modelBasic

Example implementation of flow system

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

Information

Example model demonstrating the use of the Buildings components in a larger system. This model is extended in Buildings.Fluid.Examples.FlowSystem.Simplified1, Buildings.Fluid.Examples.FlowSystem.Simplified2, Buildings.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
Buildings.Fluid.Movers.FlowControlled_dppmpSouthPump to south of building
Buildings.Fluid.FixedResistances.PressureDroppipSouth1Pipe 1 to south of building
Buildings.Fluid.FixedResistances.PressureDroppipSouth2Pipe 2 to south of building
Buildings.Fluid.Movers.FlowControlled_dppmpNorthPump to north of building
Buildings.Fluid.FixedResistances.PressureDroppipNorth2Pipe 2 to north of building
Buildings.Fluid.FixedResistances.PressureDroppipNorth1Pipe 1 to north of building
Buildings.Fluid.Actuators.Valves.TwoWayLinearvalSouth1Valves on souther tabs section 1
Buildings.Fluid.Actuators.Valves.TwoWayLinearvalSouth2Valves on souther tabs section 2
Buildings.Fluid.Actuators.Valves.TwoWayLinearvalNorth1Valves on northern tabs section 1
Buildings.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
Buildings.Fluid.Actuators.Valves.ThreeWayLinearvalSouthThree way valve for controlling supply temperature to south of building
Buildings.Fluid.Actuators.Valves.ThreeWayLinearvalNorthThree way valve for controlling supply temperature to north of building
Buildings.Fluid.HeatExchangers.PrescribedOutletheaterHeating device
Buildings.Fluid.Sources.Boundary_pTbouBoundary for setting absolute temperature
Buildings.Fluid.FixedResistances.JunctionsplSplitter
Buildings.Fluid.FixedResistances.Junctionspl1Splitter
Buildings.Fluid.Movers.FlowControlled_m_flowpumpHeaPump for circulating hot water
Modelica.Blocks.Sources.ConstantThotHot water temperature
Buildings.Fluid.Actuators.Valves.TwoWayLinearvalHeaValve for allowing water to be drawn from hot water circuit
Modelica.Blocks.Sources.PulsestepValveSet point for valves
Buildings.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
Buildings.Fluid.FixedResistances.Junctionspl2Splitter
Buildings.Fluid.FixedResistances.Junctionspl3Splitter
Buildings.Fluid.Movers.FlowControlled_m_flowpumpCooPump for circulating cold water
Buildings.Fluid.MixingVolumes.MixingVolumevolSimplified model of cold water source
Buildings.HeatTransfer.Sources.FixedTemperatureTcoldCold water temperature
Buildings.Fluid.FixedResistances.PressureDrop[4]tabsSouth1Pressure drop of southern tabs sections on collector 1
Buildings.Fluid.FixedResistances.PressureDrop[8]tabsSouth2Pressure drop of southern tabs sections on collector 2
Buildings.Fluid.FixedResistances.PressureDrop[4]tabsNorth1Pressure drop of northern tabs sections on collector 1
Buildings.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 Buildings, #763.
  • October 7, 2016, by Filip Jorissen:
    First implementation.