modelConstantSpeedPumpStage

Staging control for constant speed pumps
Diagram of ConstantSpeedPumpStageOpen the diagram
▶ Check in your browser

Extends from Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).

Information

This model describes a simple staging control for two constant-speed pumps in a chilled water plant with two chillers and a waterside economizer (WSE). The staging sequence is shown as below.

  • When WSE is enabled, all the constant speed pumps are commanded on.
  • When fully mechanical cooling (FMC) mode is enabled, the number of running constant speed pumps equals to the number of running chillers.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.TimetWaiWaiting time

Connectors

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.IntegerInputcooModCooling mode - 0:off, 1: free cooling mode; 2: partially mechanical cooling; 3: fully mechanical cooling
Modelica.Blocks.Interfaces.BooleanInputonOn signal of the plant
Modelica.Blocks.Interfaces.IntegerInputnumOnChiThe number of running chillers
Modelica.Blocks.Interfaces.RealOutput[2]yOn/off signal - 0: off; 1: on

Components

TypeNameDefaultDescription
Modelica.StateGraph.Transitioncon1Fire condition 1: free cooling to partially mechanical cooling
Modelica.StateGraph.StepWithSignaloneOnOne chiller is commanded on
Modelica.StateGraph.InitialStepoffFree cooling mode
Modelica.StateGraph.StepWithSignaltwoOnTwo chillers are commanded on
Modelica.StateGraph.Transitioncon2Fire condition 2: partially mechanical cooling to fully mechanical cooling
Modelica.StateGraph.Transitioncon3Fire condition 3: fully mechanical cooling to partially mechanical cooling
Modelica.StateGraph.Transitioncon4Fire condition 4: partially mechanical cooling to free cooling
Modelica.StateGraph.StateGraphRootstateGraphRoot
Modelica.Blocks.Tables.CombiTable1DscombiTable1Ds
Buildings.Controls.OBC.CDL.Conversions.BooleanToIntegerbooToInt
Buildings.Controls.OBC.CDL.Conversions.BooleanToIntegerbooToInt1
Buildings.Controls.OBC.CDL.Integers.AddaddInt
Buildings.Controls.OBC.CDL.Conversions.IntegerToRealintToRea
Buildings.Controls.OBC.CDL.Integers.SwitchintSwiDisable pumps when the plant is disabled
Buildings.Controls.OBC.CDL.Integers.Sources.ConstantzerConstant zero

Revisions

  • September 3, 2024, by Jianjun Hu:
    Added plant on signal to pumps control. This is for issue 3989.
  • September 11, 2017, by Michael Wetter:
    Revised switch that selects the operation mode for issue 921.
  • September 2, 2017, by Michael Wetter:
    Changed implementation to use Buildings.Applications.DataCenters.Types.CoolingModes.
  • July 30, 2017, by Yangyang Fu:
    First implementation.