each final TDisWatMin=datDes.TLooMin,
each final TDisWatMax=datDes.TLooMax) "Building and ETS";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant THeaWatSupMaxSet[nBui](
k=bui.THeaWatSup_nominal)
"Heating water supply temperature set point - Maximum value";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant TChiWatSupSet[nBui](
k=bui.TChiWatSup_nominal)
"Chilled water supply temperature set point";
Buildings.Controls.OBC.CDL.Reals.Sources.Constant THeaWatSupMinSet[nBui](
each k=28 + 273.15)
"Heating water supply temperature set point - Minimum value";
Buildings.Controls.OBC.CDL.Reals.MultiSum PPumETS(
final nin=nBui)
"ETS pump power";
Modelica.Blocks.Continuous.Integrator EPumETS(
initType=Modelica.Blocks.Types.Init.InitialState)
"ETS pump electric energy";
Modelica.Blocks.Continuous.Integrator EPumDis(
initType=Modelica.Blocks.Types.Init.InitialState)
"Distribution pump electric energy";
Modelica.Blocks.Continuous.Integrator EPumSto(
initType=Modelica.Blocks.Types.Init.InitialState)
"Storage pump electric energy";
Modelica.Blocks.Continuous.Integrator EPumPla(initType=Modelica.Blocks.Types.Init.InitialState)
"Plant pump electric energy";
Buildings.Controls.OBC.CDL.Reals.MultiSum EPum(nin=4)
"Total pump electric energy";
Buildings.Controls.OBC.CDL.Reals.MultiSum PHeaPump(
final nin=nBui)
"Heat pump power";
Modelica.Blocks.Continuous.Integrator EHeaPum(
initType=Modelica.Blocks.Types.Init.InitialState)
"Heat pump electric energy";
Buildings.Controls.OBC.CDL.Reals.MultiSum ETot(nin=2) "Total electric energy";
Buildings.DHC.Loads.BaseClasses.ConstraintViolation conVio(
final uMin(final unit="K", displayUnit="degC")=datDes.TLooMin,
final uMax(final unit="K", displayUnit="degC")=datDes.TLooMax,
final nu=3,
u(each final unit="K", each displayUnit="degC"))
"Check if loop temperatures are within given range";
equation
connect(borFie.port_b, conSto.port_aCon);
connect(pumDis.port_b, conSto.port_aDis);
connect(borFie.port_a, pumSto.port_b);
connect(conSto.port_bCon, pumSto.port_a);
connect(conPla.port_bDis, TDisWatSup.port_a);
connect(TDisWatRet.port_b, pumDis.port_a);
connect(conSto.port_bDis, TDisWatBorLvg.port_a);
connect(TDisWatBorLvg.port_b, conPla.port_aDis);
connect(THeaWatSupMaxSet.y, bui.THeaWatSupMaxSet);
connect(TChiWatSupSet.y, bui.TChiWatSupSet);
connect(pla.port_bSerAmb, conPla.port_aCon);
connect(conPla.port_bCon, pla.port_aSerAmb);
connect(THeaWatSupMinSet.y, bui.THeaWatSupMinSet);
connect(bui.PPumETS, PPumETS.u);
connect(PPumETS.y, EPumETS.u);
connect(pumDis.P, EPumDis.u);
connect(pumSto.P, EPumSto.u);
connect(pla.PPum, EPumPla.u);
connect(EPumETS.y, EPum.u[1]);
connect(EPumPla.y, EPum.u[2]);
connect(EPumDis.y, EPum.u[3]);
connect(EPumSto.y, EPum.u[4]);
connect(bui.PHea, PHeaPump.u);
connect(PHeaPump.y, EHeaPum.u);
connect(EHeaPum.y, ETot.u[1]);
connect(EPum.y, ETot.u[2]);
connect(TDisWatSup.T, conVio.u[1]);
connect(TDisWatBorLvg.T, conVio.u[2]);
connect(TDisWatRet.T, conVio.u[3]);
connect(bou.ports[1], pumDis.port_b);
end PartialSeries;
Buildings.DHC.Examples.Combined.BaseClasses.DesignDataSeries
Record with design data for series network
Information
This record contains parameter declarations used in example models of DHC systems.
