.Buildings.DHC.ETS.BaseClasses.PartialDirect

Information

Direct cooling energy transfer station (ETS) model with in-building pumping and deltaT control. The design is based on a typical district cooling ETS described in ASHRAE's District Cooling Guide. As shown in the figure below, the district and building piping are hydronically coupled. The control valve ensures that the return temperature to the district cooling network is at or above the minimum specified value. This configuration naturally results in a fluctuating building supply tempearture.

Reference

American Society of Heating, Refrigeration and Air-Conditioning Engineers. (2019). Chapter 5: End User Interface. In District Cooling Guide, Second Edition and Owner's Guide for Buildings Served by District Cooling.

Revisions

• March 11, 2024, by Michael Wetter:
  Corrected wrong displayUnit string.
• April 7, 2023, by David Blum:
  Changed to partial base class for direct so can extend to heating and cooling ETS.
• January 11, 2023, by Michael Wetter:
  Changed controls to use CDL. Changed PID to PI as default for controller.
• January 2, 2023, by Kathryn Hinkelman:
  Set pressure drops at junctions to 0 and removed parameter dp_nominal
• December 28, 2022, by Kathryn Hinkelman:
  Simplified the control implementation for the district return stream. Improved default control parameters.
• December 23, 2022, by Kathryn Hinkelman:
  Removed extraneous m*_flow_nominal parameters because mBui_flow_nominal can be used across all components. This is for #2912.
• November 11, 2022, by Michael Wetter:
  Changed check valve to use version of Buildings library, and hence no outer system is needed.
• March 20, 2022, by Chengnan Shi:
  Update with base class partial model and standard PI control.
• Novermber 13, 2019, by Kathryn Hinkelman:
  First implementation.