blockHeatExchangerPumpController
Controller for pump of storage tank with external heat exchanger
Information
Controller for heat exchanger mass flow rate.
This controller outputs the set point for the head of the heat exchanger pump
on the heating side. The set point is calculated using a PI controller that tracks
the set point for the leaving domestic hot water temperature,
with a minimum controller output equal to yMin.
By default, yMin=0.3, which corresponds to a mass flow rate
of 10% of the design flow rate.
If the measured domestic hot water flow rate is close to zero, then the set point for the pump is also set to zero in order to stop the pump if there is no domestic hot water flow rate.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.MassFlowRate | mDom_flow_nominal | Domestic hot water design flow rate (used for scaling) | |
| Modelica.Units.SI.PressureDifference | dpPum_nominal | Heating water pump head at full speed through heat exchanger | |
| Real | k | 0.1 | Proportioanl gain of circulation pump controller |
| Real | Ti | 60 | Integrator time constant of circulation pump controller |
| Real | yMin | 0.3 | Minimum controller output when pump is on |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | mDom_flow | Domestic hot water mass flow rate | |
| Modelica.Blocks.Interfaces.RealInput | TDomSet | Temperature setpoint for domestic hot water source from heater | |
| Modelica.Blocks.Interfaces.RealInput | TDom | Measured hot water temperature | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | dpPumHex | Set point for pump head on heating water side |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Reals.Hysteresis | hysMasFlo | Hysteresis used to switch secondary pump on and off | |
| Buildings.Controls.OBC.CDL.Reals.PIDWithReset | conPI | PI controller for pump | |
| Buildings.Controls.OBC.CDL.Reals.Switch | swi | Switch for pump control |
Revisions
-
October 4, 2023, by Michael Wetter:
First implementation.