modelBasic

Example implementation of flow system

Extends from Modelica.Icons.Example (Icon for runnable examples).

Information

Example model demonstrating the use of the AixLib components in a larger system. This model is extended in AixLib.Fluid.Examples.FlowSystem.Simplified1, AixLib.Fluid.Examples.FlowSystem.Simplified2, AixLib.Fluid.Examples.FlowSystem.Simplified3. In these examples, the flow network is simplified in three steps, which reduces the size of algebraic loops.

The system model is for a hydronic system with a hot and cold water production device, each having its own circulation pump. The warm and cold supply water temperatures are selected by switching the bottom two-way valves. The building consists of a west and east wing. Each wing has multiple zones that are heated or cooled using the hydronic system. Each wing has a north and south section with a different supply temperature, which is controlled using two main three way valves. In total there are therefore four supply pipes, which are each connected to four or eight emission devices in the zones. The flow through the emission devices is controlled using two way valves. The emission device itself also generates a pressure drop, represented by components tabsX. Note that the emission devices are in the real building cooling and heating concrete slabs, but this simplified example only models their flow resistance. The control model consists of dummy inputs.

Components

TypeNameDefaultDescription
AixLib.Fluid.Movers.FlowControlled_dppmpSouthPump to south of building
AixLib.Fluid.FixedResistances.PressureDroppipSouth1Pipe 1 to south of building
AixLib.Fluid.FixedResistances.PressureDroppipSouth2Pipe 2 to south of building
AixLib.Fluid.Movers.FlowControlled_dppmpNorthPump to north of building
AixLib.Fluid.FixedResistances.PressureDroppipNorth2Pipe 2 to north of building
AixLib.Fluid.FixedResistances.PressureDroppipNorth1Pipe 1 to north of building
AixLib.Fluid.Actuators.Valves.TwoWayLinearvalSouth1Valves on souther tabs section 1
AixLib.Fluid.Actuators.Valves.TwoWayLinearvalSouth2Valves on souther tabs section 2
AixLib.Fluid.Actuators.Valves.TwoWayLinearvalNorth1Valves on northern tabs section 1
AixLib.Fluid.Actuators.Valves.TwoWayLinearvalNorth2Valves on northern tabs section 2
Modelica.Blocks.Math.BooleanToIntegerbooleanToIntegerBoolean to integer conversion block
Modelica.Blocks.Sources.BooleanPulsestepPumpStep control
Modelica.Blocks.Sources.SinesineValve control signal
AixLib.Fluid.Actuators.Valves.ThreeWayLinearvalSouthThree way valve for controlling supply temperature to south of building
AixLib.Fluid.Actuators.Valves.ThreeWayLinearvalNorthThree way valve for controlling supply temperature to north of building
AixLib.Fluid.HeatExchangers.PrescribedOutletheaterHeating device
AixLib.Fluid.Sources.Boundary_pTbouBoundary for setting absolute temperature
AixLib.Fluid.FixedResistances.JunctionsplSplitter
AixLib.Fluid.FixedResistances.Junctionspl1Splitter
AixLib.Fluid.Movers.FlowControlled_m_flowpumpHeaPump for circulating hot water
Modelica.Blocks.Sources.ConstantThotHot water temperature
AixLib.Fluid.Actuators.Valves.TwoWayLinearvalHeaValve for allowing water to be drawn from hot water circuit
Modelica.Blocks.Sources.PulsestepValveSet point for valves
AixLib.Fluid.Actuators.Valves.TwoWayLinearvalCooValve for allowing water to be drawn from cold water circuit
Modelica.Blocks.Sources.RealExpressionvalCooExpCooling valve opens when heating valve is closed
AixLib.Fluid.FixedResistances.Junctionspl2Splitter
AixLib.Fluid.FixedResistances.Junctionspl3Splitter
AixLib.Fluid.Movers.FlowControlled_m_flowpumpCooPump for circulating cold water
AixLib.Fluid.MixingVolumes.MixingVolumevolSimplified model of cold water source
Modelica.Thermal.HeatTransfer.Sources.FixedTemperatureTcoldCold water temperature
AixLib.Fluid.FixedResistances.PressureDrop[4]tabsSouth1Pressure drop of southern tabs sections on collector 1
AixLib.Fluid.FixedResistances.PressureDrop[8]tabsSouth2Pressure drop of southern tabs sections on collector 2
AixLib.Fluid.FixedResistances.PressureDrop[4]tabsNorth1Pressure drop of northern tabs sections on collector 1
AixLib.Fluid.FixedResistances.PressureDrop[8]tabsNorth2Pressure drop of northern tabs sections on collector 2

Contents

NameDescription
MediumMedium model

Revisions

  • January 11, 2019 by Michael Wetter:
    Removed each statements.
    This is for #1079.
  • May 8, 2017, by Michael Wetter:
    Updated heater model.
    This is for AixLib, #763.
  • October 7, 2016, by Filip Jorissen:
    First implementation.