.Buildings.DHC.Plants.Cooling.ElectricChillerParallel

Information

This model implements a generic district central cooling plant as illustrated in the schematics below.

• The cooling is provided by two parallel chillers instantiated from Buildings.Applications.BaseClasses.Equipment.ElectricChillerParallel.
• The chilled water bypass loop is controlled to ensure a minimum flow of chilled water running through the chillers all the time.
• The condenser water is cooled by two parallel cooling towers with a bypass loop. See Buildings.DHC.Plants.Cooling.Subsystems.CoolingTowersWithBypass for the details of the modeling of the cooling towers.
• The chilled water loop is equipped with two parallel constant speed pumps, which run one-and-one with each chiller. The condenser water pumps are constant speed with prescribed mass flow rates.
• The plant operates when it receives an on signal from the external control.

The staging of the chillers is based on the calculated cooling load.

See Buildings.DHC.Plants.Cooling.Controls.ChillerStage for the detailed control logic.

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Revisions

• January 2, 2023, by Kathryn Hinkelman:
  Revised chilled water pump control to be constant speed and running 1-and-1 with chillers.
• December 14, 2022, by Kathryn Hinkelman:
  Corrected chiBypCon to control mass flow rate through the chillers.
  This is for issue 2912.
• November 16, 2022, by Michael Wetter:
  Corrected wrong assignments for chiller system mulChiSys which assigned chilled water to condenser water parameters and vice versa.
  Changed rise time of valve to 30 seconds so that it is the same as the one for the pumps.
• September 15, 2022, by Kathryn Hinkelman:
  Propagated dynamics and initialization parameters for pumps.
• March 3, 2022, by Michael Wetter:
  Moved massDynamics to Advanced tab and added assertion for correct combination of energy and mass dynamics.
  This is for issue 1542.
• August 6, 2020 by Jing Wang:
  First implementation.