Extends from Modelica.Icons.Record (Icon for records).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | nBui | 3 | Number of served buildings |
| MassFlowRate | mPumDis_flow_nominal | 95 | Nominal mass flow rate of main distribution pump [kg/s] |
| MassFlowRate | mPipDis_flow_nominal | mPumDis_flow_nominal | Nominal mass flow rate for main pipe sizing [kg/s] |
| MassFlowRate | mCon_flow_nominal[nBui] | Nominal mass flow rate in each connection line [kg/s] | |
| MassFlowRate | mPla_flow_nominal | 11.45 | Plant HX nominal mass flow rate (primary = secondary) [kg/s] |
| MassFlowRate | mSto_flow_nominal | 105 | Storage nominal mass flow rate [kg/s] |
| PressureDifference | dpPla_nominal | 50000 | Plant HX pressure drop at nomninal flow rate (primary = secondary) [Pa] |
| Real | epsPla | 0.935 | Plant HX effectiveness (constant) |
| Temperature | TLooMin | 273.15 + 6 | Minimum loop temperature [K] |
| Temperature | TLooMax | 273.15 + 17 | Maximum loop temperature [K] |
| Real | dp_length_nominal | 250 | Pressure drop per pipe length at nominal flow rate [Pa/m] |
| Length | lDis[nBui] | fill(100, nBui) | Length of the distribution pipe before each connection [m] |
| Length | lCon[nBui] | fill(10, nBui) | Length of each connection pipe (supply only, not counting return line) [m] |
| Length | lEnd | sum(lDis) | Length of the end of the distribution line (after last connection) [m] |
Modelica definition
record DesignDataSeries "Record with design data for series network"
extends Modelica.Icons.Record;
parameter Integer nBui = 3
"Number of served buildings";
parameter Modelica.Units.SI.MassFlowRate mPumDis_flow_nominal=95
"Nominal mass flow rate of main distribution pump";
parameter Modelica.Units.SI.MassFlowRate mPipDis_flow_nominal=
mPumDis_flow_nominal "Nominal mass flow rate for main pipe sizing";
parameter Modelica.Units.SI.MassFlowRate mCon_flow_nominal[nBui]
"Nominal mass flow rate in each connection line";
parameter Modelica.Units.SI.MassFlowRate mPla_flow_nominal=11.45
"Plant HX nominal mass flow rate (primary = secondary)";
parameter Modelica.Units.SI.MassFlowRate mSto_flow_nominal=105
"Storage nominal mass flow rate";
parameter Modelica.Units.SI.PressureDifference dpPla_nominal=50000
"Plant HX pressure drop at nomninal flow rate (primary = secondary)";
parameter Real epsPla = 0.935
"Plant HX effectiveness (constant)";
parameter Modelica.Units.SI.Temperature TLooMin=273.15 + 6
"Minimum loop temperature";
parameter Modelica.Units.SI.Temperature TLooMax=273.15 + 17
"Maximum loop temperature";
parameter Real dp_length_nominal(final unit="Pa/m") = 250
"Pressure drop per pipe length at nominal flow rate";
parameter Modelica.Units.SI.Length lDis[nBui]=fill(100, nBui)
"Length of the distribution pipe before each connection";
parameter Modelica.Units.SI.Length lCon[nBui]=fill(10, nBui)
"Length of each connection pipe (supply only, not counting return line)";
parameter Modelica.Units.SI.Length lEnd=sum(lDis)
"Length of the end of the distribution line (after last connection)";
end DesignDataSeries;
Buildings.DHC.Examples.Combined.BaseClasses.Zurich
Zurich
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Temperature | TSurMea | 282.98 | Mean annual surface temperature [K] |
| TemperatureDifference | TSurAmp | 9.03 | Surface temperature amplitude [K] |
| Duration | sinPha | 9132480 | Phase lag of soil surface temperature [s] |
Modelica definition
record Zurich =
Buildings.BoundaryConditions.GroundTemperature.ClimaticConstants.Generic (
TSurMea=282.98,
TSurAmp=9.03,
sinPha=9132480) "Zurich";