blockTuning

Defines a tuning parameter for the temperature prediction downstream of WSE

Information

Waterside economizer outlet temperature prediction tuning parameter subsequence per ASHRAE Guideline 36-2021, section 5.20.3.3.

The subsequence calculates the tuning parameter y as follows:

  • Decrease y in step when the WSE is disabled if the WSE remained enabled for more than wseOnTimDec period.
  • Increase y in step when the WSE is disabled if the WSE remained enabled for less than wseOnTimInc period and the cooling tower fan speed signal uTowFanSpeMax did not decrease below 100% speed while the WSE was enabled.

y initializes at 0 upon first plant start up, it holds its value when the plant is disabled, and tuning resumes from that value when the plant is re-enabled. It is limited between -0.2 and 0.5.

To avoid large integer values above larInt, the counters get reset to 0 each time any of them reaches that value.

Parameters

TypeNameDefaultDescription
Realstep0.02Incremental step used to reduce or increase the water-side economizer tuning parameter
RealwseOnTimDec3600Economizer enable time needed to allow decrease of the tuning parameter
RealwseOnTimInc1800Economizer enable time needed to allow increase of the tuning parameter

Connectors

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Interfaces.BooleanInputuWseStaWSE enable disable status
Buildings.Controls.OBC.CDL.Interfaces.RealInputuTowFanSpeMaxMaximum cooling tower fan speed signal
Buildings.Controls.OBC.CDL.Interfaces.RealOutputyTuning parameter for the waterside economizer outlet temperature prediction

Revisions

  • September 12, 2019, by Milica Grahovac:
    Revised for performance.
  • October 13, 2018, by Milica Grahovac:
    First implementation.