Example of a primary-secondary plant with four-pipe heat pump
This model illustrates the use of
Buildings.Fluid.HeatPumps.ModularReversible.TableData2DLoadDepSHC
to model a primary-secondary 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 constant-speed primary HW and CHW pumps.
- HW and CHW common legs.
- Three headered variable-speed secondary HW and CHW pumps.
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 use mostly the same logic as the one
described in
Buildings.Fluid.HeatPumps.ModularReversible.Examples.TableData2DLoadDepSHC1Only.
Only the logic that differs is presented below.
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 and rotating the primary pumps, and
- staging, rotating and controlling the secondary pumps to meet
the remote differential pressure setpoint.
Contents
| Name |
Description |
Medium |
Main medium (common for CHW and HW) |
- 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.
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