modelSeriesVariableFlowAgentControl

Example of series connection with variable district water mass flow rate with updated agent controller

Extends from Buildings.DHC.Examples.Combined.BaseClasses.PartialSeries (Partial model for series network).

Information

This model is an updated version of Buildings.DHC.Examples.Combined.SeriesVariableFlow. In particular the following have been updated:

  • The sewage water temperature, mass flow rate and ground temperature are not constant and instead have a seasonal yearly profile.
  • The distribution network pripes now use the plug-flow model to add transport delay and ground coupling to the distribution network.
  • The borefield and sewagre heat exchanger circulation pumps are controlled by an agent specific controller Buildings.DHC.Networks.Controls.AgentPump1Pipe.

References

Ettore Zanetti, David Blum, Michael Wetter (2023) Control development and sizing analysis for a 5th generation district heating and cooling network using Modelica, In Proceedings of the 15th International Modelica Conference. Aachen, Germany, Oct 9-11, 2023.

Parameters

TypeNameDefaultDescription
RealfacMul (from PartialSeries)10Building loads multiplier factor
RealdpDis_length_nominal (from PartialSeries)250Pressure drop per pipe length at nominal flow rate - Distribution line
RealdpCon_length_nominal (from PartialSeries)250Pressure drop per pipe length at nominal flow rate - Connection line
Modelica.Units.SI.LengthdhSto (from PartialSeries)Hydraulic diameter of the distribution pipe before each connection
Modelica.Units.SI.LengthdhPla (from PartialSeries)Hydraulic diameter of the distribution pipe before each connection
IntegernBui (from PartialSeries)datDes.nBuiNumber of buildings connected to DHC system
Buildings.DHC.Examples.Combined.BaseClasses.DesignDataSeriesdatDes (from PartialSeries)Design data
String[nBui]filNam{"modelica://Buildings/Resources/Data/DHC/Loads/Examples/SwissOffice_20190916.mos", "modelica://Buildings/Resources/Data/DHC/Loads/Examples/SwissResidential_20190916.mos", "modelica://Buildings/Resources/Data/DHC/Loads/Examples/SwissHospital_20190916.mos"}Library paths of the files with thermal loads as time series
Modelica.Units.SI.Lengthdiametersqrt(4*datDes.mPipDis_flow_nominal/1000/1.5/Modelica.Constants.pi)Pipe diameter (without insulation)
Modelica.Units.SI.HeightlDisPip200Distribution pipes length
Modelica.Units.SI.RadiusrPipdiameter/2Pipe external radius
Modelica.Units.SI.RadiusthiGroLay0.5Dynamic ground layer thickness
Assumptions
BooleanallowFlowReversalSer (from PartialSeries)trueSet to true to allow flow reversal in the service lines
BooleanallowFlowReversalBui (from PartialSeries)falseSet to true to allow flow reversal for in-building systems

Components

TypeNameDefaultDescription
Buildings.DHC.Examples.Combined.BaseClasses.BorefieldborFie (from PartialSeries)Bore field
Buildings.DHC.ETS.BaseClasses.Pump_m_flowpumDis (from PartialSeries)Distribution pump
Buildings.Fluid.Sources.Boundary_pTbou (from PartialSeries)Boundary pressure condition representing the expansion vessel
Buildings.DHC.ETS.BaseClasses.Pump_m_flowpumSto (from PartialSeries)Bore field pump
Buildings.DHC.Networks.Connections.Connection1Pipe_RconPla (from PartialSeries)Connection to the plant (pressure drop lumped in plant and network model)
Buildings.DHC.Networks.Connections.Connection1Pipe_RconSto (from PartialSeries)Connection to the bore field (pressure drop lumped in plant and network model)
Buildings.DHC.Plants.Heating.SewageHeatRecoverypla (from PartialSeries)Sewage heat recovery plant
Fluid.Sensors.TemperatureTwoPortTDisWatSup (from PartialSeries)District water supply temperature
Fluid.Sensors.TemperatureTwoPortTDisWatRet (from PartialSeries)District water return temperature
Fluid.Sensors.TemperatureTwoPortTDisWatBorLvg (from PartialSeries)District water borefield leaving temperature
Buildings.DHC.Loads.Combined.BaseClasses.PartialBuildingWithETS[nBui]bui (from PartialSeries)
Buildings.Controls.OBC.CDL.Reals.Sources.Constant[nBui]THeaWatSupMaxSet (from PartialSeries)Heating water supply temperature set point - Maximum value
Buildings.Controls.OBC.CDL.Reals.Sources.Constant[nBui]TChiWatSupSet (from PartialSeries)Chilled water supply temperature set point
Buildings.Controls.OBC.CDL.Reals.Sources.Constant[nBui]THeaWatSupMinSet (from PartialSeries)Heating water supply temperature set point - Minimum value
Buildings.Controls.OBC.CDL.Reals.MultiSumPPumETS (from PartialSeries)ETS pump power
Modelica.Blocks.Continuous.IntegratorEPumETS (from PartialSeries)ETS pump electric energy
Modelica.Blocks.Continuous.IntegratorEPumDis (from PartialSeries)Distribution pump electric energy
Modelica.Blocks.Continuous.IntegratorEPumSto (from PartialSeries)Storage pump electric energy
Modelica.Blocks.Continuous.IntegratorEPumPla (from PartialSeries)Plant pump electric energy
Buildings.Controls.OBC.CDL.Reals.MultiSumEPum (from PartialSeries)Total pump electric energy
Buildings.Controls.OBC.CDL.Reals.MultiSumPHeaPump (from PartialSeries)Heat pump power
Modelica.Blocks.Continuous.IntegratorEHeaPum (from PartialSeries)Heat pump electric energy
Buildings.Controls.OBC.CDL.Reals.MultiSumETot (from PartialSeries)Total electric energy
Buildings.DHC.Loads.BaseClasses.ConstraintViolationconVio (from PartialSeries)Check if loop temperatures are within given range
Modelica.Blocks.Sources.ConstantmasFloDisPlaDistrict water flow rate to plant
Buildings.Controls.OBC.CDL.Reals.Sources.Constant[nBui]THotWatSupSetHot water supply temperature set point
Buildings.Controls.OBC.CDL.Reals.Sources.Constant[nBui]TColWatCold water temperature
Buildings.DHC.Networks.Controls.MainPump1PipeconPumMain pump controller
Buildings.Controls.OBC.CDL.Reals.MultiplyByParametergaiScale with nominal mass flow rate
Modelica.Blocks.Sources.CombiTimeTableHXtemperature
Modelica.Blocks.Math.Productproduct1
.Buildings.Controls.OBC.CDL.Reals.MultiplyByParametergai1Scale with nominal mass flow rate
Fluid.Sensors.TemperatureTwoPortTDisWatSup1District water supply temperature
Fluid.Sensors.TemperatureTwoPortTDisWatRet1District water return temperature
Fluid.FixedResistances.BuriedPipes.PipeGroundCoupling[nBui + 3]pipeGroundCouplingMulti
Buildings.DHC.Networks.Controls.AgentPump1PipepumPlantControlNsew
Buildings.DHC.Networks.Controls.AgentPump1PipepumPlantControlNsewSto
Networks.Distribution1PipePlugFlow_vdis
Fluid.FixedResistances.PlugFlowPipesupDisPluFlo
Fluid.FixedResistances.PlugFlowPiperetDisPluFlo

Revisions

  • January 20, 2023, by Ettore Zanetti:
    First implementation.