modelTableData2DLoadDepSHC1Only

Information

This model illustrates the use of Buildings.Fluid.HeatPumps.ModularReversible.TableData2DLoadDepSHC to model a primary-only heating and cooling plant. The simulation covers a 24-hour period with overlapping heating and cooling loads. The heating loads reach their peak value first, the cooling loads reach it last.

The plant model includes the following components.

• Modular four-pipe heat pump with three units
• HW and CHW isolation valves represented by an equivalent actuator
• Three headered variable-speed primary HW and CHW pumps
• HW and CHW minimum flow bypass valves

A unique aggregated load is modeled on each loop by means of a cooling or heating component controlled to maintain a constant ΔT and a modulating valve controlled to track a prescribed flow rate.

The closed-loop controls includes the following logic.

• Heating and cooling plant enable: See Buildings.Templates.Plants.Controls.Enabling.Enable.
  The HW and CHW plant requests used in this logic are generated based on an opening threshold of 10 % of the equivalent terminal valves.
• Heat pump operating mode: When the heating plant is enabled and the cooling plant is disabled, the heat pump is commanded in heating-only mode. When the cooling plant is enabled and the heating plant is disabled, the heat pump is commanded in cooling-only mode. When both the cooling plant and the heating plant are enabled, the heat pump is commanded in simultaneous heating and cooling mode. When both the cooling plant and the heating plant are disabled, the heat pump is commanded off.
• HW and CHW supply temperature: The heat pump is controlled with constant setpoints equal to the design values.
• Primary HW and CHW pumps controlled to maintain a remote differential pressure setpoint: See Buildings.Templates.Plants.Controls.Pumps.Generic.StagingHeadered for the staging and rotation logic, and Buildings.Templates.Plants.Controls.Pumps.Generic.ControlDifferentialPressure for the control logic.
• Minimum flow HW and CHW bypass valves controlled to maintain the differential pressure across the heat pump HW and CHW headers at design value.

Simulating this model shows how the plant responds to a varying load by

• enabling or disabling the heating and cooling plants, and switching the heat pump operating mode accordingly,
• staging or unstaging the heat pump modules in various modes,
• actuating the corresponding isolation valves,
• staging, rotating and controlling the primary pumps to meet the remote differential pressure setpoint.
• modulating the minimum flow bypass valve to keep the header differential pressure at its design value, which, in conjunction with the isolation valves' control, effectively results in a flowrate through the heat pump heat exchangers varying linearly with the number of enabled modules on each loop.

Parameters

Connectors

Components

Contents

Name	Description
Medium	Main medium (common for CHW and HW)

Revisions

• March 23, 2026, by Antoine Gautier:
  Refactored with two separate connectors for heating and cooling on/off commands.
  This is for #4507.
• July 1, 2025, by Antoine Gautier:
  First implementation.