.Buildings.DHC.ETS.Combined.Controls.Supervisory

Information

This block implements the supervisory control functions of the ETS model Buildings.DHC.ETS.Combined.ChillerBorefield.

• Heating (resp. cooling) is enabled based on the input signal uHea (resp. uCoo) which is held for 15', meaning that, when enabled, the mode remains active for at least 15 minutes and, when disabled, the mode cannot be enabled again for at least 15 minutes. The heating and cooling enable signals should be computed externally based on a schedule (to lock out the system during off-hours), ideally in conjunction with the number of requests yielded by the terminal unit controllers, or any other signal representative of the load. Indeed, the heating water supply set point is allowed to be reset down only when heating is disabled, in which case the system performance is improved due to a lower chiller lift.
• The controller resets the heating water supply temperature based on the logic described in Buildings.DHC.ETS.Combined.Controls.Reset. Note that this resetting logic is meant to operate the chiller at low lift. The chilled water supply temperature may be also reset down by Buildings.DHC.ETS.Combined.Controls.SideCold to maintain the heating water supply temperature set point. This second resetting logic is required for the heating function of the unit, but it has a negative impact on the lift.
• Eventually the systems serving as ambient sources are controlled based on the maximum of the control signals yAmb yielded by Buildings.DHC.ETS.Combined.Controls.SideHot and Buildings.DHC.ETS.Combined.Controls.SideCold.

Revisions

• July 31, 2020, by Antoine Gautier:
  First implementation.