modelPartialFanCoil4Pipe
Extends from Buildings.DHC.Loads.BaseClasses.PartialTerminalUnit.
Information
This is a simplified partial model of a sensible only four-pipe fan coil unit for heating and cooling. It is intended to be used in conjunction with Buildings.DHC.Loads.BaseClasses.FlowDistribution, and hence it computes the water mass flow rate required to meet the temperature set point.
For the sake of simplicity, a sensible only heat exchanger model is considered.
For the sake of computational performance, a PI controller is used instead of an inverse model of the heat exchanger to assess the required water mass flow rate. Each controller output signal is mapped linearly to the water mass flow rate, from zero to its nominal value. The maximum of the two output signals is mapped linearly to the air mass flow rate, from zero to its nominal value.
The model takes the measured room air temperature as an input (as opposed to the fan inlet temperature) to maintain a valid control loop output in case of zero air flow rate.
The model is partial to allow various connectivity options on the load side: either with fluid ports or with heat ports.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| hexConfiguration | hexConHea | hexConfiguration.CounterFlow | Heating heat exchanger configuration |
| hexConfiguration | hexConCoo | hexConfiguration.CounterFlow | Cooling heat exchanger configuration |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Reals.PID | conHea | PI controller for heating | |
| Buildings.Fluid.Movers.FlowControlled_m_flow | fan | ||
| Buildings.Fluid.HeatExchangers.DryCoilEffectivenessNTU | hexHea | ||
| Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter | gaiHeaFloNom | ||
| Modelica.Blocks.Sources.RealExpression | Q_flowHea | ||
| Fluid.HeatExchangers.WetCoilEffectivenessNTU | hexWetNtu | ||
| Modelica.Blocks.Sources.RealExpression | Q_flowCoo | ||
| Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter | gaiFloNom2 | ||
| Buildings.Controls.OBC.CDL.Reals.PID | conCoo | PI controller for cooling | |
| Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter | gaiCooFloNom | Scaling | |
| Utilities.Math.SmoothMax | smoothMax | C1 maximum |
Revisions
-
February 21, 2020, by Antoine Gautier:
First implementation.