.Buildings.DHC.ETS.Combined.ChillerBorefield

Information

This model represents an energy transfer station as illustrated in the schematics below.

• The heating and cooling functions are provided by a heat recovery chiller, see Buildings.DHC.ETS.Combined.Subsystems.Chiller for the operating principles and modeling assumptions. The condenser and evaporator loops are equipped with constant speed pumps.
• The supervisory controller ensures the load balancing between the condenser side and the evaporator side of the chiller by controlling in sequence an optional geothermal borefield (priority system), the district heat exchanger (second priority system), and ultimately the chiller, by resetting down the chilled water supply temperature, see Buildings.DHC.ETS.Combined.Controls.Supervisory for a detailed description. The borefield and district heat exchanger loops are equipped with variable speed pumps modulated by the supervisory controller.

Note that the heating and cooling enable signals (uHea and uCoo) connected to this model should be switched to false when the building has no corresponding demand (e.g., based on the requests yielded by the terminal unit controllers, in conjunction with a schedule). This will significantly improve the system performance as it is a necessary condition for the chiller to be operated at a lower lift, see Buildings.DHC.ETS.Combined.Controls.Reset.

Revisions

• March 6, 2025, by Hongxiang Fu:
  Added parameters to support chilled water temperature reset.
  This is for #4133.
• November 22, 2024, by Michael Wetter:
  Reduced number of time events by replacing zero order hold with true and false hold, and increasing the minimum cycle time.
  This is for #4058.
• March 27, 2024, by David Blum:
  Update icon.
  This is for issue #3606.
• April 30, 2021, by Michael Wetter:
  Reformulated replaceable class to avoid access of components that are not in the constraining type.
  This is for issue #2471.
• July 31, 2020, by Antoine Gautier:
  First implementation.